Human habitat positioning system for NASA's space flight environmental simulator

NASA Technical Reports Server (NTRS)

Caldwell, W. F.; Tucker, J.; Keas, P.

1998-01-01

Artificial gravity by centrifugation offers an effective countermeasure to the physiologic deconditioning of chronic exposure to microgravity; however, the system requirements of rotational velocity, radius of rotation, and resultant centrifugal acceleration require thorough investigation to ascertain the ideal human-use centrifuge configuration. NASA's Space Flight Environmental Simulator (SFES), a 16-meter (52-foot) diameter, animal-use centrifuge, was recently modified to accommodate human occupancy. This paper describes the SFES Human Habitat Positioning System, the mechanism that facilitates radius of rotation variability and alignment of the centrifuge occupants with the artificial gravity vector.

Simulation of external and internal electrostatic discharges at the spacecraft system test level

NASA Technical Reports Server (NTRS)

Whittlesey, A.; Leung, P.

1984-01-01

Environmental test activities concerned with space plasma-caused charging and discharing phenomena are discussed. It is pointed out that the origin of such an electrostatic discharge (ESD) is charging of spacecraft dielectrics by an energetic plasma in geosynchronous orbit, Jupiter's magnetosphere, or other similar space environments. In dealing with environmental testing problems, it is necessary to define the location and magnitude of any ESD's in preparation for a subsequent simulation of the given conditions. Questions of external and internal charging are discussed separately. The environmental hazard from an external discharge can be assessed by viewing the dielectric surface as one side of a parallel plate capacitor. In the case of internal charging, the level of environmental concern depends on the higher energy spectrum of the ambient electrons.

Space Environmental Effects Testing Capability at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

DeWittBurns, H.; Craven, Paul; Finckenor, Miria; Nehls, Mary; Schneider, Todd; Vaughn, Jason

2012-01-01

Understanding the effects of the space environment on materials and systems is fundamental and essential for mission success. If not properly understood and designed for, the effects of the environment can lead to degradation of materials, reduction of functional lifetime, and system failure. In response to this need, the Marshall Space Flight Center has developed world class Space Environmental Effects (SEE) expertise and test facilities to simulate the space environment. Capabilities include multiple unique test systems comprising the most complete SEE testing capability available. These test capabilities include charged particle radiation (electrons, protons, ions), ultraviolet radiation (UV), vacuum ultraviolet radiation (VUV), atomic oxygen, plasma effects, space craft charging, lunar surface and planetary effects, vacuum effects, and hypervelocity impacts as well as the combination of these capabilities. In addition to the uniqueness of the individual test capabilities, MSFC is the only NASA facility where the effects of the different space environments can be tested in one location. Combined with additional analytical capabilities for pre- and post-test evaluation, MSFC is a one-stop shop for materials testing and analysis. The SEE testing and analysis are performed by a team of award winning experts nationally recognized for their contributions in the study of the effects of the space environment on materials and systems. With this broad expertise in space environmental effects and the variety of test systems and equipment available, MSFC is able to customize tests with a demonstrated ability to rapidly adapt and reconfigure systems to meet customers needs. Extensive flight experiment experience bolsters this simulation and analysis capability with a comprehensive understanding of space environmental effects.

Manufacture of Cryoshroud Surfaces for Space Simulation Chambers

NASA Technical Reports Server (NTRS)

Ash, Gary S.

2008-01-01

Environmental test chambers for space applications use internal shrouds to simulate temperature conditions encountered in space. Shroud temperatures may range from +150 C to -253 C (20 K), and internal surfaces are coated with special high emissivity/absorptivity paints. To obtain temperature uniformity over large areas, detailed thermal design is required for placement of tubing for gaseous or liquid nitrogen and helium and other exotic heat exchange fluids. The recent increase in space simulation activity related to the James Webb Space Telescope has led to the design of new cryogenic shrouds to meet critical needs in instrument package testing. This paper will review the design and manufacturing of shroud surfaces for several of these programs, including fabrication methods and the selection and application of paints for simulation chambers.

Space Power Facility-Capabilities for Space Environmental Testing Within a Single Facility

NASA Technical Reports Server (NTRS)

Sorge, Richard N.

2013-01-01

The purpose of this paper is to describe the current and near-term environmental test capabilities of the NASA Glenn Research Center's Space Power Facility (SPF) located at Sandusky, Ohio. The paper will present current and near-term capabilities for conducting electromagnetic interference and compatibility testing, base-shake sinusoidal vibration testing, reverberant acoustic testing, and thermal-vacuum testing. The paper will also present modes of transportation, handling, ambient environments, and operations within the facility to conduct those tests. The SPF is in the midst of completing and activating new or refurbished capabilities which, when completed, will provide the ability to conduct most or all required full-scale end-assembly space simulation tests at a single test location. It is envisioned that the capabilities will allow a customer to perform a wide range of space simulation tests in one facility at reasonable cost.

Installation and Characterization of Charged Particle Sources for Space Environmental Effects Testing

NASA Technical Reports Server (NTRS)

Skevington, Jennifer L.

2010-01-01

Charged particle sources are integral devices used by Marshall Space Flight Center s Environmental Effects Branch (EM50) in order to simulate space environments for accurate testing of materials and systems. By using these sources inside custom vacuum systems, materials can be tested to determine charging and discharging properties as well as resistance to sputter damage. This knowledge can enable scientists and engineers to choose proper materials that will not fail in harsh space environments. This paper combines the steps utilized to build a low energy electron gun (The "Skevington 3000") as well as the methods used to characterize the output of both the Skevington 3000 and a manufactured Xenon ion source. Such characterizations include beam flux, beam uniformity, and beam energy. Both sources were deemed suitable for simulating environments in future testing.

Ascent trajectory dispersion analysis for WTR heads-up space shuttle trajectory

NASA Technical Reports Server (NTRS)

1986-01-01

The results of a Space Transportation System ascent trajectory dispersion analysis are discussed. The purpose is to provide critical trajectory parameter values for assessing the Space Shuttle in a heads-up configuration launched from the Western Test Range (STR). This analysis was conducted using a trajectory profile based on a launch from the WTR in December. The analysis consisted of the following steps: (1) nominal trajectories were simulated under the conditions as specified by baseline reference mission guidelines; (2) dispersion trajectories were simulated using predetermined parametric variations; (3) requirements for a system-related composite trajectory were determined by a root-sum-square (RSS) analysis of the positive deviations between values of the aerodynamic heating indicator (AHI) generated by the dispersion and nominal trajectories; (4) using the RSS assessment as a guideline, the system related composite trajectory was simulated by combinations of dispersion parameters which represented major contributors; (5) an assessment of environmental perturbations via a RSS analysis was made by the combination of plus or minus 2 sigma atmospheric density variation and 95% directional design wind dispersions; (6) maximum aerodynamic heating trajectories were simulated by variation of dispersion parameters which would emulate the summation of the system-related RSS and environmental RSS values of AHI. The maximum aerodynamic heating trajectories were simulated consistent with the directional winds used in the environmental analysis.

Study of the space environmental effects on spacecraft engineering materials

NASA Technical Reports Server (NTRS)

Obrien, Susan K.; Workman, Gary L.; Smith, Guy A.

1995-01-01

The space environment in which the Space Station Freedom and other space platforms will orbit is truly a hostile environment. For example, the current estimates of the integral fluence for electrons above 1 Mev at 2000 nautical miles is above 2 x 10(exp 10) electrons/sq cm/day. and the proton integral fluence is above 1 x 109 protons/sq cm/day. At the 200 - 400 nautical miles, which is more representative of the altitude which will provide the environment for the Space Station, each of these fluences will be proportionately less; however, the data indicates that the radiation environment will obviously have an effect on structural materials exposed to the environment for long durations. The effects of this combined environment is the issue which needs to be understood for the long term exposure of structures in space. In order to better understand the effect of these hostile phenomena on spacecraft, several types of studies are worth performing in order to simulate at some level the effect of the environment. For example the effect of protons and electrons impacting structural materials are easily simulated through experiments using the Van de Graff and Pelletron accelerators currently housed in the Environmental Effects Facility at MSFC. Proton fluxes with energies of 700 Kev-2.5 Mev can be generated and used to impinge on sample targets to determine the effects of the particles. Also the Environmental Effects Facility has the capability to generate electron beams with energies from 700 Kev to 2.5 Mev. These facilities will be used in this research to simulate space environmental effects from energetic particles. Ultraviolet radiation, particularly in the ultraviolet (less than 400 nm wavelength) is less well characterized at this time. The Environmental Effects Facility has a vacuum system dedicated to studying the effects of ultraviolet radiation on specific surface materials. This particular system was assembled in a previous study (NAS8-38609) in order to perform a variety of experiments on materials proposed for the Space Station. That system has continued to function as planned and has been used in carrying out portions of the proposed study.

Simulated space environment tests on cadmium sulfide solar cells

NASA Technical Reports Server (NTRS)

Clarke, D. R.; Oman, H.

1971-01-01

Cadmium sulfide (Cu2s - CdS) solar cells were tested under simulated space environmental conditions. Some cells were thermally cycled with illumination from a Xenon-arc solar simulator. A cycle was one hour of illumination followed immediately with one-half hour of darkness. In the light, the cells reached an equilibrium temperature of 60 C (333 K) and in the dark the cell temperature dropped to -120 C (153 K). Other cells were constantly illuminated with a Xenon-arc solar simulator. The equilibrium temperature of these cells was 55 C (328 K). The black vacuum chamber walls were cooled with liquid nitrogen to simulate a space heat sink. Chamber pressure was maintained at 0.000001 torr or less. Almost all of the solar cells tested degraded in power when exposed to a simulated space environment of either thermal cycling or constant illumination. The cells tested the longest were exposed to 10.050 thermal cycles.

Utilization of a terrestrial cyanobacterium, Nostoc sp. HK-01, for space habitation

NASA Astrophysics Data System (ADS)

Kimura, Shunta; Tomita-Yokotani, Kaori; Arai, Mayumi; Yamashita, Masamichi; Katoh, Hiroshi; Ajioka, Reiko; Inoue, Kotomi

2016-07-01

A terrestrial cyanobacterium, Nostoc sp. HK-01 (hereafter HK-01), has several useful abilities for space habitation; photosynthesis, nitrogen fixation, and space environmental tolerances to vacuum, UV, gamma-ray, heavy particle beam, low and high temperature. Space environmental tolerances are important for transportation to Mars. HK-01 can grow on Martian regolith simulant (MRS) in vitro. Furthermore, HK-01 is useful as food. HK-01 may be utilized as oxygen supply, soil formation and food material for bio-chemical circulation in closed bio-ecosystems, including space habitation such as Mars. HK-01 was adopted as a biological material for the "TANPOPO" mission (JAXA et al.,), because of their high environmental tolerances. The "TANPOPO" mission is performing the space exposure experiments on the Japan Experimental Module (JEM) of the International Space Station (ISS). The results of these experiments will show the ability of HK-01 to survive in space.

Evaluation of coated columbian alloy heat shields for space shuttle thermal protection system application. Volume 1: Phase 1 - Environmental criteria and material characterization, October 1970 - March 1972

NASA Technical Reports Server (NTRS)

Black, W. E.

1972-01-01

The studies presented are directed toward establishing criteria for a niobium alloy thermal protection system for the space shuttle. Evaluation of three niobium alloys and two silicon coatings for heat shield configurations culminated in the selection of two coating/substrate combinations for environmental criteria and material characterization tests. Specimens were exposed to boost and reentry temperatures, pressure, and loads simulating a space shuttle orbiter flight profile.

25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

NASA Technical Reports Server (NTRS)

Packard, Edward

2008-01-01

Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The ESA Large Space Simulator Mechanical Ground Support Equipment for Spacecraft Testing; Temperature Stability and Control Requirements for Thermal Vacuum/Thermal Balance Testing of the Aquarius Radiometer; The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System; Return to Mercury: A Comparison of Solar Simulation and Flight Data for the MESSENGER Spacecraft; Floating Pressure Conversion and Equipment Upgrades of Two 3.5kw, 20k, Helium Refrigerators; Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load; Special ISO Class 6 Cleanroom for the Lunar Reconnaissance Orbiter (LRO) Project; A State-of-the-Art Contamination Effects Research and Test Facility Martian Dust Simulator; Cleanroom Design Practices and Their Influence on Particle Counts; Extra Terrestrial Environmental Chamber Design; Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability; SES and Acoustics at GSFC; HST Super Lightweight Interchangeable Carrier (SLIC) Static Test; Virtual Shaker Testing: Simulation Technology Improves Vibration Test Performance; Estimating Shock Spectra: Extensions beyond GEVS; Structural Dynamic Analysis of a Spacecraft Multi-DOF Shaker Table; Direct Field Acoustic Testing; Manufacture of Cryoshroud Surfaces for Space Simulation Chambers; The New LOTIS Test Facility; Thermal Vacuum Control Systems Options for Test Facilities; Extremely High Vacuum Chamber for Low Outgassing Processing at NASA Goddard; Precision Cleaning - Path to Premier; The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT; Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar; Thermal (Silicon Diode) Data Acquisition System; Aquarius's Instrument Science Data System (ISDS) Automated to Acquire, Process, Trend Data and Produce Radiometric System Assessment Reports; Exhaustive Thresholds and Resistance Checkpoints; Reconfigurable HIL Testing of Earth Satellites; FPGA Control System for the Automated Test of MicroShutters; Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM; Operationally Responsive Space Standard Bus Battery Thermal Balance Testing and Heat Dissipation Analysis; Galileo - The Serial-Production AIT Challenge; The Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Simulated Reentry Heating by Torching; Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum; High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber; The Planning and Implementation of Test Facility Improvements; and Development of a Silicon Carbide Molecular Beam Nozzle for Simulation Planetary Flybys and Low-Earth Orbit.

The Space Environmental Impact System

NASA Astrophysics Data System (ADS)

Kihn, E. A.

2009-12-01

The Space Environmental Impact System (SEIS) is an operational tool for incorporating environmental data sets into DoD Modeling and Simulation (M&S) which allows for enhanced decision making regarding acquisitions, testing, operations and planning. The SEIS system creates, from the environmental archives and developed rule-base, a tool for describing the effects of the space environment on particular military systems, both historically and in real-time. The system uses data available over the web, and in particular data provided by NASA’s virtual observatory network, as well as modeled data generated specifically for this purpose. The rule base system developed to support SEIS is an open XML based model which can be extended to events from any environmental domain. This presentation will show how the SEIS tool allows users to easily and accurately evaluate the effect of space weather in terms that are meaningful to them as well as discuss the relevant standards used in its construction and go over lessons learned from fielding an operational environmental decision tool.

Simulated Space Vacuum Ultraviolet (VUV) Exposure Testing for Polymer Films

NASA Technical Reports Server (NTRS)

Dever, Joyce A.; Pietromica, Anthony J.; Stueber, Thomas J.; Sechkar, Edward A.; Messer, Russell K.

2002-01-01

Vacuum ultraviolet (VUV) radiation of wavelengths between 115 and 200 nm produced by the sun in the space environment can cause degradation to polymer films producing changes in optical, mechanical, and chemical properties. These effects are particularly important for thin polymer films being considered for ultra-lightweight space structures, because, for most polymers, VUV radiation is absorbed in a thin surface layer. NASA Glenn Research Center has developed facilities and methods for long-term ground testing of polymer films to evaluate space environmental VUV radiation effects. VUV exposure can also be used as part of sequential simulated space environmental exposures to determine combined damaging effects. This paper will describe the effects of VUV on polymer films and the necessity for ground testing. Testing practices used at Glenn Research Center for VUV exposure testing will be described including characterization of the VUV radiation source used, calibration procedures traceable to the National Institute of Standards and Technology (NIST), and testing techniques for VUV exposure of polymer surfaces.

What LDEF means for development and testing of materials

NASA Technical Reports Server (NTRS)

Whitaker, Ann F.; Stuckey, Wayne K.; Stein, Bland A.

1993-01-01

The Long Duration Exposure Facility (LDEF) served as the ultimate laboratory to provide combined space environmental effects on materials. The LDEF structure and its 57 experiments contained an estimated 12,000 to 14,000 specimens of materials and materials processes. It not only provided information about the resistance of these materials to the space environment but gives us direction into future needs for spacecraft materials development and testing. This paper provides an overview of the materials effects observed on the satellite and suggests recommendations for the future work in space-qualified materials development and space environmental simulation.

The effects of simulated space environmental parameters on six commercially available composite materials

NASA Technical Reports Server (NTRS)

Funk, Joan G.; Sykes, George F., Jr.

1989-01-01

The effects of simulated space environmental parameters on microdamage induced by the environment in a series of commercially available graphite-fiber-reinforced composite materials were determined. Composites with both thermoset and thermoplastic resin systems were studied. Low-Earth-Orbit (LEO) exposures were simulated by thermal cycling; geosynchronous-orbit (GEO) exposures were simulated by electron irradiation plus thermal cycling. The thermal cycling temperature range was -250 F to either 200 F or 150 F. The upper limits of the thermal cycles were different to ensure that an individual composite material was not cycled above its glass transition temperature. Material response was characterized through assessment of the induced microcracking and its influence on mechanical property changes at both room temperature and -250 F. Microdamage was induced in both thermoset and thermoplastic advanced composite materials exposed to the simulated LEO environment. However, a 350 F cure single-phase toughened epoxy composite was not damaged during exposure to the LEO environment. The simuated GEO environment produced microdamage in all materials tested.

Recent advances in spacecraft thermal-control materials research.

NASA Technical Reports Server (NTRS)

Zerlaut, G. A.; Gilligan, J. E.; Gates, D. W.

1972-01-01

The state-of-the-art of spacecraft thermal-control materials technology has been significantly advanced during the past 4 years. Selective black coatings are discussed together with black paints, dielectric films on metal surfaces, and white radiator coatings. Criteria for the selection of thermal-control surfaces are considered, giving attention to prelaunch protection, the capability of being measured, reproducibility, simulator response, and aspects of a nonindigenous space environment. Progress in space simulation is related to vacuum technology, ultraviolet sources, solar wind simulation, and the production of protons. Advances have been made in the protection against space environmental effects, and in the development of thermal-control surfaces and pigments.

Electrostatic Discharge Test of Multi-Junction Solar Array Coupons After Combined Space Environmental Exposures

NASA Technical Reports Server (NTRS)

Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

2010-01-01

A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is conducting electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO/CD 11221, the ISO standard for ESD testing on solar array panels. This standard is currently in its final review with expected approval in 2010. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of 4 cells. The ESD tests are performed at the beginning of life (BOL) and at each 5-year environment exposure point. The environmental exposure sequence consists of UV radiation, electron/proton particle radiation, thermal cycling, and ion thruster plume. This paper discusses the coverglass flashover simulation, ESD test setup, and the importance of the electrical test design in simulating the on-orbit operational conditions. Results from 5th-year testing are compared to the baseline ESD characteristics determined at the BOL condition.

Remote control circuit breaker evaluation testing. [for space shuttles

NASA Technical Reports Server (NTRS)

Bemko, L. M.

1974-01-01

Engineering evaluation tests were performed on several models/types of remote control circuit breakers marketed in an attempt to gain some insight into their potential suitability for use on the space shuttle vehicle. Tests included the measurement of several electrical and operational performance parameters under laboratory ambient, space simulation, acceleration and vibration environmental conditions.

Capabilities of the Environmental Effects Branch at Marshall Space Flight Cente

NASA Technical Reports Server (NTRS)

Rogers, Jan; Finckenor, Miria; Nehls, Mary

2016-01-01

The Environmental Effects Branch at the Marshall Space Flight Center supports a myriad array of programs for NASA, DoD, and commercial space including human exploration, advanced space propulsion, improving life on Earth, and the study of the Sun, the Earth, and the solar system. The branch provides testing, evaluation, and qualification of materials for use on external spacecraft surfaces and in contamination-sensitive systems. Space environment capabilities include charged particle radiation, ultraviolet radiation, atomic oxygen, impact, plasma, and thermal vacuum, anchored by flight experiments and analysis of returned space hardware. These environmental components can be combined for solar wind or planetary surface environment studies or to evaluate synergistic effects. The Impact Testing Facility allows simulation of impacts ranging from sand and rain to micrometeoroids and orbital debris in order to evaluate materials and components for flight and ground-based systems. The Contamination Control Team is involved in the evaluation of environmentally-friendly replacements for HCFC-225 for use in propulsion oxygen systems, developing cleaning methods for additively manufactured hardware, and reducing risk for the Space Launch System.

Microgravity Simulation Facility (MSF)

NASA Technical Reports Server (NTRS)

Richards, Stephanie E. (Compiler); Levine, Howard G.; Zhang, Ye

2016-01-01

The Microgravity Simulator Facility (MSF) at Kennedy Space Center (KSC) was established to support visiting scientists for short duration studies utilizing a variety of microgravity simulator devices that negate the directional influence of the "g" vector (providing simulated conditions of micro or partial gravity). KSC gravity simulators can be accommodated within controlled environment chambers allowing investigators to customize and monitor environmental conditions such as temperature, humidity, CO2, and light exposure.

Suboptimal evolutionary novel environments promote singular altered gravity responses of transcriptome during Drosophila metamorphosis

PubMed Central

2013-01-01

Background Previous experiments have shown that the reduced gravity aboard the International Space Station (ISS) causes important alterations in Drosophila gene expression. These changes were shown to be intimately linked to environmental space-flight related constraints. Results Here, we use an array of different techniques for ground-based simulation of microgravity effects to assess the effect of suboptimal environmental conditions on the gene expression of Drosophila in reduced gravity. A global and integrative analysis, using “gene expression dynamics inspector” (GEDI) self-organizing maps, reveals different degrees in the responses of the transcriptome when using different environmental conditions or microgravity/hypergravity simulation devices. Although the genes that are affected are different in each simulation technique, we find that the same gene ontology groups, including at least one large multigene family related with behavior, stress response or organogenesis, are over represented in each case. Conclusions These results suggest that the transcriptome as a whole can be finely tuned to gravity force. In optimum environmental conditions, the alteration of gravity has only mild effects on gene expression but when environmental conditions are far from optimal, the gene expression must be tuned greatly and effects become more robust, probably linked to the lack of experience of organisms exposed to evolutionary novel environments such as a gravitational free one. PMID:23806134

Characterization of Space Environmental Effects on Candidate Solar Sail Material

NASA Technical Reports Server (NTRS)

Edwards, David; Hubbs, Whitney; Stanaland, Tesia; Munafo, Paul M. (Technical Monitor)

2002-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two if the sunfacing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. The Space Environmental Effects Team, at MSFC, is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to radiation environments simulating orbital environments. This paper describes the results of three candidate materials after exposure to a simulated Geosynchronous Transfer Orbit (GTO). This is the first known characterization of solar sail material exposed to space simulated radiation environments. The technique of radiation dose versus material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.

Simulation of Range Safety for the NASA Space Shuttle

NASA Technical Reports Server (NTRS)

Rabelo, Luis; Sepulveda, Jose; Compton, Jeppie; Turner, Robert

2005-01-01

This paper describes a simulation environment that seamlessly combines a number of safety and environmental models for the launch phase of a NASA Space Shuttle mission. The components of this simulation environment represent the different systems that must interact in order to determine the Expectation of casualties (E(sub c)) resulting from the toxic effects of the gas dispersion that occurs after a disaster affecting a Space Shuttle within 120 seconds of lift-off. The utilization of the Space Shuttle reliability models, trajectory models, weather dissemination systems, population models, amount and type of toxicants, gas dispersion models, human response functions to toxicants, and a geographical information system are all integrated to create this environment. This simulation environment can help safety managers estimate the population at risk in order to plan evacuation, make sheltering decisions, determine the resources required to provide aid and comfort, and mitigate damages in case of a disaster. This simulation environment may also be modified and used for the landing phase of a space vehicle but will not be discussed in this paper.

Space station protective coating development

NASA Technical Reports Server (NTRS)

Pippin, H. G.; Hill, S. G.

1989-01-01

A generic list of Space Station surfaces and candidate material types is provided. Environmental exposures and performance requirements for the different Space Station surfaces are listed. Coating materials and the processing required to produce a viable system, and appropriate environmental simulation test facilities are being developed. Mass loss data from the original version of the atomic oxygen test chamber and the improved facility; additional environmental exposures performed on candidate materials; and materials properties measurements on candidate coatings to determine the effects of the exposures are discussed. Methodologies of production, and coating materials, used to produce the large scale demonstration articles are described. The electronic data base developed for the contract is also described. The test chamber to be used for exposure of materials to atomic oxygen was built.

Study-simulation of space station dynamics

NASA Technical Reports Server (NTRS)

Gaitens, M. J.

1971-01-01

Matrix algebra translator and executor /MATE/ takes equations describing structural control system environmental interaction problem for flexible spacecraft components and loads them into self programming computer.

International Space Station (ISS)

NASA Image and Video Library

2001-02-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This is a view of the ECLSS and the Internal Thermal Control System (ITCS) Test Facility in building 4755, MSFC. In the foreground is the 3-module ECLSS simulator comprised of the U.S. Laboratory Module Simulator, Node 1 Simulator, and Node 3/Habitation Module Simulator. At center left is the ITCS Simulator. The main function of the ITCS is to control the temperature of equipment and hardware installed in a typical ISS Payload Rack.

International Space Station (ISS)

NASA Image and Video Library

2001-02-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This is a view of the ECLSS and the Internal Thermal Control System (ITCS) Test Facility in building 4755, MSFC. In the foreground is the 3-module ECLSS simulator comprised of the U.S. Laboratory Module Simulator, Node 1 Simulator, and Node 3/Habitation Module Simulator. On the left is the ITCS Simulator. The main function of the ITCS is to control the temperature of equipment and hardware installed in a typical ISS Payload Rack.

Evaluation and prediction of long-term environmental effects on nonmetallic materials

NASA Technical Reports Server (NTRS)

1982-01-01

Changes in functional properties of a broad spectrum of nonmetallic materials as a function of environment and exposure time were evaluated. Models for predicting long-term material performance are discussed. A literature search on specific materials in the space and simulated space environment was carried out and evaluated.

Optical Analysis of Transparent Polymeric Material Exposed to Simulated Space Environment

NASA Technical Reports Server (NTRS)

Edwards, David L.; Finckenor, Miria M.

1999-01-01

Transparent polymeric materials are being designed and utilized as solar concentrating lenses for spacecraft power and propulsion systems. These polymeric lenses concentrate solar energy onto energy conversion devices such as solar cells and thermal energy systems. The conversion efficiency is directly related to the transmissivity of the polymeric lens. The Environmental Effects Group of the Marshall Space Flight Center's Materials, Processes, and Manufacturing Department exposed a variety of materials to a simulated space environment and evaluated them for an, change in optical transmission. These materials include Lexan(TM), polyethylene terephthalate (PET). several formulations of Tefzel(TM). and Teflon(TM), and silicone DC 93-500. Samples were exposed to a minimum of 1000 Equivalent Sun Hours (ESH) of near-UV radiation (250 - 400 nm wavelength). Data will be presented on materials exposed to charged particle radiation equivalent to a five-year dose in geosynchronous orbit. These exposures were performed in MSFC's Combined Environmental Effects Test Chamber, a unique facility with the capability to expose materials simultaneously or sequentially to protons, low-energy electrons, high-energy electrons, near UV radiation and vacuum UV radiation.Prolonged exposure to the space environment will decrease the polymer film's transmission and thus reduce the conversion efficiency. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance to space environmental exposure. Spectral results and the material ranking according to transmission loss are presented.

Spacecraft environmental interactions: A joint Air Force and NASA research and technology program

NASA Technical Reports Server (NTRS)

Pike, C. P.; Purvis, C. K.; Hudson, W. R.

1985-01-01

A joint Air Force/NASA comprehensive research and technology program on spacecraft environmental interactions to develop technology to control interactions between large spacecraft systems and the charged-particle environment of space is described. This technology will support NASA/Department of Defense operations of the shuttle/IUS, shuttle/Centaur, and the force application and surveillance and detection missions, planning for transatmospheric vehicles and the NASA space station, and the AFSC military space system technology model. The program consists of combined contractual and in-house efforts aimed at understanding spacecraft environmental interaction phenomena and relating results of ground-based tests to space conditions. A concerted effort is being made to identify project-related environmental interactions of concern. The basic properties of materials are being investigated to develop or modify the materials as needed. A group simulation investigation is evaluating basic plasma interaction phenomena to provide inputs to the analytical modeling investigation. Systems performance is being evaluated by both groundbased tests and analysis.

Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Degroh, Kim K.; Banks, Bruce A.; Smith, Daniela C.

1994-01-01

Space solar power systems for use in the low Earth orbit (LEO) environment experience a variety of harsh environmental conditions. Materials used for solar power generation in LEO need to be durable to environmental threats such as atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeoroid and debris impact. Another threat to LEO solar power performance is due to contamination from other spacecraft components. This paper gives an overview of these LEO environmental issues as they relate to space solar power system materials. Issues addressed include atomic oxygen erosion of organic materials, atomic oxygen undercutting of protective coatings, UV darkening of ceramics, UV embrittlement of Teflon, effects of thermal cycling on organic composites, and contamination due to silicone and organic materials. Specific examples of samples from the Long Duration Exposure Facility (LDEF) and materials returned from the first servicing mission of the Hubble Space Telescope (HST) are presented. Issues concerning ground laboratory facilities which simulate the LEO environment are discussed along with ground-to-space correlation issues.

The Planetary and Space Simulation Facilities at DLR Cologne

NASA Astrophysics Data System (ADS)

Rabbow, Elke; Parpart, André; Reitz, Günther

2016-06-01

Astrobiology strives to increase our knowledge on the origin, evolution and distribution of life, on Earth and beyond. In the past centuries, life has been found on Earth in environments with extreme conditions that were expected to be uninhabitable. Scientific investigations of the underlying metabolic mechanisms and strategies that lead to the high adaptability of these extremophile organisms increase our understanding of evolution and distribution of life on Earth. Life as we know it depends on the availability of liquid water. Exposure of organisms to defined and complex extreme environmental conditions, in particular those that limit the water availability, allows the investigation of the survival mechanisms as well as an estimation of the possibility of the distribution to and survivability on other celestial bodies of selected organisms. Space missions in low Earth orbit (LEO) provide access for experiments to complex environmental conditions not available on Earth, but studies on the molecular and cellular mechanisms of adaption to these hostile conditions and on the limits of life cannot be performed exclusively in space experiments. Experimental space is limited and allows only the investigation of selected endpoints. An additional intensive ground based program is required, with easy to access facilities capable to simulate space and planetary environments, in particular with focus on temperature, pressure, atmospheric composition and short wavelength solar ultraviolet radiation (UV). DLR Cologne operates a number of Planetary and Space Simulation facilities (PSI) where microorganisms from extreme terrestrial environments or known for their high adaptability are exposed for mechanistic studies. Space or planetary parameters are simulated individually or in combination in temperature controlled vacuum facilities equipped with a variety of defined and calibrated irradiation sources. The PSI support basic research and were recurrently used for pre-flight test programs for several astrobiological space missions. Parallel experiments on ground provided essential complementary data supporting the scientific interpretation of the data received from the space missions.

Construction of the Hunveyor-Husar space probe model system for planetary science education and analog studies and simulations in universities and colleges of Hungary.

NASA Astrophysics Data System (ADS)

Bérczi, Sz.; Hegyi, S.; Hudoba, Gy.; Hargitai, H.; Kokiny, A.; Drommer, B.; Gucsik, A.; Pintér, A.; Kovács, Zs.

Several teachers and students had the possibility to visit International Space Camp in the vicinity of the MSFC NASA in Huntsville Alabama USA where they learned the success of simulators in space science education To apply these results in universities and colleges in Hungary we began a unified complex modelling in planetary geology robotics electronics and complex environmental analysis by constructing an experimental space probe model system First a university experimental lander HUNVEYOR Hungarian UNiversity surVEYOR then a rover named HUSAR Hungarian University Surface Analyser Rover has been built For Hunveyor the idea and example was the historical Surveyor program of NASA in the 1960-ies for the Husar the idea and example was the Pathfinder s rover Sojouner rover The first step was the construction of the lander a year later the rover followed The main goals are 1 to build the lander structure and basic electronics from cheap everyday PC compatible elements 2 to construct basic experiments and their instruments 3 to use the system as a space activity simulator 4 this simulator contains lander with on board computer for works on a test planetary surface and a terrestrial control computer 5 to harmonize the assemblage of the electronic system and instruments in various levels of autonomy from the power and communication circuits 6 to use the complex system in education for in situ understanding complex planetary environmental problems 7 to build various planetary environments for application of the

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

Arabidopsis thaliana plants are seen inside the growth chamber of the Advanced Plant Habitat (APH) Flight Unit No. 1 prior to harvest of half the plants. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in NASA Kennedy Space Center's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Space Station Environmental Control and Life Support System Test Facility at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Springer, Darlene

1989-01-01

Different aspects of Space Station Environmental Control and Life Support System (ECLSS) testing are currently taking place at Marshall Space Flight Center (MSFC). Unique to this testing is the variety of test areas and the fact that all are located in one building. The north high bay of building 4755, the Core Module Integration Facility (CMIF), contains the following test areas: the Subsystem Test Area, the Comparative Test Area, the Process Material Management System (PMMS), the Core Module Simulator (CMS), the End-use Equipment Facility (EEF), and the Pre-development Operational System Test (POST) Area. This paper addresses the facility that supports these test areas and briefly describes the testing in each area. Future plans for the building and Space Station module configurations will also be discussed.

Simulator Sickness During Emergency Procedures Training in a Helicopter Simulator: Age, Flight Experience, and Amount Learned

DTIC Science & Technology

2007-09-01

Aircrew Training Research Division, Human Resources Directorate. Smart, L. J ., Stoffregen, T. A ., & Bardy , B. G. (2002). Visually induced motion sickness...Aviation, Space, and Environmental Medicine, 60, 1043-1048. Benson, A . J . (1978). Motion sickness. In G. Dhenin & J . Ernsting (Eds.), Aviation Medicine...pp. 468-493). London: Tri-Med Books. Benson, A . J . (1988). Aetiological factors in simulator sickness. In AGARD, Motion cues in flight simulation and

Simulation of the synergistic low Earth orbit effects of vacuum thermal cycling, vacuum UV radiation, and atomic oxygen

NASA Technical Reports Server (NTRS)

Dever, Joyce A.; Degroh, Kim K.; Stidham, Curtis R.; Stueber, Thomas J.; Dever, Therese M.; Rodriguez, Elvin; Terlep, Judith A.

1992-01-01

In order to assess the low Earth orbit (LEO) durability of candidate space materials, it is necessary to use ground laboratory facilities which provide LEO environmental effects. A facility combining vacuum thermal cycling and vacuum ultraviolet (VUV) radiation has been designed and constructed at NASA Lewis Research Center for this purpose. This facility can also be operated without the VUV lamps. An additional facility can be used to provide VUV exposure only. By utilizing these facilities, followed by atomic oxygen exposure in an RF plasma asher, the effects of the individual vacuum thermal cycling and VUV environments can be compared to the effect of the combined vacuum thermal cycling/VUV environment on the atomic oxygen durability of materials. The synergistic effects of simulated LEO environmental conditions on materials were evaluated by first exposing materials to vacuum thermal cycling, VUV, and vacuum thermal cycling/VUV environments followed by exposure to atomic oxygen in an RP plasma asher. Candidate space power materials such as atomic oxygen protected polyimides and solar concentrator mirrors were evaluated using these facilities. Characteristics of the Vacuum Thermal Cycling/VUV Exposure Facility which simulates the temperature sequences and solar ultraviolet radiation exposure that would be experienced by a spacecraft surface in LEO are discussed. Results of durability evaluations of some candidate space power materials to the simulated LEO environmental conditions will also be discussed. Such results have indicated that for some materials, atomic oxygen durability is affected by previous exposure to thermal cycling and/or VUV exposure.

Environmental Factors Affecting Asthma and Allergies: Predicting and Simulating Downwind Exposure to Airborne Pollen

NASA Technical Reports Server (NTRS)

Luvall, Jeffrey; Estes, Sue; Sprigg, William A.; Nickovic, Slobodan; Huete, Alfredo; Solano, Ramon; Ratana, Piyachat; Jiang, Zhangyan; Flowers, Len; Zelicoff, Alan

2009-01-01

This slide presentation reviews the environmental factors that affect asthma and allergies and work to predict and simulate the downwind exposure to airborne pollen. Using a modification of Dust REgional Atmosphere Model (DREAM) that incorporates phenology (i.e. PREAM) the aim was to predict concentrations of pollen in time and space. The strategy for using the model to simulate downwind pollen dispersal, and evaluate the results. Using MODerate-resolution Imaging Spectroradiometer (MODIS), to get seasonal sampling of Juniper, the pollen chosen for the study, land cover on a near daily basis. The results of the model are reviewed.

Environmental Control and Life Support Systems Test Facility at MSFC

NASA Technical Reports Server (NTRS)

2001-01-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This photograph shows the development Water Processor located in two racks in the ECLSS test area at the Marshall Space Flight Center. Actual waste water, simulating Space Station waste, is generated and processed through the hardware to evaluate the performance of technologies in the flight Water Processor design.

Space-based ornithology: studying bird migration and environmental change in North America

NASA Astrophysics Data System (ADS)

Smith, James A.; Deppe, Jill L.

2008-10-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. Space based technology in concert with bird migration modeling and geographical information analysis yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At the NASA Goddard Space Flight Center, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. We use an individual-based bird biophysical migration model, driven by remotely sensed land surface data, climate and hydrologic data, and biological field observations to study migratory bird responses to environmental change in North America. Simulation allows us to study bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. We illustrate our approach by simulating the spring migration of pectoral sandpipers from the Gulf of Mexico to Alaska. Mean stopover length and trajectory patterns are consistent with field observations.

Space-Based Ornithology - Studying Bird Migration and Environmental Change in North America

NASA Technical Reports Server (NTRS)

Smith, James A.; Deppe, Jill L.

2008-01-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. Space based technology in concert with bird migration modeling and geographical information analysis yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At the NASA Goddard Space Flight Center, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. We use an individual-based bird biophysical migration model, driven by remotely sensed land surface data, climate and hydrologic data, and biological field observations to study migratory bird responses to environmental change in North America. Simulation allows us to study bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. We illustrate our approach by simulating the spring migration of pectoral sandpipers from the Gulf of Mexico to Alaska. Mean stopover length and trajectory patterns are consistent with field observations.

User's manual for a computer program for the emulation/simulation of a space station Environmental Control and Life Support System (ESCM)

NASA Technical Reports Server (NTRS)

Yanosy, James L.

1988-01-01

This manual describes how to use the Emulation Simulation Computer Model (ESCM). Based on G189A, ESCM computes the transient performance of a Space Station atmospheric revitalization subsystem (ARS) with CO2 removal provided by a solid amine water desorbed subsystem called SAWD. Many performance parameters are computed some of which are cabin CO2 partial pressure, relative humidity, temperature, O2 partial pressure, and dew point. The program allows the user to simulate various possible combinations of man loading, metabolic profiles, cabin volumes and certain hypothesized failures that could occur.

Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments

NASA Technical Reports Server (NTRS)

Johnson, Kenneth R.

1997-01-01

The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

LDEF materials overview

NASA Technical Reports Server (NTRS)

Stein, Bland A.

1993-01-01

The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The 5-year, 9-month flight of LDEF greatly enhanced the potential value of all materials on LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. NASA recognized this potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements so that the combined value of all LDEF materials data to current and future space missions will be addressed and documented. An overview of the interim LDEF materials findings of the principal investigators and the Materials Special Investigation Group is provided. These revelations are based on observations of LEO environmental effects on materials made in space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format that categorizes the revelations as 'clear findings' or 'obscure preliminary findings' (and progress toward their resolution), plus resultant needs for new space materials developments and ground simulation testing/analytical modeling, in seven categories: materials/environmental parameters and data bases; LDEF contamination; thermal control coatings and protective treatments; polymers and films; polymer-matrix composites; metals, ceramics, and optical materials; and systems-related materials. The utilization of LDEF materials data for future low-Earth orbit missions is also discussed, concentrating on Space Station Freedom. In general, the LDEF data is remarkably consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8-years; other 'space qualified' materials displayed significant environmental degradation. General contamination levels on LDEF were low, but molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions were identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

Environmental Test Program for the Mars Exploration Rover Project

NASA Technical Reports Server (NTRS)

Fisher, Terry C.; VanVelzer, Paul L.

2004-01-01

On June 10 and July 7, 2003 the National Aeronautics and Space Administration (NASA) launched two spacecraft from Cape Canaveral, Florida for a six (6) months flight to the Red Planet, Mars. The two Mars Exploration Rover spacecraft landed safely on the planet in January 2004. Prior to the successful launch, both of the spacecraft were involved in a comprehensive test campaign that included development, qualification, and protoflight test programs. Testing was performed to simulate the environments associated with launch, inter-planetary cruise, landing on the planet and Mars surface operations. Unique test requirements included operating the spacecraft while the chamber pressure was controlled to simulate the decent to the planet from deep space, high impact landing loads and rover operations on the surface of the planet at 8 Torr and -130 C. This paper will present an overview of the test program that included vibration, pyro-shock, landing loads, acoustic noise, thermal vacuum and solar simulation testing at the Jet Propulsion Laboratory (JPL) Environmental Test Laboratory facilities in Pasadena, California.

Planetary and Space Simulation Facilities PSI at DLR for Astrobiology

NASA Astrophysics Data System (ADS)

Rabbow, E.; Rettberg, P.; Panitz, C.; Reitz, G.

2008-09-01

Ground based experiments, conducted in the controlled planetary and space environment simulation facilities PSI at DLR, are used to investigate astrobiological questions and to complement the corresponding experiments in LEO, for example on free flying satellites or on space exposure platforms on the ISS. In-orbit exposure facilities can only accommodate a limited number of experiments for exposure to space parameters like high vacuum, intense radiation of galactic and solar origin and microgravity, sometimes also technically adapted to simulate extraterrestrial planetary conditions like those on Mars. Ground based experiments in carefully equipped and monitored simulation facilities allow the investigation of the effects of simulated single environmental parameters and selected combinations on a much wider variety of samples. In PSI at DLR, international science consortia performed astrobiological investigations and space experiment preparations, exposing organic compounds and a wide range of microorganisms, reaching from bacterial spores to complex microbial communities, lichens and even animals like tardigrades to simulated planetary or space environment parameters in pursuit of exobiological questions on the resistance to extreme environments and the origin and distribution of life. The Planetary and Space Simulation Facilities PSI of the Institute of Aerospace Medicine at DLR in Köln, Germany, providing high vacuum of controlled residual composition, ionizing radiation of a X-ray tube, polychromatic UV radiation in the range of 170-400 nm, VIS and IR or individual monochromatic UV wavelengths, and temperature regulation from -20°C to +80°C at the sample size individually or in selected combinations in 9 modular facilities of varying sizes are presented with selected experiments performed within.

The 11th Space Simulation Conference

NASA Technical Reports Server (NTRS)

Bond, A. C. (Editor)

1980-01-01

Subject areas range from specialized issues dealing with the space and entry environments to the environmental testing of systems and complete spacecraft of present-day vintage. Various papers consider: the test and development of several key systems of the orbiter vehicle; integrated tests of complete satellites; new and unique test facilities developed to meet the demanding requirements of high fidelity simulation of test environments; and contamination species, including the instrumentation for detection and measurement of such. Special topics include improved thermal protection methodologies and approaches, sophisticated sensor developments, and other related testing and development areas.

Model description document for a computer program for the emulation/simulation of a space station environmental control and life support system (ESCM)

NASA Technical Reports Server (NTRS)

Yanosy, James L.

1988-01-01

Emulation/Simulation Computer Model (ESCM) computes the transient performance of a Space Station air revitalization subsystem with carbon dioxide removal provided by a solid amine water desorbed subsystem called SAWD. This manual describes the mathematical modeling and equations used in the ESCM. For the system as a whole and for each individual component, the fundamental physical and chemical laws which govern their operations are presented. Assumptions are stated, and when necessary, data is presented to support empirically developed relationships.

Advanced Solid State Lighting for Human Evaluation Project

NASA Technical Reports Server (NTRS)

Zeitlin, Nancy; Holbert, Eirik

2015-01-01

Lighting intensity and color have a significant impact on human circadian rhythms. Advanced solid state lighting was developed for the Advanced Exploration System (AES) Deep Space Habitat(DSH) concept demonstrator. The latest generation of assemblies using the latest commercially available LED lights were designed for use in the Bigelow Aerospace Environmental Control and Life Support System (ECLSS) simulator and the University of Hawaii's Hawaii Space Exploration Analog and Simulation (Hi-SEAS) habitat. Agreements with both these organizations will allow the government to receive feedback on the lights and lighting algorithms from long term human interaction.

Effects of Low- Versus High-Fidelity Simulations on the Cognitive Burden and Performance of Entry-Level Paramedicine Students: A Mixed-Methods Comparison Trial Using Eye-Tracking, Continuous Heart Rate, Difficulty Rating Scales, Video Observation and Interviews.

PubMed

Mills, Brennen W; Carter, Owen B-J; Rudd, Cobie J; Claxton, Louise A; Ross, Nathan P; Strobel, Natalie A

2016-02-01

High-fidelity simulation-based training is often avoided for early-stage students because of the assumption that while practicing newly learned skills, they are ill suited to processing multiple demands, which can lead to "cognitive overload" and poorer learning outcomes. We tested this assumption using a mixed-methods experimental design manipulating psychological immersion. Thirty-nine randomly assigned first-year paramedicine students completed low- or high-environmental fidelity simulations [low-environmental fidelity simulations (LF(en)S) vs. high-environmental fidelity simulation (HF(en)S)] involving a manikin with obstructed airway (SimMan3G). Psychological immersion and cognitive burden were determined via continuous heart rate, eye tracking, self-report questionnaire (National Aeronautics and Space Administration Task Load Index), independent observation, and postsimulation interviews. Performance was assessed by successful location of obstruction and time-to-termination. Eye tracking confirmed that students attended to multiple, concurrent stimuli in HF(en)S and interviews consistently suggested that they experienced greater psychological immersion and cognitive burden than their LF(en)S counterparts. This was confirmed by significantly higher mean heart rate (P < 0.001) and National Aeronautics and Space Administration Task Load Index mental demand (P < 0.05). Although group allocation did not influence the proportion of students who ultimately revived the patient (58% vs. 30%, P < 0.10), the HF(en)S students did so significantly more quickly (P < 0.01). The LF(en)S students had low immersion resulting in greater assessment anxiety. High-environmental fidelity simulation engendered immersion and a sense of urgency in students, whereas LF(en)S created assessment anxiety and slower performance. We conclude that once early-stage students have learned the basics of a clinical skill, throwing them in the "deep end" of high-fidelity simulation creates significant additional cognitive burden but this has considerable educational merit.

Atmosphere Resource Recovery and Environmental Monitoring

NASA Technical Reports Server (NTRS)

Roman, Monsi; Howard, David

2015-01-01

Atmosphere Resource Recovery and Environmental Monitoring (ARREM) is a project focused on evolving existing and maturing emerging 'closed loop' atmosphere revitalization (AR) life support systems that produce clean, breathable air for crewmembers, and developing a suite of low mass, low power environmental monitors to detect and measure air- and waterborne constituents and contaminants. The objective is to improve reliability and efficiency, reduce mass and volume, and increase recovery of oxygen from carbon dioxide created by human metabolism from 43% to greater than 90%. The technology developments under ARREM are vital to extending human space missions from low-Earth orbit like the International Space Station to destinations deeper into space such as Mars where dependency on Earth for resupply of maintenance items and critical life support elements such as water and oxygen is not possible. The primary goal of the ARREM project is to demonstrate that systems meet the more stringent performance parameters for deep space exploration and are compatible with other systems within closed loop life support through a series of integrated tests performed in an environmental test chamber capable of simulating human metabolic activities and measuring systems outputs.

Evaluation and prediction of long-term environmental effects of nonmetallic materials, second phase

NASA Technical Reports Server (NTRS)

1983-01-01

Changes in the functional properties of a number of nonmetallic materials were evaluated experimentally as a function of simulated space environments and to use such data to develop models for accelerated test methods useful for predicting such behavioral changes. The effects of changed particle irradiations on candidate space materials are evaluated.

Vacuum Drying Technique

NASA Technical Reports Server (NTRS)

1979-01-01

At Valley Forge, Pennsylvania, General Electric Company's Space Division has a large environmental chamber for simulating the conditions under which an orbiting spacecraft operates. Normally it is used to test company-built space systems, such as NASA's Landsat and Nimbus satellites. It is also being used in a novel spinoff application-restoring water-damaged books and other paper products and textiles.

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

John "JC" Carver, a payload integration engineer with NASA Kennedy Space Center's Test and Operations Support Contract, harvests half the Arabidopsis thaliana plants inside the growth chamber of the Advanced Plant Habitat (APH) Flight Unit No. 1. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in Kennedy's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Influence of urban shapes on environmental noise: a case study in Aracaju-Brazil.

PubMed

Guedes, Italo C Montalvão; Bertoli, Stelamaris R; Zannin, Paulo H T

2011-12-15

This paper discusses the results of a study about the influence of urban shapes on environmental noise in the city of Aracaju (Brazil). The study, which involved in situ measurements and acoustic simulations using SoundPLAN software, began with an analysis of the current acoustic scenario, followed by the creation and simulation of hypothetical scenarios in as yet unoccupied sectors of the region under study. The acoustic modeling and simulations were based on measurements of equivalent-continuous sound pressure level, LAeq, and vehicle flow data, and on the region's geometrics. The results reveal that the physical characteristics of the urban shape, such as construction density, the existence of open spaces, and the shape and physical position of buildings exert a significant influence on environmental noise. Copyright © 2011 Elsevier B.V. All rights reserved.

The aero optics effect on near space laser communication optical system

NASA Astrophysics Data System (ADS)

Hu, Yuan; Fu, Yuegang; Jiang, Huilin

2013-08-01

With the developing of the space laser communication link, the performance index including higher transfer speed, extending transfer distance, and environmental adaptability, all ask the system accuracy and indexes improving. Special the developing near space platform, its environmental is extremes, the near space drone and other airplane flight speed is very quickly from the subsonic to supersonic. The aero optics effect caused by high speed will generate a thin turbulent air layer. It affects the performance of laser communication optical system by laser light vibration, deviation and so on, further more affects the performance of laser communication system working performance, even can't communication. Therefore, for achieving optical system indexes, we need do more research in optical system near space aero optics environmental adaptability. In this paper, near space link environmental characteristic are researched. And on the base of the aero optics theory, computer simulating method is applied to analyze the relationship among the altitude, the flight speed and the image dispersion. The result shows that, the aero optics effect cannot be ignored when the terminal is in low altitude or is moving with supersonic speed. The effect must be taken into considered from overall design. The result will provide the basis of research design.

Reactivation of Latent Viruses in Space

NASA Technical Reports Server (NTRS)

Pierson, D. L.; Mehta, S. K.; Tyring, S. K.; Lugg, D. J.

1999-01-01

Reactivation of latent viruses is an important health risk for people working and living in physically isolated extreme environments such as Antarctica and space. Preflight quarantine does not significantly reduce the risk associated with latent viruses, however, pharmaceutical countermeasures are available for some viruses. The molecular basis of latency is not fully understood, but physical and psychosocial stresses are known to initiate the reactivation of latent viruses. Presumably, stress induced changes in selected hormones lead to alterations in the cell- mediated immune (CMI) response resulting in increased shedding of latent viruses. Limited access to space makes the use of ground-based analogs essential. The Australian Antarctic stations serve as a good stress model and simulate many aspects of space flight. Closed environmental chambers have been used to simulate space flight since the Skylab missions and have also proven to be a valuable analog of selected aspects of space flight.

Combined Space Environmental Exposure Tests of Multi-Junction GaAs/Ge Solar Array Coupons

NASA Technical Reports Server (NTRS)

Hoang, Bao; Wong, Frankie; Corey, Ron; Gardiner, George; Funderburk, Victor V.; Gahart, Richard; Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason

2010-01-01

A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The purpose of this test program is to understand the changes and degradation of the solar array panel components, including its ESD mitigation design features in their integrated form, after multiple years (up to 15) of simulated geosynchronous space environment. These tests consist of: UV radiation, electrostatic discharge (ESD), electron/proton particle radiation, thermal cycling, and ion thruster plume exposures. The solar radiation was produced using a Mercury-Xenon lamp with wavelengths in the UV spectrum ranging from 230 to 400 nm. The ESD test was performed in the inverted-gradient mode using a low-energy electron (2.6 - 6 keV) beam exposure. The ESD test also included a simulated panel coverglass flashover for the primary arc event. The electron/proton radiation exposure included both 1.0 MeV and 100 keV electron beams simultaneous with a 40 keV proton beam. The thermal cycling included simulated transient earth eclipse for satellites in geosynchronous orbit. With the increasing use of ion thruster engines on many satellites, the combined environmental test also included ion thruster exposure to determine whether solar array surface erosion had any impact on its performance. Before and after each increment of environmental exposures, the coupons underwent visual inspection under high power magnification and electrical tests that included characterization by LAPSS, Dark I-V, and electroluminescence. This paper discusses the test objective, test methodologies, and preliminary results after 5 years of simulated exposure.

Pit formation observed in a multilayer dielectric coating as a result of simulated space environmental exposure

NASA Astrophysics Data System (ADS)

Fuqua, Peter D.; Presser, Nathan; Barrie, James D.; Meshishnek, Michael J.; Coleman, Dianne J.

2002-06-01

Certain spaceborne telescope designs require that dielectric-coated lenses be exposed to the energetic electrons and protons associated with the space environment. Test coupons that were exposed to a simulated space environment showed extensive pitting as a result of dielectric breakdown. A typical pit was 50-100 mum at the surface and extended to the substrate material, in which a 10-mum-diameter melt region was found. Pitting was not observed on similar samples that had also been overcoated with a transparent conductive thin film. Measurement of the bidirectional reflectance distribution transfer function showed that pitting caused a fivefold to tenfold increase in the scattering of visible light.

From diffusion pumps to cryopumps: The conversion of GSFC's space environment simulator

NASA Technical Reports Server (NTRS)

Cary, Ron

1992-01-01

The SES (Space Environmental Simulator), largest of the Thermal Vacuum Facilities at The Goddard Space Flight Center, recently was converted from an oil diffusion pumped chamber to a Cryopumped chamber. This modification was driven by requirements of flight projects. The basic requirement was to retain or enhance the operational parameters of the chamber such as pumping speed, ultimate vacuum, pump down time, and thermal system performance. To accomplish this task, seventeen diffusion pumps were removed and replaced with eight 1.2 meter (48 inch) diameter cryopumps and one 0.5 meter (20 inch) turbomolecular pump. The conversion was accomplished with a combination of subcontracting and in-house efforts to maximize the efficiency of implementation.

Next Steps Toward Understanding Human Habitation of Space: Environmental Impacts and Mechanisms

NASA Technical Reports Server (NTRS)

Globus, Ruth

2016-01-01

Entry into low earth orbit and beyond causes profound shifts in environmental conditions that have the potential to influence human productivity, long term health, and even survival. We now have evidence that microgravity, radiation and/or confinement in space can lead to demonstrably detrimental changes in the cardiovascular (e.g. vessel function, orthostatic intolerance), musculoskeletal (muscle atrophy, bone loss) and nervous (eye, neurovestibular) systems of astronauts. Because of both the limited number of astronauts who have flown (especially females) and the high degree of individual variability in the human population, important unanswered questions about responses to the space environment remain: What are the sex differences with respect to specific physiological systems? Are the responses age-dependent and/or reversible after return to Earth? Do observed detrimental changes that resemble accelerated aging progress continuously over time or plateau? What are the mechanisms of the biological responses? Answering these important questions certainly demands a multi-pronged approach, and the study of multicellular model organisms (such as rodents and flies) already has provided opportunities for exploring those questions in some detail. Recent long duration spaceflight experiments with rodents show that mice in space provide a mammalian model that uniquely combines the influence of reduced gravitational loading with increased physical activity. In addition, multiple investigators have shown that ground-based models that simulate aspects of spaceflight (including rodent hind limb unloading to mimic weightlessness and exposure to ionizing radiation), cause various transient and persistent detrimental consequences in multiple physiological systems. In general, we have found that adverse skeletal effects of simulated weightlessness and space radiation when combined, can be quantitatively, if not qualitatively, different from the influence of each environmental factor alone implying at least some shared underlying mechanisms. Thus, both ground based and spaceflight research utilizing model organisms provide the opportunity to better understand environmental factors and biological mechanisms that contribute to human health and survival in space.

Environmental Influences in the Simulation of a Solar Space Heating System.

DTIC Science & Technology

1980-01-01

this simulation an optimum collector size was determined from the energy requirements given by each model and a comparison made between the...Solar Collector Cross Section .. ............... 26 4. Solar System Schematic. .. .................. 31 5. Contributions to Annual Energy Cost...40 6. House Size I Annual Energy Cost. ....... ........ 46 7. House Size II Annual Energy Cost .. ..... ......... 47 8. House Size III Annual

LDEF materials: An overview of the interim findings

NASA Technical Reports Server (NTRS)

Stein, Bland A.

1992-01-01

The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effect (SEE) on materials that are unparalleled in the history of the U.S. space program. The 5.8-year flight of LDEF greatly enhanced the potential value of materials data from LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials of the same space vehicle. NASA recognized the potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment parameter analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements, so that the combined value of all LDEF materials data to current and future space missions will be assessed and documented. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. These revelations are based on observations of LEO environmental effects on materials made in-space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format which categorizes the revelations as 'clear findings' or 'confusing/unexplained findings' and resultant needs for new space materials developments and ground simulation testing/analytical modeling in seven categories: environmental parameters and data bases; LDEF contamination; thermal control coatings and protective treatments; polymers and films; polymer-matrix composites; metals, ceramics, and optical materials; and systems-related materials. General outlines of findings of the other LDEF Special Investigation Groups (Ionizing Radiation, Meteoroid and Debris, and Systems) are also included. The utilization of LDEF materials data for future low-earth orbit missions is also discussed, concentrating on Space Station Freedom. Some directions for continuing studies of LDEF materials are outlined. In general, the LDEF data is remarkable consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8-years; other 'space qualified' materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

Bright Days Ahead for Curiosity Mars Rover

NASA Image and Video Library

2011-03-18

This image shows preparation for March 2011 testing of the Mars Science Laboratory rover, Curiosity, in a space-simulation chamber; the rover will go through operational sequences in environmental conditions similar to what it will experience on Mars.

ISO WD 1856. Guideline for radiation exposure of nonmetallic materials. Present status

NASA Astrophysics Data System (ADS)

Briskman, B. A.

In the framework of the International Organization for Standardization (ISO) activity we started development of international standard series for space environment simulation at on-ground tests of materials. The proposal was submitted to ISO Technical Committee 20 (Aircraft and Space Vehicles), Subcommittee 14 (Space Systems and Operations) and was approved as Working Draft 15856 at the Los-Angeles meeting (1997). A draft of the first international standard "Space Environment Simulation for Radiation Tests of Materials" (1st version) was presented at the 7th International Symposium on Materials in Space Environment (Briskman et al, 1997). The 2nd version of the standard was limited to nonmetallic materials and presented at the 20th Space Simulation Conference (Briskman and Borson, 1998). It covers the testing of nonmetallic materials embracing also polymer composite materials including metal components (metal matrix composites) to simulated space radiation. The standard does not cover semiconductor materials. The types of simulated radiation include charged particles (electrons and protons), solar ultraviolet radiation, and soft X-radiation of solar flares. Synergistic interactions of the radiation environment are covered only for these natural and some induced environmental effects. This standard outlines the recommended methodology and practices for the simulation of space radiation on materials. Simulation methods are used to reproduce the effects of the space radiation environment on materials that are located on surfaces of space vehicles and behind shielding. It was discovered that the problem of radiation environment simulation is very complex and the approaches of different specialists and countries to the problem are sometimes quite opposite. To the present moment we developed seven versions of the standard. The last version is a compromise between these approaches. It was approved at the last ISO TC20/SC14/WG4 meeting in Houston, October 2002. At a splinter meeting of Int. Conference on Materials in a Space Environment, Noordwijk, Netherlands, ESA, June 2003, the experts from ESA, USA, France, Russia and Japan discussed the last version of the draft and approved it with a number of notes. A revised version of the standard will be presented this May at ISO TC20/SC14 meeting in Russia.

Age Induced Effects on ESD Characteristics of Solar Array Coupons After Combined Space Environmental Exposures

NASA Technical Reports Server (NTRS)

Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

2012-01-01

A set of multi-junction GaAs/Ge solar array test coupons provided by Space Systems/Loral were subjected to a sequence of 5-year increments of combined space environment exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is performing electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO standard for ESD testing on solar array panels [ISO-11221]. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of four cells constructed to form two strings. The ESD tests were performed at the beginning-of-life (BOL) and at each 5-year environment exposure point until end-of-life (EOL) at 15 years. The space environmental exposure sequence consisted of ultra-violet radiation, electron/proton particle radiation, thermal cycling, and Xenon ion thruster plume erosion. This paper describes the ESD test setup and the importance of the electrical test design in simulating the on-orbit operational conditions. Arc inception voltage results along with ESD test behavior from the BOL condition through the 15th year age condition are discussed. In addition, results from a Xenon plasma plume exposure test with an EOL coupon under the full ESD test condition will be discussed.

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

John "JC" Carver, a payload integration engineer with NASA Kennedy Space Center's Test and Operations Support Contract, opens the door to the growth chamber of the Advanced Plant Habitat (APH) Flight Unit No. 1 for a test harvest of half of the Arabidopsis thaliana plants growing within. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in Kennedy's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

John "JC" Carver, a payload integration engineer with NASA Kennedy Space Center's Test and Operations Support Contract, places Arabidopsis thaliana plants harvested from the Advanced Plant Habitat (APH) Flight Unit No. 1 into a Mini ColdBag that quickly freezes the plants. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in Kennedy's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

John "JC" Carver, a payload integration engineer with NASA Kennedy Space Center's Test and Operations Support Contract, places Arabidopsis thaliana plants harvested from the Advanced Plant Habitat (APH) Flight Unit No. 1 into an Ultra-low Freezer chilled to -150 degrees Celsius. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in Kennedy's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Pre-engineering Spaceflight Validation of Environmental Models and the 2005 HZETRN Simulation Code

NASA Technical Reports Server (NTRS)

Nealy, John E.; Cucinotta, Francis A.; Wilson, John W.; Badavi, Francis F.; Dachev, Ts. P.; Tomov, B. T.; Walker, Steven A.; DeAngelis, Giovanni; Blattnig, Steve R.; Atwell, William

2006-01-01

The HZETRN code has been identified by NASA for engineering design in the next phase of space exploration highlighting a return to the Moon in preparation for a Mars mission. In response, a new series of algorithms beginning with 2005 HZETRN, will be issued by correcting some prior limitations and improving control of propagated errors along with established code verification processes. Code validation processes will use new/improved low Earth orbit (LEO) environmental models with a recently improved International Space Station (ISS) shield model to validate computational models and procedures using measured data aboard ISS. These validated models will provide a basis for flight-testing the designs of future space vehicles and systems of the Constellation program in the LEO environment.

Evaluation of Low Earth Orbit Environmental Effects on International Space Station Thermal Control Materials

NASA Technical Reports Server (NTRS)

Dever, Joyce A.; Rutledge, Sharon K.; Hasegawa, Mark M.; Reed, Charles K.

1998-01-01

Samples of International Space Station (ISS) thermal control coatings were exposed to simulated low Earth orbit (LEO) environmental conditions to determine effects on optical properties. In one test, samples of the white paint coating Z-93P were coated with outgassed products from Tefzel(R) (ethylene tetrafluoroethylene copolymer) power cable insulation as-may occur on ISS. These samples were then exposed, along with an uncontaminated Z-93P witness sample, to vacuum ultraviolet (VUV) radiation to determine solar absorptance degradation. The Z-93P samples coated with Tefzel(R) outgassing products experienced greater increases in solar absorptance than witness samples not coated with Tefzel(R) outgassing products. In another test, samples of second surface silvered Teflon(R) FEP (fluorinated ethylene propylene), SiO. (where x=2)-coated silvered Teflon(R) FEP, and Z-93P witness samples were exposed to the combined environments of atomic oxygen and VLTV radiation to determine optical properties changes due to these simulated ISS environmental effects. This test verified the durability of these materials in the absence of contaminants.

Estimating linear temporal trends from aggregated environmental monitoring data

USGS Publications Warehouse

Erickson, Richard A.; Gray, Brian R.; Eager, Eric A.

2017-01-01

Trend estimates are often used as part of environmental monitoring programs. These trends inform managers (e.g., are desired species increasing or undesired species decreasing?). Data collected from environmental monitoring programs is often aggregated (i.e., averaged), which confounds sampling and process variation. State-space models allow sampling variation and process variations to be separated. We used simulated time-series to compare linear trend estimations from three state-space models, a simple linear regression model, and an auto-regressive model. We also compared the performance of these five models to estimate trends from a long term monitoring program. We specifically estimated trends for two species of fish and four species of aquatic vegetation from the Upper Mississippi River system. We found that the simple linear regression had the best performance of all the given models because it was best able to recover parameters and had consistent numerical convergence. Conversely, the simple linear regression did the worst job estimating populations in a given year. The state-space models did not estimate trends well, but estimated population sizes best when the models converged. We found that a simple linear regression performed better than more complex autoregression and state-space models when used to analyze aggregated environmental monitoring data.

[Habitability and life support systems].

PubMed

Nefedov, Iu G; Adamovich, B A

1988-01-01

This paper discusses various aspects of space vehicle habitability and life support systems. It describes variations in the chemical and microbial composition of an enclosed atmosphere during prolonged real and simulated flights. The paper gives a detailed description of life support systems and environmental investigations onboard the Mir station. It also outlines the development of space vehicle habitability and life support systems as related to future flights.

KSC00pp0692

NASA Image and Video Library

2000-05-29

Research scientist Vadim Rygalov describes a new low-pressure water-recycling experiment being designed to help simulate plant growth conditions on Mars. The research he is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long-duration spaceflight and environmental/ecological stewardship

KSC-00pp0692

NASA Image and Video Library

2000-05-29

Research scientist Vadim Rygalov describes a new low-pressure water-recycling experiment being designed to help simulate plant growth conditions on Mars. The research he is performing is one of many studies at the Biological Sciences Branch in the Spaceport Engineering and Technology Directorate at Kennedy Space Center. The branch's operations and research areas include life sciences Space Shuttle payloads, bioregenerative life-support for long-duration spaceflight and environmental/ecological stewardship

REVIEW OF SIMULATION METHODS FOR SPATIALLY-EXPLICIT POPULATION-LEVEL RISK ASSESSMENT

EPA Science Inventory

Factors that significantly impact population dynamics, such as resource availability and exposure to stressors, frequently vary over space and thereby determine the heterogeneous spatial distributions of organisms. Considering this fact, the US Environmental Protection Agency's ...

Regional Spectral Model simulations of the summertime regional climate over Taiwan and adjacent areas

Treesearch

Ching-Teng Lee; Ming-Chin Wu; Shyh-Chin Chen

2005-01-01

The National Centers for Environmental Prediction (NCEP) regional spectral model (RSM) version 97 was used to investigate the regional summertime climate over Taiwan and adjacent areas for June-July-August of 1990 through 2000. The simulated sea-level-pressure and wind fields of RSM1 with 50-km grid space are similar to the reanalysis, but the strength of the...

Rapid Ascent Simulation at NASA-MSFC

NASA Technical Reports Server (NTRS)

Sisco, Jimmy D.

2004-01-01

The Environmental Test Facility (ETF), located at NASA-Marshall Space Flight Center, Huntsville, Alabama, has provided thermal vacuum testing for several major programs since the 1960's. The ETF consists of over 13 thermal vacuum chambers sized and configured to handle the majority of test payloads. The majority of tests require a hard vacuum with heating and cryogenics. NASA's Return-to-Flight program requested testing to simulate a launch from the ground to flight using vacuum, heating and cryogenics. This paper describes an effective method for simulating a launch.

ASTRYD: A new numerical tool for aircraft cabin and environmental noise prediction

NASA Astrophysics Data System (ADS)

Berhault, J.-P.; Venet, G.; Clerc, C.

ASTRYD is an analytical tool, developed originally for underwater applications, that computes acoustic pressure distribution around three-dimensional bodies in closed spaces like aircraft cabins. The program accepts data from measurements or other simulations, processes them in the time domain, and delivers temporal evolutions of the acoustic pressures and accelerations, as well as the radiated/diffracted pressure at arbitrary points located in the external/internal space. A typical aerospace application is prediction of acoustic load on satellites during the launching phase. An aeronautic application is engine noise distribution on a business jet body for prediction of environmental and cabin noise.

Preparing for Solar and Thermal Testing of Curiosity Mars Rover

NASA Image and Video Library

2011-03-18

This image shows preparation for March 2011 testing of the Mars Science Laboratory rover, Curiosity, in a space-simulation chamber; the rover will go through operational sequences in environmental conditions similar to what it will experience on Mars.

Environmental control and life support system analysis tools for the Space Station era

NASA Technical Reports Server (NTRS)

Blakely, R. L.; Rowell, L. F.

1984-01-01

This paper describes the concept of a developing emulation, simulation, sizing, and technology assessment program (ESSTAP) which can be used effectively for the various functional disciplines (structures, power, ECLSS, etc.) beginning with the initial system selection and conceptual design processes and continuing on through the mission operation and growth phases of the Space Station for the purpose of minimizing overall program costs. It will discuss the basic requirements for these tools, as currently envisioned for the Environmental Control and Life Support System (ECLSS), identifying their intended and potential uses and applications, and present examples and status of several representative tools. The development and applications of a Space Station Atmospheric Revitalization Subsystem (ARS) demonstration model to be used for concent verification will also be discussed.

Advanced Plant Habitat Test Harvest

NASA Image and Video Library

2017-08-24

John "JC" Carver, a payload integration engineer with NASA Kennedy Space Center's Test and Operations Support Contract, uses a FluorPen to measure the chlorophyll fluorescence of Arabidopsis thaliana plants inside the growth chamber of the Advanced Plant Habitat (APH) Flight Unit No. 1. Half the plants were then harvested. The harvest is part of an ongoing verification test of the APH unit, which is located inside the International Space Station Environmental Simulator in Kennedy's Space Station Processing Facility. The APH undergoing testing at Kennedy is identical to one on the station and uses red, green and broad-spectrum white LED lights to grow plants in an environmentally controlled chamber. The seeds grown during the verification test will be grown on the station to help scientists understand how these plants adapt to spaceflight.

Simulated microgravity allows to demonstrate cell-to-cell communication in bacteria

NASA Astrophysics Data System (ADS)

Mastroleo, Felice; van Houdt, Rob; Mergeay, Max; Hendrickx, Larissa; Wattiez, Ruddy; Leys, Natalie

Through the MELiSSA project, the European Space Agency aims to develop a closed life support system for oxygen, water and food production to support human life in space in forth-coming long term space exploration missions. This production is based on the recycling of the missions organic waste, including CO2 and minerals. The photosynthetic bacterium Rhodospir-illum rubrum S1H is used in MELiSSA to degrade organics with light energy and is the first MELiSSA organism that has been studied in space related environmental conditions (Mastroleo et al., 2009). It was tested in actual space flight to the International Space Station (ISS) as well as in ground simulations of ISS-like ionizing radiation and microgravity. In the present study, R. rubrum S1H was cultured in liquid medium in 2 devices simulating microgravity conditions, i.e. the Rotating Wall Vessel (RWV) and the Random Positioning Machine (RPM). The re-sponse of the bacterium was evaluated at both the transcriptomic and proteomic levels using respectively a dedicated whole-genome microarray and high-throughput gel-free quantitative proteomics. Both at transcriptomic and proteomic level, the bacterium showed a significant response to cultivation in simulated microgravity. The response to low fluid shear modeled microgravity in RWV was different than to randomized microgravity in RPM. Nevertheless, both tests pointed out a change in and a likely interrelation between cell-to-cell communica-tion (i.e. quorum sensing) and cell pigmentation (i.e. photosynthesis) for R. rubrum S1H in microgravity conditions. A new type of cell-to-cell communication molecule in R. rubrum S1H was discovered and characterized. It is hypothised that the lack of convection currents and the fluid quiescence in (simulated) microgravity limits communications molecules to be spread throughout the medium. Cultivation in this new artificial environment of simulated micro-gravity has showed new properties of this well know bacterium. Understanding how cell-to-cell communication regulates photosynthesis and potentially cell aggregation may be an unique tool to understand, characterize and then optimize biodegradation processes in photobioreactors, in space or on Earth. Mastroleo F., Van Houdt R., Leroy B., Benotmane M. A., Janssen A., Mergeay M., Vanhavere F., Hendrickx L., Wattiez R. and Leys N. Experimental design and environmental parameters affect Rhodospirillum rubrum S1H response to space flight. ISME J 2009;3:1402-1419. The presented work was financially supported by the European Space Agency (ESA-PRODEX), the Belgian Science Policy (Belspo) (PRODEX agreements No C90247 No 90094) and the SCK•CEN PhD AWM grant of F. Mastroleo. We are grateful to C. Lasseur and C. Paillé, both from ESTEC/ESA, for their constant support and advice.

Quantification of wind flow in the European Mars Simulation Wind Tunnel Facility

NASA Astrophysics Data System (ADS)

Holstein-Rathlou, C.; Merrison, J. P.; Iversen, J. J.; Nornberg, P.

2012-04-01

We present the European Mars Simulation Wind Tunnel facility, a unique prototype facility capable of simulating a wide range of environmental conditions, such as those which can be found at the surface of Earth or Mars. The chamber complements several other large-scale simulation facilities at Aarhus University, Denmark. The facility consists of a 50 m3 environmental chamber capable of operating at low pressure (0.02 - 1000 mbar) and cryogenic temperatures (-130 °C up to +60 °C). This chamber houses a re-circulating wind tunnel capable of generating wind speeds up to 25 m/s and has a dust injection system that can produce suspended particulates (aerosols). It employs a unique LED based optical illumination system (solar simulator) and an advanced network based control system. Laser based optoelectronic instrumentation is used to quantify and monitor wind flow, dust suspension and deposition. This involves a commercial Laser Doppler Anemometer (LDA) and a Particle Dynamics Analysis receiver (PDA), which are small laser based instruments specifically designed for measuring wind speed and sizes of particles situated in a wind flow. Wind flow calibrations will be performed with the LDA system and presented. Pressure and temperature calibrations will follow in order to enable the facility to be used for the testing, development, calibration and comparison of e.g. meteorological sensors under a wide range of environmental conditions as well as multi-disciplinary scientific studies. The wind tunnel is accessible to international collaborators and space agencies for instrument testing, calibration and qualification. It has been financed by the European Space Agency (ESA) as well as the Aarhus University Science Faculty and the Villum Kann Rasmussen Foundation.

An interim overview of LDEF materials findings

NASA Technical Reports Server (NTRS)

Stein, Brad A.

1992-01-01

The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. In general, the LDEF data is remarkably consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8 years; other 'space qualified' materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

Automation of closed environments in space for human comfort and safety

NASA Technical Reports Server (NTRS)

Cogley, Allen C.; Tucker, Nathan P.

1992-01-01

For prolonged missions into space and colonization outside the Earth's atmosphere, development of Environmental Control and Life Support Systems (ECLSS) are essential to provide astronauts with habitable environments. The Kansas State University Advanced Design Team have researched and designed a control system for an ECLSS like that on Space Station Freedom. The following milestones have been accomplished: (1) completed computer simulation of the CO2 Removal Assembly; (2) created a set of rules for the expert control system of the CO2 Removal Assembly; (3) created a classical controls system for the CO2 Removal Assembly; (4) established a means of communication between the mathematical model and the two controls systems; and (5) analyzed the dynamic response of the simulation and compared the two methods of control.

A study of the durability of beryllium rocket engines. [space shuttle reaction control system

NASA Technical Reports Server (NTRS)

Paster, R. D.; French, G. C.

1974-01-01

An experimental test program was performed to demonstrate the durability of a beryllium INTEREGEN rocket engine when operating under conditions simulating the space shuttle reaction control system. A vibration simulator was exposed to the equivalent of 100 missions of X, Y, and Z axes random vibration to demonstrate the integrity of the recently developed injector-to-chamber braze joint. An off-limits engine was hot fired under extreme conditions of mixture ratio, chamber pressure, and orifice plugging. A durability engine was exposed to six environmental cycles interspersed with hot-fire tests without intermediate cleaning, service, or maintenance. Results from this program indicate the ability of the beryllium INTEREGEN engine concept to meet the operational requirements of the space shuttle reaction control system.

Dispersion analysis for baseline reference mission 1. [flight simulation and trajectory analysis for space shuttle orbiter

NASA Technical Reports Server (NTRS)

Kuhn, A. E.

1975-01-01

A dispersion analysis considering 3 sigma uncertainties (or perturbations) in platform, vehicle, and environmental parameters was performed for the baseline reference mission (BRM) 1 of the space shuttle orbiter. The dispersion analysis is based on the nominal trajectory for the BRM 1. State vector and performance dispersions (or variations) which result from the indicated 3 sigma uncertainties were studied. The dispersions were determined at major mission events and fixed times from lift-off (time slices) and the results will be used to evaluate the capability of the vehicle to perform the mission within a 3 sigma level of confidence and to determine flight performance reserves. A computer program is given that was used for dynamic flight simulations of the space shuttle orbiter.

Atomic oxygen effects on thin film space coatings studied by spectroscopic ellipsometry, atomic force microscopy, and laser light scattering

NASA Technical Reports Server (NTRS)

Synowicki, R. A.; Hale, Jeffrey S.; Woollam, John A.

1992-01-01

The University of Nebraska is currently evaluating Low Earth Orbit (LEO) simulation techniques as well as a variety of thin film protective coatings to withstand atomic oxygen (AO) degradation. Both oxygen plasma ashers and an electron cyclotron resonance (ECR) source are being used for LEO simulation. Thin film coatings are characterized by optical techniques including Variable Angle Spectroscopic Ellipsometry, Optical spectrophotometry, and laser light scatterometry. Atomic Force Microscopy (AFM) is also used to characterize surface morphology. Results on diamondlike carbon (DLC) films show that DLC degrades with simulated AO exposure at a rate comparable to Kapton polyimide. Since DLC is not as susceptible to environmental factors such as moisture absorption, it could potentially provide more accurate measurements of AO fluence on short space flights.

Space station dynamics, attitude control and momentum management

NASA Technical Reports Server (NTRS)

Sunkel, John W.; Singh, Ramen P.; Vengopal, Ravi

1989-01-01

The Space Station Attitude Control System software test-bed provides a rigorous environment for the design, development and functional verification of GN and C algorithms and software. The approach taken for the simulation of the vehicle dynamics and environmental models using a computationally efficient algorithm is discussed. The simulation includes capabilities for docking/berthing dynamics, prescribed motion dynamics associated with the Mobile Remote Manipulator System (MRMS) and microgravity disturbances. The vehicle dynamics module interfaces with the test-bed through the central Communicator facility which is in turn driven by the Station Control Simulator (SCS) Executive. The Communicator addresses issues such as the interface between the discrete flight software and the continuous vehicle dynamics, and multi-programming aspects such as the complex flow of control in real-time programs. Combined with the flight software and redundancy management modules, the facility provides a flexible, user-oriented simulation platform.

Space life sciences: search for signatures of life, and space flight environmental effects on the nervous system.

PubMed

2004-01-01

This volume contains selected papers of the Joint COSPAR-IAC event "Search for signatures of life in the solar system, terrestrial analogues and simulation experiments" held during the World Space Congress 2002 in Houston, Texas, USA. The first section of the volume reports on the rich variety of terrestrial microbial communities adapted to extreme environments, such as microbial life at very low temperatures in permafrost and ice layers, at high salt concentrations, as inhabitants of rocks and the microbial recolonization of impact-shocked rocks. These communities are suggested to serve as analogues for extraterrestrial habitats, which are also described in this section. The second section deals with the detection of biomarkers and signatures from extinct life on Earth, which might provide clues for detection of potential extraterrestrial biomarkers. This section is followed by reports of experiments in space and in the laboratory simulating space conditions, such as the prebiotic organic chemistry, the chemistry of dust particles to be detected during the Cassini mission to Saturn, as well as the photochemistry of biological systems exposed to space or planetary surface conditions. The second part of the issue contains papers from the session "The nervous system: space flight environmental factors effects--present results and new perspectives." The presentations in this session explored various aspects of the effects of exposure to protons and heavy particles on central nervous system function and on behavior. The second series of papers examines the effects of exposure to heavy particles and protons on neurochemistry and on behavior.

Development of Models for High Precision Simulation of the Space Mission Microscope

NASA Astrophysics Data System (ADS)

Bremer, Stefanie; List, Meike; Selig, Hanns; Lämmerzahl, Claus

MICROSCOPE is a French space mission for testing the Weak Equivalence Principle (WEP). The mission goal is the determination of the Eötvös parameter with an accuracy of 10-15. This will be achieved by means of two high-precision capacitive differential accelerometers, that are built by the French institute ONERA. At the German institute ZARM drop tower tests are carried out to verify the payload performance. Additionally, the mission data evaluation is prepared in close cooperation with the French partners CNES, ONERA and OCA. Therefore a comprehensive simulation of the real system including the science signal and all error sources is built for the development and testing of data reduction and data analysis algorithms to extract the WEP violation signal. Currently, the High Performance Satellite Dynamics Simulator (HPS), a cooperation project of ZARM and the DLR Institute of Space Systems, is adapted to the MICROSCOPE mission for the simulation of test mass and satellite dynamics. Models of environmental disturbances like solar radiation pressure are considered, too. Furthermore detailed modeling of the on-board capacitive sensors is done.

Analysis of the effects of simulated synergistic LEO environment on solar panels

NASA Astrophysics Data System (ADS)

Allegri, G.; Corradi, S.; Marchetti, M.; Scaglione, S.

2007-02-01

The effects due to the LEO environment exposure of a solar array primary structure are here presented and discussed in detail. The synergistic damaging components featuring LEO environment are high vacuum, thermal cycling, neutral gas, ultraviolet (UV) radiation and cold plasma. The synergistic effects due to these environmental elements are simulated by "on ground" tests, performed in the Space Environment Simulator (SAS) at the University of Rome "La Sapienza"; numerical simulations are performed by the Space Environment Information System (SPENVIS), developed by the European Space Agency (ESA). A "safe life" design for a solar array primary structure is developed, taking into consideration the combined damaging action of the LEO environment components; therefore results from both numerical and experimental simulations are coupled within the framework of a standard finite element method (FEM) based design. The expected durability of the solar array primary structure, made of laminated sandwich composite, is evaluated assuming that the loads exerted on the structure itself are essentially dependent on thermo-elastic stresses. The optical degradation of surface materials and the stiffness and strength degradation of structural elements are taken into account to assess the global structural durability of the solar array under characteristic operative conditions in LEO environment.

Computer simulation results of attitude estimation of earth orbiting satellites

NASA Technical Reports Server (NTRS)

Kou, S. R.

1976-01-01

Computer simulation results of attitude estimation of Earth-orbiting satellites (including Space Telescope) subjected to environmental disturbances and noises are presented. Decomposed linear recursive filter and Kalman filter were used as estimation tools. Six programs were developed for this simulation, and all were written in the basic language and were run on HP 9830A and HP 9866A computers. Simulation results show that a decomposed linear recursive filter is accurate in estimation and fast in response time. Furthermore, for higher order systems, this filter has computational advantages (i.e., less integration errors and roundoff errors) over a Kalman filter.

Mimicking Mars: a vacuum simulation chamber for testing environmental instrumentation for Mars exploration.

PubMed

Sobrado, J M; Martín-Soler, J; Martín-Gago, J A

2014-03-01

We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10(-6) mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

Creating the Deep Space Environment for Testing the James Webb Space Telescope (JWST) at NASA Johnson Space Center's Chamber A

NASA Technical Reports Server (NTRS)

Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

2013-01-01

Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

Creating the Deep Space Environment for Testing the James Webb Space Telescope at NASA Johnson Space Center's Chamber A

NASA Technical Reports Server (NTRS)

Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

2013-01-01

Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft.) in diameter and 36.6 m (120 ft.) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope, which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to minimize dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

Creating the Deep Space Environment for Testing the James Webb Space Telescope at the Johnson Space Center's Chamber A

NASA Technical Reports Server (NTRS)

Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.

2012-01-01

Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960's to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and the modifications were funded, by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink and, the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in the overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

NASA Technical Reports Server (NTRS)

Ray, Charles D.; Perry, Jay L.; Callahan, David M.

2000-01-01

As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

Degradation of the Adhesive Properties of MD-944 Diode Tape by Simulated Low Earth Orbit Environmental Factors

NASA Technical Reports Server (NTRS)

Albyn, K.; Finckenor, M.

2006-01-01

The International Space Station (ISS) solar arrays utilize MD-944 diode tape with silicone pressure-sensitive adhesive to protect the underlying diodes and also provide a high-emittance surface. On-orbit, the silicone adhesive will be exposed and ultimately convert to a glass-like silicate due to atomic oxygen (AO). The current operational plan is to retract ISS solar array P6 and leave it stored under load for a long duration (6 mo or more). The exposed silicone adhesive must not cause the solar array to stick to itself or cause the solar array to fail during redeployment. The Environmental Effects Branch at Marshall Space Flight Center, under direction from the ISS Program Office Environments Team, performed simulated space environment exposures with 5-eV AO, near ultraviolet radiation and ionizing radiation. The exposed diode tape samples were put under preload and then the resulting blocking force was measured using a tensile test machine. Test results indicate that high-energy AO, ultraviolet radiation, and electron ionizing radiation exposure all reduce the blocking force for a silicone-to-silicone bond. AO exposure produces the most significant reduction in blocking force

Simulated Solar Flare X-Ray and Thermal Cycling Durability Evaluation of Hubble Space Telescope Thermal Control Candidate Replacement Materials

NASA Technical Reports Server (NTRS)

deGroh, Kim K.; Banks, Bruce A.; Sechkar, Edward A.; Scheiman, David A.

1998-01-01

During the Hubble Space Telescope (HST) second servicing mission (SM2), astronauts noticed that the multilayer insulation (MLI) covering the telescope was damaged. Large pieces of the outer layer of MLI (aluminized Teflon fluorinated ethylene propylene (Al-FEP)) were torn in several locations around the telescope. A piece of curled up Al-FEP was retrieved by the astronauts and was found to be severely embrittled, as witnessed by ground testing. Goddard Space Flight Center (GSFC) organized a HST MLI Failure Review Board (FRB) to determine the damage mechanism of FEP in the HST environment, and to recommend replacement insulation material to be installed on HST during the third servicing mission (SM3) in 1999. Candidate thermal control replacement materials were chosen by the FRB and tested for environmental durability under various exposures and durations. This paper describes durability testing of candidate materials which were exposed to charged particle radiation, simulated solar flare x-ray radiation and thermal cycling under load. Samples were evaluated for changes in solar absorptance and tear resistance. Descriptions of environmental exposures and durability evaluations of these materials are presented.

KSC-2010-5293

NASA Image and Video Library

2010-10-21

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, testing of the Tilt-Up Umbilical Arm (TUUA) prototype's Environmental Control System Quick Disconnect takes place in the Launch Equipment Test Facility's 6,000-square-foot high bay. The prototype is used to demonstrate the safe disconnect and retraction of ground umbilical plates and associated hardware of a launch vehicle's upper stage and service module. The Environmental Control System consists of regulated air, which would be used to purge an inner tank and crew module. Since 1977, the facility has supported NASA’s Launch Services, shuttle, International Space Station, and Constellation programs, as well as commercial providers. The facility recently underwent a major upgrade to support even more programs, projects and customers. It houses a cable fabrication and molding shop, pneumatics shop, machine and weld shop and full-scale control room. Outside, the facility features a water flow test loop, vehicle motion simulator, 600-ton test fixture, launch simulation towers and a cryogenic system. Photo credit: NASA/Jack Pfaller

KSC-2010-5290

NASA Image and Video Library

2010-10-21

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, testing of the Tilt-Up Umbilical Arm (TUUA) prototype's Environmental Control System Quick Disconnect takes place in the Launch Equipment Test Facility's 6,000-square-foot high bay. The prototype is used to demonstrate the safe disconnect and retraction of ground umbilical plates and associated hardware of a launch vehicle's upper stage and service module. The Environmental Control System consists of regulated air, which would be used to purge an inner tank and crew module. Since 1977, the facility has supported NASA’s Launch Services, shuttle, International Space Station, and Constellation programs, as well as commercial providers. The facility recently underwent a major upgrade to support even more programs, projects and customers. It houses a cable fabrication and molding shop, pneumatics shop, machine and weld shop and full-scale control room. Outside, the facility features a water flow test loop, vehicle motion simulator, 600-ton test fixture, launch simulation towers and a cryogenic system. Photo credit: NASA/Jack Pfaller

KSC-2010-5292

NASA Image and Video Library

2010-10-21

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, testing of the Tilt-Up Umbilical Arm (TUUA) prototype's Environmental Control System Quick Disconnect takes place in the Launch Equipment Test Facility's 6,000-square-foot high bay. The prototype is used to demonstrate the safe disconnect and retraction of ground umbilical plates and associated hardware of a launch vehicle's upper stage and service module. The Environmental Control System consists of regulated air, which would be used to purge an inner tank and crew module. Since 1977, the facility has supported NASA’s Launch Services, shuttle, International Space Station, and Constellation programs, as well as commercial providers. The facility recently underwent a major upgrade to support even more programs, projects and customers. It houses a cable fabrication and molding shop, pneumatics shop, machine and weld shop and full-scale control room. Outside, the facility features a water flow test loop, vehicle motion simulator, 600-ton test fixture, launch simulation towers and a cryogenic system. Photo credit: NASA/Jack Pfaller

KSC-2010-5291

NASA Image and Video Library

2010-10-21

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, testing of the Tilt-Up Umbilical Arm (TUUA) prototype's Environmental Control System Quick Disconnect takes place in the Launch Equipment Test Facility's 6,000-square-foot high bay. The prototype is used to demonstrate the safe disconnect and retraction of ground umbilical plates and associated hardware of a launch vehicle's upper stage and service module. The Environmental Control System consists of regulated air, which would be used to purge an inner tank and crew module. Since 1977, the facility has supported NASA’s Launch Services, shuttle, International Space Station, and Constellation programs, as well as commercial providers. The facility recently underwent a major upgrade to support even more programs, projects and customers. It houses a cable fabrication and molding shop, pneumatics shop, machine and weld shop and full-scale control room. Outside, the facility features a water flow test loop, vehicle motion simulator, 600-ton test fixture, launch simulation towers and a cryogenic system. Photo credit: NASA/Jack Pfaller

Three-dimensional motor schema based navigation

NASA Technical Reports Server (NTRS)

Arkin, Ronald C.

1989-01-01

Reactive schema-based navigation is possible in space domains by extending the methods developed for ground-based navigation found within the Autonomous Robot Architecture (AuRA). Reformulation of two dimensional motor schemas for three dimensional applications is a straightforward process. The manifold advantages of schema-based control persist, including modular development, amenability to distributed processing, and responsiveness to environmental sensing. Simulation results show the feasibility of this methodology for space docking operations in a cluttered work area.

Range Systems Simulation for the NASA Shuttle: Emphasis on Disaster and Prevention Management During Lift-Off

NASA Technical Reports Server (NTRS)

Rabelo, Lisa; Sepulveda, Jose; Moraga, Reinaldo; Compton, Jeppie; Turner, Robert

2005-01-01

This article describes a decision-making system composed of a number of safety and environmental models for the launch phase of a NASA Space Shuttle mission. The components of this distributed simulation environment represent the different systems that must collaborate to establish the Expectation of Casualties (E(sub c)) caused by a failed Space Shuttle launch and subsequent explosion (accidental or instructed) of the spacecraft shortly after liftoff. This decision-making tool employs Space Shuttle reliability models, trajectory models, a blast model, weather dissemination systems, population models, amount and type of toxicants, gas dispersion models, human response functions to toxicants, and a geographical information system. Since one of the important features of this proposed simulation environment is to measure blast, toxic, and debris effects, the clear benefits is that it can help safety managers not only estimate the population at risk, but also to help plan evacuations, make sheltering decisions, establish the resources required to provide aid and comfort, and mitigate damages in case of a disaster.

On-chip photonic particle sensor

NASA Astrophysics Data System (ADS)

Singh, Robin; Ma, Danhao; Agarwal, Anu; Anthony, Brian

2018-02-01

We propose an on-chip photonic particle sensor design that can perform particle sizing and counting for various environmental applications. The sensor is based on micro photonic ring resonators that are able to detect the presence of the free space particles through the interaction with their evanescent electric field tail. The sensor can characterize a wide range of the particle size ranging from a few nano meters to micron ( 1 micron). The photonic platform offers high sensitivity, compactness, fast response of the device. Further, FDTD simulations are performed to analyze different particle-light interactions. Such a compact and portable platform, packaged with integrated photonic circuit provides a useful sensing modality in space shuttle and environmental applications.

STS-55 MS3 Bernard A. Harris, Jr in EMU at JSC's WETF for EVA simulation

NASA Image and Video Library

1991-11-08

S91-51058 (Dec 1991) --- Partially attired in a special training version of the Extravehicular Mobility Unit (EMU) space suit, astronaut Bernard A. Harris Jr. is pictured before a training session at the Johnson Space Center's (JSC) Weightless Environment Training Facility (WET-F). Minutes later the STS-55 mission specialist was in a 25-feet deep pool simulating a contingency extravehicular activity (EVA). The platform on which he is standing was used to lower him into the water where, with the aid of weights on his environmentally-controlled pressurized suit, he was able to achieve neutral buoyancy. There is no scheduled EVA for the 1993 flight but each space flight crew includes astronauts trained for a variety of contingency tasks that could require exiting the shirt-sleeve environment of a Shuttle's cabin.

Space shuttle I-tube radiator testing at Johnson Space Center, May 1976, volume 1

NASA Technical Reports Server (NTRS)

Scheps, P. B.

1976-01-01

During the two weeks of thermal vacuum testing a representative forward panel was successfully operated in a variety of simulated environmental conditions. Performance limits for both high and low load operations were established. Confidence in the stable operation of the panel throughout its typical operating range was verified by the testing, and design studies were conducted to analyze the effects of the payload bay door, and the panel deployment angle, on performance.

Handbook on passive thermal control coatings

NASA Technical Reports Server (NTRS)

Mookherji, T. K.; Hayes, J. D.

1973-01-01

A handbook of passive thermal control surfaces data pertaining to the heat transfer requirements of spacecraft is presented. Passive temperature control techniques and the selection of control surfaces are analyzed. The space environmental damage mechanisms in passive thermal control surfaces are examined. Data on the coatings for which technical information is available are presented in tabular form. Emphasis was placed on consulting only those references where the experimental simulation of the space environment appeared to be more appropriate.

Aerospace Medicine and Biology: A Continuing Bibliography with Indexes, Supplement 194

NASA Technical Reports Server (NTRS)

1979-01-01

Articles on the biological, physiological, psychological, and environmental effects to which man is subjected to during and following simulated or actual flight in the earth's atmosphere or in interplanetary space are presented. The emphasis is on applied research more than fundamental studies or theoretical principles.

The Use of Environmental Test Facilities for Purposes Beyond Their Original Design

NASA Technical Reports Server (NTRS)

Fisher, Terry C.; Marner, W. J.

2000-01-01

Increasing demands from space flight project offices are requiring environmental testing facilities to become more versatile with increased capabilities. At the same time, maintaining a cost-effective approach to test operations has driven efforts to use these facilities for purposes beyond their original design. This paper presents an overview of the Jet Propulsion Laboratory's efforts to provide JPL's space flight projects with test facilities to meet unique test requirements and to serve the needs of selected outside customers. The large number of recent Mars Missions, including the Mars Pathfinder project, have required testing of components and systems in a Martian surface environment in facilities originally designed for deep space testing. The unique problems associated with performing these tests are discussed, along with practical solutions. Other unique test requirements are discussed including the use of space simulation chambers for testing high altitude balloon gondolas and the use of vacuum chambers for system level test firing of an ion propulsion engine.

Characterization of Space Environmental Effects on Candidate Solar Sail Material

NASA Technical Reports Server (NTRS)

Edwards, David; Hubbs, Whitney; Stanaland, Tesia; Altstatt, Richard

2002-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A sail operates on the principle that photons, originating from the sun, impart pressure and provide a source of spacecraft propulsion. The pressure can be increased, by a factor of two if the sun-facing surface is perfectly reflective. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail materials to evaluate the thermo-optical and mechanical properties after exposure to a simulated Geosynchronous Transfer Orbit (GTO) radiation environment. The technique of radiation dose verses material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.

Environmental surfaces and the compression of perceived visual space

PubMed Central

Bian, Zheng; Andersen, George J.

2011-01-01

The present study examined whether the compression of perceived visual space varies according to the type of environmental surface being viewed. To examine this issue, observers made exocentric distance judgments when viewing simulated 3D scenes. In 4 experiments, observers viewed ground and ceiling surfaces and performed either an L-shaped matching task (Experiments 1, 3, and 4) or a bisection task (Experiment 2). Overall, we found considerable compression of perceived exocentric distance on both ground and ceiling surfaces. However, the perceived exocentric distance was less compressed on a ground surface than on a ceiling surface. In addition, this ground surface advantage did not vary systematically as a function of the distance in the scene. These results suggest that the perceived visual space when viewing a ground surface is less compressed than the perceived visual space when viewing a ceiling surface and that the perceived layout of a surface varies as a function of the type of the surface. PMID:21669858

A Simulation Based Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Moore, Michael; Bielski, Paul; Crues, Edwin Z.

2017-01-01

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

A Simulation Based Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

2017-01-01

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control system, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions, and to assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Space time modelling of air quality for environmental-risk maps: A case study in South Portugal

NASA Astrophysics Data System (ADS)

Soares, Amilcar; Pereira, Maria J.

2007-10-01

Since the 1960s, there has been a strong industrial development in the Sines area, on the southern Atlantic coast of Portugal, including the construction of an important industrial harbour and of, mainly, petrochemical and energy-related industries. These industries are, nowadays, responsible for substantial emissions of SO2, NOx, particles, VOCs and part of the ozone polluting the atmosphere. The major industries are spatially concentrated in a restricted area, very close to populated areas and natural resources such as those protected by the European Natura 2000 network. Air quality parameters are measured at the emissions' sources and at a few monitoring stations. Although air quality parameters are measured on an hourly basis, the lack of representativeness in space of these non-homogeneous phenomena makes even their representativeness in time questionable. Hence, in this study, the regional spatial dispersion of contaminants is also evaluated, using diffusive-sampler (Radiello Passive Sampler) campaigns during given periods. Diffusive samplers cover the entire space extensively, but just for a limited period of time. In the first step of this study, a space-time model of pollutants was built, based on a stochastic simulation-direct sequential simulation-with local spatial trend. The spatial dispersion of the contaminants for a given period of time-corresponding to the exposure time of the diffusive samplers-was computed by ordinary kriging. Direct sequential simulation was applied to produce equiprobable spatial maps for each day of that period, using the kriged map as a spatial trend and the daily measurements of pollutants from the monitoring stations as hard data. In the second step, the following environmental risk and costs maps were computed from the set of simulated realizations of pollutants: (i) maps of the contribution of each emission to the pollutant concentration at any spatial location; (ii) costs of badly located monitoring stations.

Agreement for NASA/OAST - USAF/AFSC space interdependency on spacecraft environment interaction

NASA Technical Reports Server (NTRS)

Pike, C. P.; Stevens, N. J.

1980-01-01

A joint AF/NASA comprehensive program on spacecraft environment interactions consists of combined contractual and in house efforts aimed at understanding spacecraft environment ineraction phenomena and relating ground test results to space conditions. Activities include: (1) a concerted effort to identify project related environmental interactions; (2) a materials investigation to measure the basic properties of materials and develop or modify materials as needed; and (3) a ground simulation investigation to evaluate basic plasma interaction phenomena and provide inputs to the analytical modeling investigation. Systems performance is evaluated by both ground tests and analysis. There is an environmental impact investigation to determine the effect of future large spacecraft on the charged particle environment. Space flight investigations are planned to verify the results. The products of this program are test standards and design guidelines which summarize the technology, specify test criteria, and provide techniques to minimize or eliminate system interactions with the charged particle environment.

Thermal properties of granulated materials.

NASA Technical Reports Server (NTRS)

Wechsler, A. E.; Glaser, P. E.; Fountain, J. A.

1972-01-01

Review of the thermophysical properties of granular materials or silicates believed to simulate the lunar surface layer. Emphasis is placed on thermal conductivity data and the effects of material and environmental variables on the thermal conductivity. There are three basic mechanisms of heat transfer in particulate materials: conduction by the gas contained in the void spaces between the particles; conduction within the solid particles and across the interparticle contacts; and thermal radiation within the particles, across the void spaces between particle surfaces, and between void spaces themselves. Gas and solid conduction, thermal radiation, and the interaction between conduction and radiation are considered.

A dynamic human water and electrolyte balance model for verification and optimization of life support systems in space flight applications

NASA Astrophysics Data System (ADS)

Hager, P.; Czupalla, M.; Walter, U.

2010-11-01

In this paper we report on the development of a dynamic MATLAB SIMULINK® model for the water and electrolyte balance inside the human body. This model is part of an environmentally sensitive dynamic human model for the optimization and verification of environmental control and life support systems (ECLSS) in space flight applications. An ECLSS provides all vital supplies for supporting human life on board a spacecraft. As human space flight today focuses on medium- to long-term missions, the strategy in ECLSS is shifting to closed loop systems. For these systems the dynamic stability and function over long duration are essential. However, the only evaluation and rating methods for ECLSS up to now are either expensive trial and error breadboarding strategies or static and semi-dynamic simulations. In order to overcome this mismatch the Exploration Group at Technische Universität München (TUM) is developing a dynamic environmental simulation, the "Virtual Habitat" (V-HAB). The central element of this simulation is the dynamic and environmentally sensitive human model. The water subsystem simulation of the human model discussed in this paper is of vital importance for the efficiency of possible ECLSS optimizations, as an over- or under-scaled water subsystem would have an adverse effect on the overall mass budget. On the other hand water has a pivotal role in the human organism. Water accounts for about 60% of the total body mass and is educt and product of numerous metabolic reactions. It is a transport medium for solutes and, due to its high evaporation enthalpy, provides the most potent medium for heat load dissipation. In a system engineering approach the human water balance was worked out by simulating the human body's subsystems and their interactions. The body fluids were assumed to reside in three compartments: blood plasma, interstitial fluid and intracellular fluid. In addition, the active and passive transport of water and solutes between those compartments was modeled dynamically. A kidney model regulates the electrolyte concentration in body fluids (osmolality) in narrow confines and a thirst mechanism models the urge to ingest water. A controlled exchange of water and electrolytes with other human subsystems, as well as with the environment, is implemented. Finally, the changes in body composition due to muscle growth are accounted for. The outcome of this is a dynamic water and electrolyte balance, which is capable of representing body reactions like thirst and headaches, as well as heat stroke and collapse, as a response to its work load and environment.

Utility of Emulation and Simulation Computer Modeling of Space Station Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Yanosy, James L.

1988-01-01

Over the years, computer modeling has been used extensively in many disciplines to solve engineering problems. A set of computer program tools is proposed to assist the engineer in the various phases of the Space Station program from technology selection through flight operations. The development and application of emulation and simulation transient performance modeling tools for life support systems are examined. The results of the development and the demonstration of the utility of three computer models are presented. The first model is a detailed computer model (emulation) of a solid amine water desorbed (SAWD) CO2 removal subsystem combined with much less detailed models (simulations) of a cabin, crew, and heat exchangers. This model was used in parallel with the hardware design and test of this CO2 removal subsystem. The second model is a simulation of an air revitalization system combined with a wastewater processing system to demonstrate the capabilities to study subsystem integration. The third model is that of a Space Station total air revitalization system. The station configuration consists of a habitat module, a lab module, two crews, and four connecting nodes.

Optical Analysis of Transparent Polymeric Material Exposed to Simulated Space Environment

NASA Technical Reports Server (NTRS)

Edwards, David L.; Finckenor, Miria M.

2000-01-01

Many innovations in spacecraft power and propulsion have been recently tested at NASA, particularly in non-chemical propulsion. One improvement in solar array technology is solar concentration using thin polymer film Fresnel lenses. Weight and cost savings were proven with the Solar Concentrator Arrays with Refractive Linear Element Technology (SCARLET)-II array on NASA's Deep Space I spacecraft. The Fresnel lens concentrates solar energy onto high-efficiency solar cells, decreasing the area of solar cells needed for power. Continued efficiency of this power system relies on the thin film's durability in the space environment and maintaining transmission in the 300 - 1000 nm bandwidth. Various polymeric materials have been tested for use in solar concentrators, including Lexan(TM), polyethylene terephthalate (PET), several formulations of Tefzel(Tm) and Teflon(TM), and DC 93-500, the material selected for SCARLET-II. Also tested were several innovative materials including Langley Research Center's CPI and CP2 polymers and atomic oxygen- resistant polymers developed by Triton Systems, Inc. The Environmental Effects Group of the Marshall Space Flight Center's Materials, Processes, and Manufacturing Department exposed these materials to simulated space environment and evaluated them for any change in optical transmission. Samples were exposed to a minimum of 1000 equivalent Sun hours of near-UV radiation (250 - 400 nm wavelength). Materials that appeared robust after near-UV exposure were then exposed to charged particle radiation equivalent to a five-year dose in geosynchronous orbit. These exposures were performed in MSFC's Combined Environmental Effects Test Chamber, a unique facility with the capability to expose materials simultaneously or sequentially to protons, low-energy electrons, high-energy electrons, near UV radiation and vacuum UV radiation. Reflectance measurements can be made on the samples in vacuum. Prolonged exposure to the space environment will decrease the polymer film's transmission and thus reduce the conversion efficiency. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance to space environmental exposure. Spectral results and the material ranking according to transmission loss are presented.

Shortcomings in ground testing, environment simulations, and performance predictions for space applications

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.

1992-01-01

This paper addresses the issues involved in radiation testing of devices and subsystems to obtain the data that are required to predict the performance and survivability of satellite systems for extended missions in space. The problems associated with space environmental simulations, or the lack thereof, in experiments intended to produce information to describe the degradation and behavior of parts and systems are discussed. Several types of radiation effects in semiconductor components are presented, as for example: ionization dose effects, heavy ion and proton induced Single Event Upsets (SEUs), and Single Event Transient Upsets (SETUs). Examples and illustrations of data relating to these ground testing issues are provided. The primary objective of this presentation is to alert the reader to the shortcomings, pitfalls, variabilities, and uncertainties in acquiring information to logically design electronic subsystems for use in satellites or space stations with long mission lifetimes, and to point out the weaknesses and deficiencies in the methods and procedures by which that information is obtained.

Performance of Mixed Layer Models in Simulating SST in the Equatorial Pacific Ocean

DTIC Science & Technology

2008-02-23

also used Environmental Model ( GDEM ) climatology [NA VOCEANO, for global validation. 2003]. The density difference values were chosen, so that the [6...were initialized from the monthly different at two different locations. Values of SS range from mean temperature and salinity for August from the GDEM ...environmental model ( GDEM -V) Version 3.0, OAML-DBD-72, 34 pp, Chassignet, E. P., H. E. Hurlburt, 0. M. Smedstad, G. R. Halliwell, A. J. Stennis Space Center

Nineteenth Space Simulation Conference Cost Effective Testing for the 21st Century

NASA Technical Reports Server (NTRS)

Stecher, Joseph L., III (Compiler)

1997-01-01

The Nineteenth Space Simulation Conference was hosted by the Institute of Environmental Sciences (IES) and was supported by the American Institute of Aeronautics and Astronautics (AIAA), the American Society for Testing and Materials (ASTM), the National Aeronautics and Space Administration (NASA), and the Canadian Space Agency (CSA). These proceedings attest to the scope of the conference; papers were presented on topics as diverse as shuttle payload contamination effects, simulating Martian environment for testing, to state-of-the-art 6-axis hydraulic shaker testing system. A good cross section of the international aerospace community took advantage of the opportunity to get together, to share their experiences, and to participate in the technical sessions. The two invited keynote speakers were Lieutenant General Malcolm O'Neill (USA, Ret.), past Director of BMDO, and Mr. Thomas Coughlin, Space Programs Manager at the Johns Hopkins University Applied Physics Laboratory. Their most informative and thought provoking talks were on cost effective testing approaches in Defense Department programs for the 21st Century and what part testing plays in the faster, better, cheaper approach for the NEAR and APL programs, respectively. The preceding tutorial and the tour of the Garber Facility of the Air and Space Museum rounded out a comprehensive conference contributing to the knowledge base vital to cost effective testing for successful missions into the 21st Century.

Testing flight software on the ground: Introducing the hardware-in-the-loop simulation method to the Alpha Magnetic Spectrometer on the International Space Station

NASA Astrophysics Data System (ADS)

Sun, Wenhao; Cai, Xudong; Meng, Qiao

2016-04-01

Complex automatic protection functions are being added to the onboard software of the Alpha Magnetic Spectrometer. A hardware-in-the-loop simulation method has been introduced to overcome the difficulties of ground testing that are brought by hardware and environmental limitations. We invented a time-saving approach by reusing the flight data as the data source of the simulation system instead of mathematical models. This is easy to implement and it works efficiently. This paper presents the system framework, implementation details and some application examples.

International Space Station (ISS)

NASA Image and Video Library

2001-02-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This is an exterior view of the U.S. Laboratory Module Simulator containing the ECLSS Internal Thermal Control System (ITCS) testing facility at MSFC. At the bottom right is the data acquisition and control computers (in the blue equipment racks) that monitor the testing in the facility. The ITCS simulator facility duplicates the function, operation, and troubleshooting problems of the ITCS. The main function of the ITCS is to control the temperature of equipment and hardware installed in a typical ISS Payload Rack.

Magnetic Testing, and Modeling, Simulation and Analysis for Space Applications

NASA Technical Reports Server (NTRS)

Boghosian, Mary; Narvaez, Pablo; Herman, Ray

2012-01-01

The Aerospace Corporation (Aerospace) and Lockheed Martin Space Systems (LMSS) participated with Jet Propulsion Laboratory (JPL) in the implementation of a magnetic cleanliness program of the NASA/JPL JUNO mission. The magnetic cleanliness program was applied from early flight system development up through system level environmental testing. The JUNO magnetic cleanliness program required setting-up a specialized magnetic test facility at Lockheed Martin Space Systems for testing the flight system and a testing program with facility for testing system parts and subsystems at JPL. The magnetic modeling, simulation and analysis capability was set up and performed by Aerospace to provide qualitative and quantitative magnetic assessments of the magnetic parts, components, and subsystems prior to or in lieu of magnetic tests. Because of the sensitive nature of the fields and particles scientific measurements being conducted by the JUNO space mission to Jupiter, the imposition of stringent magnetic control specifications required a magnetic control program to ensure that the spacecraft's science magnetometers and plasma wave search coil were not magnetically contaminated by flight system magnetic interferences. With Aerospace's magnetic modeling, simulation and analysis and JPL's system modeling and testing approach, and LMSS's test support, the project achieved a cost effective approach to achieving a magnetically clean spacecraft. This paper presents lessons learned from the JUNO magnetic testing approach and Aerospace's modeling, simulation and analysis activities used to solve problems such as remnant magnetization, performance of hard and soft magnetic materials within the targeted space system in applied external magnetic fields.

Mimicking Mars: A vacuum simulation chamber for testing environmental instrumentation for Mars exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sobrado, J. M., E-mail: sobradovj@inta.es; Martín-Soler, J.; Martín-Gago, J. A.

We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10{sup −6} mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source andmore » its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.« less

State-dependent sensorimotor processing: gaze and posture stability during simulated flight in birds.

PubMed

McArthur, Kimberly L; Dickman, J David

2011-04-01

Vestibular responses play an important role in maintaining gaze and posture stability during rotational motion. Previous studies suggest that these responses are state dependent, their expression varying with the environmental and locomotor conditions of the animal. In this study, we simulated an ethologically relevant state in the laboratory to study state-dependent vestibular responses in birds. We used frontal airflow to simulate gliding flight and measured pigeons' eye, head, and tail responses to rotational motion in darkness, under both head-fixed and head-free conditions. We show that both eye and head response gains are significantly higher during flight, thus enhancing gaze and head-in-space stability. We also characterize state-specific tail responses to pitch and roll rotation that would help to maintain body-in-space orientation during flight. These results demonstrate that vestibular sensorimotor processing is not fixed but depends instead on the animal's behavioral state.

State-dependent sensorimotor processing: gaze and posture stability during simulated flight in birds

PubMed Central

McArthur, Kimberly L.

2011-01-01

Vestibular responses play an important role in maintaining gaze and posture stability during rotational motion. Previous studies suggest that these responses are state dependent, their expression varying with the environmental and locomotor conditions of the animal. In this study, we simulated an ethologically relevant state in the laboratory to study state-dependent vestibular responses in birds. We used frontal airflow to simulate gliding flight and measured pigeons′ eye, head, and tail responses to rotational motion in darkness, under both head-fixed and head-free conditions. We show that both eye and head response gains are significantly higher during flight, thus enhancing gaze and head-in-space stability. We also characterize state-specific tail responses to pitch and roll rotation that would help to maintain body-in-space orientation during flight. These results demonstrate that vestibular sensorimotor processing is not fixed but depends instead on the animal's behavioral state. PMID:21307332

Electro-optic and holographic measurement techniques for the atmospheric sciences. [considering spacecraft simulation applications

NASA Technical Reports Server (NTRS)

Moore, W. W., Jr.; Lemons, J. F.; Kurtz, R. L.; Liu, H.-K.

1977-01-01

A comprehensive examination is made of recent advanced research directions in the applications of electro-optical and holographic instrumentations and methods to atmospheric sciences problems. In addition, an overview is given of the in-house research program for environmental and atmospheric measurements with emphasis on particulates systems. Special treatment is made of the instrument methods and applications work in the areas of laser scattering spectrometers and pulsed holography sizing systems. Selected engineering tests data on space simulation chamber programs are discussed.

International Space Station (ISS)

NASA Image and Video Library

2001-02-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This photograph shows the development Water Processor located in two racks in the ECLSS test area at the Marshall Space Flight Center. Actual waste water, simulating Space Station waste, is generated and processed through the hardware to evaluate the performance of technologies in the flight Water Processor design.

Interplanetary Transit Simulations Using the International Space Station

NASA Technical Reports Server (NTRS)

Charles, J. B.; Arya, Maneesh

2010-01-01

It has been suggested that the International Space Station (ISS) be utilized to simulate the transit portion of long-duration missions to Mars and near-Earth asteroids (NEA). The ISS offers a unique environment for such simulations, providing researchers with a high-fidelity platform to study, enhance, and validate technologies and countermeasures for these long-duration missions. From a space life sciences perspective, two major categories of human research activities have been identified that will harness the various capabilities of the ISS during the proposed simulations. The first category includes studies that require the use of the ISS, typically because of the need for prolonged weightlessness. The ISS is currently the only available platform capable of providing researchers with access to a weightless environment over an extended duration. In addition, the ISS offers high fidelity for other fundamental space environmental factors, such as isolation, distance, and accessibility. The second category includes studies that do not require use of the ISS in the strictest sense, but can exploit its use to maximize their scientific return more efficiently and productively than in ground-based simulations. In addition to conducting Mars and NEA simulations on the ISS, increasing the current increment duration on the ISS from 6 months to a longer duration will provide opportunities for enhanced and focused research relevant to long-duration Mars and NEA missions. Although it is currently believed that increasing the ISS crew increment duration to 9 or even 12 months will pose little additional risk to crewmembers, additional medical monitoring capabilities may be required beyond those currently used for the ISS operations. The use of the ISS to simulate aspects of Mars and NEA missions seems practical, and it is recommended that planning begin soon, in close consultation with all international partners.

Preliminary Measurements of Thin Film Solar Cells

NASA Image and Video Library

1967-06-21

George Mazaris, works with an assistant to obtain the preliminary measurements of cadmium sulfide thin-film solar cells being tested in the Space Environmental Chamber at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Lewis’ Photovoltaic Fundamentals Section was investigating thin-film alternatives to the standard rigid and fragile solar cells. The cadmium sulfide semiconductors were placed in a light, metallized substrate that could be rolled or furled during launch. The main advantage of the thin-film solar cells was their reduced weight. Lewis researchers, however, were still working on improving the performance of the semiconductor. The new thin-film solar cells were tested in a space simulation chamber in the CW-6 test cell in the Engine Research Building. The chamber created a simulated altitude of 200 miles. Sunlight was simulated by a 5000-watt xenon light. Some two dozen cells were exposed to 15 minutes of light followed by 15 minutes of darkness to test their durability in the constantly changing illumination of Earth orbit. This photograph was taken for use in a NASA recruiting publication.

Association, roost use and simulated disruption of Myotis septentrionalis maternity colonies

USGS Publications Warehouse

Silvis, Alexander; Ford, W. Mark; Britzke, Eric R.; Johnson, Joshua B.

2014-01-01

How wildlife social and resource networks are distributed on the landscape and how animals respond to resource loss are important aspects of behavioral ecology. For bats, understanding these responses may improve conservation efforts and provide insights into adaptations to environmental conditions. We tracked maternity colonies of northern bats (Myotis septentrionalis) at Fort Knox, Kentucky, USA to evaluate their social and resource networks and space use. Roost and social network structure differed between maternity colonies. Overall roost availability did not appear to be strongly related to network characteristics or space use. In simulations for our two largest networks, roost removal was related linearly to network fragmentation; despite this, networks were relatively robust, requiring removal of >20% of roosts to cause network fragmentation. Results from our analyses indicate that northern bat behavior and space use may differ among colonies and potentially across the maternity season. Simulation results suggest that colony social structure is robust to fragmentation caused by random loss of small numbers of roosts. Flexible social dynamics and tolerance of roost loss may be adaptive strategies for coping with ephemeral conditions in dynamic forest habitats.

Advanced Plant Habitat Flight Unit #1

NASA Image and Video Library

2017-07-24

Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a quality technician checks the hardware for the Advanced Plant Habitat flight unit. The flight unit is an exact replica of the APH that was delivered to the International Space Station. Validation tests and post-delivery checkout was performed to prepare for space station in-orbit APH activities. The flight unit will be moved to the International Space Station Environmental Simulator to begin an experiment verification test for the science that will fly on the first mission, PH-01. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the space station.

Advanced Plant Habitat Flight Unit #1

NASA Image and Video Library

2017-07-24

Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, quality technicians check the hardware for the Advanced Plant Habitat flight unit. The flight unit is an exact replica of the APH that was delivered to the International Space Station. Validation tests and post-delivery checkout was performed to prepare for space station in-orbit APH activities. The flight unit will be moved to the International Space Station Environmental Simulator to begin an experiment verification test for the science that will fly on the first mission, PH-01. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the space station.

Advanced Plant Habitat Flight Unit #1

NASA Image and Video Library

2017-07-24

Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, quality technicians check components of the hardware for the Advanced Plant Habitat flight unit. The flight unit is an exact replica of the APH that was delivered to the International Space Station. Validation tests and post-delivery checkout was performed to prepare for space station in-orbit APH activities. The flight unit will be moved to the International Space Station Environmental Simulator to begin an experiment verification test for the science that will fly on the first mission, PH-01. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the space station.

Advanced Plant Habitat Flight Unit #1

NASA Image and Video Library

2017-07-24

Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a quality technician checks the control panel on hardware for the Advanced Plant Habitat flight unit. The flight unit is an exact replica of the APH that was delivered to the International Space Station. Validation tests and post-delivery checkout was performed to prepare for space station in-orbit APH activities. The flight unit will be moved to the International Space Station Environmental Simulator to begin an experiment verification test for the science that will fly on the first mission, PH-01. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the space station.

Is the adaptation to UV stress correlated with a higher resistance to other environmental stressors? First results of the space experiment ADAPT

NASA Astrophysics Data System (ADS)

Rettberg, Petra; Wassmann, Marko; Rabbow, Elke; Moeller, Ralf; Panitz, Corinna; Horneck, Gerda; Douki, Thierry; Cadet, Jean

The effects of one of the most important environmental factors that have influenced the biolog-ical evolution on earth, solar UV radiation, was investigated in the space experiment ADAPT in the ESA facility EXPOSE on the European ISS module Columbus. Three highly resistant microorganims from very distinct terrestrial habitats were selected: Bacillus subtilis, a well characterised spore forming soil bacterium, a natural community of cyanobacteria colonising rocks and a species of halophilic archaea isolated from rock salt, Halococcus dombrowskii. The capability of the three different microorganisms to survive in a qualitatively and quantitatively different UV climate like that in space and on Mars was investigated in EXPOSE and its effects as well as its interaction with other environmental parameters were characterised at the cellular and molecular level. In the EXPOSE facility the environmental parameters of space were provided by the exposure of samples in vented sample carriers under MgF2 windows allowing the transmittance of solar UV wavelengths down to 110 nm. In addition, the environmental conditions on the surface of Mars were simulated in earth orbit by using closed sample carriers with martian atmosphere and pressure and a martian UV climate realised by the use of suitable cut-off filters and the extraterrestrial solar UV radiation. Due to the different composition of the martian atmosphere and it's low pressure, the martian UV radiation climate is significantly different from that of today's earth. Energy-rich biologically harmful UVB and UVC radiation can penetrate to the surface of Mars. This UV radiation spectrum resembles that of the early earth before the rise of the atmospheric oxygen concentration. In the experiment ADAPT I the model organism Bacillus subtilis was used to test the hypothesis experimentally whether longer-lasting selective pressure by a mars-like UV radiation spectrum results in a higher UV resistance as well as in a higher resistance against the simultaneous action of further `extreme' environmental factors that exist in space or on other planets like vacuum / low pressure or cosmic radiation. In preparation of ADAPT a continuos culture of Bacillus subtilis 168 cells was grown for 700 generations under periodical polychromatic mars-like UV irradiation. Populations that evolved under this UV stress were about 4.7fold more resistant than the ancestral and non-UV evolved populations. In addition to the acquired increased UV resistance, further changes in microbial stress response to hydrogen peroxide, increased salinity and desiccation were observed in UV-evolved cells. For the space experiment spores of the strain MW01, isolated from this UV-resistant population, were exposed in earth orbit to space and simulated martian conditions. The biological endpoints under investigation include among others survival, mutation induction, loss of sporulation capability. The results of this experiment will contribute to our understanding of the adaptability of life to extreme environments on earth and on other planets in general.

Acceleration levels on board the Space Station and a tethered elevator for micro and variable-gravity applications

NASA Technical Reports Server (NTRS)

Lorenzini, E. C.; Cosmo, M.; Vetrella, S.; Moccia, A.

1988-01-01

This paper investigates the dynamics and acceleration levels of a new tethered system for micro and variable-gravity applications. The system consists of two platforms tethered on opposite sides to the Space Station. A fourth platform, the elevator, is placed in between the Space Station and the upper platform. Variable-g levels on board the elevator are obtained by moving this facility along the upper tether, while micro-g experiments are carried out on board the Space Station. By controlling the length of the lower tether the position of the system CM can be maintained on board the Space Station despite variations of the station's distribution of mass. The paper illustrates the mathematical model, the environmental perturbations and the control techniques which have been adopted for the simulation and control of the system dynamics. Two sets of results from two different simulation runs are shown. The first set shows the system dynamics and the acceleration spectra on board the Space Station and the elevator during station-keeping. The second set of results demonstrates the capability of the elevator to attain a preselected g-level.

Simulation of the dynamic environment for missile component testing: Demonstration

NASA Technical Reports Server (NTRS)

Chang, Kurng Y.

1989-01-01

The problems in defining a realistic test requirement for missile and space vehicle components can be classified into two categories: (1) definition of the test environment representing the expected service condition, and (2) simulation of the desired environment in the test laboratory. Recently, a new three-dimensional (3-D) test facility was completed at the U.S. Army Harry Diamond Laboratory (HDL) to simulate triaxial vibration input to a test specimen. The vibration test system is designed to support multi-axial vibration tests over the frequency range of 5 to 2000 Hertz. The availability of this 3-D test system motivates the development of new methodologies addressing environmental definition and simulation.

Lessons Learned from Biosphere 2: When Viewed as a Ground Simulation/Analogue for Long Duration Human Space Exploration and Settlement

NASA Astrophysics Data System (ADS)

MacCallum, T.; Poynter, J.; Bearden, D.

A human mission to Mars, or a base on the Moon or Mars, is a longer and more complex mission than any space endeavor undertaken to date. Ground simulations provide a relevant, analogous environment for testing technologies and learning how to manage complex, long duration missions, while addressing inherent mission risks. Multiphase human missions and settlements that may preclude a rapid return to Earth, require high fidelity, end-to-end, at least full mission duration tests in order to evaluate a system's ability to sustain the crew for the entire mission and return the crew safely to Earth. Moreover, abort scenarios are essentially precluded in many mission scenarios, though certain risks may only become evident late in the mission. Aging and compounding effects cannot be simulated through accelerated tests for all aspects of the mission. Until such high fidelity long duration simulations are available, and in order to help prepare those simulations and mission designs, it is important to extract as many lessons as possible from analogous environments. Possibly the best analogue for a long duration space mission is the two year mission of Biosphere 2. Biosphere 2 is a three-acre materially closed ecological system that supported eight crewmembers with food, air and water in a sunlight driven bioregenerative system for two years. It was designed for research applicable to environmental management on Earth and the development of human life support for space. A brief overview of the two-year Biosphere 2 mission is presented, followed by select data and lessons learned that are applicable to the design and operation of a long duration human space mission, settlement or test bed. These lessons include technical, programmatic, and psychological issues

Re-design of a physically-based catchment scale agrochemical model for the simulation of parameter spaces and flexible transformation schemes

NASA Astrophysics Data System (ADS)

Stegen, Ronald; Gassmann, Matthias

2017-04-01

The use of a broad variation of agrochemicals is essential for the modern industrialized agriculture. During the last decades, the awareness of the side effects of their use has grown and with it the requirement to reproduce, understand and predict the behaviour of these agrochemicals in the environment, in order to optimize their use and minimize the side effects. The modern modelling has made great progress in understanding and predicting these chemicals with digital methods. While the behaviour of the applied chemicals is often investigated and modelled, most studies only simulate parent chemicals, considering total annihilation of the substance. However, due to a diversity of chemical, physical and biological processes, the substances are rather transformed into new chemicals, which themselves are transformed until, at the end of the chain, the substance is completely mineralized. During this process, the fate of each transformation product is determined by its own environmental characteristics and the pathway and results of transformation can differ largely by substance and environmental influences, that can occur in different compartments of the same site. Simulating transformation products introduces additional model uncertainties. Thus, the calibration effort increases compared to simulations of the transport and degradation of the primary substance alone. The simulation of the necessary physical processes needs a lot of calculation time. Due to that, few physically-based models offer the possibility to simulate transformation products at all, mostly at the field scale. The few models available for the catchment scale are not optimized for this duty, i.e. they are only able to simulate a single parent compound and up to two transformation products. Thus, for simulations of large physico-chemical parameter spaces, the enormous calculation time of the underlying hydrological model diminishes the overall performance. In this study, the structure of the model ZIN-AGRITRA is re-designed for the transport and transformation of an unlimited amount of agrochemicals in the soil-water-plant system at catchment scale. The focus is, besides a good hydrological standard, on a flexible variation of transformation processes and the optimization for the use of large numbers of different substances. Due to the new design, a reduction of the calculation time per tested substance is acquired, allowing faster testing of parameter spaces. Additionally, the new concept allows for the consideration of different transformation processes and products in different environmental compartments. A first test of calculation time improvements and flexible transformation pathways was performed in a Mediterranean meso-scale catchment, using the insecticide Chlorpyrifos and two of its transformation products, which emerge from different transformation processes, as test substances.

Environmental impact analysis with the airspace concept evaluation system

NASA Technical Reports Server (NTRS)

Augustine, Stephen; Capozzi, Brian; DiFelici, John; Graham, Michael; Thompson, Terry; Miraflor, Raymond M. C.

2005-01-01

The National Aeronautics and Space Administration (NASA) Ames Research Center has developed the Airspace Concept Evaluation System (ACES), which is a fast-time simulation tool for evaluating Air Traffic Management (ATM) systems. This paper describes linking a capability to ACES which can analyze the environmental impact of proposed future ATM systems. This provides the ability to quickly evaluate metrics associated with environmental impacts of aviation for inclusion in multi-dimensional cost-benefit analysis of concepts for evolution of the National Airspace System (NAS) over the next several decades. The methodology used here may be summarized as follows: 1) Standard Federal Aviation Administration (FAA) noise and emissions-inventory models, the Noise Impact Routing System (NIRS) and the Emissions and Dispersion Modeling System (EDMS), respectively, are linked to ACES simulation outputs; 2) appropriate modifications are made to ACES outputs to incorporate all information needed by the environmental models (e.g., specific airframe and engine data); 3) noise and emissions calculations are performed for all traffic and airports in the study area for each of several scenarios, as simulated by ACES; and 4) impacts of future scenarios are compared to the current NAS baseline scenario. This paper also provides the results of initial end-to-end, proof-of-concept runs of the integrated ACES and environmental-modeling capability. These preliminary results demonstrate that if no growth is likely to be impeded by significant environmental impacts that could negatively affect communities throughout the nation.

Modeling of space environment impact on nanostructured materials. General principles

NASA Astrophysics Data System (ADS)

Voronina, Ekaterina; Novikov, Lev

2016-07-01

In accordance with the resolution of ISO TC20/SC14 WG4/WG6 joint meeting, Technical Specification (TS) 'Modeling of space environment impact on nanostructured materials. General principles' which describes computer simulation methods of space environment impact on nanostructured materials is being prepared. Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. Most such standards are related to production and characterization of nanostructures, however there is no ISO documents concerning nanomaterials behavior in different environmental conditions, including the space environment. The given TS deals with the peculiarities of the space environment impact on nanostructured materials (i.e. materials with structured objects which size in at least one dimension lies within 1-100 nm). The basic purpose of the document is the general description of the methodology of applying computer simulation methods which relate to different space and time scale to modeling processes occurring in nanostructured materials under the space environment impact. This document will emphasize the necessity of applying multiscale simulation approach and present the recommendations for the choice of the most appropriate methods (or a group of methods) for computer modeling of various processes that can occur in nanostructured materials under the influence of different space environment components. In addition, TS includes the description of possible approximations and limitations of proposed simulation methods as well as of widely used software codes. This TS may be used as a base for developing a new standard devoted to nanomaterials applications for spacecraft.

Appendices to the user's manual for a computer program for the emulation/simulation of a space station environmental control and life support system

NASA Technical Reports Server (NTRS)

Yanosy, James L.

1988-01-01

A user's Manual for the Emulation Simulation Computer Model was published previously. The model consisted of a detailed model (emulation) of a SAWD CO2 removal subsystem which operated with much less detailed (simulation) models of a cabin, crew, and condensing and sensible heat exchangers. The purpose was to explore the utility of such an emulation/simulation combination in the design, development, and test of a piece of ARS hardware - SAWD. Extensions to this original effort are presented. The first extension is an update of the model to reflect changes in the SAWD control logic which resulted from the test. In addition, slight changes were also made to the SAWD model to permit restarting and to improve the iteration technique. The second extension is the development of simulation models for more pieces of air and water processing equipment. Models are presented for: EDC, Molecular Sieve, Bosch, Sabatier, a new condensing heat exchanger, SPE, SFWES, Catalytic Oxidizer, and multifiltration. The third extension is to create two system simulations using these models. The first system presented consists of one air and one water processing system, the second a potential Space Station air revitalization system.

Laser Induced Breakdown Spectroscopy for Elemental Analysis in Environmental, Cultural Heritage and Space Applications: A Review of Methods and Results

PubMed Central

Gaudiuso, Rosalba; Dell’Aglio, Marcella; De Pascale, Olga; Senesi, Giorgio S.; De Giacomo, Alessandro

2010-01-01

Analytical applications of Laser Induced Breakdown Spectroscopy (LIBS), namely optical emission spectroscopy of laser-induced plasmas, have been constantly growing thanks to its intrinsic conceptual simplicity and versatility. Qualitative and quantitative analysis can be performed by LIBS both by drawing calibration lines and by using calibration-free methods and some of its features, so as fast multi-elemental response, micro-destructiveness, instrumentation portability, have rendered it particularly suitable for analytical applications in the field of environmental science, space exploration and cultural heritage. This review reports and discusses LIBS achievements in these areas and results obtained for soils and aqueous samples, meteorites and terrestrial samples simulating extraterrestrial planets, and cultural heritage samples, including buildings and objects of various kinds. PMID:22163611

Laser induced breakdown spectroscopy for elemental analysis in environmental, cultural heritage and space applications: a review of methods and results.

PubMed

Gaudiuso, Rosalba; Dell'Aglio, Marcella; De Pascale, Olga; Senesi, Giorgio S; De Giacomo, Alessandro

2010-01-01

Analytical applications of Laser Induced Breakdown Spectroscopy (LIBS), namely optical emission spectroscopy of laser-induced plasmas, have been constantly growing thanks to its intrinsic conceptual simplicity and versatility. Qualitative and quantitative analysis can be performed by LIBS both by drawing calibration lines and by using calibration-free methods and some of its features, so as fast multi-elemental response, micro-destructiveness, instrumentation portability, have rendered it particularly suitable for analytical applications in the field of environmental science, space exploration and cultural heritage. This review reports and discusses LIBS achievements in these areas and results obtained for soils and aqueous samples, meteorites and terrestrial samples simulating extraterrestrial planets, and cultural heritage samples, including buildings and objects of various kinds.

The development of composite materials for spacecraft precision reflector panels

NASA Technical Reports Server (NTRS)

Tompkins, Stephen S.; Bowles, David E.; Funk, Joan G.; Towell, Timothy W.; Lavoie, J. A.

1990-01-01

One of the critical technology needs for large precision reflectors required for future astrophysics and optical communications is in the area of structural materials. Therefore, a major area of the Precision Segmented Reflector Program at NASA is to develop lightweight composite reflector panels with durable, space environmentally stable materials which maintain both surface figure and required surface accuracy necessary for space telescope applications. Results from the materials research and development program at NASA Langley Research Center are discussed. Advanced materials that meet the reflector panel requirements are identified. Thermal, mechanical and durability properties of candidate materials after exposure to simulated space environments are compared to the baseline material.

Nuclear Thermal Propulsion (NTP) Development Activities at the NASA Marshall Space Flight Center - 2006 Accomplishments

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2007-01-01

In 2005-06, the Prometheus program funded a number of tasks at the NASA-Marshall Space Flight Center (MSFC) to support development of a Nuclear Thermal Propulsion (NTP) system for future manned exploration missions. These tasks include the following: 1. NTP Design Develop Test & Evaluate (DDT&E) Planning 2. NTP Mission & Systems Analysis / Stage Concepts & Engine Requirements 3. NTP Engine System Trade Space Analysis and Studies 4. NTP Engine Ground Test Facility Assessment 5. Non-Nuclear Environmental Simulator (NTREES) 6. Non-Nuclear Materials Fabrication & Evaluation 7. Multi-Physics TCA Modeling. This presentation is a overview of these tasks and their accomplishments

The Study of Simulated Space Radiation Environment Effect on Conductive Properties of ITO Thermal Control Materials

NASA Astrophysics Data System (ADS)

Wei-Quan, Feng; Chun-Qing, Zhao; Zi-Cai, Shen; Yi-Gang, Ding; Fan, Zhang; Yu-Ming, Liu; Hui-Qi, Zheng; Xue, Zhao

In order to prevent detrimental effects of ESD caused by differential surface charging of spacecraft under space environments, an ITO transparent conductive coating is often deposited on the thermal control materials outside spacecraft. Since the ITO coating is exposed in space environment, the environment effects on electrical property of ITO coatings concern designers of spacecraft deeply. This paper introduces ground tests to simulate space radiation environmental effects on conductive property of ITO coating. Samples are made of ITO/OSR, ITO/Kapton/Al and ITO/FEP/Ag thermal control coatings. Simulated space radiation environment conditions are NUV of 500ESH, 40 keV electron of 2 × 1016 е/cm2, 40 keV proton of 2.5 × 1015 p/cm2. Conductive property is surface resistivity measured in-situ in vacuum. Test results proved that the surface resistivity for all ITO coatings have a sudden decrease in the beginning of environment test. The reasons for it may be the oxygen vacancies caused by vacuum and decayed RIC caused by radiation. Degradation in conductive properties caused by irradiation were found. ITO/FEP/Ag exhibits more degradation than other two kinds. The conductive property of ITO/kapton/Al is stable for vacuum irradiation. The analysis of SEM and XPS found more crackers and less Sn and In concentration after irradiation which may be the reason for conductive property degradation.

Optimal design of wind barriers using 3D computational fluid dynamics simulations

NASA Astrophysics Data System (ADS)

Fang, H.; Wu, X.; Yang, X.

2017-12-01

Desertification is a significant global environmental and ecological problem that requires human-regulated control and management. Wind barriers are commonly used to reduce wind velocity or trap drifting sand in arid or semi-arid areas. Therefore, optimal design of wind barriers becomes critical in Aeolian engineering. In the current study, we perform 3D computational fluid dynamics (CFD) simulations for flow passing through wind barriers with different structural parameters. To validate the simulation results, we first inter-compare the simulated flow field results with those from both wind-tunnel experiments and field measurements. Quantitative analyses of the shelter effect are then conducted based on a series of simulations with different structural parameters (such as wind barrier porosity, row numbers, inter-row spacing and belt schemes). The results show that wind barriers with porosity of 0.35 could provide the longest shelter distance (i.e., where the wind velocity reduction is more than 50%) thus are recommended in engineering designs. To determine the optimal row number and belt scheme, we introduce a cost function that takes both wind-velocity reduction effects and economical expense into account. The calculated cost function show that a 3-row-belt scheme with inter-row spacing of 6h (h as the height of wind barriers) and inter-belt spacing of 12h is the most effective.

Parallel computing method for simulating hydrological processesof large rivers under climate change

NASA Astrophysics Data System (ADS)

Wang, H.; Chen, Y.

2016-12-01

Climate change is one of the proverbial global environmental problems in the world.Climate change has altered the watershed hydrological processes in time and space distribution, especially in worldlarge rivers.Watershed hydrological process simulation based on physically based distributed hydrological model can could have better results compared with the lumped models.However, watershed hydrological process simulation includes large amount of calculations, especially in large rivers, thus needing huge computing resources that may not be steadily available for the researchers or at high expense, this seriously restricted the research and application. To solve this problem, the current parallel method are mostly parallel computing in space and time dimensions.They calculate the natural features orderly thatbased on distributed hydrological model by grid (unit, a basin) from upstream to downstream.This articleproposes ahigh-performancecomputing method of hydrological process simulation with high speedratio and parallel efficiency.It combinedthe runoff characteristics of time and space of distributed hydrological model withthe methods adopting distributed data storage, memory database, distributed computing, parallel computing based on computing power unit.The method has strong adaptability and extensibility,which means it canmake full use of the computing and storage resources under the condition of limited computing resources, and the computing efficiency can be improved linearly with the increase of computing resources .This method can satisfy the parallel computing requirements ofhydrological process simulation in small, medium and large rivers.

From "Below Dignity" to "Above It All": Origins and Early History of Underwater Neutral Buoyancy Simulation of Weightlessness for EVA Procedures Development and Training

NASA Technical Reports Server (NTRS)

Charles, John B.

2013-01-01

An attempt to clarify some vague memories of underwater studies of astronaut capabilities in space led Dr. John Charles to become acquainted with Sam Mattingly, one of the pioneers in the field, and to greater insights into Mattingly's work simulating Gemini EVAs in the mid-1960s. Charles recounted major accomplishments by Environmental Research Associates (ERA), Mattingly's company for contracting with NASA Langley on several early studies. ERA's work was considered within the context of contemporary efforts to simulate weightlessness and the widespread development of neutral buoyancy facilities after ERA's successful demonstration for Gemini 12.

Ballistic Performance of Porous-Ceramic, Thermal-Protection-Systems

NASA Technical Reports Server (NTRS)

Christiansen, E. L.; Davis, B. A.; Miller, J. E.; Bohl, W. E.; Foreman, C. D.

2009-01-01

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Space Shuttle and are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s, and the findings of the influence of material equation-of-state on the simulation of the impact event to characterize the ballistic performance of these materials. These results will be compared with heritage models1 for these materials developed from testing at lower velocities. Assessments of predicted spacecraft risk based upon these tests and simulations will also be discussed.

A Novel Approach for Modeling Chemical Reaction in Generalized Fluid System Simulation Program

NASA Technical Reports Server (NTRS)

Sozen, Mehmet; Majumdar, Alok

2002-01-01

The Generalized Fluid System Simulation Program (GFSSP) is a computer code developed at NASA Marshall Space Flight Center for analyzing steady state and transient flow rates, pressures, temperatures, and concentrations in a complex flow network. The code, which performs system level simulation, can handle compressible and incompressible flows as well as phase change and mixture thermodynamics. Thermodynamic and thermophysical property programs, GASP, WASP and GASPAK provide the necessary data for fluids such as helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, water, a hydrogen, isobutane, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, several refrigerants, nitrogen trifluoride and ammonia. The program which was developed out of need for an easy to use system level simulation tool for complex flow networks, has been used for the following purposes to name a few: Space Shuttle Main Engine (SSME) High Pressure Oxidizer Turbopump Secondary Flow Circuits, Axial Thrust Balance of the Fastrac Engine Turbopump, Pressurized Propellant Feed System for the Propulsion Test Article at Stennis Space Center, X-34 Main Propulsion System, X-33 Reaction Control System and Thermal Protection System, and International Space Station Environmental Control and Life Support System design. There has been an increasing demand for implementing a combustion simulation capability into GFSSP in order to increase its system level simulation capability of a liquid rocket propulsion system starting from the propellant tanks up to the thruster nozzle for spacecraft as well as launch vehicles. The present work was undertaken for addressing this need. The chemical equilibrium equations derived from the second law of thermodynamics and the energy conservation equation derived from the first law of thermodynamics are solved simultaneously by a Newton-Raphson method. The numerical scheme was implemented as a User Subroutine in GFSSP.

Advanced Plant Habitat Flight Unit #1

NASA Image and Video Library

2017-07-24

Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, LED plant growth lights are being checked out on the hardware for the Advanced Plant Habitat flight unit. The flight unit is an exact replica of the APH that was delivered to the International Space Station. Validation tests and post-delivery checkout was performed to prepare for space station in-orbit APH activities. The flight unit will be moved to the International Space Station Environmental Simulator to begin an experiment verification test for the science that will fly on the first mission, PH-01. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the space station.

Radiation: Physical Characterization and Environmental Measurements

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session WP4, the discussion focuses on the following topics: Production of Neutrons from Interactions of GCR-Like Particles; Solar Particle Event Dose Distributions, Parameterization of Dose-Time Profiles; Assessment of Nuclear Events in the Body Produced by Neutrons and High-Energy Charged Particles; Ground-Based Simulations of Cosmic Ray Heavy Ion Interactions in Spacecraft and Planetary Habitat Shielding Materials; Radiation Measurements in Space Missions; Radiation Measurements in Civil Aircraft; Analysis of the Pre-Flight and Post-Flight Calibration Procedures Performed on the Liulin Space Radiation Dosimeter; and Radiation Environment Monitoring for Astronauts.

Dynamic analysis of space structures including elastic, multibody, and control behavior

NASA Technical Reports Server (NTRS)

Pinson, Larry; Soosaar, Keto

1989-01-01

The problem is to develop analysis methods, modeling stategies, and simulation tools to predict with assurance the on-orbit performance and integrity of large complex space structures that cannot be verified on the ground. The problem must incorporate large reliable structural models, multi-body flexible dynamics, multi-tier controller interaction, environmental models including 1g and atmosphere, various on-board disturbances, and linkage to mission-level performance codes. All areas are in serious need of work, but the weakest link is multi-body flexible dynamics.

Processing of nutritious, safe and acceptable foods from cells candidate crops

NASA Astrophysics Data System (ADS)

Fu, B.; Nelson, P. E.; Irvine, R.; Kanach, L. L.

A controlled ecological life-support system (CELSS) is required to sustain life for long-duration space missions. The challenge is preparing a wide variety of tasty, familiar, and nutritious foods from CELSS candidate crops under space environmental conditions. Conventional food processing technologies will have to be modified to adapt to the space environment. Extrusion is one of the processes being examined as a means of converting raw plant biomass into familiar foods. A nutrition-improved pasta has been developed using cowpea as a replacement for a portion of the durum semolina. A freeze-drying system that simulates the space conditions has also been developed. Other technologies that would fulfill the requirements of a CELSS will also be addressed.

Processing of nutritious, safe and acceptable foods from CELSS candidate crops

NASA Technical Reports Server (NTRS)

Fu, B.; Nelson, P. E.; Irvine, R.; Kanach, L. L.; Mitchell, C. A. (Principal Investigator)

1996-01-01

A controlled ecological life-support system (CELSS) is required to sustain life for long-duration space missions. The challenge is preparing a wide variety of tasty, familiar, and nutritious foods from CELSS candidate crops under space environmental conditions. Conventional food processing technologies will have to be modified to adapt to the space environment. Extrusion is one of the processes being examined as a means of converting raw plant biomass into familiar foods. A nutrition-improved pasta has been developed using cowpea as a replacement for a portion of the durum semolina. A freeze-drying system that simulates the space conditions has also been developed. Other technologies that would fulfill the requirements of a CELSS will also be addressed.

Comparative proteomic analysis of rice after seed ground simulated radiation and spaceflight explains the radiation effects of space environment

NASA Astrophysics Data System (ADS)

Wang, Wei; Shi, Jinming; Liang, Shujian; Lei, Huang; Shenyi, Zhang; Sun, Yeqing

In previous work, we compared the proteomic profiles of rice plants growing after seed space-flights with ground controls by two-dimensional difference gel electrophoresis (2-D DIGE) and found that the protein expression profiles were changed after seed space environment exposures. Spaceflight represents a complex environmental condition in which several interacting factors such as cosmic radiation, microgravity and space magnetic fields are involved. Rice seed is in the process of dormant of plant development, showing high resistance against stresses, so the highly ionizing radiation (HZE) in space is considered as main factor causing biological effects to seeds. To further investigate the radiation effects of space environment, we performed on-ground simulated HZE particle radiation and compared between the proteomes of seed irra-diated plants and seed spaceflight (20th recoverable satellite) plants from the same rice variety. Space ionization shows low-dose but high energy particle effects, for searching the particle effects, ground radiations with the same low-dose (2mGy) but different liner energy transfer (LET) values (13.3KeV/µm-C, 30KeV/µm-C, 31KeV/µm-Ne, 62.2KeV/µm-C, 500Kev/µm-Fe) were performed; using 2-D DIGE coupled with clustering and principle component analysis (PCA) for data process and comparison, we found that the holistic protein expression patterns of plants irradiated by LET-62.2KeV/µm carbon particles were most similar to spaceflight. In addition, although space environment presents a low-dose radiation (0.177 mGy/day on the satellite), the equivalent simulated radiation dose effects should still be evaluated: radiations of LET-62.2KeV/µm carbon particles with different cumulative doses (2mGy, 20mGy, 200mGy, 2000mGy) were further carried out and resulted that the 2mGy radiation still shared most similar proteomic profiles with spaceflight, confirming the low-dose effects of space radiation. Therefore, in the protein expression level, ground simulation method could be utilized to simu-late the space radiation biological effects and such a comparative proteomic work might explain both energy and dose effects of space radiation environment.

A scheme for the uniform mapping and monitoring of earth resources and environmental complexes using ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Poulton, C. E. (Principal Investigator); Welch, R. I.

1973-01-01

There are no author-identified significant results in this report. Progress on plans for the development and testing of a practical procedure and system for the uniform mapping and monitoring of natural ecosystems and environmental complexes from space-acquired imagery is discussed. With primary emphasis on ERTS-1 imagery, but supported by appropriate aircraft photography as necessary, the objectives are to accomplish the following: (1) Develop and test in a few selected sites and areas of the western United States a standard format for an ecological and land use legend for making natural resource inventories on a simulated global basis. (2) Based on these same limited geographic areas, identify the potentialities and limitations of the legend concept for the recognition and annotation of ecological analogs and environmental complexes. An additional objective is to determine the optimum combination of space photography, aerial photography, ground data, human data analysis, and automatic data analysis for estimating crop yield in the rice growing areas of California and Louisiana.

Exploring the Limits of High Altitude GPS for Future Lunar Missions

NASA Technical Reports Server (NTRS)

Ashman, Benjamin W.; Parker, Joel J.; Bauer, Frank H.; Esswein, Michael

2018-01-01

An increasing number of spacecraft are relying on the Global Positioning System (GPS) for navigation at altitudes near or above the GPS constellation itself - the region known as the Space Service Volume (SSV). While the formal definition of the SSV ends at geostationary altitude, the practical limit of high-altitude space usage is not known, and recent missions have demonstrated that signal availability is sufficient for operational navigation at altitudes halfway to the moon. This paper presents simulation results based on a high-fidelity model of the GPS constellation, calibrated and validated through comparisons of simulated GPS signal availability and strength with flight data from recent high-altitude missions including the Geostationary Operational Environmental Satellite 16 (GOES-16) and the Magnetospheric Multiscale (MMS) mission. This improved model is applied to the transfer to a lunar near-rectilinear halo orbit (NRHO) of the class being con- sidered for the international Deep Space Gateway concept. The number of GPS signals visible and their received signal strengths are presented as a function of receiver altitude in order to explore the practical upper limit of high-altitude space usage of GPS.

Exploring the Limits of High Altitude GPS for Future Lunar Missions

NASA Technical Reports Server (NTRS)

Ashman, Benjamin W.; Parker, Joel J. K.; Bauer, Frank H.; Esswein, Michael

2018-01-01

An increasing number of spacecraft are relying on the Global Positioning System (GPS) for navigation at altitudes near or above the GPS constellation itself - the region known as the Space Service Volume (SSV). While the formal definition of the SSV ends at geostationary altitude, the practical limit of high-altitude space usage is not known, and recent missions have demonstrated that signal availability is sufficient for operational navigation at altitudes halfway to the moon. This paper presents simulation results based on a high-fidelity model of the GPS constellation, calibrated and validated through comparisons of simulated GPS signal availability and strength with flight data from recent high-altitude missions including the Geostationary Operational Environmental Satellite 16 (GOES-16) and the Magnetospheric Multiscale (MMS) mission. This improved model is applied to the transfer to a lunar near-rectilinear halo orbit (NRHO) of the class being considered for the international Deep Space Gateway concept. The number of GPS signals visible and their received signal strengths are presented as a function of receiver altitude in order to explore the practical upper limit of high-altitude space usage of GPS.

The Exercise and Environmental Physiology of Extravehicular Activity

NASA Technical Reports Server (NTRS)

Cowell, S. A.; Stocks, J. M.; Evans, D. G.; Simonson, S. R.; Greenleaf, J. E.; Dalton, Bonnie P. (Technical Monitor)

2000-01-01

Over the history of human expansion into space, extravehicular activity (EVA) has become indispensable for both daily living in weightlessness and for further space exploration. The physiological factors involved in the performance of extensive EVA, necessary for construction and maintenance of the International Space Station and during future human interplanetary missions, require further examination. An understanding of the physiological aspects of exercise and thermoregulation in the EVA environment will help to insure the health, safety, and efficiency of working astronauts. To that end, this review will focus on the interaction of the exercise and environmental aspects of EVA, as well as exercise during spaceflight and ground-based simulations such as bed-rest deconditioning. It will examine inflight exercise thermoregulation, and exercise, muscular strength, supine vs. seated exercise, exercise thermoregulation, and exercise in a hypobaric environment. Due to the paucity of data from controlled human research in this area, it is clear that more scientific studies are needed to insure safe and efficient extravehicular activity.

Space-borne profiling of atmospheric thermodynamic variables with Raman lidar: performance simulations.

PubMed

Di Girolamo, Paolo; Behrendt, Andreas; Wulfmeyer, Volker

2018-04-02

The performance of a space-borne water vapour and temperature lidar exploiting the vibrational and pure rotational Raman techniques in the ultraviolet is simulated. This paper discusses simulations under a variety of environmental and climate scenarios. Simulations demonstrate the capability of Raman lidars deployed on-board low-Earth-orbit satellites to provide global-scale water vapour mixing ratio and temperature measurements in the lower to middle troposphere, with accuracies exceeding most observational requirements for numerical weather prediction (NWP) and climate research applications. These performances are especially attractive for measurements in the low troposphere in order to close the most critical gaps in the current earth observation system. In all climate zones, considering vertical and horizontal resolutions of 200 m and 50 km, respectively, mean water vapour mixing ratio profiling precision from the surface up to an altitude of 4 km is simulated to be 10%, while temperature profiling precision is simulated to be 0.40-0.75 K in the altitude interval up to 15 km. Performances in the presence of clouds are also simulated. Measurements are found to be possible above and below cirrus clouds with an optical thickness of 0.3. This combination of accuracy and vertical resolution cannot be achieved with any other space borne remote sensing technique and will provide a breakthrough in our knowledge of global and regional water and energy cycles, as well as in the quality of short- to medium-range weather forecasts. Besides providing a comprehensive set of simulations, this paper also provides an insight into specific possible technological solutions that are proposed for the implementation of a space-borne Raman lidar system. These solutions refer to technological breakthroughs gained during the last decade in the design and development of specific lidar devices and sub-systems, primarily in high-power, high-efficiency solid-state laser sources, low-weight large aperture telescopes, and high-gain, high-quantum efficiency detectors.

Active Matrix OLED Test Report

NASA Technical Reports Server (NTRS)

Salazar, George

2013-01-01

This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits from the environmental testing results by understanding its performance limitations/shortcomings to improve subsequent generations of AMOLED technology. Note that the AMOLED used in this test was not deSigned for the space environment but rather for commercial/industrial terrestrial applications.

Robust Multivariable Optimization and Performance Simulation for ASIC Design

NASA Technical Reports Server (NTRS)

DuMonthier, Jeffrey; Suarez, George

2013-01-01

Application-specific-integrated-circuit (ASIC) design for space applications involves multiple challenges of maximizing performance, minimizing power, and ensuring reliable operation in extreme environments. This is a complex multidimensional optimization problem, which must be solved early in the development cycle of a system due to the time required for testing and qualification severely limiting opportunities to modify and iterate. Manual design techniques, which generally involve simulation at one or a small number of corners with a very limited set of simultaneously variable parameters in order to make the problem tractable, are inefficient and not guaranteed to achieve the best possible results within the performance envelope defined by the process and environmental requirements. What is required is a means to automate design parameter variation, allow the designer to specify operational constraints and performance goals, and to analyze the results in a way that facilitates identifying the tradeoffs defining the performance envelope over the full set of process and environmental corner cases. The system developed by the Mixed Signal ASIC Group (MSAG) at the Goddard Space Flight Center is implemented as a framework of software modules, templates, and function libraries. It integrates CAD tools and a mathematical computing environment, and can be customized for new circuit designs with only a modest amount of effort as most common tasks are already encapsulated. Customization is required for simulation test benches to determine performance metrics and for cost function computation.

Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report

NASA Technical Reports Server (NTRS)

Salazar, George A.

2013-01-01

This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits from the environmental testing results by understanding its performance limitations/shortcomings to improve subsequent generations of AMOLED technology. Note that the AMOLED used in this test was not deSigned for the space environment but rather for commercial/industrial terrestrial applications.

A High Fidelity Approach to Data Simulation for Space Situational Awareness Missions

NASA Astrophysics Data System (ADS)

Hagerty, S.; Ellis, H., Jr.

2016-09-01

Space Situational Awareness (SSA) is vital to maintaining our Space Superiority. A high fidelity, time-based simulation tool, PROXOR™ (Proximity Operations and Rendering), supports SSA by generating realistic mission scenarios including sensor frame data with corresponding truth. This is a unique and critical tool for supporting mission architecture studies, new capability (algorithm) development, current/future capability performance analysis, and mission performance prediction. PROXOR™ provides a flexible architecture for sensor and resident space object (RSO) orbital motion and attitude control that simulates SSA, rendezvous and proximity operations scenarios. The major elements of interest are based on the ability to accurately simulate all aspects of the RSO model, viewing geometry, imaging optics, sensor detector, and environmental conditions. These capabilities enhance the realism of mission scenario models and generated mission image data. As an input, PROXOR™ uses a library of 3-D satellite models containing 10+ satellites, including low-earth orbit (e.g., DMSP) and geostationary (e.g., Intelsat) spacecraft, where the spacecraft surface properties are those of actual materials and include Phong and Maxwell-Beard bidirectional reflectance distribution function (BRDF) coefficients for accurate radiometric modeling. We calculate the inertial attitude, the changing solar and Earth illumination angles of the satellite, and the viewing angles from the sensor as we propagate the RSO in its orbit. The synthetic satellite image is rendered at high resolution and aggregated to the focal plane resolution resulting in accurate radiometry even when the RSO is a point source. The sensor model includes optical effects from the imaging system [point spread function (PSF) includes aberrations, obscurations, support structures, defocus], detector effects (CCD blooming, left/right bias, fixed pattern noise, image persistence, shot noise, read noise, and quantization noise), and environmental effects (radiation hits with selectable angular distributions and 4-layer atmospheric turbulence model for ground based sensors). We have developed an accurate flash Light Detection and Ranging (LIDAR) model that supports reconstruction of 3-dimensional information on the RSO. PROXOR™ contains many important imaging effects such as intra-frame smear, realized by oversampling the image in time and capturing target motion and jitter during the integration time.

Optimization of life support systems and their systems reliability

NASA Technical Reports Server (NTRS)

Fan, L. T.; Hwang, C. L.; Erickson, L. E.

1971-01-01

The identification, analysis, and optimization of life support systems and subsystems have been investigated. For each system or subsystem that has been considered, the procedure involves the establishment of a set of system equations (or mathematical model) based on theory and experimental evidences; the analysis and simulation of the model; the optimization of the operation, control, and reliability; analysis of sensitivity of the system based on the model; and, if possible, experimental verification of the theoretical and computational results. Research activities include: (1) modeling of air flow in a confined space; (2) review of several different gas-liquid contactors utilizing centrifugal force: (3) review of carbon dioxide reduction contactors in space vehicles and other enclosed structures: (4) application of modern optimal control theory to environmental control of confined spaces; (5) optimal control of class of nonlinear diffusional distributed parameter systems: (6) optimization of system reliability of life support systems and sub-systems: (7) modeling, simulation and optimal control of the human thermal system: and (8) analysis and optimization of the water-vapor eletrolysis cell.

SToRM: A numerical model for environmental surface flows

USGS Publications Warehouse

Simoes, Francisco J.

2009-01-01

SToRM (System for Transport and River Modeling) is a numerical model developed to simulate free surface flows in complex environmental domains. It is based on the depth-averaged St. Venant equations, which are discretized using unstructured upwind finite volume methods, and contains both steady and unsteady solution techniques. This article provides a brief description of the numerical approach selected to discretize the governing equations in space and time, including important aspects of solving natural environmental flows, such as the wetting and drying algorithm. The presentation is illustrated with several application examples, covering both laboratory and natural river flow cases, which show the model’s ability to solve complex flow phenomena.

Simulation of physical and chemical processes in support of space missions

NASA Astrophysics Data System (ADS)

Kochan, H.; Sears, D.; Colangeli, L.; Ehrenfreund, P.

For many years, phenomena on planetary surfaces have been simulated under space conditions on Earth-bound laboratories. In a six-year program at the German Aerospace Center, Cologne, phenomena on cometary surfaces were studied and provided new insights that enhanced the data from space missions. Similar simulation techniques are being applied in a new research program at DLR in preparation for the rendezvous of the Rosetta space craft with comet Wirtanen at 3 A.U and for the Mars Express mission with the British Beagle 2 lander which will search for traces of life. The Arkansas-Oklahoma Center for Space and Planetary Sciences is preparing to conduct experiments that will aid in the interpretation of images from Mars orbiters in terms of fluid and dust storm processes and help design instrumentation for deployment on Mars. Of particular interest is the question of the present location of the water that was apparently once abundant on Mars. Additional experiments at the new U.S. facility will help interpret images of Eros obtained by the NEAR spacecraft and to prepare for future sample return missions to near-Earth asteroids while providing fundamental insights into regolith mechanics and regolith- atmosphere interactions. The activities in the Cosmic Physics Laboratory of Naples are focused on the simulation of materials and processes active in space in the perspective of studying how physical and chemical properties of cosmic relevant species evolve depending on environmental conditions. This approach is complemented by investigation on actual extraterrestrial samples, such as meteorites and interplanetary dust particles. The approach is useful to characterize the performances of space instruments for remote and/or in -situ exploration of Solar System bodies, also in the view of searching features of exobiological relevance. One of the key objectives of the Soft matter/Astrobiology laboratory at Leiden University is to study the formation, evolution and survival of organic molecules in space and their delivery to the early planets via comets and meteorites in support of current and future space missions. For this purpose a simulation chamber has been recently equipped at the European Space Agency which is testing the behaviour or organics on the Martian surface and their implications for extinct and extant life on Mars.

Space Environmental Effects on Colored Coatings and Anodizes

NASA Technical Reports Server (NTRS)

Kamenetzky, Rachel R.; Finckenor, Miria M.; Vaughn, Jason A.

1999-01-01

Colored coatings and anodizes are used on spacecraft as markers and astronaut visual aids. These materials must be stable in the space environment and withstand atomic oxygen, ultraviolet radiation, particulate radiation, thermal cycling, and high vacuum without significant change in optical and mechanical properties. A variety of colored coatings and anodizes have been exposed to simulated space environments at Marshall Space Flight Center and also actual space environment as part of the Passive Optical Sample Assembly (POSA) - I flight experiment. Colored coatings were developed by AZ Technology, Huntsville, AL, under a NASA contract for International Space Station (ISS). These include yellow, red, blue, and black paints suitable for Extra-Vehicular Activity (EVA) visual aids and ISS emblems. AaChron, Inc., Minneapolis, MN, developed stable colored anodizes, also in yellow, red, blue, and black, for astronaut visual aids. These coatings were exposed in the laboratory to approximately 550 equivalent sun-hours of solar ultraviolet radiation and approximately 1 x 10(exp 21) atoms/sq cm of atomic oxygen in vacuum. The AZ Technology yellow colored coating, designated TMS800IY, and all four AaChron colored anodizes were flown on POSA-I. POSA-I was a Risk Mitigation Experiment for ISS. It was attached to the exterior of the Mir space station docking module by EVA and was exposed for 18 months. The laboratory-simulated space environment, the natural space environment and the unique environment of an orbiting, active space station and their effects on these developmental materials are discussed.

Growth of pea epicotyl in low magnetic field: implication for space research.

PubMed

Negishi, Y; Hashimoto, A; Tsushima, M; Dobrota, C; Yamashita, M; Nakamura, T

1999-01-01

A magnetic field is an inescapable environmental factor for plants on the earth. However, its impact on plant growth is not well understood. In order to survey how magnetic fields affect plant, Alaska pea seedlings were incubated under low magnetic field (LMF) and also in the normal geo-magnetic environment. Two-day-old etiolated seedlings were incubated in a magnetic shield box and in a control box. Sedimentation of amyloplasts was examined in the epicotyls of seedlings grown under these two conditions. The elongation of epicotyls was promoted by LMF. Elongation was most prominent in the middle part of the epicotyls. Cell elongation and increased osmotic pressure of cell sap were found in the epidermal cells exposed to LMF. When the gravitational environment was 1G, the epicotyls incubated under both LMF and normal geomagnetic field grew straight upward and amyloplasts sedimented similarly. However, under simulated microgravity (clinostat), epicotyl and cell elongation was promoted. Furthermore, the epicotyls bent and amyloplasts were dispersed in the cells in simulated microgravity. The dispersion of amyloplasts may relate to the posture control in epicotyl growth under simulated microgravity generated by 3D clinorotation, since it was not observed under LMF in 1G. Since enhanced elongation of cells was commonly seen both at LMF and in simulated microgravity, all elongation on the 3D-clinostat could result from pseudo-low magnetic field, as a by-product of clinorotation. (i.e., clinostat results could be based on randomization of magnetic field together with randomization of gravity vector.) Our results point to the possible use of space for studies in magnetic biology. With space experiments, the effects of dominant environmental factors, such as gravity on plants, could be neutralized or controlled for to reveal magnetic effects more clearly. c1999 COSPAR. Published by Elsevier Science Ltd.

Combined Effects of Simulated Microgravity and Radiation Exposure on Osteoclast Cell Fusion.

PubMed

Shanmugarajan, Srinivasan; Zhang, Ye; Moreno-Villanueva, Maria; Clanton, Ryan; Rohde, Larry H; Ramesh, Govindarajan T; Sibonga, Jean D; Wu, Honglu

2017-11-18

The loss of bone mass and alteration in bone physiology during space flight are one of the major health risks for astronauts. Although the lack of weight bearing in microgravity is considered a risk factor for bone loss and possible osteoporosis, organisms living in space are also exposed to cosmic radiation and other environmental stress factors. As such, it is still unclear as to whether and by how much radiation exposure contributes to bone loss during space travel, and whether the effects of microgravity and radiation exposure are additive or synergistic. Bone is continuously renewed through the resorption of old bone by osteoclast cells and the formation of new bone by osteoblast cells. In this study, we investigated the combined effects of microgravity and radiation by evaluating the maturation of a hematopoietic cell line to mature osteoclasts. RAW 264.7 monocyte/macrophage cells were cultured in rotating wall vessels that simulate microgravity on the ground. Cells under static 1g or simulated microgravity were exposed to γ rays of varying doses, and then cultured in receptor activator of nuclear factor-κB ligand (RANKL) for the formation of osteoclast giant multinucleated cells (GMCs) and for gene expression analysis. Results of the study showed that radiation alone at doses as low as 0.1 Gy may stimulate osteoclast cell fusion as assessed by GMCs and the expression of signature genes such as tartrate resistant acid phosphatase ( Trap ) and dendritic cell-specific transmembrane protein ( Dcstamp ). However, osteoclast cell fusion decreased for doses greater than 0.5 Gy. In comparison to radiation exposure, simulated microgravity induced higher levels of cell fusion, and the effects of these two environmental factors appeared additive. Interestingly, the microgravity effect on osteoclast stimulatory transmembrane protein ( Ocstamp ) and Dcstamp expressions was significantly higher than the radiation effect, suggesting that radiation may not increase the synthesis of adhesion molecules as much as microgravity.

Comparison of Observed Beta Cloth Interactions with Simulated and Actual Space Environment

NASA Technical Reports Server (NTRS)

Kamenetzy, R. R.; Finckenor, M. M.

1999-01-01

A common component of multilayer insulation blankets is beta cloth, a woven fiberglass cloth impregnated with Teflon(TM). It is planned for extensive use on the International Space Station. The Environmental Etl'ects Group of the Marshall Space Flight Center Materials, Processing, and Manufacturing Department has investigated the impact of atomic oxygen (AO) and ultraviolet (UV) radiation on the optical properties of plain and aluminized beta cloth. both in the laboratory and as part of long-duration flight experiments. These investigations indicate that beta cloth is susceptible to darkening in the presence of UV radiation, dependent on the additives used. AO interactions resulted in bleaching of the beta cloth.

Upgrades to Electronic Speckle Interferometer (ESPI) Operation and Data Analysis at NASA's Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Connelly, Joseph; Blake, Peter; Jones, Joycelyn

2008-01-01

The authors report operational upgrades and streamlined data analysis of a commissioned electronic speckle interferometer (ESPI) in a permanent in-house facility at NASA's Goddard Space Flight Center. Our ESPI was commercially purchased for use by the James Webb Space Telescope (JWST) development team. We have quantified and reduced systematic error sources, improved the software operability with a user-friendly graphic interface, developed an instrument simulator, streamlined data analysis for long-duration testing, and implemented a turn-key approach to speckle interferometry. We also summarize results from a test of the JWST support structure (previously published), and present new results from several pieces of test hardware at various environmental conditions.

Simulation of Martian dust accumulation on surfaces

NASA Technical Reports Server (NTRS)

Perez-Davis, Marla E.; Gaier, James R.; Kress, Robert; Grimalda, Justus

1990-01-01

Future NASA space missions include the possibility of manned landings and exploration of Mars. Environmental and operational constraints unique to Mars must be considered when selecting and designing the power system to be used on the Mars surface. A technique is described which was developed to simulate the deposition of dust on surfaces. Three kinds of dust materials were studied: aluminum oxide, basalt, and iron oxide. The apparatus was designed using the Stokes and Stokes-Cunningham law for particle fallout, with additional consideration given to particle size and shape. Characterization of the resulting dust films on silicon dioxide, polytetrafluoroethylene, indium tin oxide, diamondlike carbon, and other surfaces are discussed based on optical transmittance measurements. The results of these experiments will guide future studies which will consider processes to remove the dust from surfaces under Martian environmental conditions.

Reproduction in the space environment: Part I. Animal reproductive studies

NASA Technical Reports Server (NTRS)

Santy, P. A.; Jennings, R. T.; Craigie, D.

1990-01-01

Mankind's exploration and colonization of the frontier of space will ultimately depend on men's and women's ability to live, work, and reproduce in the space environment. This paper reviews animal studies, from microorganisms to mammals, done in space or under space-simulated conditions, which identify some of the key areas which might interfere with human reproductive physiology and/or embryonic development. Those space environmental factors which impacted almost all species included: microgravity, artificial gravity, radiation, and closed life support systems. These factors may act independently and in combination to produce their effects. To date, there have been no studies which have looked at the entire process of reproduction in any animal species. This type of investigation will be critical in understanding and preventing the problems which will affect human reproduction. Part II will discuss these problems directly as they relate to human physiology.

Marshall Space Flight Center's Impact Testing Facility Capabilities

NASA Technical Reports Server (NTRS)

Evans, Steve; Finchum, Andy; Hubbs, Whitney; Gray, Perry

2008-01-01

Marshall Space Flight Center's (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960s, then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California, The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility's unique capabilities were deemed a 'National Asset' by the DoD, The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Relocated test equipment was dated and in need of upgrade. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. Future ITF improvements will be focused on continued instrumentation and performance enhancements. These enhancements will allow further, more in-depth, characterization of rain drop demise characterization and evaluation of ice crystal impact. Performance enhancements also include increasing the upper velocity limit of the current environmental guns to allow direct environmental simulation for missile components. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas guns, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

Marshall Space Flight Center's Impact Testing Facility Capabilities

NASA Technical Reports Server (NTRS)

Evans, Steve; Finchum, Andy; Hubbs, Whitney

2008-01-01

Marshall Space Flight Center's (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960% then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California. The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility's unique capabilities were deemed a "National Asset" by the DoD. The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Relocated test equipment was dated and in need of upgrade. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. Future ITF improvements will be focused on continued instrumentation and performance enhancements. These enhancements will allow further, more in-depth, characterization of rain drop demise characterization and evaluation of ice crystal impact. Performance enhancements also include increasing the upper velocity limit of the current environmental guns to allow direct environmental simulation for missile components. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas grins, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

Correlated seed failure as an environmental veto to synchronize reproduction of masting plants.

PubMed

Bogdziewicz, Michał; Steele, Michael A; Marino, Shealyn; Crone, Elizabeth E

2018-07-01

Variable, synchronized seed production, called masting, is a widespread reproductive strategy in plants. Resource dynamics, pollination success, and, as described here, environmental veto are possible proximate mechanisms driving masting. We explored the environmental veto hypothesis, which assumes that reproductive synchrony is driven by external factors preventing reproduction in some years, by extending the resource budget model of masting with correlated reproductive failure. We ran this model across its parameter space to explore how key parameters interact to drive seeding dynamics. Next, we parameterized the model based on 16 yr of seed production data for populations of red (Quercus rubra) and white (Quercus alba) oaks. We used these empirical models to simulate seeding dynamics, and compared simulated time series with patterns observed in the field. Simulations showed that resource dynamics and reproduction failure can produce masting even in the absence of pollen coupling. In concordance with this, in both oaks, among-year variation in resource gain and correlated reproductive failure were necessary and sufficient to reproduce masting, whereas pollen coupling, although present, was not necessary. Reproductive failure caused by environmental veto may drive large-scale synchronization without density-dependent pollen limitation. Reproduction-inhibiting weather events are prevalent in ecosystems, making described mechanisms likely to operate in many systems. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

Utility of an emulation and simulation computer model for air revitalization system hardware design, development, and test

NASA Technical Reports Server (NTRS)

Yanosy, J. L.; Rowell, L. F.

1985-01-01

Efforts to make increasingly use of suitable computer programs in the design of hardware have the potential to reduce expenditures. In this context, NASA has evaluated the benefits provided by software tools through an application to the Environmental Control and Life Support (ECLS) system. The present paper is concerned with the benefits obtained by an employment of simulation tools in the case of the Air Revitalization System (ARS) of a Space Station life support system. Attention is given to the ARS functions and components, a computer program overview, a SAND (solid amine water desorbed) bed model description, a model validation, and details regarding the simulation benefits.

Cognitive Neuroscience in Space

PubMed Central

De la Torre, Gabriel G.

2014-01-01

Humans are the most adaptable species on this planet, able to live in vastly different environments on Earth. Space represents the ultimate frontier and a true challenge to human adaptive capabilities. As a group, astronauts and cosmonauts are selected for their ability to work in the highly perilous environment of space, giving their best. Terrestrial research has shown that human cognitive and perceptual motor performances deteriorate under stress. We would expect to observe these effects in space, which currently represents an exceptionally stressful environment for humans. Understanding the neurocognitive and neuropsychological parameters influencing space flight is of high relevance to neuroscientists, as well as psychologists. Many of the environmental characteristics specific to space missions, some of which are also present in space flight simulations, may affect neurocognitive performance. Previous work in space has shown that various psychomotor functions degrade during space flight, including central postural functions, the speed and accuracy of aimed movements, internal timekeeping, attentional processes, sensing of limb position and the central management of concurrent tasks. Other factors that might affect neurocognitive performance in space are illness, injury, toxic exposure, decompression accidents, medication side effects and excessive exposure to radiation. Different tools have been developed to assess and counteract these deficits and problems, including computerized tests and physical exercise devices. It is yet unknown how the brain will adapt to long-term space travel to the asteroids, Mars and beyond. This work represents a comprehensive review of the current knowledge and future challenges of cognitive neuroscience in space from simulations and analog missions to low Earth orbit and beyond. PMID:25370373

Status of the Correlation Process of the V-HAB Simulation with Ground Tests and ISS Telemetry Data

NASA Technical Reports Server (NTRS)

Ploetner, P.; Roth, C.; Zhukov, A.; Czupalla, M.; Anderson, M.; Ewert, M.

2013-01-01

The Virtual Habitat (V-HAB) is a dynamic Life Support System (LSS) simulation, created for investigation of future human spaceflight missions. It provides the capability to optimize LSS during early design phases. The focal point of the paper is the correlation and validation of V-HAB against ground test and flight data. In order to utilize V-HAB to design an Environmental Control and Life Support System (ECLSS) it is important to know the accuracy of simulations, strengths and weaknesses. Therefore, simulations of real systems are essential. The modeling of the International Space Station (ISS) ECLSS in terms of single technologies as well as an integrated system and correlation against ground and flight test data is described. The results of the simulations make it possible to prove the approach taken by V-HAB.

Evolution of space food in Nostoc sp. HK-01

NASA Astrophysics Data System (ADS)

Tomita-Yokotani, Kaori; Yamashita, Masamichi; Hashimoto, Hirofumi; Sato, Seigo; Kimura, Yasuko; Katoh, Hiroshi; Arai, Mayumi

2012-07-01

Habitation in outer space is one of our challenges. We have been studying future space agriculture to provide food and oxygen for the habitation area in the space environment, on Mars. A cyanobacteria, Nostoc sp. HK-01, has high several outer space environmental tolerance. We have already confirmed that Nostoc sp.HK-01 had an ability to grow for over several years on the Martian regolith simulant in a laboratory experiment. Nostoc sp HK-01 would have high contribution to change the atmosphere in Mars as a photosynthetic creature. In outer environment, all of materials have to circulate for all of creature living in artificial eco-systems on Mars. This material has several functions as the utilization in space agriculture. Here, we are proposing using them as a food after its growing on Mars. We are trying to determine the best conditions and evolution for space food using Nostoc sp.HK-01 and studying the proposal of utilization of cyanobacteria, Nostoc sp HK-01, for the variation of meal as space agriculture.

A new approach for data acquisition at the JPL space simulators

NASA Technical Reports Server (NTRS)

Fisher, Terry C.

1992-01-01

In 1990, a personal computer based data acquisition system was put into service for the Space Simulators and Environmental Test Laboratory at the Jet Propulsion Laboratory (JPL) in Pasadena, California. The new system replaced an outdated minicomputer system which had been in use since 1980. This new data acquisition system was designed and built by JPL for the specific task of acquiring thermal test data in support of space simulation and thermal vacuum testing at JPL. The data acquisition system was designed using powerful personal computers and local-area-network (LAN) technology. Reliability, expandability, and maintainability were some of the most important criteria in the design of the data system and in the selection of hardware and software components. The data acquisition system is used to record both test chamber operational data and thermal data from the unit under test. Tests are conducted in numerous small thermal vacuum chambers and in the large solar simulator and range in size from individual components using only 2 or 3 thermocouples to entire planetary spacecraft requiring in excess of 1200 channels of test data. The system supports several of these tests running concurrently. The previous data system is described along with reasons for its replacement, the types of data acquired, the new data system, and the benefits obtained from the new system including information on tests performed to date.

Species sorting and patch dynamics in harlequin metacommunities affect the relative importance of environment and space.

PubMed

Leibold, Mathew A; Loeuille, Nicolas

2015-12-01

Metacommunity theory indicates that variation in local community structure can be partitioned into components including those related to local environmental conditions vs. spatial effects and that these can be quantified using statistical methods based on variation partitioning. It has been hypothesized that joint associations of community composition with environment and space could be due to patch dynamics involving colonization-extinction processes in environmentally heterogeneous landscapes but this has yet to be theoretically shown. We develop a two-patch, type-two, species competition model in such a "harlequin" landscape (where different patches have different environments) to evaluate how composition is related to environmental and spatial effects as a function of background extinction rate. Using spatially implicit analytical models, we find that the environmental association of community composition declines with extinction rate as expected. Using spatially explicit simulation models, we further find that there is an increase in the spatial structure with extinction due to spatial patterning into clusters that are not related to environmental conditions but that this increase is limited. Natural metacommunities often show both environment and spatial determination even under conditions of relatively high isolation and these could be more easily explained by our model than alternative metacommunity models.

Space Environmental Effects Testing and Characterization of the Candidate Solar Sail Material Aluminized Mylar

NASA Technical Reports Server (NTRS)

Edwards, D. L.; Hubbs, W. S.; Wertz, G. E.; Alstatt, R.; Munafo, Paul (Technical Monitor)

2001-01-01

The usage of solar sails as a propellantless propulsion system has been proposed for many years. The technical challenges associated with solar sails are fabrication of ultralightweight films, deploying the sails and controlling the spacecraft. Integral to all these challenges is the mechanical property integrity of the sail while exposed to the harsh environment of space. This paper describes testing and characterization of a candidate solar sail material, Aluminized Mylar. This material was exposed to a simulated Geosynchronous Transfer Orbit (GTO) and evaluated by measuring thermooptical and mechanical property changes. Testing procedures and results are presented.

Space Environmental Testing of the Electrodynamic Dust Shield Technology

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Mackey, P. J.; Hogue, M. D.; Johansen, M .R.; Yim, H.; Delaune, P. B.; Clements, J. S.

2013-01-01

NASA's exploration missions to Mars and the moon may be jeopardized by dust that will adhere to surfaces of (a) Optical systems, viewports and solar panels, (b) Thermal radiators, (c) Instrumentation, and (d) Spacesuits. We have developed an active dust mitigation technology, the Electrodynamic Dust Shield, a multilayer coating that can remove dust and also prevents its accumulation Extensive testing in simulated laboratory environments and on a reduced gravity flight shows that high dust removal performance can be achieved Long duration exposure to the space environment as part of the MISSE-X payload will validate the technology for lunar missions.

Evaluation and prediction of long-term environmental effects of nonmetallic materials

NASA Technical Reports Server (NTRS)

Papazian, H.

1985-01-01

The properties of a number of nonmetallic materials were evaluated experimentally in simulated space environments in order to develop models for accelerated test methods useful for predicting such behavioral changes. Graphite-epoxy composites were exposed to thermal cycling. Adhesive foam tapes were subjected to a vacuum environment. Metal-matrix composites were tested for baseline data. Predictive modeling designed to include strength and aging effects on composites, polymeric films, and metals under such space conditions (including the atomic oxygen environment) is discussed. The Korel 8031-00 high strength adhesive foam tape was shown to be superior to the other two tested.

Impact of space environment on stability of medicines: Challenges and prospects.

PubMed

Mehta, Priti; Bhayani, Dhara

2017-03-20

To upkeep health of astronauts in a unique, isolated, and extreme environment of space is the primary goal for a successful space mission, hence, safe and efficacious medications are essential for the wellness of astronauts. Space medication has been challenged with problems related to efficacy. Along with altered physiology, one of the possible reasons could be instability of space medications in the presence of harsh spaceflight environmental conditions. Altered physical and chemical stability can result in reduced potency which can result in reduced efficacy. Right now, medicines from the International Space Station are replaced before their expiration. But, for longer duration missions to Mars or any other asteroid, there will not be any chance of replacement of medicines. Hence, it is desired that medicines maintain the shelf-life throughout the space mission. Stability of medicines used for short term or long term space missions cannot be judged by drug stability guidelines based on terrestrial environmental factors. Unique environmental conditions related to spaceflight include microgravity, excessive vibration, hard vacuum, humidity variation, temperature differences and excessive radiation, which may cause instability of medicines. This write-up provides a review of the problem and countermeasure approaches for pharmaceuticals exposed to the space environment. The first part of the article discusses thought processes behind outlining of International Conference on Harmonization drug stability guidelines, Q1A (R2) and Q1B, and its acceptance limits for accelerated stability study. The second part of the article describes the difference in the radiation environment of deep space compared to radiation environment inside the space shuttle based on penetration power of different types of radiation. In the third part of the article, various promising approaches are listed which can be used for assurance of space medicine stability. One of the approaches is the use of ground-based space simulation analogues and statistical treatment to data to calculate failure rate of drugs and probabilistic risk assessment. Another approach is to innovate storage and packaging technology using radiation harden polymer or using cryogenic temperatures. Copyright © 2017 Elsevier B.V. All rights reserved.

An Astrobiological Experiment to Explore the Habitability of Tidally Locked M-Dwarf Planets

NASA Astrophysics Data System (ADS)

Angerhausen, Daniel; Sapers, Haley; Simoncini, Eugenio; Lutz, Stefanie; Alexandre, Marcelo da Rosa; Galante, Douglas

2014-04-01

We present a summary of a three-year academic research proposal drafted during the Sao Paulo Advanced School of Astrobiology (SPASA) to prepare for upcoming observations of tidally locked planets orbiting M-dwarf stars. The primary experimental goal of the suggested research is to expose extremophiles from analogue environments to a modified space simulation chamber reproducing the environmental parameters of a tidally locked planet in the habitable zone of a late-type star. Here we focus on a description of the astronomical analysis used to define the parameters for this climate simulation.

Advanced Exploration Systems Atmosphere Resource Recovery and Environmental Monitoring

NASA Technical Reports Server (NTRS)

Perry, J.; Abney, M.; Conrad, R.; Garber, A.; Howard, D.; Kayatin, M.; Knox, J.; Newton, R.; Parrish, K.; Roman, M.;

Lightweight Ablative and Ceramic Thermal Protection System Materials for NASA Exploration Systems Vehicles

NASA Technical Reports Server (NTRS)

Valentine, Peter G.; Lawrence, Timothy W.; Gubert, Michael K.; Milos, Frank S.; Kiser, James D.; Ohlhorst, Craig W.; Koenig, John R.

2006-01-01

As a collaborative effort among NASA Centers, the "Lightweight Nonmetallic Thermal Protection Materials Technology" Project was set up to assist mission/vehicle design trade studies, to support risk reduction in thermal protection system (TPS) material selections, to facilitate vehicle mass optimization, and to aid development of human-rated TPS qualification and certification plans. Missions performing aerocapture, aerobraking, or direct aeroentry rely on advanced heatshields that allow reductions in spacecraft mass by minimizing propellant requirements. Information will be presented on candidate materials for such reentry approaches and on screening tests conducted (material property and space environmental effects tests) to evaluate viable candidates. Seventeen materials, in three classes (ablatives, tiles, and ceramic matrix composites), were studied. In additional to physical, mechanical, and thermal property tests, high heat flux laser tests and simulated-reentry oxidation tests were performed. Space environmental effects testing, which included exposures to electrons, atomic oxygen, and hypervelocity impacts, was also conducted.

Environmentally stable all-PM all-fiber giant chirp oscillator.

PubMed

Erkintalo, Miro; Aguergaray, Claude; Runge, Antoine; Broderick, Neil G R

2012-09-24

We report on an environmentally stable giant chirp oscillator operating at 1030 nm. Thanks to the use of a nonlinear amplifying loop mirror as the mode-locker, we are able to extract pulse energies in excess of 10 nJ from a robust all-PM cavity with no free-space elements. Extensive numerical simulations reveal that the output oscillator energy and duration can simply be up-scaled through the lengthening of the cavity with suitably positioned single-mode fiber. Experimentally, using different cavity lengths we have achieved environmentally stable mode-locking at 10, 3.7 and 1.7 MHz with corresponding pulse energies of 2.3, 10 and 16 nJ. In all cases external grating-pair compression below 400 fs has been demonstrated.

Reflectivity of the AL-N coating: results of mechanical and environmental tests

NASA Astrophysics Data System (ADS)

Anisimov, Vladimir P.; Anisimova, Irina A.; Kashirin, Victor A.; Moldosanov, Kamil A.; Skrynnikov, Alexander M.

2002-09-01

This paper concerns a behavior of the total hemispherical reflectance (THR) of the Al-N coating in the course of mechanical and environmental tests. The Al-N coating has been designed to reduce the stray sunlight background in the satellite-borne optical instruments and charge-particles-analyzing apparatus operating in open space under intensive solar radiation. Usually, this problem arises when a density of instruments installed on the satellite is high and it is difficult to avoid getting to instrument the light reflected by neighboring devices. Resolution of this problem is also important in connection with development of the extra-atmosphere Far UV astronomy. The THR measurement results are presented for 10 wavelengths wihtin a range from 400 to 927 nm, and also at 121.6 nm, the most intensive line of the solar UV spectrum able to result in considerable contribution to the detector noise in space devices. The samples of the Al-N coating were exposed to standard mechanical loads including the vibratory loads, linear overloads, and impacts, to which the space equipment may be subjected when shipping to the space-vehicle launching site and also when lauching. The samples were also exposed to environmental tests simulating the vacuum, humidity, and cyclic temperature conditions, which may influence the space instruments while shipping, storing, launching, in flight, and under operating conditions. The THR measurements of the samples were made following exposure to each test. The THRs of tested samples at the wavelength of 121.6 nm were as low as 1.5-2%.

Thermal performance of gaseous-helium-purged tank-mounted multilayer insulation system during ground-hold and space-hold thermal cycling and exposure to water vapor

NASA Technical Reports Server (NTRS)

Sumner, I. E.

1978-01-01

An experimental investigation was conducted to determine (1) the ground-hold and space-hold thermal performance of a multilayer insulation (MLI) system mounted on a spherical, liquid-hydrogen propellant tank and (2) the degradation to the space-hold thermal performance of the insulation system that resulted from both thermal cycling and exposure to moisture. The propellant tank had a diameter of 1.39 meters (4.57ft). The MLI consisted of two blankets of insulation; each blanket contained 15 double-aluminized Mylar radiation shields separated by double silk net spacers. Nineteen tests simulating basic cryogenic spacecraft thermal (environmental) conditions were conducted. These tests typically included initial helium purge, liquid-hydrogen fill and ground-hold, ascent, space-hold, and repressurization. No significant degradation of the space-hold thermal performance due to thermal cycling was noted.

Environmentally-induced voltage limitations in large space power systems

NASA Technical Reports Server (NTRS)

Stevens, N. J.

1984-01-01

Large power systems proposed for future space missions imply higher operating voltage requirements which, in turn, will interact with the space plasma environment. The effects of these interactions can only be inferred because of the limited data base of ground simulations, small test samples, and two space flight experiments. This report evaluates floating potentials for a 100 kW power system operating at 300, 500, 750, and 1000 volts in relation to this data base. Of primary concern is the possibility of discharging to space. The implications of such discharges were studied at the 500 volt operational setting. It was found that discharging can shut down the power system if the discharge current exceeds the array short circuit current. Otherwise, a power oscillation can result that ranges from 2 to 20 percent, depending upon the solar array area involved in the discharge. Means of reducing the effect are discussed.

Use of Human Modeling Simulation Software in the Task Analysis of the Environmental Control and Life Support System Component Installation Procedures

NASA Technical Reports Server (NTRS)

Estes, Samantha; Parker, Nelson C. (Technical Monitor)

2001-01-01

Virtual reality and simulation applications are becoming widespread in human task analysis. These programs have many benefits for the Human Factors Engineering field. Not only do creating and using virtual environments for human engineering analyses save money and time, this approach also promotes user experimentation and provides increased quality of analyses. This paper explains the human engineering task analysis performed on the Environmental Control and Life Support System (ECLSS) space station rack and its Distillation Assembly (DA) subsystem using EAI's human modeling simulation software, Jack. When installed on the International Space Station (ISS), ECLSS will provide the life and environment support needed to adequately sustain crew life. The DA is an Orbital Replaceable Unit (ORU) that provides means of wastewater (primarily urine from flight crew and experimental animals) reclamation. Jack was used to create a model of the weightless environment of the ISS Node 3, where the ECLSS is housed. Computer aided drawings of the ECLSS rack and DA system were also brought into the environment. Anthropometric models of a 95th percentile male and 5th percentile female were used to examine the human interfaces encountered during various ECLSS and DA tasks. The results of the task analyses were used in suggesting modifications to hardware and crew task procedures to improve accessibility, conserve crew time, and add convenience for the crew. This paper will address some of those suggested modifications and the method of presenting final analyses for requirements verification.

Results of the Simulation and Assimilation of Doppler Wind Lidar Observations in Preparation for European Space Agency's Aeolus Mission

NASA Technical Reports Server (NTRS)

McCarty, Will

2011-01-01

With the launch of the European Space Agency's Aeolus Mission in 2013, direct spaceborne measurements of vertical wind profiles are imminent via Doppler wind lidar technology. Part of the preparedness for such missions is the development of the proper data assimilation methodology for handling such observations. Since no heritage measurements exist in space, the Joint Observing System Simulation Experiment (Joint OSSE) framework has been utilized to generate a realistic proxy dataset as a precursor to flight. These data are being used for the development of the Gridpoint Statistical Interpolation (GSI) data assimilation system utilized at a number of centers through the United States including the Global Modeling and Assimilation Office (GMAO) at NASA/Goddard Space Flight Center and at the National Centers for Environmental Prediction (NOAA/NWS/NCEP) as an activity through the Joint Center for Satellite Data Assimilation. An update of this ongoing effort will be presented, including the methodology of proxy data generation, the limitations of the proxy data, the handling of line-of-sight wind measurements within the GSI, and the impact on both analyses and forecasts with the addition of the new data type.

A study on resistance to ultraviolet radiation of POSS-TiO2/epoxy nanocomposites

NASA Astrophysics Data System (ADS)

Peng, Dequn; Qin, Wei; Wu, Xiaohong

2015-06-01

Ultraviolet (UV) radiation is a severe space environmental factor, which is harmful to the durability of the polymeric materials of the spacecraft. For this reason, a novel POSS-TiO2/EP nanocomposite was synthesized by incorporating the POSS-TiO2 organic-inorganic hybrid into the epoxy (EP) resin. The effects of UV radiation on EP resin and on POSS-TiO2/EP nanocomposites were investigated in a ground-based simulator that simulates space radiation conditions. Compared with EP resin, the value of bend strength for 5.0 wt% POSS-TiO2/EP varied in a small range before and after UV radiation. Meanwhile, a typical tough feature was observed from the SEM photo for POSS-TiO2/EP nanocomposite after UV exposure. This result indicated that the POSS-TiO2/EP exhibited the excellent properties of anti-space ultraviolet radiation. The thermo gravimetric (TG) results showed that the addition of POSS-TiO2 improved the thermal-stability of EP resin matrix. The synthesized nanocomposites in this work could be used in the satellites to enhance their adaptability to the space environment and extend their service life.

Space Weathering Experiments on Spacecraft Materials

NASA Technical Reports Server (NTRS)

Engelhart, D. P.; Cooper, R.; Cowardin, H.; Maxwell, J.; Plis, E.; Ferguson, D.; Barton, D.; Schiefer, S.; Hoffmann, R.

2017-01-01

A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers found in multi-layered spacecraft insulation (MLI) induced by electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons like those seen in orbit. These chemical changes have been shown to alter a material's optical reflectance, among other material properties. This paper presents the initial experimental results of MLI materials exposed to various fluences of high energy electrons, designed to simulate a portion of the geosynchronous Earth orbit (GEO) space environment. It is shown that the spectral reflectance of some of the tested materials changes as a function of electron dose. These results provide an experimental benchmark for analysis of aging effects on satellite systems which can be used to improve remote sensing and space situational awareness. They also provide preliminary analysis on those materials that are most likely to comprise the high area-to-mass ratio (HAMR) population of space debris in the geosynchronous orbit environment. Finally, the results presented in this paper serve as a proof of concept for simulated environmental aging of spacecraft polymers that should lead to more experiments using a larger subset of spacecraft materials.

JAMS - a software platform for modular hydrological modelling

NASA Astrophysics Data System (ADS)

Kralisch, Sven; Fischer, Christian

2015-04-01

Current challenges of understanding and assessing the impacts of climate and land use changes on environmental systems demand for an ever-increasing integration of data and process knowledge in corresponding simulation models. Software frameworks that allow for a seamless creation of integrated models based on less complex components (domain models, process simulation routines) have therefore gained increasing attention during the last decade. JAMS is an Open-Source software framework that has been especially designed to cope with the challenges of eco-hydrological modelling. This is reflected by (i) its flexible approach for representing time and space, (ii) a strong separation of process simulation components from the declarative description of more complex models using domain specific XML, (iii) powerful analysis and visualization functions for spatial and temporal input and output data, and (iv) parameter optimization and uncertainty analysis functions commonly used in environmental modelling. Based on JAMS, different hydrological and nutrient-transport simulation models were implemented and successfully applied during the last years. We will present the JAMS core concepts and give an overview of models, simulation components and support tools available for that framework. Sample applications will be used to underline the advantages of component-based model designs and to show how JAMS can be used to address the challenges of integrated hydrological modelling.

Phoenix Lowered into Thermal Vacuum Chamber

NASA Technical Reports Server (NTRS)

2007-01-01

NASA's Phoenix Mars Lander was lowered into a thermal vacuum chamber at Lockheed Martin Space Systems, Denver, in December 2006.

The spacecraft was folded in its aeroshell and underwent environmental testing that simulated the extreme conditions the spacecraft will see during its nine-and-a-half-month cruse to Mars.

The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

Simulated space environmental effects on a polyetherimide and its carbon fiber-reinforced composites

NASA Technical Reports Server (NTRS)

Kern, Kristen T.; Stancil, Phillip C.; Harries, Wynford L.; Long, Edward R., Jr.; Thibeault, Sheila A.

1993-01-01

The selection of materials for spacecraft construction requires identification of candidate materials which can perform reliably in the space environment. Understanding the effects of the space environment on the materials is an important step in the selection of candidate materials. This work examines the effects of energetic electrons, thermal cycling, electron radiation in conjunction with thermal cycling, and atomic oxygen on a thermoplastic polyetherimide and its carbon-fiber-reinforced composites. Composite materials made with non-sized fibers as well as materials made with fibers sized with an epoxy were evaluated. The mechanical and thermomechanical properties of the materials were studied and spectroscopic techniques were used to investigate the mechanisms for the observed effects. Considerations for future material development are suggested.

Ion implantation effects in 'cosmic' dust grains

NASA Technical Reports Server (NTRS)

Bibring, J. P.; Langevin, Y.; Maurette, M.; Meunier, R.; Jouffrey, B.; Jouret, C.

1974-01-01

Cosmic dust grains, whatever their origin may be, have probably suffered a complex sequence of events including exposure to high doses of low-energy nuclear particles and cycles of turbulent motions. High-voltage electron microscope observations of micron-sized grains either naturally exposed to space environmental parameters on the lunar surface or artificially subjected to space simulated conditions strongly suggest that such events could drastically modify the mineralogical composition of the grains and considerably ease their aggregation during collisions at low speeds. Furthermore, combined mass spectrometer and ionic analyzer studies show that small carbon compounds can be both synthesized during the implantation of a mixture of low-energy D, C, N ions in various solids and released in space by ion sputtering.

Mapping analysis and planning system for the John F. Kennedy Space Center

NASA Technical Reports Server (NTRS)

Hall, C. R.; Barkaszi, M. J.; Provancha, M. J.; Reddick, N. A.; Hinkle, C. R.; Engel, B. A.; Summerfield, B. R.

1994-01-01

Environmental management, impact assessment, research and monitoring are multidisciplinary activities which are ideally suited to incorporate a multi-media approach to environmental problem solving. Geographic information systems (GIS), simulation models, neural networks and expert-system software are some of the advancing technologies being used for data management, query, analysis and display. At the 140,000 acre John F. Kennedy Space Center, the Advanced Software Technology group has been supporting development and implementation of a program that integrates these and other rapidly evolving hardware and software capabilities into a comprehensive Mapping, Analysis and Planning System (MAPS) based in a workstation/local are network environment. An expert-system shell is being developed to link the various databases to guide users through the numerous stages of a facility siting and environmental assessment. The expert-system shell approach is appealing for its ease of data access by management-level decision makers while maintaining the involvement of the data specialists. This, as well as increased efficiency and accuracy in data analysis and report preparation, can benefit any organization involved in natural resources management.

Liquid Nitrogen (Oxygen Simulant) Thermodynamic Vent System Test Data Analysis

NASA Technical Reports Server (NTRS)

Hedayat, A.; Nelson, S. L.; Hastings, L. J.; Flachbart, R. H.; Tucker, S. P.

2005-01-01

In designing systems for the long-term storage of cryogens in low-gravity (space) environments, one must consider the effects of thermal stratification on tank pressure that will occur due to environmental heat leaks. During low-gravity operations, a Thermodynamic Vent System (TVS) concept is expected to maintain tank pressure without propellant resettling. A series of TVS tests was conducted at NASA Marshall Space Flight Center (MSFC) using liquid nitrogen (LN2) as a liquid oxygen (LO2) simulant. The tests were performed at tank til1 levels of 90%, 50%, and 25%, and with a specified tank pressure control band. A transient one-dimensional TVS performance program is used to analyze and correlate the test data for all three fill levels. Predictions and comparisons of ullage pressure and temperature and bulk liquid saturation pressure and temperature with test data are presented.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

ARGES: an Expert System for Fault Diagnosis Within Space-Based ECLS Systems

NASA Technical Reports Server (NTRS)

Pachura, David W.; Suleiman, Salem A.; Mendler, Andrew P.

1988-01-01

ARGES (Atmospheric Revitalization Group Expert System) is a demonstration prototype expert system for fault management for the Solid Amine, Water Desorbed (SAWD) CO2 removal assembly, associated with the Environmental Control and Life Support (ECLS) System. ARGES monitors and reduces data in real time from either the SAWD controller or a simulation of the SAWD assembly. It can detect gradual degradations or predict failures. This allows graceful shutdown and scheduled maintenance, which reduces crew maintenance overhead. Status and fault information is presented in a user interface that simulates what would be seen by a crewperson. The user interface employs animated color graphics and an object oriented approach to provide detailed status information, fault identification, and explanation of reasoning in a rapidly assimulated manner. In addition, ARGES recommends possible courses of action for predicted and actual faults. ARGES is seen as a forerunner of AI-based fault management systems for manned space systems.

Behavior of ionic conducting IPN actuators in simulated space conditions

NASA Astrophysics Data System (ADS)

Fannir, Adelyne; Plesse, Cédric; Nguyen, Giao T. M.; Laurent, Elisabeth; Cadiergues, Laurent; Vidal, Frédéric

2016-04-01

The presentation focuses on the performances of flexible all-polymer electroactive actuators under space-hazardous environmental factors in laboratory conditions. These bending actuators are based on high molecular weight nitrile butadiene rubber (NBR), poly(ethylene oxide) (PEO) derivative and poly(3,4-ethylenedioxithiophene) (PEDOT). The electroactive PEDOT is embedded within the PEO/NBR membrane which is subsequently swollen with an ionic liquid as electrolyte. Actuators have been submitted to thermal cycling test between -25 to 60°C under vacuum (2.4 10-8 mbar) and to ionizing Gamma radiations at a level of 210 rad/h during 100 h. Actuators have been characterized before and after space environmental condition ageing. In particular, the viscoelasticity properties and mechanical resistance of the materials have been determined by dynamic mechanical analysis and tensile tests. The evolution of the actuation properties as the strain and the output force have been characterized as well. The long-term vacuuming, the freezing temperature and the Gamma radiations do not affect significantly the thermomechanical properties of conducting IPNs actuators. Only a slight decrease on actuation performances has been observed.

Capabilities of the Materials Contamination Team at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burns, Howard; Albyn, Keith; Edwards, David; Boothe, Richard; Finchum, Charles; Finckenor, Miria

2003-01-01

The Materials Contamination Team at the Marshall Space Flight Center (MSFC) has been recognized for its contributions supporting the National Aeronautics and Space Administration (NASA) spacecraft development programs. These programs include the Reusable Solid Rocket Motor (RSRM), Chandra X-Ray Observatory, and the International Space Station (ISS). The Environmental Effects Group, with the Materials Contamination Team and the Space Environmental Effects Team has been an integral part of NASA's success by the testing, evaluation, and qualification of materials, hardware, and processes. This paper focuses on the capabilities of the Materials Contamination Team. The Materials Contamination Team's realm of responsibility includes establishing contamination control during all phases of hardware development, including design, manufacturing, assembly, test, transportation, launch site processing, on-orbit exposure, return, and refurbishment. The team continues its mission of reducing the risk of equipment failure due to molecular or particulate contamination. Contamination is a concern in the Space Shuttle with sensitive bond-lines and reactive fluid (liquid oxygen) compatibility as well as for spacecraft with sensitive optics, such as Hubble Space Telescope and Chandra X-ray Observatory. The Materials Contamination Team has a variety of facilities and instrumentation capable of contaminant detection, identification, and monitoring. The team addresses material applications dealing with environments, including production facilities, clean rooms, and on-orbit exposure. The optically stimulated electron emission (OSEE) system, the Ultraviolet (UV) fluorescence (UVF) surface contamination detection, and the Surface Optics Corporation 400 (SOC 400) portable hand-held Fourier Transform Infrared (FTIR) spectrometer are state-of-the-art tools for in-process molecular contamination detection. The team of engineers and technicians also develop contamination calibration standards and evaluate new surface cleanliness inspection technologies. The team utilizes facilities for on-orbit simulation testing of materials for outgassing and molecular film deposition characteristics in the presence of space environmental effects, such as Atomic Oxygen (AO) and UV radiation exposure. The Materials Contamination Team maintains databases for process materials as well as outgassing and optical compatibility test results for specific environments.

Technology development program for an advanced microsheet glass concentrator

NASA Technical Reports Server (NTRS)

Richter, Scott W.; Lacy, Dovie E.

1990-01-01

Solar Dynamic Space Power Systems are candidate electrical power generating systems for future NASA missions. One of the key components in a solar dynamic power system is the concentrator which collects the sun's energy and focuses it into a receiver. In 1985, the NASA Lewis Research Center initiated the Advanced Solar Dynamic Concentrator Program with funding from NASA's Office of Aeronautics and Space Technology (OAST). The objectives of the Advanced Concentrator Program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived (7 to 10 years) space solar dynamic concentrators. The Advanced Concentrator Program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. The Advanced Microsheet Glass Concentrator Program, a reflector concept, that is currently being investigated both in-house and under contract is discussed.

Prototype space station automation system delivered and demonstrated at NASA

NASA Technical Reports Server (NTRS)

Block, Roger F.

1987-01-01

The Automated Subsystem Control for Life Support System (ASCLSS) program has successfully developed and demonstrated a generic approach to the automation and control of Space Station subsystems. The hierarchical and distributed real time controls system places the required controls authority at every level of the automation system architecture. As a demonstration of the automation technique, the ASCLSS system automated the Air Revitalization Group (ARG) of the Space Station regenerative Environmental Control and Life Support System (ECLSS) using real-time, high fidelity simulators of the ARG processess. This automation system represents an early flight prototype and an important test bed for evaluating Space Station controls technology including future application of ADA software in real-time control and the development and demonstration of embedded artificial intelligence and expert systems (AI/ES) in distributed automation and controls systems.

Simulating Wake Vortex Detection with the Sensivu Doppler Wind Lidar Simulator

NASA Technical Reports Server (NTRS)

Ramsey, Dan; Nguyen, Chi

2014-01-01

In support of NASA's Atmospheric Environment Safety Technologies NRA research topic on Wake Vortex Hazard Investigation, Aerospace Innovations (AI) investigated a set of techniques for detecting wake vortex hazards from arbitrary viewing angles, including axial perspectives. This technical report describes an approach to this problem and presents results from its implementation in a virtual lidar simulator developed at AI. Threedimensional data volumes from NASA's Terminal Area Simulation System (TASS) containing strong turbulent vortices were used as the atmospheric domain for these studies, in addition to an analytical vortex model in 3-D space. By incorporating a third-party radiative transfer code (BACKSCAT 4), user-defined aerosol layers can be incorporated into atmospheric models, simulating attenuation and backscatter in different environmental conditions and altitudes. A hazard detection algorithm is described that uses a twocomponent spectral model to identify vortex signatures observable from arbitrary angles.

Downscaling Reanalysis over Continental Africa with a Regional Model: NCEP Versus ERA Interim Forcing

NASA Technical Reports Server (NTRS)

Druyan, Leonard M.; Fulakeza, Matthew B.

2013-01-01

Five annual climate cycles (1998-2002) are simulated for continental Africa and adjacent oceans by a regional atmospheric model (RM3). RM3 horizontal grid spacing is 0.44deg at 28 vertical levels. Each of 2 simulation ensembles is driven by lateral boundary conditions from each of 2 alternative reanalysis data sets. One simulation downs cales National Center for Environmental Prediction reanalysis 2 (NCPR2) and the other the European Centre for Medium Range Weather Forecasts Interim reanalysis (ERA-I). NCPR2 data are archived at 2.5deg grid spacing, while a recent version of ERA-I provides data at 0.75deg spacing. ERA-I-forced simulations are recomrp. ended by the Coordinated Regional Downscaling Experiment (CORDEX). Comparisons of the 2 sets of simulations with each other and with observational evidence assess the relative performance of each downscaling system. A third simulation also uses ERA-I forcing, but degraded to the same horizontal resolution as NCPR2. RM3-simulated pentad and monthly mean precipitation data are compared to Tropical Rainfall Measuring Mission (TRMM) data, gridded at 0.5deg, and RM3-simulated circulation is compared to both reanalyses. Results suggest that each downscaling system provides advantages and disadvantages relative to the other. The RM3/NCPR2 achieves a more realistic northward advance of summer monsoon rains over West Africa, but RM3/ERA-I creates the more realistic monsoon circulation. Both systems recreate some features of JulySeptember 1999 minus 2002 precipitation differences. Degrading the resolution of ERA-I driving data unrealistically slows the monsoon circulation and considerably diminishes summer rainfall rates over West Africa. The high resolution of ERA-I data, therefore, contributes to the quality of the downscaling, but NCPR2laterai boundary conditions nevertheless produce better simulations of some features.

Estimation of vegetation photosynthetic capacity from space-based measurements of chlorophyll fluorescence for terrestrial biosphere models.

PubMed

Zhang, Yongguang; Guanter, Luis; Berry, Joseph A; Joiner, Joanna; van der Tol, Christiaan; Huete, Alfredo; Gitelson, Anatoly; Voigt, Maximilian; Köhler, Philipp

2014-12-01

Photosynthesis simulations by terrestrial biosphere models are usually based on the Farquhar's model, in which the maximum rate of carboxylation (Vcmax ) is a key control parameter of photosynthetic capacity. Even though Vcmax is known to vary substantially in space and time in response to environmental controls, it is typically parameterized in models with tabulated values associated to plant functional types. Remote sensing can be used to produce a spatially continuous and temporally resolved view on photosynthetic efficiency, but traditional vegetation observations based on spectral reflectance lack a direct link to plant photochemical processes. Alternatively, recent space-borne measurements of sun-induced chlorophyll fluorescence (SIF) can offer an observational constraint on photosynthesis simulations. Here, we show that top-of-canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and present an approach to invert Vcmax from SIF data. We use the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) balance model to derive empirical relationships between seasonal Vcmax and SIF which are used to solve the inverse problem. We evaluate our Vcmax estimation method at six agricultural flux tower sites in the midwestern US using spaced-based SIF retrievals. Our Vcmax estimates agree well with literature values for corn and soybean plants (average values of 37 and 101 μmol m(-2)  s(-1) , respectively) and show plausible seasonal patterns. The effect of the updated seasonally varying Vcmax parameterization on simulated gross primary productivity (GPP) is tested by comparing to simulations with fixed Vcmax values. Validation against flux tower observations demonstrate that simulations of GPP and light use efficiency improve significantly when our time-resolved Vcmax estimates from SIF are used, with R(2) for GPP comparisons increasing from 0.85 to 0.93, and for light use efficiency from 0.44 to 0.83. Our results support the use of space-based SIF data as a proxy for photosynthetic capacity and suggest the potential for global, time-resolved estimates of Vcmax . © 2014 John Wiley & Sons Ltd.

The adaptation rate of a quantitative trait in an environmental gradient

NASA Astrophysics Data System (ADS)

Hermsen, R.

2016-12-01

The spatial range of a species habitat is generally determined by the ability of the species to cope with biotic and abiotic variables that vary in space. Therefore, the species range is itself an evolvable property. Indeed, environmental gradients permit a mode of evolution in which range expansion and adaptation go hand in hand. This process can contribute to rapid evolution of drug resistant bacteria and viruses, because drug concentrations in humans and livestock treated with antibiotics are far from uniform. Here, we use a minimal stochastic model of discrete, interacting organisms evolving in continuous space to study how the rate of adaptation of a quantitative trait depends on the steepness of the gradient and various population parameters. We discuss analytical results for the mean-field limit as well as extensive stochastic simulations. These simulations were performed using an exact, event-driven simulation scheme that can deal with continuous time-, density- and coordinate-dependent reaction rates and could be used for a wide variety of stochastic systems. The results reveal two qualitative regimes. If the gradient is shallow, the rate of adaptation is limited by dispersion and increases linearly with the gradient slope. If the gradient is steep, the adaptation rate is limited by mutation. In this regime, the mean-field result is highly misleading: it predicts that the adaptation rate continues to increase with the gradient slope, whereas stochastic simulations show that it in fact decreases with the square root of the slope. This discrepancy underscores the importance of discreteness and stochasticity even at high population densities; mean-field results, including those routinely used in quantitative genetics, should be interpreted with care.

The adaptation rate of a quantitative trait in an environmental gradient.

PubMed

Hermsen, R

2016-11-30

The spatial range of a species habitat is generally determined by the ability of the species to cope with biotic and abiotic variables that vary in space. Therefore, the species range is itself an evolvable property. Indeed, environmental gradients permit a mode of evolution in which range expansion and adaptation go hand in hand. This process can contribute to rapid evolution of drug resistant bacteria and viruses, because drug concentrations in humans and livestock treated with antibiotics are far from uniform. Here, we use a minimal stochastic model of discrete, interacting organisms evolving in continuous space to study how the rate of adaptation of a quantitative trait depends on the steepness of the gradient and various population parameters. We discuss analytical results for the mean-field limit as well as extensive stochastic simulations. These simulations were performed using an exact, event-driven simulation scheme that can deal with continuous time-, density- and coordinate-dependent reaction rates and could be used for a wide variety of stochastic systems. The results reveal two qualitative regimes. If the gradient is shallow, the rate of adaptation is limited by dispersion and increases linearly with the gradient slope. If the gradient is steep, the adaptation rate is limited by mutation. In this regime, the mean-field result is highly misleading: it predicts that the adaptation rate continues to increase with the gradient slope, whereas stochastic simulations show that it in fact decreases with the square root of the slope. This discrepancy underscores the importance of discreteness and stochasticity even at high population densities; mean-field results, including those routinely used in quantitative genetics, should be interpreted with care.

Potential space applications of nanomaterials and standartization issues

NASA Astrophysics Data System (ADS)

Voronina, Ekaterina; Novikov, Lev

Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions as well as in the construction of inhabited bases on the Moon. Nanocomposites with nanoclays, carbon nanotubes and various nanoparticles as fillers are one of the most promising materials for space applications. They may be used as light-weighted and strong structural materials as well as functional and smart materials of general and specific applications, e.g. thermal stabilization, radiation shielding, electrostatic charge mitigation, protection of atomic oxygen influence and space debris impact, etc. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. In this presentation, a brief review of existing standards and standards under development in this field is given. Most such standards are related to nanoparticles and nanotube production and characterization, thus the next important step in this activity is the creation of standards on nanomaterial properties and their behavior in different environmental conditions, including extreme environments. The near-Earth’s space is described as an extreme environment for materials due to high vacuum, space radiation, hot and cold plasma, micrometeoroids and space debris, temperature differences, etc. Existing experimental and theoretical data demonstrate that nanomaterials response to various space environment effects may differ substantially from the one of conventional bulk spacecraft materials. Therefore, it is necessary to determine the space environment components, critical for nanomaterials, and to develop novel methods of the mathematical and experimental simulation of the space environment impact on nanomaterials. Computer simulation is a very important scientific tool for explaining various phenomena and predicting the behavior of existing and designing materials under different conditions. The changes in the materials properties, caused by the space environment impact, are determined with structural parameters and processes that are related to different spatial scales: from the size of atoms and molecules to the size of macroobjects. To study nanomaterial response to the space environment, it is necessary to investigate and simulate processes occurring at nanoscale and to reveal various links between them and the processes, typical for the micro- and macroscale. Therefore, the multiscale simulation approach is needed, and different methods for various scales should be applied. In this presentation some approaches to multiscale computer simulation of the impact of some space environment components on nanomaterials are presented and discussed.

Laboratory investigation on super-Earths atmospheres

NASA Astrophysics Data System (ADS)

Erculiani, M. S.; Claudi, R. U.; Lessio, L.; Farisato, G.; Giro, E.; Cocola, L.; Billi, D.; D'alessandro, M.; Pace, E.; Schierano, D.; Benatti, S.; Bonavita, M.; Galletta, G.

2014-04-01

In the framework of Atmosphere in a Test Tube, at the Astronomical Observatory of Padova (INAF) we are going to perform experiments aimed to understand the possible modification of the atmosphere by photosynthetic biota present on the planet surface. This goal can be achieved simulating M star planetary environmental conditions. The bacteria that are being studied are Acaryochloris marina, Chroococcidiopsis spp. and Halomicronema hingdechloris. Tests will be performed with LISA or MINI-LISA ambient simulator in the laboratory of the Padova Astronomic Observatory. In this paper we describe the whole road map to follow in order to perform experiments and to obtain useful data to be compared with the real ones that will be obtained by the future space missions. Starting by a fiducial experiment we will modify either environmental and thermodynamical properties in order to simulate both real irradiation by an M star and gas mixture mimicing super earths atmospheres. These laboratory tests could be used as a guideline in order to understand whether chemical disequilibrium of O2, CO2 and CH4 could be ascribed to biotic life forms.

On the precision of aero-thermal simulations for TMT

NASA Astrophysics Data System (ADS)

Vogiatzis, Konstantinos; Thompson, Hugh

2016-08-01

Environmental effects on the Image Quality (IQ) of the Thirty Meter Telescope (TMT) are estimated by aero-thermal numerical simulations. These simulations utilize Computational Fluid Dynamics (CFD) to estimate, among others, thermal (dome and mirror) seeing as well as wind jitter and blur. As the design matures, guidance obtained from these numerical experiments can influence significant cost-performance trade-offs and even component survivability. The stochastic nature of environmental conditions results in the generation of a large computational solution matrix in order to statistically predict Observatory Performance. Moreover, the relative contribution of selected key subcomponents to IQ increases the parameter space and thus computational cost, while dictating a reduced prediction error bar. The current study presents the strategy followed to minimize prediction time and computational resources, the subsequent physical and numerical limitations and finally the approach to mitigate the issues experienced. In particular, the paper describes a mesh-independence study, the effect of interpolation of CFD results on the TMT IQ metric, and an analysis of the sensitivity of IQ to certain important heat sources and geometric features.

Simulation of Flow Through Porous Anode in Mfc at Higher Power Density

NASA Astrophysics Data System (ADS)

Su, W. W.; Xu, Y. S.; Yan, W. W.; Liu, Y.

Microbial fuel cell (MFC) is a new environmental friendly energy device which has received greatly attention due to its technology for producing electricity directly from organic or inorganic matter using bacteria as catalyst. To date, many studies have been carried out on advective flow through porous anode in a continuous flow MFC. However, the precise mechanical mechanism of flow through porous anode and the quantified relationship between porous media and MFC performance are not yet clearly understood. It has been found experimentally the power density can be increased apparently at certain spacing configuration. Based on these available experimental data, we studied the effect of spacing between electrodes and the Darcy number of porous anode on the power generation performance of MFC using lattice Boltzmann method. The simulation results indicated that the spacing between electrodes significantly influence the flow velocity profile and residence time in the MFC. Moreover, it was found that the Darcy number of porous anode could regulate the output efficiency of MFC. Our results would be helpful to optimize MFC design.

Electronic and mechanical improvement of the receiving terminal of a free-space microwave power transmission system

NASA Technical Reports Server (NTRS)

Brown, W. C.

1977-01-01

Significant advancements were made in a number of areas: improved efficiency of basic receiving element at low power density levels, improved resolution and confidence in efficiency measurements mathematical modelling and computer simulation of the receiving element and the design, construction, and testing of an environmentally protected two-plane construction suitable for low cost, highly automated construction of large receiving arrays.

Acoustic mode coupling induced by shallow water nonlinear internal waves: sensitivity to environmental conditions and space-time scales of internal waves.

PubMed

Colosi, John A

2008-09-01

While many results have been intuited from numerical simulation studies, the precise connections between shallow-water acoustic variability and the space-time scales of nonlinear internal waves (NLIWs) as well as the background environmental conditions have not been clearly established analytically. Two-dimensional coupled mode propagation through NLIWs is examined using a perturbation series solution in which each order n is associated with nth-order multiple scattering. Importantly, the perturbation solution gives resonance conditions that pick out specific NLIW scales that cause coupling, and seabed attenuation is demonstrated to broaden these resonances, fundamentally changing the coupling behavior at low frequency. Sound-speed inhomogeneities caused by internal solitary waves (ISWs) are primarily considered and the dependence of mode coupling on ISW amplitude, range width, depth structure, location relative to the source, and packet characteristics are delineated as a function of acoustic frequency. In addition, it is seen that significant energy transfer to modes with initially low or zero energy involves at least a second order scattering process. Under moderate scattering conditions, comparisons of first order, single scattering theoretical predictions to direct numerical simulation demonstrate the accuracy of the approach for acoustic frequencies upto 400 Hz and for single as well as multiple ISW wave packets.

Exploring information transmission in gene networks using stochastic simulation and machine learning

NASA Astrophysics Data System (ADS)

Park, Kyemyung; Prüstel, Thorsten; Lu, Yong; Narayanan, Manikandan; Martins, Andrew; Tsang, John

How gene regulatory networks operate robustly despite environmental fluctuations and biochemical noise is a fundamental question in biology. Mathematically the stochastic dynamics of a gene regulatory network can be modeled using chemical master equation (CME), but nonlinearity and other challenges render analytical solutions of CMEs difficult to attain. While approaches of approximation and stochastic simulation have been devised for simple models, obtaining a more global picture of a system's behaviors in high-dimensional parameter space without simplifying the system substantially remains a major challenge. Here we present a new framework for understanding and predicting the behaviors of gene regulatory networks in the context of information transmission among genes. Our approach uses stochastic simulation of the network followed by machine learning of the mapping between model parameters and network phenotypes such as information transmission behavior. We also devised ways to visualize high-dimensional phase spaces in intuitive and informative manners. We applied our approach to several gene regulatory circuit motifs, including both feedback and feedforward loops, to reveal underexplored aspects of their operational behaviors. This work is supported by the Intramural Program of NIAID/NIH.

An automation simulation testbed

NASA Technical Reports Server (NTRS)

Cook, George E.; Sztipanovits, Janos; Biegl, Csaba; Karsai, Gabor; Springfield, James F.; Mutammara, Atheel

1988-01-01

The work being done in porting ROBOSIM (a graphical simulation system developed jointly by NASA-MSFC and Vanderbilt University) to the HP350SRX graphics workstation is described. New additional ROBOSIM features, like collision detection and new kinematics simulation methods are also discussed. Based on the experiences of the work on ROBOSIM, a new graphics structural modeling environment is suggested which is intended to be a part of a new knowledge-based multiple aspect modeling testbed. The knowledge-based modeling methodologies and tools already available are described. Three case studies in the area of Space Station automation are also reported. First a geometrical structural model of the station is presented. This model was developed using the ROBOSIM package. Next the possible application areas of an integrated modeling environment in the testing of different Space Station operations are discussed. One of these possible application areas is the modeling of the Environmental Control and Life Support System (ECLSS), which is one of the most complex subsystems of the station. Using the multiple aspect modeling methodology, a fault propagation model of this system is being built and is described.

Teaching Heliophysics Science to Undergraduates in an Engineering Context

NASA Astrophysics Data System (ADS)

Baker, J. B.; Sweeney, D. G.; Ruohoniemi, J.

2013-12-01

In recent years, space research at Virginia Tech has experienced rapid growth since the initiation of the Center for Space Science and Engineering Research (Space@VT) during the summer of 2007. The Space@VT center resides in the College of Engineering and currently comprises approximately 30-40 faculty and students. Space@VT research encompasses a wide spectrum of science and engineering activities including: magnetosphere-ionosphere data analysis; ground- and space-based instrument development; spacecraft design and environmental interactions; and numerical space plasma simulations. In this presentation, we describe how Space@VT research is being integrated into the Virginia Tech undergraduate engineering curriculum via classroom instruction and hands-on group project work. In particular, we describe our experiences teaching a new sophomore course titled 'Exploration of the Space Environment' which covers a broad range of scientific, engineering, and societal aspects associated with the exploration and technological exploitation of space. Topics covered include: science of the space environment; space weather hazards and societal impacts; elementary orbital mechanics and rocket propulsion; spacecraft engineering subsystems; and applications of space-based technologies. We also describe a high-altitude weather balloon project which has been offered as a 'hands-on' option for fulfilling the course project requirements of the course.

Entropy generation method to quantify thermal comfort.

PubMed

Boregowda, S C; Tiwari, S N; Chaturvedi, S K

2001-12-01

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study is needed in the future to fully establish the validity of the OTCI formula and the model. One of the practical applications of this index is that could it be integrated in thermal control systems to develop human-centered environmental control systems for potential use in aircraft, mass transit vehicles, intelligent building systems, and space vehicles.

Entropy generation method to quantify thermal comfort

NASA Technical Reports Server (NTRS)

Boregowda, S. C.; Tiwari, S. N.; Chaturvedi, S. K.

2001-01-01

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study is needed in the future to fully establish the validity of the OTCI formula and the model. One of the practical applications of this index is that could it be integrated in thermal control systems to develop human-centered environmental control systems for potential use in aircraft, mass transit vehicles, intelligent building systems, and space vehicles.

Predicted torque equilibrium attitude utilization for Space Station attitude control

NASA Technical Reports Server (NTRS)

Kumar, Renjith R.; Heck, Michael L.; Robertson, Brent P.

1990-01-01

An approximate knowledge of the torque equilibrium attitude (TEA) is shown to improve the performance of a control moment gyroscope (CMG) momentum management/attitude control law for Space Station Freedom. The linearized equations of motion are used in conjunction with a state transformation to obtain a control law which uses full state feedback and the predicted TEA to minimize both attitude excursions and CMG peak and secular momentum. The TEA can be computationally determined either by observing the steady state attitude of a 'controlled' spacecraft using arbitrary initial attitude, or by simulating a fixed attitude spacecraft flying in desired orbit subject to realistic environmental disturbance models.

NASA KSC Intern Final Paper

NASA Technical Reports Server (NTRS)

Colton, Andrew

2012-01-01

I am finishing up my internship with the Application & Simulation group at NASA Kennedy Space Center (KSC). During this internship I was working with the Plant Habitat development team. The Plant Habitat provides a large enclosed, environmentally controlled chamber designed to support commercial and fundamental plant research onboard the International Space Station (ISS). The work that I did was for the prototype of the Graphical User Interface (GUI) display. This display is used by the scientists to monitor the system health, start new experiment configurations, and get real-time information about the experiment as its being run. This display is developed using the Qt Framework Integrated Development Environment (IDE) and the programming language C++.

Supplemental final environmental impact statement for advanced solid rocket motor testing at Stennis Space Center

NASA Technical Reports Server (NTRS)

1990-01-01

Since the Final Environmental Impact Statement (FEIS) and Record of Decision on the FEIS describing the potential impacts to human health and the environment associated with the program, three factors have caused NASA to initiate additional studies regarding these issues. These factors are: (1) The U.S. Army Corps of Engineers and the Environmental Protection Agency (EPA) agreed to use the same comprehensive procedures to identify and delineate wetlands; (2) EPA has given NASA further guidance on how best to simulate the exhaust plume from the Advanced Solid Rocket Motor (ASRM) testing through computer modeling, enabling more realistic analysis of emission impacts; and (3) public concerns have been raised concerning short and long term impacts on human health and the environment from ASRM testing.

Active learning in forensic science using Brownfield Action in a traditional or hybrid course in earth, environmental, or engineering sciences

NASA Astrophysics Data System (ADS)

Bower, P.; Liddicoat (2), J.

2009-04-01

Brownfield Action (BA - http://www.brownfieldaction.org) is a web-based, interactive, three-dimensional digital space and learning simulation in which students form geotechnical consulting companies and work collaboratively to explore and solve problems in environmental forensics. BA is being used in the United States at 10 colleges and universities in earth, environmental, or engineering sciences undergraduate and graduate courses. As a semester-long activity or done in modular form for specific topics, BA encourages active learning that requires attention to detail, intuition, and positive interaction between peers that results in Phase 1 and Phase 2 Environmental Site Assessments. Besides use in higher education courses, BA also can be adapted for instruction to local, state, and federal governmental employees, and employees in industry where brownfields need to be investigated or require remediation.

Liquid hydrogen and liquid oxygen feedline passive recirculation analysis

NASA Astrophysics Data System (ADS)

Holt, Kimberly Ann; Cleary, Nicole L.; Nichols, Andrew J.; Perry, Gretchen L. E.

The primary goal of the National Launch System (NLS) program was to design an operationally efficient, highly reliable vehicle with minimal recurring launch costs. To achieve this goal, trade studies of key main propulsion subsystems were performed to specify vehicle design requirements. These requirements include the use of passive recirculation to thermally condition the liquid hydrogen (LH2) and liquid oxygen (LO2) propellant feed systems and Space Transportation Main Engine (STME) fuel pumps. Rockwell International (RI) proposed a joint independent research and development (JIRAD) program with Marshall Space Flight Center (MSFC) to study the LH2 feed system passive recirculation concept. The testing was started in July 1992 and completed in November 1992. Vertical and sloped feedline designs were used. An engine simulator was attached at the bottom of the feedline. This simulator had strip heaters that were set to equal the corresponding heat input from different engines. A computer program is currently being used to analyze the passive recirculation concept in the LH2 vertical feedline tests. Four tests, where the heater setting is the independent variable, were chosen. While the JIRAD with RI was underway, General Dynamics Space Systems (GDSS) proposed a JIRAD with MSFC to explore passive recirculation in the LO2 feed system. Liquid nitrogen (LN2) is being used instead of LO2 for safety and economic concerns. To date, three sets of calibration tests have been completed on the sloped LN2 test article. The environmental heat was calculated from the calibration tests in which the strip heaters were turned off. During the LH2 testing, the environmental heat was assumed to be constant. Therefore, the total heat was equal to the environmental heat flux plus the heater input. However, the first two sets of LN2 calibration tests have shown that the environmental heat flux varies with heater input. A Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA/FLUINT) model is currently being built to determine if this variation in environmental heat is due to a change in the wall temperature.

Recent Results of NASA's Space Environments and Effects Program

NASA Technical Reports Server (NTRS)

Minor, Jody L.; Brewer, Dana S.

1998-01-01

The Space Environments and Effects (SEE) Program is a multi-center multi-agency program managed by the NASA Marshall Space Flight Center. The program evolved from the Long Duration Exposure Facility (LDEF), analysis of LDEF data, and recognition of the importance of the environments and environmental effects on future space missions. It is a very comprehensive and focused approach to understanding the space environments, to define the best techniques for both flight and ground-based experimentation, to update the models which predict both the environments and the environmental effects on spacecraft, and finally to ensure that this information is properly maintained and inserted into spacecraft design programs. Formal funding of the SEE Program began initially in FY95. A NASA Research Announcement (NRA) solicited research proposals in the following categories: 1) Engineering environment definitions; 2) Environments and effects design guidelines; 3) Environments and effects assessment models and databases; and, 4) Flight/ground simulation/technology assessment data. This solicitation resulted in funding for eighteen technology development activities (TDA's). This paper will present and describe technical results rom the first set of TDA's of the SEE Program. It will also describe the second set of technology development activities which are expected to begin in January 1998. These new technology development activities will enable the SEE Program to start numerous new development activities in support of mission customer needs.

3D mapping and simulation of Geneva Lake environmental data

NASA Astrophysics Data System (ADS)

Villard, Roch; Maignan, Michel; Kanevski, Mikhail; Rapin, Francois; Klein, Audrey

2010-05-01

The Geneva Lake is the biggest alpine and subalpine lake in central Europe. The depth of this lake is 309 meters and its total volume of water is 89 billions m3. It takes, on average, around twelve years so that waters of the lake are completely brewed. Furthermore the Geneva lake waters are rich in dissolved substances as carbonate, sulfate. The quantity of particles in suspension in the lake, which mainly arrived from the Rhône, is nowadays around height million of tones. The International Commission for the Leman Lake (CIPEL) works about the improvement of the quality of this lake since 1962. In the present study three dimensional environmental data (temperature, oxygen and nitrate) which cover the period from 1954 to 2008, for a total of 27'500 cases are investigated. We are interested to study the evolution of the temperature of the lake because there is an impact on the reproduction of fishes and also because the winter brewing of the water makes the re-oxygenation of deep-water. In order that biological balance is maintained in a lake, there must be enough oxygen in the water. Moreover, we work on nitrate distribution and evolution because contributions in fertilizers cause eutrophication of lake. The data are very numerous when we consider the time series, some of them with more than 300 occurrences, but there are between 2 and 15 data available for spatial cartography. The basic methodology used for the analysis, mapping and simulations of 3D patterns of environmental data is based on geostatistical predictions (family of kriging models) and conditional stochastic simulations. Spatial and temporal variability, 3D monitoring networks changing over time, make this study challenging. An important problem is also to make interpolation/simulations over a long period of time, like ten years. One way used to overcome this problem, consists in using a weighted average of ten variograms during this period. 3D mapping was carried out using environment data for several depths. Applying all data comprehensive analysis both in space and in time was performed. The evolution of the distribution of environmental parameters and their difference in space between two periods and also several times series were studied. Furthermore with the analysis of temporal measurements depending on spatial coordinates (x, y, z) the trends, periodicity, and seasonal variation or cycles were evaluated. First results demonstrate no global warming in such environment. However certain currents and their evolution in the lake were identified. Then, we can see the movement of cold and hot waters in the lake during time and in space. A main question posed by ecologists is: is there any global warming of the lake? According to the results based on date 1954-1980, no global warming either of the "Small Lake" (Geneva) or the whole lake was put into evidence. However the temperatures of the different parts of the lake vary from one year to another year with significant differences of warming, respectively cooling of different areas and at different depths. The graphical representations of time series of temperature at one location for different depths show clearly the annual rhythm and also other frequencies (11 years). The historical well known "cold years" are well identified. At some years, one can observe an inversion of temperature when the cold water in the depth comes upwards to the surface. Spatial patterns are also found for the nitrate content in water. The future developments deal with multivariate analysis and simulations of environmental and pollution data in the lake.

NASA GRC and MSFC Space-Plasma Arc Testing Procedures

NASA Technical Reports Server (NTRS)

Ferguson, Dale C.; Vayner, Boris V.; Galofaro, Joel T.; Hillard, G. Barry; Vaughn, Jason; Schneider, Todd

2007-01-01

Tests of arcing and current collection in simulated space plasma conditions have been performed at the NASA Glenn Research Center (GRC) in Cleveland, Ohio, for over 30 years and at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, for almost as long. During this period, proper test conditions for accurate and meaningful space simulation have been worked out, comparisons with actual space performance in spaceflight tests and with real operational satellites have been made, and NASA has achieved our own internal standards for test protocols. It is the purpose of this paper to communicate the test conditions, test procedures, and types of analysis used at NASA GRC and MSFC to the space environmental testing community at large, to help with international space-plasma arcing-testing standardization. Discussed herein are neutral gas conditions, plasma densities and uniformity, vacuum chamber sizes, sample sizes and Debye lengths, biasing samples versus self-generated voltages, floating samples versus grounded samples, test electrical conditions, arc detection, preventing sustained discharges during testing, real samples versus idealized samples, validity of LEO tests for GEO samples, extracting arc threshold information from arc rate versus voltage tests, snapover, current collection, and glows at positive sample bias, Kapton pyrolysis, thresholds for trigger arcs, sustained arcs, dielectric breakdown and Paschen discharge, tether arcing and testing in very dense plasmas (i.e. thruster plumes), arc mitigation strategies, charging mitigation strategies, models, and analysis of test results. Finally, the necessity of testing will be emphasized, not to the exclusion of modeling, but as part of a complete strategy for determining when and if arcs will occur, and preventing them from occurring in space.

HYDRA, a new tool for mechanical testing

NASA Technical Reports Server (NTRS)

Brinkmann, P. W.

1994-01-01

The introduction outlines the verification concept for programs of the European Space Agency (ESA). The role of the Agency in coordinating the activities of major European space test centers is summarized. Major test facilities of the environmental test center at ESTEC, the Space Research and Technology Center of ESA, are shown and their specific characteristics are highlighted with special emphasis on the 6-degree-of-freedom (6-DOF) hydraulic shaker. The specified performance characteristics for sine and transient tests are presented. Results of single-axis hardware tests and 6-DOF computer simulations are included. Efforts employed to protect payloads against accidental damage in case of malfunctions of the facility are listed. Finally the operational advantages of the facility, as well as the possible use of the HYDRA control system design for future applications are indicated.

Space-based Ornithology-Studying Bird Migration and Environmental Change in North America

NASA Technical Reports Server (NTRS)

Smith, James; Deppe, Jill

2008-01-01

Natural fluctuations in the availability of critical stopover sites coupled with anthropogenic destruction of wetlands, land-use change, and anticipated losses due to climate change present migratory birds with a formidable challenge. We have developed an individual-based, spatially explicit bird migration model that simulates the migration routes, timing and energy budgets of individual birds under dynamic weather and land surface conditions. Our model incorporates biophysical constraints, individual bird energy status, bird behavior, and flight aerodynamics. We model the speed, direction, and timing of individual birds moving through a user specified Lagrangian grid. The model incorporates environmental properties including wind speed and direction, topography, dynamic hydrologic properties of the landscape, and environmental suitability. The model is driven by important variables estimated from satellite observations of the land surface, by data assimilation products from weather and climate models, and biological field data. We illustrate the use of the model to study the impact of both short- and long-term environmental variatios, e.g. climate, drought, anthropogenic, on migration timing (phenology), spatial pattern, and fitness (survival and reproductive success). We present several theoretical simulations of the spring migration of Pectoral Sandpiper (Calidris melanotos) in North America with emphasis on the Central flyway from the Gulf of Mexico to Alaska.

[Taylor and Hill, Incorporated's JSC Cryo Chamber A

NASA Technical Reports Server (NTRS)

Morales, Rito

2008-01-01

NASA commissioned construction of an environmental simulation test chamber which was completed in 1964 at Johnson Space Center (JSC) in Houston, Texas. The facility, Chamber A, was invaluable for testing spacecraft and satellites before deployment to space. By testing spacecraft in an environment similar to the one they would be functioning in, potential problems could be addressed before launch. A new addition to NASA's observatory inventory is called the James Webb Space Telescope (JWST), after a former Administrator of NASA. The new telescope will have 7 times the mirror area of the Hubble, with a target destination approximately one million miles from earth. Scheduled for launch in 2013, the JWST will allow scientists the ability to see, for the first time, the first galaxies that formed in the early Universe. Pre-launch testing of JWST must be performed in environments that approximate its final target space environment as closely as possible.

Progressive Sampling Technique for Efficient and Robust Uncertainty and Sensitivity Analysis of Environmental Systems Models: Stability and Convergence

NASA Astrophysics Data System (ADS)

Sheikholeslami, R.; Hosseini, N.; Razavi, S.

2016-12-01

Modern earth and environmental models are usually characterized by a large parameter space and high computational cost. These two features prevent effective implementation of sampling-based analysis such as sensitivity and uncertainty analysis, which require running these computationally expensive models several times to adequately explore the parameter/problem space. Therefore, developing efficient sampling techniques that scale with the size of the problem, computational budget, and users' needs is essential. In this presentation, we propose an efficient sequential sampling strategy, called Progressive Latin Hypercube Sampling (PLHS), which provides an increasingly improved coverage of the parameter space, while satisfying pre-defined requirements. The original Latin hypercube sampling (LHS) approach generates the entire sample set in one stage; on the contrary, PLHS generates a series of smaller sub-sets (also called `slices') while: (1) each sub-set is Latin hypercube and achieves maximum stratification in any one dimensional projection; (2) the progressive addition of sub-sets remains Latin hypercube; and thus (3) the entire sample set is Latin hypercube. Therefore, it has the capability to preserve the intended sampling properties throughout the sampling procedure. PLHS is deemed advantageous over the existing methods, particularly because it nearly avoids over- or under-sampling. Through different case studies, we show that PHLS has multiple advantages over the one-stage sampling approaches, including improved convergence and stability of the analysis results with fewer model runs. In addition, PLHS can help to minimize the total simulation time by only running the simulations necessary to achieve the desired level of quality (e.g., accuracy, and convergence rate).

Costs of harvesting forest biomass on steep slopes with a small cable yarder: results from field trials and simulations

Treesearch

John E. Baumgras; Chris B. LeDoux

1986-01-01

Cable yarding can reduce the environmental impact of timber harvesting on steep slopes by increasing road spacing and reducing soil disturbance. To determine the cost of harvesting forest biomass with a small cable yarder, a 13.4 kW (18 hp) skyline yarder was tested on two southern Appalachian sites. At both sites, fuelwood was harvested from the boles of hardwood...

The Effects of Atropine Sulfate on Aviator Performance

DTIC Science & Technology

1989-09-01

Bozzetti, L. P. (1976). Simulated flying performance after marihuana intoxication. Aviation, Space, and Environmental Medicine , 47(2), 124-128. 14. Taylor... Medicine , 46(3), 304-308. 8. Asknes, E. G. (1954). Effects of small doses of alcohol upon performance in a Link trainer. Journal of Aviation Medicine ...assessed by two Link trainer tasks using experienced pilots. Aerospace Medicine , 45(10), 1180-1189. 10. Henry, P. H., Flueck, J. A., Sanford, J. F

Evaluation of Airborne Precision Spacing in a Human-in-the-Loop Experiment

NASA Technical Reports Server (NTRS)

Barmore, Bryan E.; Abbott, Terence S.; Capron, William R.

2005-01-01

A significant bottleneck in the current air traffic system occurs at the runway. Expanding airports and adding new runways will help solve this problem; however, this comes with significant costs: financially, politically and environmentally. A complementary solution is to safely increase the capacity of current runways. This can be achieved by precisely spacing aircraft at the runway threshold, with a resulting reduction in the spacing bu er required under today s operations. At NASA's Langley Research Center, the Airspace Systems program has been investigating airborne technologies and procedures that will assist the flight crew in achieving precise spacing behind another aircraft. A new spacing clearance allows the pilot to follow speed cues from a new on-board guidance system called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR). AMSTAR receives Automatic Dependent Surveillance-Broadcast (ADS-B) reports from an assigned, leading aircraft and calculates the appropriate speed for the ownship to fly to achieve the desired spacing interval, time- or distance-based, at the runway threshold. Since the goal is overall system capacity, the speed guidance algorithm is designed to provide system-wide benefits and stability to a string of arriving aircraft. An experiment was recently performed at the NASA Langley Air Traffic Operations Laboratory (ATOL) to test the flexibility of Airborne Precision Spacing operations under a variety of operational conditions. These included several types of merge and approach geometries along with the complementary merging and in-trail operations. Twelve airline pilots and four controllers participated in this simulation. Performance and questionnaire data were collected from a total of eighty-four individual arrivals. The pilots were able to achieve precise spacing with a mean error of 0.5 seconds and a standard deviation of 4.7 seconds. No statistically significant di erences in spacing performance were found between in-trail and merging operations or among the three modeled airspaces. Questionnaire data showed general acceptance for both pilots and controllers. These results reinforce previous findings from full-mission simulation and flight evaluation of the in-trail operations. This paper reviews the results of this simulation in detail.

James Webb Space Telescope (JWST) Integrated Science Instruments Module (ISIM) Cryo-Vacuum (CV) Test Campaign Summary

NASA Technical Reports Server (NTRS)

Yew, Calinda; Lui, Yan; Whitehouse, Paul; Banks, Kimberly

2016-01-01

JWST Integrated Science Instruments Module (ISIM) completed its system-level space simulation testing program at the NASA Goddard Space Flight Center (GSFC). In March 2016, ISIM was successfully delivered to the next level of integration with the Optical Telescope Element (OTE), to form OTIS (OTE + ISIM), after concluding a series of three cryo-vacuum (CV) tests. During these tests, the complexity of the mission has generated challenging requirements that demand highly reliable system performance and capabilities from the Space Environment Simulator (SES) vacuum chamber. The first test served as a risk reduction test; the second test provided the initial verification of the fully-integrated flight instruments; and the third test verified the system in its final flight configuration following mechanical environmental tests (vibration and acoustics). From one test to the next, shortcomings of the facility were uncovered and associated improvements in operational capabilities and reliability of the facility were required to enable the project to verify system-level requirements. This paper: (1) provides an overview of the integrated mechanical and thermal facility systems required to achieve the objectives of JWST ISIM testing, (2) compares the overall facility performance and instrumentation results from the three ISIM CV tests, and (3) summarizes lessons learned from the ISIM testing campaign.

Transcriptomics, NF-κB Pathway, and Their Potential Spaceflight-Related Health Consequences

PubMed Central

Zhang, Ye; Moreno-Villanueva, Maria; Krieger, Stephanie; Ramesh, Govindarajan T.; Neelam, Srujana; Wu, Honglu

2017-01-01

In space, living organisms are exposed to multiple stress factors including microgravity and space radiation. For humans, these harmful environmental factors have been known to cause negative health impacts such as bone loss and immune dysfunction. Understanding the mechanisms by which spaceflight impacts human health at the molecular level is critical not only for accurately assessing the risks associated with spaceflight, but also for developing effective countermeasures. Over the years, a number of studies have been conducted under real or simulated space conditions. RNA and protein levels in cellular and animal models have been targeted in order to identify pathways affected by spaceflight. Of the many pathways responsive to the space environment, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) network appears to commonly be affected across many different cell types under the true or simulated spaceflight conditions. NF-κB is of particular interest, as it is associated with many of the spaceflight-related health consequences. This review intends to summarize the transcriptomics studies that identified NF-κB as a responsive pathway to ground-based simulated microgravity or the true spaceflight condition. These studies were carried out using either human cell or animal models. In addition, the review summarizes the studies that focused specifically on NF-κB pathway in specific cell types or organ tissues as related to the known spaceflight-related health risks including immune dysfunction, bone loss, muscle atrophy, central nerve system (CNS) dysfunction, and risks associated with space radiation. Whether the NF-κB pathway is activated or inhibited in space is dependent on the cell type, but the potential health impact appeared to be always negative. It is argued that more studies on NF-κB should be conducted to fully understand this particular pathway for the benefit of crew health in space. PMID:28561779

Transcriptomics, NF-κB Pathway, and Their Potential Spaceflight-Related Health Consequences.

PubMed

Zhang, Ye; Moreno-Villanueva, Maria; Krieger, Stephanie; Ramesh, Govindarajan T; Neelam, Srujana; Wu, Honglu

2017-05-31

In space, living organisms are exposed to multiple stress factors including microgravity and space radiation. For humans, these harmful environmental factors have been known to cause negative health impacts such as bone loss and immune dysfunction. Understanding the mechanisms by which spaceflight impacts human health at the molecular level is critical not only for accurately assessing the risks associated with spaceflight, but also for developing effective countermeasures. Over the years, a number of studies have been conducted under real or simulated space conditions. RNA and protein levels in cellular and animal models have been targeted in order to identify pathways affected by spaceflight. Of the many pathways responsive to the space environment, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) network appears to commonly be affected across many different cell types under the true or simulated spaceflight conditions. NF-κB is of particular interest, as it is associated with many of the spaceflight-related health consequences. This review intends to summarize the transcriptomics studies that identified NF-κB as a responsive pathway to ground-based simulated microgravity or the true spaceflight condition. These studies were carried out using either human cell or animal models. In addition, the review summarizes the studies that focused specifically on NF-κB pathway in specific cell types or organ tissues as related to the known spaceflight-related health risks including immune dysfunction, bone loss, muscle atrophy, central nerve system (CNS) dysfunction, and risks associated with space radiation. Whether the NF-κB pathway is activated or inhibited in space is dependent on the cell type, but the potential health impact appeared to be always negative. It is argued that more studies on NF-κB should be conducted to fully understand this particular pathway for the benefit of crew health in space.

Climate-based models for West Nile Culex mosquito vectors in the Northeastern US

NASA Astrophysics Data System (ADS)

Gong, Hongfei; Degaetano, Arthur T.; Harrington, Laura C.

2011-05-01

Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong correlation between the timing of early population increases (as early warning of West Nile virus risk) and decreases in late summer. Simulated abundance was highly correlated with actual mosquito capture in New Jersey light traps and validated with field data. This climate-based model simulates the population dynamics of both the adult and immature mosquito life stage of Culex arbovirus vectors in the Northeastern US. It is expected to have direct and practical application for mosquito control and West Nile prevention programs.

Research and test facilities

NASA Technical Reports Server (NTRS)

1993-01-01

A description is given of each of the following Langley research and test facilities: 0.3-Meter Transonic Cryogenic Tunnel, 7-by 10-Foot High Speed Tunnel, 8-Foot Transonic Pressure Tunnel, 13-Inch Magnetic Suspension & Balance System, 14-by 22-Foot Subsonic Tunnel, 16-Foot Transonic Tunnel, 16-by 24-Inch Water Tunnel, 20-Foot Vertical Spin Tunnel, 30-by 60-Foot Wind Tunnel, Advanced Civil Transport Simulator (ACTS), Advanced Technology Research Laboratory, Aerospace Controls Research Laboratory (ACRL), Aerothermal Loads Complex, Aircraft Landing Dynamics Facility (ALDF), Avionics Integration Research Laboratory, Basic Aerodynamics Research Tunnel (BART), Compact Range Test Facility, Differential Maneuvering Simulator (DMS), Enhanced/Synthetic Vision & Spatial Displays Laboratory, Experimental Test Range (ETR) Flight Research Facility, General Aviation Simulator (GAS), High Intensity Radiated Fields Facility, Human Engineering Methods Laboratory, Hypersonic Facilities Complex, Impact Dynamics Research Facility, Jet Noise Laboratory & Anechoic Jet Facility, Light Alloy Laboratory, Low Frequency Antenna Test Facility, Low Turbulence Pressure Tunnel, Mechanics of Metals Laboratory, National Transonic Facility (NTF), NDE Research Laboratory, Polymers & Composites Laboratory, Pyrotechnic Test Facility, Quiet Flow Facility, Robotics Facilities, Scientific Visualization System, Scramjet Test Complex, Space Materials Research Laboratory, Space Simulation & Environmental Test Complex, Structural Dynamics Research Laboratory, Structural Dynamics Test Beds, Structures & Materials Research Laboratory, Supersonic Low Disturbance Pilot Tunnel, Thermal Acoustic Fatigue Apparatus (TAFA), Transonic Dynamics Tunnel (TDT), Transport Systems Research Vehicle, Unitary Plan Wind Tunnel, and the Visual Motion Simulator (VMS).

Saturn Apollo Program

NASA Image and Video Library

1963-05-10

The Marshall Space Flight Center (MSFC) played a crucial role in the development of the huge Saturn rockets that delivered humans to the moon in the 1960s. Many unique facilities existed at MSFC for the development and testing of the Saturn rockets. Affectionately nicknamed “The Arm Farm”, the Random Motion/ Lift-Off Simulator was one of those unique facilities. This facility was developed to test the swingarm mechanisms that were used to hold the rocket in position until lift-off. The Arm Farm provided the capability of testing the detachment and reconnection of various arms under brutally realistic conditions. The 18-acre facility consisted of more than a half dozen arm test positions and one position for testing access arms used by the Apollo astronauts. Each test position had two elements: a vehicle simulator for duplicating motions during countdown and launch; and a section duplicating the launch tower. The vehicle simulator duplicated the portion of the vehicle skin that contained the umbilical connections and personnel access hatches. Driven by a hydraulic servo system, the vehicle simulator produced relative motion between the vehicle and tower. On the Arm Farm, extreme environmental conditions (such as a launch scrub during an approaching Florida thunderstorm) could be simulated. The dramatic scenes that the Marshall engineers and technicians created at the Arm Farm permitted the gathering of crucial technical and engineering data to ensure a successful real time launch from the Kennedy Space Center.

Saturn Apollo Program

NASA Image and Video Library

1967-07-28

The Marshall Space Flight Center (MSFC) played a crucial role in the development of the huge Saturn rockets that delivered humans to the moon in the 1960s. Many unique facilities existed at MSFC for the development and testing of the Saturn rockets. Affectionately nicknamed “The Arm Farm”, the Random Motion/ Lift-Off Simulator was one of those unique facilities. This facility was developed to test the swingarm mechanisms that were used to hold the rocket in position until lift-off. The Arm Farm provided the capability of testing the detachment and reconnection of various arms under brutally realistic conditions. The 18-acre facility consisted of more than a half dozen arm test positions and one position for testing access arms used by the Apollo astronauts. Each test position had two elements: a vehicle simulator for duplicating motions during countdown and launch; and a section duplicating the launch tower. The vehicle simulator duplicated the portion of the vehicle skin that contained the umbilical connections and personnel access hatches. Driven by a hydraulic servo system, the vehicle simulator produced relative motion between the vehicle and tower. On the Arm Farm, extreme environmental conditions (such as a launch scrub during an approaching Florida thunderstorm) could be simulated. The dramatic scenes that the Marshall engineers and technicians created at the Arm Farm permitted the gathering of crucial technical and engineering data to ensure a successful real time launch from the Kennedy Space Center.

KSC-2014-2896

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Researchers review procedures for harvesting the outredgeous red lettuce leaves in the Veggie plant growth system inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

Simulation of the Summer Monsoon Rainfall over East Asia using the NCEP GFS Cumulus Parameterization at Different Horizontal Resolutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Kyo-Sun; Hong, Song You; Yoon, Jin-Ho

2014-10-01

The most recent version of Simplified Arakawa-Schubert (SAS) cumulus scheme in National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) (GFS SAS) has been implemented into the Weather and Research Forecasting (WRF) model with a modification of triggering condition and convective mass flux to become depending on model’s horizontal grid spacing. East Asian Summer Monsoon of 2006 from June to August is selected to evaluate the performance of the modified GFS SAS scheme. Simulated monsoon rainfall with the modified GFS SAS scheme shows better agreement with observation compared to the original GFS SAS scheme. The original GFS SAS schememore » simulates the similar ratio of subgrid-scale precipitation, which is calculated from a cumulus scheme, against total precipitation regardless of model’s horizontal grid spacing. This is counter-intuitive because the portion of resolved clouds in a grid box should be increased as the model grid spacing decreases. This counter-intuitive behavior of the original GFS SAS scheme is alleviated by the modified GFS SAS scheme. Further, three different cumulus schemes (Grell and Freitas, Kain and Fritsch, and Betts-Miller-Janjic) are chosen to investigate the role of a horizontal resolution on simulated monsoon rainfall. The performance of high-resolution modeling is not always enhanced as the spatial resolution becomes higher. Even though improvement of probability density function of rain rate and long wave fluxes by the higher-resolution simulation is robust regardless of a choice of cumulus parameterization scheme, the overall skill score of surface rainfall is not monotonically increasing with spatial resolution.« less

Automation of closed environments in space for human comfort and safety

NASA Technical Reports Server (NTRS)

1992-01-01

This report culminates the work accomplished during a three year design project on the automation of an Environmental Control and Life Support System (ECLSS) suitable for space travel and colonization. The system would provide a comfortable living environment in space that is fully functional with limited human supervision. A completely automated ECLSS would increase astronaut productivity while contributing to their safety and comfort. The first section of this report, section 1.0, briefly explains the project, its goals, and the scheduling used by the team in meeting these goals. Section 2.0 presents an in-depth look at each of the component subsystems. Each subsection describes the mathematical modeling and computer simulation used to represent that portion of the system. The individual models have been integrated into a complete computer simulation of the CO2 removal process. In section 3.0, the two simulation control schemes are described. The classical control approach uses traditional methods to control the mechanical equipment. The expert control system uses fuzzy logic and artificial intelligence to control the system. By integrating the two control systems with the mathematical computer simulation, the effectiveness of the two schemes can be compared. The results are then used as proof of concept in considering new control schemes for the entire ECLSS. Section 4.0 covers the results and trends observed when the model was subjected to different test situations. These results provide insight into the operating procedures of the model and the different control schemes. The appendix, section 5.0, contains summaries of lectures presented during the past year, homework assignments, and the completed source code used for the computer simulation and control system.

Humanizing outer space: architecture, habitability, and behavioral health

NASA Astrophysics Data System (ADS)

Harrison, Albert A.

2010-03-01

Space architecture is the theory and practice of designing and building environments for humans in outer space. In our present century professional astronauts and cosmonauts will remain a focus for space architects, but new designs must better accommodate passengers (tourists and industrial workers) and settlers who set forth to establish off-world societies. Psychologists and architects can work together to assure good spaceflight behavioral health, defined by a lack of neuropsychiatric dysfunction, and the presence of high levels of personal adjustment, cordial interpersonal relations, and positive interactions with the physical and social environments. By designing and constructing facilities that are occupant centered and activity oriented, architects increase habitability thereby decreasing environmental challenges to behavioral health. Simulators and spaceflight-analogous environments make it possible to test design solutions prior to their deployment in space. This paper concludes with suggestions for increasing collaboration between architects and psychologists. These include increased sharing of hypotheses and data, articulating complementary research styles, and mutual advocacy for early, potent, and sustained involvement in mission planning and execution.

Space Science

NASA Image and Video Library

2002-02-01

This photograph depicts the Solar X-Ray Imager (SXI) being installed in the X-Ray Calibration Facility (XRCF) vacuum chamber for testing at the Marshall Space Flight Center (MSFC). The XRCF vacuum chamber simulates a space environment with low temperature and pressure. The x-ray images from SXI on the Geostationary Operational Environmental Satellite-12 (GOES-12) will be used by the National Oceanic and Atmospheric Administration (NOAA) and U.S. Air Force to forecast the intensity and speed of solar disturbances that could destroy satellite electronics or disrupt long-distance radio communications. The SXI will observe solar flares, coronal mass ejections, coronal holes, and active regions in the x-ray region of the electromagnetic spectrum. These features are the dominant sources of disturbances in space weather. The imager instrument consists of a telescope assembly with a 6.3-inch (16-centimeter) diameter grazing incidence mirror and a detector system. The imager was developed, tested, and calibrated by MSFC, in conjunction with the NASA Goddard Space Flight Center and U.S. Air Force.

Varieties of virtualization

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.

1991-01-01

Natural environments have a content, i.e., the objects in them; a geometry, i.e., a pattern of rules for positioning and displacing the objects; and a dynamics, i.e., a system of rules describing the effects of forces acting on the objects. Human interaction with most common natural environments has been optimized by centuries of evolution. Virtual environments created through the human-computer interface similarly have a content, geometry, and dynamics, but the arbitrary character of the computer simulation creating them does not insure that human interaction with these virtual environments will be natural. The interaction, indeed, could be supernatural but it also could be impossible. An important determinant of the comprehensibility of a virtual environment is the correspondence between the environmental frames of reference and those associated with the control of environmental objects. The effects of rotation and displacement of control frames of reference with respect to corresponding environmental references differ depending upon whether perceptual judgement or manual tracking performance is measured. The perceptual effects of frame of reference displacement may be analyzed in terms of distortions in the process of virtualizing the synthetic environment space. The effects of frame of reference displacement and rotation have been studied by asking subjects to estimate exocentric direction in a virtual space.

The interaction of high voltage systems with the environments of the Moon and Mars

NASA Technical Reports Server (NTRS)

Hillard, G. Barry; Kolecki, Joseph C.

1993-01-01

High voltage systems designed for use on the lunar and Martian surfaces or in orbit will interact with environmental components such as electrically charged dust, low pressure atmospheres, ionospheric plasmas and neutrals, and chemically reactive species. As the Space Exploration Initiative (SEI) advances from the realm of feasibility study to that of conceptual design, guidelines will be required to ensure that these effects are properly accounted for. A first step in providing such guidelines is the prioritization of interactions for each of the space or surface environments that will be encountered. For those issues that are identified as high priority, the state of environmental knowledge, emphasizing essential data, must be determined. This report describes possible means of obtaining such information, including ground tests, modeling and analysis, and flight experiments. The development of computational tools which will enable engineers to simulate and thereby quantify the interactions will be especially considered. Our analysis is drawn from various study and workshop activities undertaken within the last two years.

Test Before You Fly - High Fidelity Planetary Environment Simulation

NASA Technical Reports Server (NTRS)

Craven, Paul; Ramachandran, Narayanan; Vaughn, Jason; Schneider, Todd; Nehls, Mary

2012-01-01

The lunar surface environment will present many challenges to the survivability of systems developed for long duration lunar habitation and exploration of the lunar, or any other planetary, surface. Obstacles will include issues pertaining especially to the radiation environment (solar plasma and electromagnetic radiation) and lunar regolith dust. The Planetary Environments Chamber is one piece of the MSFC capability in Space Environmental Effects Test and Analysis. Comprised of many unique test systems, MSFC has the most complete set of SEE test capabilities in one location allowing examination of combined space environmental effects without transporting already degraded, potentially fragile samples over long distances between tests. With this system, the individual and combined effects of the lunar radiation and regolith environment on materials, sub-systems, and small systems developed for the lunar return can be investigated. This combined environments facility represents a unique capability to NASA, in which tests can be tailored to any one aspect of the lunar environment (radiation, temperature, vacuum, regolith) or to several of them combined in a single test.

Qualitative differences in memory for vista and environmental spaces are caused by opaque borders, not movement or successive presentation.

PubMed

Meilinger, Tobias; Strickrodt, Marianne; Bülthoff, Heinrich H

2016-10-01

Two classes of space define our everyday experience within our surrounding environment: vista spaces, such as rooms or streets which can be perceived from one vantage point, and environmental spaces, for example, buildings and towns which are grasped from multiple views acquired during locomotion. However, theories of spatial representations often treat both spaces as equal. The present experiments show that this assumption cannot be upheld. Participants learned exactly the same layout of objects either within a single room or spread across multiple corridors. By utilizing a pointing and a placement task we tested the acquired configurational memory. In Experiment 1 retrieving memory of the object layout acquired in environmental space was affected by the distance of the traveled path and the order in which the objects were learned. In contrast, memory retrieval of objects learned in vista space was not bound to distance and relied on different ordering schemes (e.g., along the layout structure). Furthermore, spatial memory of both spaces differed with respect to the employed reference frame orientation. Environmental space memory was organized along the learning experience rather than layout intrinsic structure. In Experiment 2 participants memorized the object layout presented within the vista space room of Experiment 1 while the learning procedure emulated environmental space learning (movement, successive object presentation). Neither factor rendered similar results as found in environmental space learning. This shows that memory differences between vista and environmental space originated mainly from the spatial compartmentalization which was unique to environmental space learning. Our results suggest that transferring conclusions from findings obtained in vista space to environmental spaces and vice versa should be made with caution. Copyright © 2016 Elsevier B.V. All rights reserved.

Considerations in STS payload environmental verification

NASA Technical Reports Server (NTRS)

Keegan, W. B.

1978-01-01

Considerations regarding the Space Transportation System (STS) payload environmental verification are reviewed. It is noted that emphasis is placed on testing at the subassembly level and that the basic objective of structural dynamic payload verification is to ensure reliability in a cost-effective manner. Structural analyses consist of: (1) stress analysis for critical loading conditions, (2) model analysis for launch and orbital configurations, (3) flight loads analysis, (4) test simulation analysis to verify models, (5) kinematic analysis of deployment/retraction sequences, and (6) structural-thermal-optical program analysis. In addition to these approaches, payload verification programs are being developed in the thermal-vacuum area. These include the exposure to extreme temperatures, temperature cycling, thermal-balance testing and thermal-vacuum testing.

Mars Science Laboratory Spacecraft Assembled for Testing

NASA Technical Reports Server (NTRS)

2008-01-01

The major components of NASA's Mars Science Laboratory spacecraft cruise stage atop the aeroshell, which has the descent stage and rover inside were connected together in October 2008 for several weeks of system testing, including simulation of launch vibrations and deep-space environmental conditions.

These components will be taken apart again, for further work on each of them, after the environmental testing. The Mars Science Laboratory spacecraft is being assembled and tested for launch in 2011.

This image was taken inside the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory, Pasadena, Calif., which manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology.

Bayesian model-emulation of stochastic gravitational-wave spectra for probes of the final-parsec problem with pulsar-timing arrays

NASA Astrophysics Data System (ADS)

Taylor, Stephen R.; Simon, Joseph; Sampson, Laura

2017-01-01

The final parsec of supermassive black-hole binary evolution is subject to the complex interplay of stellar loss-cone scattering, circumbinary disk accretion, and gravitational-wave emission, with binary eccentricity affected by all of these. The strain spectrum of gravitational-waves in the pulsar-timing band thus encodes rich information about the binary population's response to these various environmental mechanisms. Current spectral models have heretofore followed basic analytic prescriptions, and attempt to investigate these final-parsec mechanisms in an indirect fashion. Here we describe a new technique to directly probe the environmental properties of supermassive black-hole binaries through "Bayesian model-emulation". We perform black-hole binary population synthesis simulations at a restricted set of environmental parameter combinations, compute the strain spectra from these, then train a Gaussian process to learn the shape of the spectrum at any point in parameter space. We describe this technique, demonstrate its efficacy with a program of simulated datasets, then illustrate its power by directly constraining final-parsec physics in a Bayesian analysis of the NANOGrav 5-year dataset. The technique is fast, flexible, and robust.

Bayesian model-emulation of stochastic gravitational-wave spectra for probes of the final-parsec problem with pulsar-timing arrays

NASA Astrophysics Data System (ADS)

Taylor, Stephen; Simon, Joseph; Sampson, Laura

2017-01-01

The final parsec of supermassive black-hole binary evolution is subject to the complex interplay of stellar loss-cone scattering, circumbinary disk accretion, and gravitational-wave emission, with binary eccentricity affected by all of these. The strain spectrum of gravitational-waves in the pulsar-timing band thus encodes rich information about the binary population's response to these various environmental mechanisms. Current spectral models have heretofore followed basic analytic prescriptions, and attempt to investigate these final-parsec mechanisms in an indirect fashion. Here we describe a new technique to directly probe the environmental properties of supermassive black-hole binaries through ``Bayesian model-emulation''. We perform black-hole binary population synthesis simulations at a restricted set of environmental parameter combinations, compute the strain spectra from these, then train a Gaussian process to learn the shape of spectrum at any point in parameter space. We describe this technique, demonstrate its efficacy with a program of simulated datasets, then illustrate its power by directly constraining final-parsec physics in a Bayesian analysis of the NANOGrav 5-year dataset. The technique is fast, flexible, and robust.

The environment associated with significant tornadoes in Bangladesh

NASA Astrophysics Data System (ADS)

Bikos, Dan; Finch, Jonathan; Case, Jonathan L.

2016-01-01

This paper investigates the environmental parameters favoring significant tornadoes in Bangladesh through a simulation of ten high-impact events. A climatological perspective is first presented on classifying significant tornadoes in Bangladesh, noting the challenges since reports of tornadoes are not documented in a formal manner. The statistical relationship between United States and Bangladesh tornado-related deaths suggests that significant tornadoes do occur in Bangladesh so this paper identifies the most significant tornadic events and analyzes the environmental conditions associated with these events. Given the scarcity of observational data to assess the near-storm environment in this region, high-resolution (3-km horizontal grid spacing) numerical weather prediction simulations are performed for events identified to be associated with a significant tornado. In comparison to similar events over the United States, significant tornado environments in Bangladesh are characterized by relatively high convective available potential energy, sufficient deep-layer vertical shear, and a propensity for deviant (i.e., well to the right of the mean flow) storm motion along a low-level convergence boundary.

Space shuttle solid rocket booster recovery system definition. Volume 2: SRB water impact Monte Carlo computer program, user's manual

NASA Technical Reports Server (NTRS)

1973-01-01

The HD 220 program was created as part of the space shuttle solid rocket booster recovery system definition. The model was generated to investigate the damage to SRB components under water impact loads. The random nature of environmental parameters, such as ocean waves and wind conditions, necessitates estimation of the relative frequency of occurrence for these parameters. The nondeterministic nature of component strengths also lends itself to probabilistic simulation. The Monte Carlo technique allows the simultaneous perturbation of multiple independent parameters and provides outputs describing the probability distribution functions of the dependent parameters. This allows the user to determine the required statistics for each output parameter.

Visualization of simulated urban spaces: inferring parameterized generation of streets, parcels, and aerial imagery.

PubMed

Vanegas, Carlos A; Aliaga, Daniel G; Benes, Bedrich; Waddell, Paul

2009-01-01

Urban simulation models and their visualization are used to help regional planning agencies evaluate alternative transportation investments, land use regulations, and environmental protection policies. Typical urban simulations provide spatially distributed data about number of inhabitants, land prices, traffic, and other variables. In this article, we build on a synergy of urban simulation, urban visualization, and computer graphics to automatically infer an urban layout for any time step of the simulation sequence. In addition to standard visualization tools, our method gathers data of the original street network, parcels, and aerial imagery and uses the available simulation results to infer changes to the original urban layout and produce a new and plausible layout for the simulation results. In contrast with previous work, our approach automatically updates the layout based on changes in the simulation data and thus can scale to a large simulation over many years. The method in this article offers a substantial step forward in building integrated visualization and behavioral simulation systems for use in community visioning, planning, and policy analysis. We demonstrate our method on several real cases using a 200 GB database for a 16,300 km2 area surrounding Seattle.

Small Multi-Purpose Research Facility (SMiRF)

NASA Image and Video Library

2015-10-15

NASA Glenn engineer Monica Guzik in the Small Multi-Purpose Research Facility (SMiRF). The facility provides the ability to simulate the environmental conditions encountered in space for a variety of cryogenic applications such as thermal protection systems, fluid transfer operations and propellant level gauging. SMiRF is a low-cost, small-scale screening facility for concept and component testing of a wide variety of hardware and is capable of testing cryogenic hydrogen, oxygen, methane and nitrogen.

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 97

NASA Technical Reports Server (NTRS)

1972-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 94)

NASA Technical Reports Server (NTRS)

1971-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 96

NASA Technical Reports Server (NTRS)

1971-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Aerospace medicine and biology: A continuing bibliography with indexes, supplement

NASA Technical Reports Server (NTRS)

1972-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 100)

NASA Technical Reports Server (NTRS)

1972-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. Reference describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Advances in cryogenic foam insulations.

NASA Technical Reports Server (NTRS)

Lemons, C. R.; Salmassy, O. K.; Watts, C. R.

1971-01-01

Description of a discretely oriented thread-reinforced polyurethane foam thermal insulation system for liquid hydrogen fuel tanks. The 3-D foam and glass liner composite is designed to be adhesively bonded to the inside surface of the tank wall and to be in direct contact with liquid hydrogen. All elements of this insulation composite are capable of sustaining the loads and environmental conditions imposed by testing under simulated Space Shuttle vehicle requirements at temperatures between -423 and +350 F.

Survival of akinetes (resting-state cells of cyanobacteria) in low earth orbit and simulated extraterrestrial conditions.

PubMed

Olsson-Francis, Karen; de la Torre, Rosa; Towner, Martin C; Cockell, Charles S

2009-12-01

Cyanobacteria are photosynthetic organisms that have been considered for space applications, such as oxygen production in bioregenerative life support systems, and can be used as a model organism for understanding microbial survival in space. Akinetes are resting-state cells of cyanobacteria that are produced by certain genera of heterocystous cyanobacteria to survive extreme environmental conditions. Although they are similar in nature to endospores, there have been no investigations into the survival of akinetes in extraterrestrial environments. The aim of this work was to examine the survival of akinetes from Anabaena cylindrica in simulated extraterrestrial conditions and in Low Earth Orbit (LEO). Akinetes were dried onto limestone rocks and sent into LEO for 10 days on the ESA Biopan VI. In ground-based experiments, the rocks were exposed to periods of desiccation, vacuum (0.7×10(-3) kPa), temperature extremes (-80 to 80°C), Mars conditions (-27°C, 0.8 kPa, CO(2)) and UV radiation (325-400 nm). A proportion of the akinete population was able to survive a period of 10 days in LEO and 28 days in Mars simulated conditions, when the rocks were not subjected to UV radiation. Furthermore, the akinetes were able to survive 28 days of exposure to desiccation and low temperature with high viability remaining. Yet long periods of vacuum and high temperature were lethal to the akinetes. This work shows that akinetes are extreme-tolerating states of cyanobacteria that have a practical use in space applications and yield new insight into the survival of microbial resting-state cells in space conditions.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. The test team gathered for an event to mark the end of testing. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. Patrick Simpkins, director of Engineering, speaks to the test team during an event to mark the end of testing. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. The test team gathered with a special banner during an event to mark the end of testing. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. One of the test team members signs a banner during an event to mark the end of testing. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

Orion Service Module Umbilical (OSMU) Testing Complete

NASA Image and Video Library

2016-10-19

Testing of the Orion Service Module Umbilical (OSMU) was completed at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida. The OSMU was attached to Vehicle Motion Simulator 1 for a series of simulated launch tests to validate it for installation on the mobile launcher. The test team signed a special banner during an event to mark the end of testing. The mobile launcher tower will be equipped with a number of lines, called umbilicals that will connect to the Space Launch System rocket and Orion spacecraft for Exploration Mission-1 (EM-1). The OSMU will be located high on the mobile launcher tower and, prior to launch, will transfer liquid coolant for the electronics and air for the Environmental Control System to the Orion service module that houses these critical systems to support the spacecraft. Kennedy's Engineering Directorate is providing support to the Ground Systems Development and Operations Program for testing of the OSMU. EM-1 is scheduled to launch in 2018.

The Environmental Impact of a Wave Dragon Array Operating in the Black Sea

PubMed Central

Rusu, Eugen

2013-01-01

The present work describes a study related to the influence on the shoreline dynamics of a wave farm consisting of Wave Dragon devices operating in the western side of the Black Sea. Based on historical data analysis of the wave climate, the most relevant environmental conditions that could occur were defined, and for these cases, simulations with SWAN spectral phase averaged wave model were performed. Two situations were considered for the most representative patterns: model simulations without any wave energy converter and simulations considering a wave farm consisting of six Wave Dragon devices. Comparisons of the wave model outputs have been carried out in both geographical and spectral spaces. The results show that although a significant influence appears near the wave farm, this gradually decreases to the coast line level. In order to evaluate the influence of the wave farm on the longshore currents, a nearshore circulation modeling system was used. In relative terms, the longshore current velocities appear to be more sensitive to the presence of the wave farm than the significant wave height. Finally, the possible impact on the marine flora and fauna specific to the target area was also considered and discussed. PMID:23844401

The environmental impact of a Wave Dragon array operating in the Black Sea.

PubMed

Diaconu, Sorin; Rusu, Eugen

2013-01-01

The present work describes a study related to the influence on the shoreline dynamics of a wave farm consisting of Wave Dragon devices operating in the western side of the Black Sea. Based on historical data analysis of the wave climate, the most relevant environmental conditions that could occur were defined, and for these cases, simulations with SWAN spectral phase averaged wave model were performed. Two situations were considered for the most representative patterns: model simulations without any wave energy converter and simulations considering a wave farm consisting of six Wave Dragon devices. Comparisons of the wave model outputs have been carried out in both geographical and spectral spaces. The results show that although a significant influence appears near the wave farm, this gradually decreases to the coast line level. In order to evaluate the influence of the wave farm on the longshore currents, a nearshore circulation modeling system was used. In relative terms, the longshore current velocities appear to be more sensitive to the presence of the wave farm than the significant wave height. Finally, the possible impact on the marine flora and fauna specific to the target area was also considered and discussed.

Evaluation of Low-Earth-Orbit Environmental Effects on International Space Station Thermal Control Materials

NASA Technical Reports Server (NTRS)

Dever, Joyce A.

1998-01-01

Many spacecraft thermal control coatings in low Earth orbit (LEO) can be affected by solar ultraviolet radiation and atomic oxygen. Ultraviolet radiation can darken some polymers and oxides commonly used in thermal control materials. Atomic oxygen can erode polymer materials, but it may reverse the ultraviolet-darkening effect on oxides. Maintaining the desired solar absorptance for thermal control coatings is important to assure the proper operating temperature of the spacecraft. Thermal control coatings to be used on the International Space Station (ISS) were evaluated for their performance after exposure in the NASA Lewis Research Center's Atomic Oxygen-Vacuum Ultraviolet Exposure (AO-VUV) facility. This facility simulated the LEO environments of solar vacuum ultraviolet (VUV) radiation (wavelength range, 115 to 200 nanometers (nm)) and VUV combined with atomic oxygen. Solar absorptance was measured in vacuo to eliminate the "bleaching" effects of ambient oxygen on VUV-induced degradation. The objective of these experiments was to determine solar absorptance increases of various thermal control materials due to exposure to simulated LEO conditions similar to those expected for ISS. Work was done in support of ISS efforts at the requests of Boeing Space and Defense Systems and Lockheed Martin Vought Systems.

Space station molecular sieve development

NASA Technical Reports Server (NTRS)

Chang, C.; Rousseau, J.

1986-01-01

An essential function of a space environmental control system is the removal of carbon dioxide (CO2) from the atmosphere to control the partial pressure of this gas at levels lower than 3 mm Hg. The use of regenerable solid adsorbents for this purpose was demonstrated effectively during the Skylab mission. Earlier sorbent systems used zeolite molecular sieves. The carbon molecular sieve is a hydrophobic adsorbent with excellent potential for space station application. Although carbon molecular sieves were synthesized and investigated, these sieves were designed to simulate the sieving properties of 5A zeolite and for O2/N2 separation. This program was designed to develop hydrophobic carbon molecular sieves for CO2 removal from a space station crew environment. It is a first phase effort involved in sorbent material development and in demonstrating the utility of such a material for CO2 removal on space stations. The sieve must incorporate the following requirements: it must be hydrophobic; it must have high dynamic capacity for carbon dioxide at the low partial pressure of the space station atmosphere; and it must be chemiclly stable and will not generate contaminants.

Influence of World and Gravity Model Selection on Surface Interacting Vehicle Simulations

NASA Technical Reports Server (NTRS)

Madden, Michael M.

2007-01-01

A vehicle simulation is surface-interacting if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. Modeling of gravity is an influential environmental factor for surface-interacting simulations. Gravity is the free-fall acceleration observed from a world-fixed frame that rotates with the world. Thus, gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. In surface-interacting simulations, the fidelity of gravity at heights above the surface is more significant than gravity fidelity at locations in inertial space. A surface-interacting simulation cannot treat the gravity model separately from the world model, which simulates the motion and shape of the world. The world model's simulation of the world's rotation, or lack thereof, produces the centrifugal acceleration component of gravity. The world model s reproduction of the world's shape will produce different positions relative to the world center for a given height above the surface. These differences produce variations in the gravitation component of gravity. This paper examines the actual performance of world and gravity/gravitation pairs in a simulation using the Earth.

Screens as light biological variable in microgravitational space environment.

NASA Astrophysics Data System (ADS)

Schlacht, S.; Masali, M.

Foreword The ability of the biological organisms to orient themselves and to synchronize on the variations of the solar rhythms is a fundamental aspect in the planning of the human habitat above all when habitat is confined in the Space the planetary and in satellite outer space settlements In order to simulate the experience of the astronauts in long duration missions one of the dominant characteristics of the Space confined habitats is the absence of the earthlings solar cycles references The Sun is the main references and guidelines of the biological compass and timepiece The organism functions are influenced from the variation of the light in the round of the 24 hours the human circadian rhythms In these habitats it is therefore necessary to reproduce the color and intensity of the solar light variations along the arc of the day according to defined scientific programs assuring a better performance of the human organism subsubsection Multilayer Foldable Screens as biological environmental variable In the project Multilayer Foldable Screens are the monitors posed in the ceiling of an Outer Space habitat and are made of liquid crystals and covered with Kevlar they stand for a modulate and flexible structure for different arrangements and different visions Screens work sout s on all the solar light frequencies and display the images that the subject needs They are characterized from the emission of an environmental light that restores the earthly solar cycle for intensity and color temperature to irradiate

[Research progress and development trend of quantitative assessment techniques for urban thermal environment.

PubMed

Sun, Tie Gang; Xiao, Rong Bo; Cai, Yun Nan; Wang, Yao Wu; Wu, Chang Guang

2016-08-01

Quantitative assessment of urban thermal environment has become a focus for urban climate and environmental science since the concept of urban heat island has been proposed. With the continual development of space information and computer simulation technology, substantial progresses have been made on quantitative assessment techniques and methods of urban thermal environment. The quantitative assessment techniques have been developed to dynamics simulation and forecast of thermal environment at various scales based on statistical analysis of thermal environment on urban-scale using the historical data of weather stations. This study reviewed the development progress of ground meteorological observation, thermal infrared remote sensing and numerical simulation. Moreover, the potential advantages and disadvantages, applicability and the development trends of these techniques were also summarized, aiming to add fundamental knowledge of understanding the urban thermal environment assessment and optimization.

The AEDC aerospace chamber 7V: An advanced test capability for infrared surveillance and seeker sensors

NASA Technical Reports Server (NTRS)

Simpson, W. R.

1994-01-01

An advanced sensor test capability is now operational at the Air Force Arnold Engineering Development Center (AEDC) for calibration and performance characterization of infrared sensors. This facility, known as the 7V, is part of a broad range of test capabilities under development at AEDC to provide complete ground test support to the sensor community for large-aperture surveillance sensors and kinetic kill interceptors. The 7V is a state-of-the-art cryo/vacuum facility providing calibration and mission simulation against space backgrounds. Key features of the facility include high-fidelity scene simulation with precision track accuracy and in-situ target monitoring, diffraction limited optical system, NIST traceable broadband and spectral radiometric calibration, outstanding jitter control, environmental systems for 20 K, high-vacuum, low-background simulation, and an advanced data acquisition system.

New insights in the bacterial spore resistance to extreme terrestrial and extraterrestrial factors

NASA Astrophysics Data System (ADS)

Moeller, Ralf; Horneck, Gerda; Reitz, Guenther

Based on their unique resistance to various space parameters, Bacillus endospores are one of the model systems used for astrobiological studies. The extremely high resistance of bacterial endospores to environmental stress factors has intrigued researchers since long time and many characteristic spore features, especially those involved in the protection of spore DNA, have already been uncovered. The disclosure of the complete genomic sequence of Bacillus subtilis 168, one of the often used astrobiological model system, and the rapid development of tran-scriptional microarray techniques have opened new opportunities of gaining further insights in the enigma of spore resistance. Spores of B. subtilis were exposed to various extreme ter-restrial and extraterrestrial stressors to reach a better understanding of the DNA protection and repair strategies, which them to cope with the induced DNA damage. Following physical stress factors of environmental importance -either on Earth or in space -were selected for this thesis: (i) mono-and polychromatic UV radiation, (ii) ionizing radiation, (iii) exposure to ultrahigh vacuum; and (iv) high shock pressures simulating meteorite impacts. To reach a most comprehensive understanding of spore resistance to those harsh terrestrial or simulated extraterrestrial conditions, a standardized experimental protocol of the preparation and ana-lyzing methods was established including the determination of the following spore responses: (i) survival, (ii) induced mutations, (iii) DNA damage, (iv) role of different repair pathways by use of a set of repair deficient mutants, and (v) transcriptional responses during spore germi-nation by use of genome-wide transcriptome analyses and confirmation by RT-PCR. From this comprehensive set of data on spore resistance to a variety of environmental stress parameters a model of a "built-in" transcriptional program of bacterial spores in response to DNA damaging treatments to ensure DNA restoration during germination has been developed.

Boosting for detection of gene-environment interactions.

PubMed

Pashova, H; LeBlanc, M; Kooperberg, C

2013-01-30

In genetic association studies, it is typically thought that genetic variants and environmental variables jointly will explain more of the inheritance of a phenotype than either of these two components separately. Traditional methods to identify gene-environment interactions typically consider only one measured environmental variable at a time. However, in practice, multiple environmental factors may each be imprecise surrogates for the underlying physiological process that actually interacts with the genetic factors. In this paper, we develop a variant of L(2) boosting that is specifically designed to identify combinations of environmental variables that jointly modify the effect of a gene on a phenotype. Because the effect modifiers might have a small signal compared with the main effects, working in a space that is orthogonal to the main predictors allows us to focus on the interaction space. In a simulation study that investigates some plausible underlying model assumptions, our method outperforms the least absolute shrinkage and selection and Akaike Information Criterion and Bayesian Information Criterion model selection procedures as having the lowest test error. In an example for the Women's Health Initiative-Population Architecture using Genomics and Epidemiology study, the dedicated boosting method was able to pick out two single-nucleotide polymorphisms for which effect modification appears present. The performance was evaluated on an independent test set, and the results are promising. Copyright © 2012 John Wiley & Sons, Ltd.

The Shale Hills Sensorium for Embedded Sensors, Simulation, & Visualization: A Prototype for Land-Vegetation-Atmosphere Interactions

NASA Astrophysics Data System (ADS)

Duffy, C.

2008-12-01

The future of environmental observing systems will utilize embedded sensor networks with continuous real- time measurement of hydrologic, atmospheric, biogeochemical, and ecological variables across diverse terrestrial environments. Embedded environmental sensors, benefitting from advances in information sciences, networking technology, materials science, computing capacity, and data synthesis methods, are undergoing revolutionary change. It is now possible to field spatially-distributed, multi-node sensor networks that provide density and spatial coverage previously accessible only via numerical simulation. At the same time, computational tools are advancing rapidly to the point where it is now possible to simulate the physical processes controlling individual parcels of water and solutes through the complete terrestrial water cycle. Our goal for the Penn State Critical Zone Observatory is to apply environmental sensor arrays, integrated hydrologic models, and state-of-the-art visualization deployed and coordinated at a testbed within the Penn State Experimental Forest. The Shale Hills Hydro_Sensorium prototype proposed here is designed to observe land-atmosphere interactions in four-dimensional (space and time). The term Hydro_Sensorium implies the totality of physical sensors, models and visualization tools that allow us to perceive the detailed space and time complexities of the water and energy cycle for a watershed or river basin for all physical states and fluxes (groundwater, soil moisture, temperature, streamflow, latent heat, snowmelt, chemistry, isotopes etc.). This research will ultimately catalyze the study of complex interactions between the land surface, subsurface, biological and atmospheric systems over a broad range of scales. The sensor array would be real-time and fully controllable by remote users for "computational steering" and data fusion. Presently fully-coupled physical models are being developed that link the atmosphere-land-vegetation-subsurface system into a fully-coupled distributed system. During the last 5 years the Penn State Integrated Hydrologic Modeling System has been under development as an open-source community modeling project funded by NSF EAR/GEO and NSF CBET/ENG. PIHM represents a strategy for the formulation and solution of fully-coupled process equations at the watershed and river basin scales, and includes a tightly coupled GIS tool for data handling, domain decomposition, optimal unstructured grid generation, and model parameterization. The sensor and simulation system has the following elements: 1) extensive, spatially-distributed, non- invasive, smart sensor networks to gather massive geologic, hydrologic, and geochemical data; 2) stochastic information fusion methods; 3) spatially-explicit multiphysics models/solutions of the land-vegetation- atmosphere system; and 4) asynchronous, parallel/distributed, adaptive algorithms for rapidly simulating the states of a basin at high resolution, 5) signal processing tools for data mining and parameter estimation, and 6) visualization tools. The prototype proposed sensor array and simulation system proposed here will offer a coherent new approach to environmental predictions with a fully integrated observing system design. We expect that the Shale Hills Hydro_Sensorium may provide the needed synthesis of information and conceptualization necessary to advance predictive understanding in complex hydrologic systems.

Evaluation of the Performance of the Mars Environmental Compatibility Assessment Electrometer

NASA Technical Reports Server (NTRS)

Mantovani, James G.

2002-01-01

The Mars Environmental Compatibility Assessment (MECA) electrometer is an instrument that was designed jointly by researchers at the Jet Propulsion Laboratory and the Kennedy Space Center, and is intended to fly on a future space exploration mission of the surface of Mars. The electrometer was designed primarily to study (1) the electrostatic interaction between the Martian soil and five different types of insulators, which are attached to the electrometer, as the electrometer is rubbed over the Martian soil. The MECA/Electrometer is also capable of measuring (2) the presence of charged particles in the Martian atmosphere, (3) the local electric field strength, and (4) the local temperature. The goal of the research project described in this report was to test and evaluate the measurement capabilities of the MECA/Electrometer under simulated Martian surface conditions using facilities located in the Labs and Testbeds Division at the Kennedy Space Center. The results of this study indicate that the Martian soil simulant can triboelectrically charge up the insulator surface. However, the maximum charge buildup did not exceed 18% of the electrometer's full-range sensitivity when rubbed vigorously, and is more likely to be as low as 1% of the maximum range when rubbed through soil. This indicates that the overall gain of the MECA/Electrometer could be increased by a factor of 50 if measurements at the 50% level of full-range sensitivity are desired. The ion gauge, which detects the presence of charged particles, was also evaluated over a pressure range from 10 to 400 Torr (13 to 533 mbar). The electric field sensor was also evaluated. Although the temperature sensor was not evaluated due to project time constraints, it was previously reported to work properly.

Evaluation of The Performance of The Mars Environmental Compatibility Assessment Electrometer

NASA Technical Reports Server (NTRS)

Mantovani, James G.

2001-01-01

The Mars Environmental Compatibility Assessment (MECA) electrometer is an instrument that was designed jointly by researchers at the Jet Propulsion Laboratory and the Kennedy Space Center, and is intended to fly on a future space exploration mission of the surface of Mars. The electrometer was designed primarily to study (1) the electrostatic interaction between the Martian soil and five different types of insulators, which are attached to the electrometer, as the electrometer is rubbed over the Martian soil. The MECA/Electrometer is also capable of measuring (2) the presence of charged particles in the Martian atmosphere, (3) the local electric field strength, and (4) the local temperature. The goal of the research project described in this report was to test and evaluate the measurement capabilities of the MECA/Electrometer under simulated Martian surface conditions using facilities located in the Labs and Testbeds Division at the Kennedy Space Center. The results of this study indicate that the Martian soil simulant can triboelectrically charge up the insulator surface. However, the maximum charge buildup did not exceed 18% of the electrometer's full-range sensitivity when rubbed vigorously, and is more likely to be as low as 1% of the maximum range when rubbed through soil. This indicates that the overall gain of the MECA/Electrometer could be increased by a factor of 50 if measurements at the 50% level of full-range sensitivity are desired. The ion gauge, which detects the presence of charged particles, was also evaluated over a pressure range from 10 to 400 Torr (13 to 533 mbar). The electric field sensor was also evaluated. Although the temperature sensor was not evaluated due to project time constraints, it was previously reported to work properly.

Chemochromic Hydrogen Sensors

NASA Technical Reports Server (NTRS)

Wiggins, Bryan C.

2007-01-01

As fossil fuel supplies decline, hydrogen is quickly becoming an increasingly important fuel source. Currently hydrogen is the prime fuel of today's space vehicles (e.g., Space Shuttle) and featured as a fuel for some prototype vehicles such as the BMW seven series model. Hydrogen is a colorless, odorless gas with a 4% lower explosive limit which makes leak detection a priority. In an effort to support the use of hydrogen, a chemochromic (color changing) sensor was developed that is robust, simple to use, and does not require active operation. It can be made into a thin tape which can be conveniently used for leak detection at flanges, valves, or outlets. Chemochromic sensors can be either reversible or irreversible; however, irreversible chemochromic sensors will be analyzed in this report. The irreversible sensor is useful during hazardous operations when personnel cannot be present. To actively monitor leaks, testing of the irreversible sensor against environmental effects was completed and results indicated this material is suitable for outdoor use in the harsh beachside environment of Kennedy Space Center. The experiments in this report will give additional results to the environmental testing by adding solid rocket booster residue as a variable. The primary motivation for these experiments is to prepare the sensors for the launch pad environment at the Kennedy Space Center. In an effort to simulate the atmosphere at the pads before and after launch, the chemochromic sensors are exposed to solid rocket residue under various conditions.

Simulation of Canopy CO2/H2O Fluxes for a Rubber (Hevea Brasiliensis) Plantation in Central Cambodia: The Effect of the Regular Spacing of Planted Trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumagai, Tomo'omi; Mudd, Ryan; Miyazawa, Yoshiyuki

We developed a soil-vegetation-atmosphere transfer (SVAT) model applicable to simulating CO2 and H2O fluxes from the canopies of rubber plantations, which are characterized by distinct canopy clumping produced by regular spacing of plantation trees. Rubber (Hevea brasiliensis Müll. Arg.) plantations, which are rapidly expanding into both climatically optimal and sub-optimal environments throughout mainland Southeast Asia, potentially change the partitioning of water, energy, and carbon at multiple scales, compared with traditional land covers it is replacing. Describing the biosphere-atmosphere exchange in rubber plantations via SVAT modeling is therefore essential to understanding the impacts on environmental processes. The regular spacing of plantationmore » trees creates a peculiar canopy structure that is not well represented in most SVAT models, which generally assumes a non-uniform spacing of vegetation. Herein we develop a SVAT model applicable to rubber plantation and an evaluation method for its canopy structure, and examine how the peculiar canopy structure of rubber plantations affects canopy CO2 and H2O exchanges. Model results are compared with measurements collected at a field site in central Cambodia. Our findings suggest that it is crucial to account for intensive canopy clumping in order to reproduce observed rubber plantation fluxes. These results suggest a potentially optimal spacing of rubber trees to produce high productivity and water use efficiency.« less

Free-flying dynamics and control of an astronaut assistant robot based on fuzzy sliding mode algorithm

NASA Astrophysics Data System (ADS)

Gao, Qing; Liu, Jinguo; Tian, Tongtong; Li, Yangmin

2017-09-01

Space robots can perform some tasks in harsh environment as assistants of astronauts or substitutions of astronauts. Taking the limited working time and the arduous task of the astronauts in the space station into account, an astronaut assistant robot (AAR-2) applied in the space station is proposed and designed in this paper. The AAR-2 is achieved with some improvements on the basis of AAR-1 which was designed before. It can exploit its position and attitude sensors and control system to free flight or hover in the space cabin. And it also has a definite environmental awareness and artificial intelligence to complete some specified tasks under the control of astronauts or autonomously. In this paper, it mainly analyzes and controls the 6-DOF motion of the AAR-2. Firstly, the system configuration of AAR-2 is specifically described, and the movement principles are analyzed. Secondly, according to the physical model of the AAR-2, the Newton - Euler equation is applied in the preparation of space dynamics model of 6-DOF motion. Then, according to the mathematical model's characteristics which are nonlinear and strong coupling, a dual closed loop position and attitude controller based on fuzzy sliding mode control is proposed and designed. Finally, simulation experiments are appropriate to provide for AAR-2 control system by using Matlab/Simulink. From the simulation results it can be observed that the designed fuzzy sliding mode controller can control the 6-DOF motion of AAR-2 quickly and precisely.

The Berkeley Environmental Simulation Laboratory: Its Use In Environmental Impact Assessment.

ERIC Educational Resources Information Center

Appleyard, Donald; And Others

An environmental simulation laboratory at the University of California, Berkeley, is testing the adequacy of different techniques for simulating environmental experiences. Various levels of realism, with various costs, are available in different presentation modes. The simulations can aid in communication about and the resolution of environmental…

A cumulative index to a continuing bibliography on aerospace medicine and biology, January 1972

NASA Technical Reports Server (NTRS)

1972-01-01

Subject coverage concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Each entry consists of a standard citation accompanied by its abstract.

Effect of Heat on Wounded Warriors in Ground Combat Vehicles: Insights from the Army Medical Community, and the Simulation of a Novel Method for Soldier Thermal Control

DTIC Science & Technology

2012-08-01

soldiers via microclimate cooling [13]. Unfortunately, a common method for direct cooling of the soldiers – surface cooling – can cause cutaneous...Intermittent, Regional Microclimate Cooling," Journal of Applied Physiology, vol. 94, pp. 1841-48, 2003. [18] L. A. Stephenson, C. R. Vernieuw, W...Leammukda and M. A. Kolka, "Skin Temperature Feedback Optimizes Microclimate Cooling," Aviation, Space and Environmental Medicine, vol. 78, pp. 377-382

Avoiding chaos in Wonderland

NASA Astrophysics Data System (ADS)

Kohring, G. A.

2006-08-01

Wonderland, a compact, integrated economic, demographic and environmental model, is investigated using methods developed for studying critical phenomena. Simulation results show the parameter space separates into two phases, one of which contains the property of long term, sustainable development. By employing information contain in the phase diagram, an optimal strategy involving pollution taxes is developed as a means of moving a system initially in a unsustainable region of the phase diagram into a region of sustainability while ensuring minimal regret with respect to long-term economic growth.

A Webb in a Golden Cage

NASA Image and Video Library

2013-03-07

This photograph shows support structures wrapped in gold thermal blankets that look like a golden cage. The structure is housed within the vacuum chamber called the Space Environment Simulator, or SES. The SES is located at NASA's Goddard Space Flight Center in Greenbelt, Md., where components of the James Webb Space Telescope are being tested to withstand the extreme temperatures of space. The entire structure is a system of supports and thermal control devices for the series of thermal tests. Visible in the photo is the lower GESHA (Ground Environmental SES Hardware Assembly).The box in the center photo is a group of four LN2 (liquid nitrogen) panels that are designed to keep it at around 100 kelvins. The panels surround the primary mirror of the OTE (Optical Telescope Element) Simulator or OSIM. When NASA's Webb telescope launches in 2018, it will fly a million miles from Earth and enable scientists on Earth to see the most detailed pictures of the universe. For another photo of the SES, visit: www.nasa.gov/topics/technology/features/webb_osim.html For more information about NASA's James Webb Space Telescope, visit: www.jwst.nasa.gov Photo: NASA/Chris Gunn Text: NASA/Rob Gutro NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Space use optimisation and sustainability-environmental assessment of space use concepts.

PubMed

van den Dobbelsteen, Andy; de Wilde, Sebastiaan

2004-11-01

In this paper, as part of a diptych, we discuss the factor space as a means of improving the environmental performance of building projects. There are indicators for space use efficiency and several more or less broadly supported methods for assessment of environmental issues such as ecological quality, use of building materials and energy consumption. These are discussed in this paper. Assessment methods coupling space use to environmental indicators had not been available until now. Beforehand, plans with different spatial properties could therefore not be environmentally compared. We present a method for the implementation of space use in assessments concerning sustainability. This method was applied to the urban case study presented in our second paper in this journal. In this paper, we also present solutions for improved environmental performance through intensive and multiple use of space in the second, third and fourth dimension.

Integrating GIS and ABM to Explore Spatiotemporal Dynamics

NASA Astrophysics Data System (ADS)

Sun, M.; Jiang, Y.; Yang, C.

2013-12-01

Agent-based modeling as a methodology for the bottom-up exploration with the account of adaptive behavior and heterogeneity of system components can help discover the development and pattern of the complex social and environmental system. However, ABM is a computationally intensive process especially when the number of system components becomes large and the agent-agent/agent-environmental interaction is modeled very complex. Most of traditional ABM frameworks developed based on CPU do not have a satisfying computing capacity. To address the problem and as the emergence of advanced techniques, GPU computing with CUDA can provide powerful parallel structure to enable the complex simulation of spatiotemporal dynamics. In this study, we first develop a GPU-based ABM system. Secondly, in order to visualize the dynamics generated from the movement of agent and the change of agent/environmental attributes during the simulation, we integrate GIS into the ABM system. Advanced geovisualization technologies can be utilized for representing the spatiotemporal change events, such as proper 2D/3D maps with state-of-the-art symbols, space-time cube and multiple layers each of which presents pattern in one time-stamp, etc. Thirdly, visual analytics which include interactive tools (e.g. grouping, filtering, linking, etc.) is included in our ABM-GIS system to help users conduct real-time data exploration during the progress of simulation. Analysis like flow analysis and spatial cluster analysis can be integrated according to the geographical problem we want to explore.

The future of simulations for space applications

NASA Astrophysics Data System (ADS)

Matsumoto, H.

Space development has been rapidly increasing and there will be huge investment by business markets for space development and applications such as space factory and Solar Power Station (SPS). In such a situation, we would like to send a warning message regarding the future space simulations. It is widely recognized that space simulation have been contributing to the quantitative understanding of various plasma phenomena occurring in the solarterrestrial environment. In the current century, however, in addition to the conventional contribution to the solar-terrestrial physics, we also have to pay our attention to the application of space simulation for human activities in space. We believe that space simulations can be a a powerful and helpful tool for the understanding the spacecraft-environment interactions occurring in space development and applications. The global influence by exhausted heavy ions from electric propulsion on the plasmasphere can be also analyzed by the combination of MHD and particle simulations. The results obtained in the simulations can provide us very significant and beneficial information so that we can minimize the undesirable effects in space development and applications. 1 Brief history of ISSS and contribution to the space plasma physics Numerical simulation has been largely recognized as a powerful tool in the advance of space plasma physics. The International School for Space Simulation (ISSS) series was set up in order to emphasize such a recognition in the early eighties, on the common initiative of M. Ashour-Abdalla, R. Gendrin, T. Sato and myself. The preceding five ISSS's (in Japan, USA, France, Japan, and Japan again) have greatly contributed to the promotion of and advance of computer simulations as well as the education of students trying to start the simulation study for their own research objectives.

Low Earth orbital atomic oxygen environmental simulation facility for space materials evaluation

NASA Technical Reports Server (NTRS)

Stidham, Curtis R.; Banks, Bruce A.; Stueber, Thomas J.; Dever, Joyce A.; Rutledge, Sharon K.; Bruckner, Eric J.

1993-01-01

Simulation of low Earth orbit atomic oxygen for accelerated exposure in ground-based facilities is necessary for the durability evaluation of space power system component materials for Space Station Freedom (SSF) and future missions. A facility developed at the National Aeronautics and Space Administrations's (NASA) Lewis Research Center provides accelerated rates of exposure to a directed or scattered oxygen beam, vacuum ultraviolet (VUV) radiation, and offers in-situ optical characterization. The facility utilizes an electron-cyclotron resonance (ECR) plasma source to generate a low energy oxygen beam. Total hemispherical spectral reflectance of samples can be measured in situ over the wavelength range of 250 to 2500 nm. Deuterium lamps provide VUV radiation intensity levels in the 115 to 200 nm range of three to five equivalent suns. Retarding potential analyses show distributed ion energies below 30 electron volts (eV) for the operating conditions most suited for high flux, low energy testing. Peak ion energies are below the sputter threshold energy (approximately 30 eV) of the protective coatings on polymers that are evaluated in the facility, thus allowing long duration exposure without sputter erosion. Neutral species are expected to be at thermal energies of approximately .04 eV to .1 eV. The maximum effective flux level based on polyimide Kapton mass loss is 4.4 x 10 exp 6 atoms/((sq. cm)*s), thus providing a highly accelerated testing capability.

Brownfield Action Online - An Interactive Undergraduate Science Course in Environmental Forensics

NASA Astrophysics Data System (ADS)

Liddicoat, Joseph; Bower, Peter

2014-05-01

Brownfield Action (BA) is a web-based, interactive, three dimensional digital space and learning simulation in which students form geotechnical consulting companies and work collectively to explore problems in environmental forensics. Created at Barnard College (BC) in conjunction with the Center for New Media Teaching and Learning at Columbia University, BA has a 12-year history at BC of use in one semester of a two-semester Introduction to Environmental Science course that is taken by more than 100 female undergraduate non-science majors to satisfy their science requirement. The pedagogical methods and design of the BA model are grounded in a substantial research literature focused on the design, use, and effectiveness of games and simulation in education. The successful use of the BA simulation at BC and 14 other institutions in the U.S. is described in Bower et al. (2011 and 2014). Soon to be taught online to non-traditional undergraduate students, BA has 15 modules that include a reconnaissance survey; scale; topographic, bedrock, and water table maps; oral and written reports from residents and the municipal government; porosity and permeability measurements of the regolith (sand) in the area of interest; hydrocarbon chemistry; direction and velocity of groundwater flow; and methods of geophysical exploration (soil gas, ground penetrating radar, magnetic metal detection, excavation, and drilling). Student performance is assessed by weekly exercises and a semester ending Environmental Site Assessment Phase I Report that summarizes the individual and collective discoveries about a contaminated subsurface plume that emanates from a leaking underground storage tank at a gasoline station upgrade from the water well that serves the surrounding community. Texts for the course are Jonathan Harr's A Civil Action and Rachel Carson's Silent Spring, which are accompanied by questions that direct the reading.

Environmental Modeling, Technology, and Communication for Land Falling Tropical Cyclone/Hurricane Prediction

PubMed Central

Tuluri, Francis; Reddy, R. Suseela; Anjaneyulu, Y.; Colonias, John; Tchounwou, Paul

2010-01-01

Katrina (a tropical cyclone/hurricane) began to strengthen reaching a Category 5 storm on 28th August, 2005 and its winds reached peak intensity of 175 mph and pressure levels as low as 902 mb. Katrina eventually weakened to a category 3 storm and made a landfall in Plaquemines Parish, Louisiana, Gulf of Mexico, south of Buras on 29th August 2005. We investigate the time series intensity change of the hurricane Katrina using environmental modeling and technology tools to develop an early and advanced warning and prediction system. Environmental Mesoscale Model (Weather Research Forecast, WRF) simulations are used for prediction of intensity change and track of the hurricane Katrina. The model is run on a doubly nested domain centered over the central Gulf of Mexico, with grid spacing of 90 km and 30 km for 6 h periods, from August 28th to August 30th. The model results are in good agreement with the observations suggesting that the model is capable of simulating the surface features, intensity change and track and precipitation associated with hurricane Katrina. We computed the maximum vertical velocities (Wmax) using Convective Available Kinetic Energy (CAPE) obtained at the equilibrium level (EL), from atmospheric soundings over the Gulf Coast stations during the hurricane land falling for the period August 21–30, 2005. The large vertical atmospheric motions associated with the land falling hurricane Katrina produced severe weather including thunderstorms and tornadoes 2–3 days before landfall. The environmental modeling simulations in combination with sounding data show that the tools may be used as an advanced prediction and communication system (APCS) for land falling tropical cyclones/hurricanes. PMID:20623002

Effects of running with backpack loads during simulated gravitational transitions: Improvements in postural control

NASA Astrophysics Data System (ADS)

Brewer, Jeffrey David

The National Aeronautics and Space Administration is planning for long-duration manned missions to the Moon and Mars. For feasible long-duration space travel, improvements in exercise countermeasures are necessary to maintain cardiovascular fitness, bone mass throughout the body and the ability to perform coordinated movements in a constant gravitational environment that is six orders of magnitude higher than the "near weightlessness" condition experienced during transit to and/or orbit of the Moon, Mars, and Earth. In such gravitational transitions feedback and feedforward postural control strategies must be recalibrated to ensure optimal locomotion performance. In order to investigate methods of improving postural control adaptation during these gravitational transitions, a treadmill based precision stepping task was developed to reveal changes in neuromuscular control of locomotion following both simulated partial gravity exposure and post-simulation exercise countermeasures designed to speed lower extremity impedance adjustment mechanisms. The exercise countermeasures included a short period of running with or without backpack loads immediately after partial gravity running. A novel suspension type partial gravity simulator incorporating spring balancers and a motor-driven treadmill was developed to facilitate body weight off loading and various gait patterns in both simulated partial and full gravitational environments. Studies have provided evidence that suggests: the environmental simulator constructed for this thesis effort does induce locomotor adaptations following partial gravity running; the precision stepping task may be a helpful test for illuminating these adaptations; and musculoskeletal loading in the form of running with or without backpack loads may improve the locomotor adaptation process.

Space Propulsion Research Facility (B-2): An Innovative, Multi-Purpose Test Facility

NASA Technical Reports Server (NTRS)

Hill, Gerald M.; Weaver, Harold F.; Kudlac, Maureen T.; Maloney, Christian T.; Evans, Richard K.

2011-01-01

The Space Propulsion Research Facility, commonly referred to as B-2, is designed to hot fire rocket engines or upper stage launch vehicles with up to 890,000 N force (200,000 lb force), after environmental conditioning of the test article in simulated thermal vacuum space environment. As NASA s third largest thermal vacuum facility, and the largest designed to store and transfer large quantities of propellant, it is uniquely suited to support developmental testing associated with large lightweight structures and Cryogenic Fluid Management (CFM) systems, as well as non-traditional propulsion test programs such as Electric and In-Space propulsion. B-2 has undergone refurbishment of key subsystems to support the NASA s future test needs, including data acquisition and controls, vacuum, and propellant systems. This paper details the modernization efforts at B-2 to support the Nation s thermal vacuum/propellant test capabilities, the unique design considerations implemented for efficient operations and maintenance, and ultimately to reduce test costs.

Environmental enrichment choices of shelter cats.

PubMed

Ellis, J J; Stryhn, H; Spears, J; Cockram, M S

2017-08-01

Choices made by cats between different types of environmental enrichment may help shelters to prioritize how to most effectively enrich cat housing, especially when limited by space or funds. This study investigates the environmental enrichment use of cats in a choice test. Twenty-six shelter cats were kept singularly in choice chambers for 10days. Each chamber had a central area and four centrally-linked compartments containing different types of environmental enrichment: 1) an empty control, 2) a prey-simulating toy, 3) a perching opportunity, and 4) a hiding opportunity. Cat movement between compartments was quantitatively recorded using a data-logger. Enriched compartments were visited significantly more frequently during the light period than during the dark period. Cats spent a significantly greater percentage of time in the hiding compartment (median=55%, IQR=46) than in the toy compartment (median=2%, IQR=9), or in the empty control compartment (median=4%, IQR=4). These results provide additional evidence to support the value of a hiding box to cats housed in a novel environment, in that they choose hiding relative to other types of environmental enrichment. Copyright © 2017 Elsevier B.V. All rights reserved.

Polymerisation processes in expoy resins under influence of free space environment

NASA Astrophysics Data System (ADS)

Kondyurin, A.; Lauke, B.; Kondyurina, I.

A creation of large size constructions in space or on celestial bodies is possible by the way of chemical reactions of liquid viscous components under space environment conditions [1-2]. In particular, a new technology for large-size space module for electronic components, energy and materials production is developed on the basis of polymerisation technique. The factors of free space environment have a significant influence on the polymerisation processes. The polymerisation processes in active liquid components are sensitive to microgravitation, temperature variations (-150{ldots}+1500C), high vacuum (10-3{ldots}10-7 Pa), atomic oxygen flux (on LEO), UV and VUV irradiations, X-ray and γ -irradiations, high energy electron and ion fluxes. Experiments of polymerisation processes under simulated free space conditions were conducted. The influences of high vacuum, high energy ion beam and rf- and mw-plasma on polymerisation of epoxy resins were observed. The effects of low molecular components evaporations, free radical formations, additional chemical reactions and mixing processes during polymerisation were observed. Our results showed, that the space factors can initiate the polymerisation reaction in epoxy matrix of glass and carbon fibre composites. The result can be used for a technology for large size constructions on Earth orbit, in far space and on space bodies as for deployed antennas, solar sail stringers, solar shield stringers, frame for large-size space station, frame for Moon, Mars, asteroids bases, frame for space plant on Earth orbit and on other celestial bodies. The study was partially supported by Alexander von Humboldt Foundation (A. Kondyurin) and European Space Agency, ESTEC (contract 17083/03/NL/Sfe "Space Environmental Effects on the Polymerisation of Composite Structures"). 1. A.Kondyurin, B.Lauke, Polymerisation processes in simulated free space conditions, Proceedings of the 9th International Symposium on Materials in a Space Environment, Noordwijk, The Netherlands, 16-20 June, 2003, ESA SP-540, September 2003, pp.75-80. 2. V.A.Briskman, T.M.Yudina, K.G.Kostarev, A.V.Kondyurin, V.B.Leontyev, M.G.Levkovich, A.L.Mashinsky, G.S.Nechitailo, Polymerization in microgravity as a new process in space technology, Acta Astronautica, vol.48, N2-3, 2001, pp.169-180.

Cardiovascular Deconditioning in Humans: Human Studies Core

NASA Technical Reports Server (NTRS)

Williams, Gordon

1999-01-01

Major cardiovascular problems, secondary to cardiovascular deconditioning, may occur on extended space missions. While it is generally assumed that the microgravity state is the primary cause of cardiovascular deconditioning, sleep deprivation and disruption of diurnal rhythms may also play an important role. Factors that could be modified by either or both of these perturbations include: autonomic function and short-term cardiovascular reflexes, vasoreactivity, circadian rhythm of cardiovascular hormones (specifically the renin-angiotensin system) and renal sodium handling and hormonal influences on that process, venous compliance, cardiac mass, and cardiac conduction processes. The purpose of the Human Studies Core is to provide the infrastructure to conduct human experiments which will allow for the assessment of the likely role of such factors in the space travel associated cardiovascular deconditioning process and to develop appropriate countermeasures. The Core takes advantage of a newly-created Intensive Physiologic Monitoring (IPM) Unit at the Brigham and Women's Hospital, Boston, MA, to perform these studies. The Core includes two general experimental protocols. The first protocol involves a head down tilt bed-rest study to simulate microgravity. The second protocol includes the addition of a disruption of circadian rhythms to the simulated microgravity environment. Before and after each of these environmental manipulations, the subjects will undergo acute stressors simulating changes in volume and/or stress, which could occur in space and on return to Earth. The subjects are maintained in a rigidly controlled environment with fixed light/dark cycles, activity pattern, and dietary intake of nutrients, fluids, ions and calories.

KSC-2014-2898

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, the bellows has been removed from around the Veggie plant growth system so that the plant pillows containing the outredgeous red lettuce leaves can be removed. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

KSC-2014-2901

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Jim Smodell, a technician with SGT, removes the plant pillows containing the outredgeous red lettuce leaves from the Veggie plant growth system inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

KSC-2014-2897

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jim Smodell, a technician with SGT, prepares to remove the bellows from the Veggie plant growth system containing the outredgeous red lettuce leaves. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

The space elevator: a new tool for space studies.

PubMed

Edwards, Bradley C

2003-06-01

The objective has been to develop a viable scenario for the construction, deployment and operation of a space elevator using current or near future technology. This effort has been primarily a paper study with several experimental tests of specific systems. Computer simulations, engineering designs, literature studies and inclusion of existing programs have been utilized to produce a design for the first space elevator. The results from this effort illustrate a viable design using current and near-term technology for the construction of the first space elevator. The timeline for possible construction is within the coming decades and estimated costs are less than $10 B. The initial elevator would have a 5 ton/day capacity and operating costs near $100/lb for payloads going to any Earth orbit or traveling to the Moon, Mars, Venus or the asteroids. An operational space elevator would allow for larger and much longer-term biological space studies at selectable gravity levels. The high-capacity and low operational cost of this system would also allow for inexpensive searches for life throughout our solar system and the first tests of environmental engineering. This work is supported by a grant from the NASA Institute for Advanced Concepts (NIAC).

Mission Simulation of Space Lidar Measurements for Seasonal and Regional CO2 Variations

NASA Technical Reports Server (NTRS)

Kawa, Stephan; Collatz, G. J.; Mao, J.; Abshire, J. B.; Sun, X.; Weaver, C. J.

2010-01-01

Results of mission simulation studies are presented for a laser-based atmospheric [82 sounder. The simulations are based on real-time carbon cycle process modeling and data analysis. The mission concept corresponds to the Active Sensing of [82 over Nights, Days, and Seasons (ASCENDS) recommended by the US National Academy of Sciences Decadal Survey of Earth Science and Applications from Space. One prerequisite for meaningful quantitative sensor evaluation is realistic CO2 process modeling across a wide range of scales, i.e., does the model have representative spatial and temporal gradients? Examples of model comparison with data will be shown. Another requirement is a relatively complete description of the atmospheric and surface state, which we have obtained from meteorological data assimilation and satellite measurements from MODIS and [ALIPS0. We use radiative transfer model calculations, an instrument model with representative errors ' and a simple retrieval approach to complete the cycle from "nature" run to "pseudo-data" CO2, Several mission and instrument configuration options are examined/ and the sensitivity to key design variables is shown. We use the simulation framework to demonstrate that within reasonable technological assumptions for the system performance, relatively high measurement precision can be obtained, but errors depend strongly on environmental conditions as well as instrument specifications. Examples are also shown of how the resulting pseudo - measurements might be used to address key carbon cycle science questions.

Studies of social group dynamics under isolated conditions. Objective summary of the literature as it relates to potential problems of long duration space flight

NASA Technical Reports Server (NTRS)

Vinograd, S. P.

1974-01-01

Scientific literature which deals with the study of human behavior and crew interaction in situations simulating long term space flight is summarized and organized. A bibliography of all the pertinent U.S. literature available is included, along with definitions of the behavioral characteristics terms employed. The summarized studies are analyzed according to behavioral factors and environmental conditions. The analysis consist of two matrices. (1) The matrix of factors studied correlates each research study area and individual study with the behavioral factors that were investigated in the study. (2) The matrix of conclusions identifies those studies whose investigators appeared to draw specific conclusions concerning questions of importance to NASA.

Technology development of fabrication techniques for advanced solar dynamic concentrators

NASA Technical Reports Server (NTRS)

Richter, Scott W.

1991-01-01

The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

Institutional environmental impact statement (space shuttle development and operations) amendment no. 1. [space shuttle operations at Kennedy Space Center

NASA Technical Reports Server (NTRS)

1973-01-01

Data are presented to support the environmental impact statement on space shuttle actions at Kennedy Space Center. Studies indicate that land use to accommodate space shuttle operations may have the most significant impact. The impacts on air, water and noise quality are predicted to be less on the on-site environment. Considerations of operating modes indicate that long and short term land use will not affect wildlife productivity. The potential for adverse environmental impact is small and such impacts will be local, short in duration, controllable, and environmentally acceptable.

Hydrological Modelling and Sensitivity Analysis Using Topmodel and Simulated Annealing Techniques.application To The Haute-mentue Catchment(switzerland).

NASA Astrophysics Data System (ADS)

Balin Talamba, D.; Higy, C.; Joerin, C.; Musy, A.

The paper presents an application concerning the hydrological modelling for the Haute-Mentue catchment, located in western Switzerland. A simplified version of Topmodel, developed in a Labview programming environment, was applied in the aim of modelling the hydrological processes on this catchment. Previous researches car- ried out in this region outlined the importance of the environmental tracers in studying the hydrological behaviour and an important knowledge has been accumulated dur- ing this period concerning the mechanisms responsible for runoff generation. In con- formity with the theoretical constraints, Topmodel was applied for an Haute-Mentue sub-catchment where tracing experiments showed constantly low contributions of the soil water during the flood events. The model was applied for two humid periods in 1998. First, the model calibration was done in order to provide the best estimations for the total runoff. Instead, the simulated components (groundwater and rapid flow) showed far deviations from the reality indicated by the tracing experiments. Thus, a new calibration was performed including additional information given by the environ- mental tracing. The calibration of the model was done by using simulated annealing (SA) techniques, which are easy to implement and statistically allow for converging to a global minimum. The only problem is that the method is time and computer consum- ing. To improve this, a version of SA was used which is known as very fast-simulated annealing (VFSA). The principles are the same as for the SA technique. The random search is guided by certain probability distribution and the acceptance criterion is the same as for SA but the VFSA allows for better taking into account the ranges of vari- ation of each parameter. Practice with Topmodel showed that the energy function has different sensitivities along different dimensions of the parameter space. The VFSA algorithm allows differentiated search in relation with the sensitivity of the param- eters. The environmental tracing was used in the aim of constraining the parameter space in order to better simulate the hydrological behaviour of the catchment. VFSA outlined issues for characterising the significance of Topmodel input parameters as well as their uncertainty for the hydrological modelling.

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Code of Federal Regulations, 2010 CFR

2010-07-01

... vehicles tested using a simulation of the environmental test cell for air conditioning emission testing. 86... tested using a simulation of the environmental test cell for air conditioning emission testing. This section is applicable for vehicles which are tested using a simulation of the environmental test cell...

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Code of Federal Regulations, 2013 CFR

2013-07-01

... vehicles tested using a simulation of the environmental test cell for air conditioning emission testing. 86... tested using a simulation of the environmental test cell for air conditioning emission testing. This section is applicable for vehicles which are tested using a simulation of the environmental test cell...

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Code of Federal Regulations, 2012 CFR

2012-07-01

... vehicles tested using a simulation of the environmental test cell for air conditioning emission testing. 86... tested using a simulation of the environmental test cell for air conditioning emission testing. This section is applicable for vehicles which are tested using a simulation of the environmental test cell...

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Code of Federal Regulations, 2011 CFR

2011-07-01

... vehicles tested using a simulation of the environmental test cell for air conditioning emission testing. 86... tested using a simulation of the environmental test cell for air conditioning emission testing. This section is applicable for vehicles which are tested using a simulation of the environmental test cell...

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Code of Federal Regulations, 2014 CFR

2014-07-01

... vehicles tested using a simulation of the environmental test cell for air conditioning emission testing. 86... tested using a simulation of the environmental test cell for air conditioning emission testing. This section is applicable for vehicles which are tested using a simulation of the environmental test cell...

The impact of contextualization on immersion in healthcare simulation.

PubMed

Engström, Henrik; Andersson Hagiwara, Magnus; Backlund, Per; Lebram, Mikael; Lundberg, Lars; Johannesson, Mikael; Sterner, Anders; Maurin Söderholm, Hanna

2016-01-01

The aim of this paper is to explore how contextualization of a healthcare simulation scenarios impacts immersion, by using a novel objective instrument, the Immersion Score Rating Instrument. This instrument consists of 10 triggers that indicate reduced or enhanced immersion among participants in a simulation scenario. Triggers refer to events such as jumps in time or space (sign of reduced immersion) and natural interaction with the manikin (sign of enhanced immersion) and can be used to calculate an immersion score. An experiment using a randomized controlled crossover design was conducted to compare immersion between two simulation training conditions for prehospital care: one basic and one contextualized. The Immersion Score Rating Instrument was used to compare the total immersion score for the whole scenario, the immersion score for individual mission phases, and to analyze differences in trigger occurrences. A paired t test was used to test for significance. The comparison shows that the overall immersion score for the simulation was higher in the contextualized condition. The average immersion score was 2.17 (sd = 1.67) in the contextualized condition and -0.77 (sd = 2.01) in the basic condition ( p  < .001). The immersion score was significantly higher in the contextualized condition in five out of six mission phases. Events that might be disruptive for the simulation participants' immersion, such as interventions of the instructor and illogical jumps in time or space, are present to a higher degree in the basic scenario condition; while events that signal enhanced immersion, such as natural interaction with the manikin, are more frequently observed in the contextualized condition. The results suggest that contextualization of simulation training with respect to increased equipment and environmental fidelity as well as functional task alignment might affect immersion positively and thus contribute to an improved training experience.

Simulate different environments TDLAS On the analysis of the test signal strength

NASA Astrophysics Data System (ADS)

Li, Xin; Zhou, Tao; Jia, Xiaodong

2014-12-01

TDLAS system is the use of the wavelength tuning characteristics of the laser diode, for detecting the absorption spectrum of the gas absorption line. Detecting the gas space, temperature, pressure and flow rate and concentration. The use of laboratory techniques TDLAS gas detection, experimental simulation engine combustion water vapor and smoke. using an optical lens system receives the signal acquisition and signal interference test analysis. Analog water vapor and smoke in two different environments in the sample pool interference. In both experiments environmental interference gas absorption in the optical signal acquisition, signal amplitude variation analysis, and records related to the signal data. In order to study site conditions in the engine combustion process for signal acquisition provides an ideal experimental data .

Haughton-Mars Project (HMP)/NASA 2006 Lunar Medical Contingency Simulation: An Overview

NASA Technical Reports Server (NTRS)

Scheuring, R. A.; Jones, J. A.; Lee, P.; Comtois, J. M.; Chappell, S.; Rafiq, A.; Braham, S.; Hodgson, E.; Sullivan, P.; Wilkinson, N.

2006-01-01

Medical requirements are currently being developed for NASA's space exploration program. Lunar surface operations for crews returning to the moon will be performed on a daily basis to conduct scientific research and construct a lunar habitat. Inherent to aggressive surface activities is the potential risk of injury to crew members. To develop an evidence-base for handling medical contingencies on the lunar surface, a simulation project was conducted using the moon-Mars analog environment at Devon Island, Nunavut, high Canadian Arctic. A review of the Apollo lunar surface activities and personal communications with Apollo lunar crew members provided a knowledge base of plausible scenarios that could potentially injure an astronaut during a lunar extravehicular activity. Objectives were established to 1) demonstrate stabilization, field extraction and transfer an injured crew member to the habitat and 2) evaluate audio, visual and biomedical communication capabilities with ground controllers at multiple mission control centers. The simulation project s objectives were achieved. Among these objectives were 1) extracting a crew member from a sloped terrain by a two-member team in a 1-g analog environment, 2) establishing real-time communication to multiple space centers, 3) providing biomedical data to flight controllers and crew members, and 4) establishing a medical diagnosis and treatment plan from a remote site. The simulation project provided evidence for the types of equipment and methods needed for planetary space exploration. During the project, the crew members were confronted with a number of unexpected scenarios including environmental, communications, EVA suit, and navigation challenges. These trials provided insight into the challenges of carrying out a medical contingency in an austere environment. The knowledge gained from completing the objectives of this project will be incorporated into the exploration medical requirements involving an incapacited astronaut on the lunar surface.

Relationship between environmental management with quality of kampong space room (Case study: RW 3 of Sukun Sub District, Malang City)

NASA Astrophysics Data System (ADS)

Wardhani, D. K.; Azmi, D. S.; Purnamasari, W. D.

2017-06-01

RW 3 Sukun Malang was one of kampong that won the competition kampong environment and had managed to maintain the preservation of the kampong. Society of RW 3 Sukun undertake various activities to manage the environment by optimizing the use of kampong space. Despite RW 3 Sukun had conducted environmental management activities, there are several locations in the kampong space that less well maintained. The purpose of this research was to determine the relation of environmental management with the quality of kampong space in RW 3 Sukun. This research used qualitative and quantitative research approaches. Quantitative research conducted by using descriptive statistical analysis in assessing the quality of kampong space with weighting, scoring, and overlay maps. Quantitative research was also conducted on the relation analysis of environmental management with the quality of kampong space by using typology analysis and pearson correlation analysis. Qualitative research conducted on the analysis of environmental management and the relation analysis of environmental management with the quality of kampong space. Result of this research indicates that environmental management in RW 3 Sukun have relation with the quality of kampong space.

Full-size solar dynamic heat receiver thermal-vacuum tests

NASA Technical Reports Server (NTRS)

Sedgwick, L. M.; Kaufmann, K. J.; Mclallin, K. L.; Kerslake, Thomas W.

1991-01-01

The testing of a full-size, 120 kW, solar dynamic heat receiver utilizing high-temperature thermal energy storage is described. The purpose of the test program was to quantify receiver thermodynamic performance, operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber with liquid nitrogen cold shrouds and an aperture cold plate to partly simulate a low-Earth-orbit environment. The cavity of the receiver was heated by an infrared quartz lamp heater with 30 independently controllable zones to allow axially and circumferentially varied flux distributions. A closed-Brayton cycle engine simulator conditioned a helium-xenon gas mixture to specific interface conditions to simulate the various operational modes of the solar dynamic power module on the Space Station Freedom. Inlet gas temperature, pressure, and flow rate were independently varied. A total of 58 simulated orbital cycles, each 94 minutes in duration, was completed during the test conduct period.

Full-size solar dynamic heat receiver thermal-vacuum tests

NASA Technical Reports Server (NTRS)

Sedgwick, L. M.; Kaufmann, K. J.; Mclallin, K. L.; Kerslake, T. W.

1991-01-01

The testing of a full-size, 102 kW, solar dynamic heat receiver utilizing high-temperature thermal energy storage is described. The purpose of the test program was to quantify receiver thermodynamic performance, operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber with liquid nitrogen cold shrouds and an aperture cold plate to partly simulate a low-Earth-orbit environment. The cavity of the receiver was heated by an infrared quartz lamp heater with 30 independently controllable zones to allow axially and circumferentially varied flux distributions. A closed-Brayton cycle engine simulator conditioned a helium-xenon gas mixture to specific interface conditions to simulate the various operational modes of the solar dynamic power module on the Space Station Freedom. Inlet gas temperature, pressure, and flow rate were independently varied. A total of 58 simulated orbital cycles, each 94 minutes in duration, was completed during the test period.

Full-size solar dynamic heat receiver thermal-vacuum tests

NASA Astrophysics Data System (ADS)

Sedgwick, L. M.; Kaufmann, K. J.; McLallin, K. L.; Kerslake, T. W.

The testing of a full-size, 102 kW, solar dynamic heat receiver utilizing high-temperature thermal energy storage is described. The purpose of the test program was to quantify receiver thermodynamic performance, operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber with liquid nitrogen cold shrouds and an aperture cold plate to partly simulate a low-Earth-orbit environment. The cavity of the receiver was heated by an infrared quartz lamp heater with 30 independently controllable zones to allow axially and circumferentially varied flux distributions. A closed-Brayton cycle engine simulator conditioned a helium-xenon gas mixture to specific interface conditions to simulate the various operational modes of the solar dynamic power module on the Space Station Freedom. Inlet gas temperature, pressure, and flow rate were independently varied. A total of 58 simulated orbital cycles, each 94 minutes in duration, was completed during the test period.

Radiation Beamline Testbeds for the Simulation of Planetary and Spacecraft Environments for Human and Robotic Mission Risk Assessment

NASA Technical Reports Server (NTRS)

Wilkins, Richard

2010-01-01

The Center for Radiation Engineering and Science for Space Exploration (CRESSE) at Prairie View A&M University, Prairie View, Texas, USA, is establishing an integrated, multi-disciplinary research program on the scientific and engineering challenges faced by NASA and the international space community caused by space radiation. CRESSE focuses on space radiation research directly applicable to astronaut health and safety during future long term, deep space missions, including Martian, lunar, and other planetary body missions beyond low earth orbit. The research approach will consist of experimental and theoretical radiation modeling studies utilizing particle accelerator facilities including: 1. NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory; 2. Proton Synchrotron at Loma Linda University Medical Center; and 3. Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Laboratory. Specifically, CRESSE investigators are designing, developing, and building experimental test beds that simulate the lunar and Martian radiation environments for experiments focused on risk assessment for astronauts and instrumentation. The testbeds have been designated the Bioastronautics Experimental Research Testbeds for Environmental Radiation Nostrum Investigations and Education (BERT and ERNIE). The designs of BERT and ERNIE will allow for a high degree of flexibility and adaptability to modify experimental configurations to simulate planetary surface environments, planetary habitats, and spacecraft interiors. In the nominal configuration, BERT and ERIE will consist of a set of experimental zones that will simulate the planetary atmosphere (Solid CO2 in the case of the Martian surface.), the planetary surface, and sub-surface regions. These experimental zones can be used for dosimetry, shielding, biological, and electronic effects radiation studies in support of space exploration missions. BERT and ERNIE are designed to be compatible with the experimental areas associated with the above facilities. CRESSE has broad expertise in space radiation in the areas of space radiation environment modeling, Monte-Carlo radiation transport modeling, space radiation instrumentation and dosimetry, radiation effects on electronics, and multi-functional composite shielding materials. The BERT and ERNIE testbeds will be utilized in individual and collaborative research incorporating this expertise. The research goal is to maximize the technical readiness level (TRL) of radiation instrumentation for human and robotic missions, optimizing the return value of CRESSE for NASA exploration and international co-operative missions. Outcomes and knowledge from research utilizing BERT and ERNIE will be applied to a variety of scientific and engineering disciplines vital for safe and reliable execution of future space exploration missions, which can be negatively impacted by the space radiation environment. The testbeds will be central to a variety of university educational activities and educational goals of NASA. Specifically, BERT and ERNIE will enhance educational opportunities in science, technology, engineering and mathematics (STEM) disciplines for engineering and science students at PVAMU, a historically black college/university. Preliminary data on prototype testbed configurations, including simulated lunar regolith (JSC-1A stimulant based on Apollo 11 samples), regolith/polyethylene composites, and dry ice, will be presented to demonstrate the usefulness of BERT and ERNIE in radiation beam line experiments.

Radiation beamline testbeds for the simulation of planetary and spacecraft environments for human and robotic mission risk assessment

NASA Astrophysics Data System (ADS)

Wilkins, Richard

The Center for Radiation Engineering and Science for Space Exploration (CRESSE) at Prairie View A&M University, Prairie View, Texas, USA, is establishing an integrated, multi-disciplinary research program on the scientific and engineering challenges faced by NASA and the inter-national space community caused by space radiation. CRESSE focuses on space radiation research directly applicable to astronaut health and safety during future long term, deep space missions, including Martian, lunar, and other planetary body missions beyond low earth orbit. The research approach will consist of experimental and theoretical radiation modeling studies utilizing particle accelerator facilities including: 1. NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory; 2. Proton Synchrotron at Loma Linda University Med-ical Center; and 3. Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Laboratory. Specifically, CRESSE investigators are designing, developing, and building experimental test beds that simulate the lunar and Martian radiation environments for experiments focused on risk assessment for astronauts and instrumentation. The testbeds have been designated the Bioastronautics Experimental Research Testbeds for Environmental Radiation Nostrum Investigations and Education (BERT and ERNIE). The designs of BERT and ERNIE will allow for a high degree of flexibility and adaptability to modify experimental configurations to simulate planetary surface environments, planetary habitats, and spacecraft interiors. In the nominal configuration, BERT and ERIE will consist of a set of experimental zones that will simulate the planetary atmosphere (Solid CO2 in the case of the Martian surface.), the planetary surface, and sub-surface regions. These experimental zones can be used for dosimetry, shielding, biological, and electronic effects radiation studies in support of space exploration missions. BERT and ERNIE are designed to be compatible with the experimental areas associated with the above facilities. CRESSE has broad expertise in space radiation in the areas of space radiation environment modeling, Monte-Carlo radiation transport modeling, space radiation instrumentation and dosimetry, radiation effects on electronics, and multi-functional composite shielding materi-als. The BERT and ERNIE testbeds will be utilized in individual and collaborative research incorporating this expertise. The research goal is to maximize the technical readiness level (TRL) of radiation instrumentation for human and robotic missions, optimizing the return value of CRESSE for NASA exploration and international co-operative missions. Outcomes and knowledge from research utilizing BERT and ERNIE will be applied to a variety of scien-tific and engineering disciplines vital for safe and reliable execution of future space exploration missions, which can be negatively impacted by the space radiation environment. The testbeds will be central to a variety of university educational activities and educational goals of NASA. Specifically, BERT and ERNIE will enhance educational opportunities in science, technol-ogy, engineering and mathematics (STEM) disciplines for engineering and science students at PVAMU, a historically black college/university. Preliminary data on prototype testbed configurations, including simulated lunar regolith (JSC-1A stimulant based on Apollo 11 samples), regolith/polyethylene composites, and dry ice, will be presented to demonstrate the usefulness of BERT and ERNIE in radiation beam line experiments.

Thermal airborne multispectral aster simulator and its preliminary results

NASA Astrophysics Data System (ADS)

Mills, F.; Kannari, Y.; Watanabe, H.; Sano, M.; Chang, S. H.

1994-03-01

An Airborne ASTER Simulator (AAS) is being developed for the Japan Resources Observation System Organization (JAROS) by the Geophysical Environmental Research (GER) Corporation. The first test flights of the AAS were over Cuprite, Nevada; Long Valley, California; and Death Valley, California, in December 1991. Preliminary laboratory tests at NASA's Stennis Space Center (SSC) were completed in April 1992. The results of the these tests indicate the AAS can discriminate between silicate and non-silicate rocks. The improvements planned for the next two years may give a spectral Full-Width at Half-Maximum (FWHM) of 0.3 μm and NEΔT of 0.2 - 0.5°K. The AAS has the potential to become a good tool for airborne TIR research and can be used for simulations of future satellite-borne TIR sensors. Flight tests over Cuprite, Nevada, and Castaic Lake, California, are planned for October-December 1992.

Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China.

PubMed

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2015-11-09

Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution-severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems.

Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China

PubMed Central

Gong, Jian; Yang, Jianxin; Tang, Wenwu

2015-01-01

Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution—severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems. PMID:26569270

Environmental Control and Life Support Systems Test Facility at MSFC

NASA Technical Reports Server (NTRS)

2001-01-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. In this photograph, the life test area on the left of the MSFC ECLSS test facility is where various subsystems and components are tested to determine how long they can operate without failing and to identify components needing improvement. Equipment tested here includes the Carbon Dioxide Removal Assembly (CDRA), the Urine Processing Assembly (UPA), the mass spectrometer filament assemblies and sample pumps for the Major Constituent Analyzer (MCA). The Internal Thermal Control System (ITCS) simulator facility (in the module in the right) duplicates the function and operation of the ITCS in the ISS U.S. Laboratory Module, Destiny. This facility provides support for Destiny, including troubleshooting problems related to the ITCS.

The Role of Gravity on the Reproduction of Arabidopsis Plants

NASA Technical Reports Server (NTRS)

Hoshizaki, T.

1985-01-01

The presence of gravity as a necessary environmental factor for higher plants to complete their life cycle was examined. Arabidopsis thalliana (L.) Heynh. Columbia strain plants were grown continuously for three generations in a simulated micro-g environment as induced by horizontal clinostats. Growth, development and reproduction were followed. The Arabidopsis plants were selected for three generations on clinostats because: (1) a short life cycle of around 35 days; (2) the cells of third generation plants would in theory be free of gravity imprint; and (3) a third generation plant would therefore more than likely grow and respond like a plant growing in a micro-g environment. It is found that gravity is not a required environmental factor for higher plants to complete their life cycle, at least as tested by a horizontal clinostat. Clinostatting does not prevent the completion of the plant life cycle. However, clinostatting does appear to slow down the reproductive process of Arabidopsis plants. Whether higher plants can continue to reproduce for many generations in a true micro-g environment of space can only be determined by long duration experiments in space.

Teaching undergraduate nursing students about environmental health: addressing public health issues through simulation.

PubMed

Stanley, Mary Jo; Rojas, Deb

2014-01-01

Schools of nursing are challenged to find clinical placements in public health settings. Use of simulation can address situations unique to public health, with attention to specific concerns, such as environmental health. Environmental health is an integral part of public health nursing and is a standard of professional practice. Current simulations focus on acute care situations, offering limited scenarios with a public health perspective and excluding environmental health. This study's simulation scenario was created to enhance nursing students' understanding of public health concepts within an environmental health context. Outcomes from the simulation include the need for integration of environmental issues in public health teaching. Students stated that this scenario provided a broader understanding of the environmental influences that can affect the client's and family's health. This scenario fills a void in simulation content, while providing an interactive teaching and learning strategy to help students to apply knowledge to practice. Copyright 2014, SLACK Incorporated.

Simulated Aging of Spacecraft External Materials on Orbit

NASA Astrophysics Data System (ADS)

Khatipov, S.

Moscow State Engineering Physics Institute (MIFI), in cooperation with Air Force Research Laboratory's Satellite Assessment Center (SatAC), the European Office of Aerospace Research and Development (EOARD), and the International Science and Technology Center (ISTC), has developed a database describing the changes in optical properties of materials used on the external surfaces of spacecraft due to space environmental factors. The database includes data acquired from tests completed under contract with the ISTC and EOARD, as well as from previous Russian materials studies conducted within the last 30 years. The space environmental factors studied are for those found in Low Earth Orbits (LEO) and Geosynchronous orbits (GEO), including electron irradiation at 50, 100, and 200 keV, proton irradiation at 50, 150, 300, and 500 keV, and ultraviolet irradiation equivalent to 1 sun-year. The material characteristics investigated were solar absorption (aS), spectral reflectance (rl), solar reflectance (rS), emissivity (e), spectral transmission coefficient (Tl), solar transmittance (TS), optical density (D), relative optical density (D/x), Bi-directional Reflectance Distribution Function (BRDF), and change of appearance and color in the visible wavelengths. The materials tested in the project were thermal control coatings (paints), multilayer insulation (films), and solar cells. The ability to predict changes in optical properties of spacecraft materials is important to increase the fidelity of space observation tools, better understand observation of space objects, and increase the longevity of spacecraft. The end goal of our project is to build semi-empirical mathematical models to predict the long-term effects of space aging as a function of time and orbit.

A Novel Simulation Technician Laboratory Design: Results of a Survey-Based Study

PubMed Central

Hughes, Patrick G; Friedl, Ed; Ortiz Figueroa, Fabiana; Cepeda Brito, Jose R; Frey, Jennifer; Birmingham, Lauren E; Atkinson, Steven Scott

2016-01-01

Objective  The purpose of this study was to elicit feedback from simulation technicians prior to developing the first simulation technician-specific simulation laboratory in Akron, OH. Background Simulation technicians serve a vital role in simulation centers within hospitals/health centers around the world. The first simulation technician degree program in the US has been approved in Akron, OH. To satisfy the requirements of this program and to meet the needs of this special audience of learners, a customized simulation lab is essential.  Method A web-based survey was circulated to simulation technicians prior to completion of the lab for the new program. The survey consisted of questions aimed at identifying structural and functional design elements of a novel simulation center for the training of simulation technicians. Quantitative methods were utilized to analyze data. Results Over 90% of technicians (n=65) think that a lab designed explicitly for the training of technicians is novel and beneficial. Approximately 75% of respondents think that the space provided appropriate audiovisual (AV) infrastructure and space to evaluate the ability of technicians to be independent. The respondents think that the lab needed more storage space, visualization space for a large number of students, and more space in the technical/repair area. Conclusions  A space designed for the training of simulation technicians was considered to be beneficial. This laboratory requires distinct space for technical repair, adequate bench space for the maintenance and repair of simulators, an appropriate AV infrastructure, and space to evaluate the ability of technicians to be independent. PMID:27096134

A Novel Simulation Technician Laboratory Design: Results of a Survey-Based Study.

PubMed

Ahmed, Rami; Hughes, Patrick G; Friedl, Ed; Ortiz Figueroa, Fabiana; Cepeda Brito, Jose R; Frey, Jennifer; Birmingham, Lauren E; Atkinson, Steven Scott

2016-03-16

OBJECTIVE : The purpose of this study was to elicit feedback from simulation technicians prior to developing the first simulation technician-specific simulation laboratory in Akron, OH. Simulation technicians serve a vital role in simulation centers within hospitals/health centers around the world. The first simulation technician degree program in the US has been approved in Akron, OH. To satisfy the requirements of this program and to meet the needs of this special audience of learners, a customized simulation lab is essential. A web-based survey was circulated to simulation technicians prior to completion of the lab for the new program. The survey consisted of questions aimed at identifying structural and functional design elements of a novel simulation center for the training of simulation technicians. Quantitative methods were utilized to analyze data. Over 90% of technicians (n=65) think that a lab designed explicitly for the training of technicians is novel and beneficial. Approximately 75% of respondents think that the space provided appropriate audiovisual (AV) infrastructure and space to evaluate the ability of technicians to be independent. The respondents think that the lab needed more storage space, visualization space for a large number of students, and more space in the technical/repair area. CONCLUSIONS : A space designed for the training of simulation technicians was considered to be beneficial. This laboratory requires distinct space for technical repair, adequate bench space for the maintenance and repair of simulators, an appropriate AV infrastructure, and space to evaluate the ability of technicians to be independent.

The transition of ground-based space environmental effects testing to the space environment

NASA Technical Reports Server (NTRS)

Zaat, Stephen V.; Schaefer, Glen A.; Wallace, John F.

1991-01-01

The goal of the space flight program at the Center for Commercial Development of Space (CCDS)--Materials for Space Structures is to provide environmentally stable structural materials to support the continued humanization and commercialization of the space frontier. Information on environmental stability will be obtained through space exposure, evaluation, documentation, and subsequent return to the supplier of the candidate material for internal investigation. This program provides engineering and scientific service to space systems development firms and also exposes CCDS development candidate materials to space environments representative of in-flight conditions. The maintenance of a technological edge in space for NASA suggests the immediate search for space materials that maintain their structural integrity and remain environmentally stable. The materials being considered for long-lived space structures are complex, high strength/weight ratio composites. In order for these new candidate materials to qualify for use in space structures, they must undergo strenuous testing to determine their reliability and stability when subjected to the space environment. Ultraviolet radiation, atomic oxygen, debris/micrometeoroids, charged particles radiation, and thermal fatigue all influence the design of space structural materials. The investigation of these environmental interactions is the key purpose of this center. Some of the topics discussed with respect to the above information include: the Space Transportation System, mission planning, spaceborne experiments, and space flight payloads.

The Effects of Simulated Weightlessness on Susceptibility to Viral and Bacterial Infections Using a Murine Model

NASA Technical Reports Server (NTRS)

Gould, C. L.

1985-01-01

Certain immunological responses may be compromised as a result of changes in environmental conditions, such as the physiological adaptation to and from the weightlessness which occurs during space flight and recovery. A murine antiorthostatic model was developed to simulate weightlessness. Using this model, the proposed study will determine if differences in susceptibility to viral and bacterial infections exist among mice suspended in an antiorthostatic orientation to simulate weightlessness, mice suspended in an orthostatic orientation to provide a stressful situation without the condition of weightlessness simulation, and non-suspended control mice. Inbred mouse strains which are resistant to the diabetogenic effects of the D variant of encephalomyocarditis virus (EMC-D) and the lethal effects of Salmonella typhimurium will be evaluated. Glucose tolerance tests will be performed on all EMC-D-infected and non-infected control groups. The incidence of EMC-D-induced diabetes and the percentage survival of S. typhimurium-infected animals will be determined in each group. An additional study will determine the effects of simulated weightlessness on murine responses to exogenous interferon.

The dwarf galaxy population of nearby galaxy clusters

NASA Astrophysics Data System (ADS)

Lisker, Thorsten; Wittmann, Carolin; Pak, Mina; Janz, Joachim; Bialas, Daniel; Peletier, Reynier; Grebel, Eva; Falcon Barroso, Jesus; Toloba, Elisa; Smakced Collaboration, Focus Collaboration

2015-01-01

The Fornax, Virgo, Ursa Major and Perseus galaxy clusters all have very different characteristics, in terms of their density, mass, and large-scale environment. We can regard these clusters as laboratories for studying environmental influence on galaxy evolution, using the sensitive low-mass galaxies as probes for external mechanisms. Here we report on recent and ongoing observational studies of the said clusters with imaging and spectroscopy, as well as on the interpretation of present-day cluster galaxy populations with the aid of cosmological simulations.Multicolor imaging data allow us to identify residual star formation in otherwise red early-type dwarf galaxies, which hold clues to the strength of gas stripping processes. Major-axis spectra and 2D kinematical maps provide insight regarding the amount of rotational support and how much dynamical heating a dwarf galaxy may have experienced. To this end, dedicated N-body simulations that follow the evolution of galaxies since early epochs reveal their path through parameter space, and can be compared to observations in order to understand the time-integrated effect of environmental influence.

NASA Specialized Center for Research and Training (NSCORT) in space environmental health

NASA Technical Reports Server (NTRS)

Clarkson, Thomas W.; Utell, Mark J.; Morgenthaler, George W.; Eberhardt, Ralph; Rabin, Robert

1992-01-01

Activities of the Center for Space Environmental Health (CSEH), one of several NSCORTs supported by NASA in order to advance knowledge in environmental health in space habitats, are reviewed. Research in environmental health will define the standards or requirements needed to protect human health. This information will affect mission plans and the design of space habitats. This reseach will study unique contaminant stresses and lead to risk models for human health and performance.

Older People's Perceptions of Pedestrian Friendliness and Traffic Safety: An Experiment Using Computer-Simulated Walking Environments.

PubMed

Kahlert, Daniela; Schlicht, Wolfgang

2015-08-21

Traffic safety and pedestrian friendliness are considered to be important conditions for older people's motivation to walk through their environment. This study uses an experimental study design with computer-simulated living environments to investigate the effect of micro-scale environmental factors (parking spaces and green verges with trees) on older people's perceptions of both motivational antecedents (dependent variables). Seventy-four consecutively recruited older people were randomly assigned watching one of two scenarios (independent variable) on a computer screen. The scenarios simulated a stroll on a sidewalk, as it is 'typical' for a German city. In version 'A,' the subjects take a fictive walk on a sidewalk where a number of cars are parked partially on it. In version 'B', cars are in parking spaces separated from the sidewalk by grass verges and trees. Subjects assessed their impressions of both dependent variables. A multivariate analysis of covariance showed that subjects' ratings on perceived traffic safety and pedestrian friendliness were higher for Version 'B' compared to version 'A'. Cohen's d indicates medium (d = 0.73) and large (d = 1.23) effect sizes for traffic safety and pedestrian friendliness, respectively. The study suggests that elements of the built environment might affect motivational antecedents of older people's walking behavior.

SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

NASA Technical Reports Server (NTRS)

Winternitz, Luke; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven;

SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

NASA Technical Reports Server (NTRS)

Winternitz, Luke M. B.; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven;

NASA/SDIO Space Environmental Effects on Materials Workshop, part 2

NASA Technical Reports Server (NTRS)

Teichman, Louis A. (Compiler); Stein, Bland A. (Compiler)

1989-01-01

The National Aeronautics and Space Administration (NASA) and the Strategic Defense Initiative Organization (SDIO) cosponsored a workshop on Space Environmental Effects on Materials. The joint workshop was designed to inform participants of the present state of knowledge regarding space environmental effects on materials and to identify knowledge gaps that prevent informed decisions on the best use of advanced materials in space for long duration NASA and SDIO missions. Establishing priorities for future ground based and space based materials research was a major goal of the workshop. The end product of the workshop was an assessment of the current state-of-the-art in space environmental effects on materials in order to develop a national plan for spaceflight experiments.

Smart active pilot-in-the-loop systems

NASA Astrophysics Data System (ADS)

Thomas, Segun

1995-04-01

Representation of on-orbit microgravity environment in a 1-g environment is a continuing problem in space engineering analysis, procedures development and crew training. A way of adequately depicting weightlessness in the performance of on-orbit tasks is by a realistic (or real-time) computer based representation that provides the look, touch, and feel of on-orbit operation. This paper describes how a facility, the Systems Engineering Simulator at the Johnson Space Center, is utilizing recent advances in computer processing power and multi- processing capability to intelligently represent all systems, sub-systems and environmental elements associated with space flight operations. It first describes the computer hardware and interconnection between processors; the computer software responsible for task scheduling, health monitoring, sub-system and environment representation; control room and crew station. It then describes, the mathematical models that represent the dynamics of contact between the Mir and the Space Shuttle during the upcoming US and Russian Shuttle/Mir space mission. Results are presented comparing the response of the smart, active pilot-in-the-loop system to non-time critical CRAY model. A final example of how these systems are utilized is given in the development that supported the highly successful Hubble Space Telescope repair mission.

GSFC Space Simulation Laboratory Contamination Philosophy: Efficient Space Simulation Chamber Cleaning Techniques

NASA Technical Reports Server (NTRS)

Roman, Juan A.; Stitt, George F.; Roman, Felix R.

1997-01-01

This paper will provide a general overview of the molecular contamination philosophy of the Space Simulation Test Engineering Section and how the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) space simulation laboratory controls and maintains the cleanliness of all its facilities, thereby, minimizing down time between tests. It will also briefly cover the proper selection and safety precautions needed when using some chemical solvents for wiping, washing, or spraying thermal shrouds when molecular contaminants increase to unacceptable background levels.

Evaluating marginal likelihood with thermodynamic integration method and comparison with several other numerical methods

DOE PAGES

Liu, Peigui; Elshall, Ahmed S.; Ye, Ming; ...

2016-02-05

Evaluating marginal likelihood is the most critical and computationally expensive task, when conducting Bayesian model averaging to quantify parametric and model uncertainties. The evaluation is commonly done by using Laplace approximations to evaluate semianalytical expressions of the marginal likelihood or by using Monte Carlo (MC) methods to evaluate arithmetic or harmonic mean of a joint likelihood function. This study introduces a new MC method, i.e., thermodynamic integration, which has not been attempted in environmental modeling. Instead of using samples only from prior parameter space (as in arithmetic mean evaluation) or posterior parameter space (as in harmonic mean evaluation), the thermodynamicmore » integration method uses samples generated gradually from the prior to posterior parameter space. This is done through a path sampling that conducts Markov chain Monte Carlo simulation with different power coefficient values applied to the joint likelihood function. The thermodynamic integration method is evaluated using three analytical functions by comparing the method with two variants of the Laplace approximation method and three MC methods, including the nested sampling method that is recently introduced into environmental modeling. The thermodynamic integration method outperforms the other methods in terms of their accuracy, convergence, and consistency. The thermodynamic integration method is also applied to a synthetic case of groundwater modeling with four alternative models. The application shows that model probabilities obtained using the thermodynamic integration method improves predictive performance of Bayesian model averaging. As a result, the thermodynamic integration method is mathematically rigorous, and its MC implementation is computationally general for a wide range of environmental problems.« less

Resistance of Bacterial Endospores to Outer Space for Planetary Protection Purposes—Experiment PROTECT of the EXPOSE-E Mission

PubMed Central

Moeller, Ralf; Cadet, Jean; Douki, Thierry; Mancinelli, Rocco L.; Nicholson, Wayne L.; Panitz, Corinna; Rabbow, Elke; Rettberg, Petra; Spry, Andrew; Stackebrandt, Erko; Vaishampayan, Parag; Venkateswaran, Kasthuri J.

2012-01-01

Abstract Spore-forming bacteria are of particular concern in the context of planetary protection because their tough endospores may withstand certain sterilization procedures as well as the harsh environments of outer space or planetary surfaces. To test their hardiness on a hypothetical mission to Mars, spores of Bacillus subtilis 168 and Bacillus pumilus SAFR-032 were exposed for 1.5 years to selected parameters of space in the experiment PROTECT during the EXPOSE-E mission on board the International Space Station. Mounted as dry layers on spacecraft-qualified aluminum coupons, the “trip to Mars” spores experienced space vacuum, cosmic and extraterrestrial solar radiation, and temperature fluctuations, whereas the “stay on Mars” spores were subjected to a simulated martian environment that included atmospheric pressure and composition, and UV and cosmic radiation. The survival of spores from both assays was determined after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few survivors were recovered from spores exposed in monolayers. Spores in multilayers survived better by several orders of magnitude. All other environmental parameters encountered by the “trip to Mars” or “stay on Mars” spores did little harm to the spores, which showed about 50% survival or more. The data demonstrate the high chance of survival of spores on a Mars mission, if protected against solar irradiation. These results will have implications for planetary protection considerations. Key Words: Planetary protection—Bacterial spores—Space experiment—Simulated Mars mission. Astrobiology 12, 445–456. PMID:22680691

NIST activities in support of space-based radiometric remote sensing

NASA Astrophysics Data System (ADS)

Rice, Joseph P.; Johnson, B. Carol

2001-06-01

We provide an historical overview of NIST research and development in radiometry for space-based remote sensing. The applications in this field can be generally divided into two areas: environmental and defense. In the environmental remote sensing area, NIST has had programs with agencies such as the National Aeronautical and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) to verify and improve traceability of the radiometric calibration of sensors that fly on board Earth-observing satellites. These produce data used in climate models and weather prediction. Over the years, the scope of activities has expanded from existing routine calibration services for artifacts such as lamps, diffusers, and filters, to development and off-site deployment of portable radiometers for radiance- and irradiance-scale intercomparisons. In the defense remote sensing area, NIST has had programs with agencies such as the Department of Defense (DOD) for support of calibration of small, low-level infrared sources in a low infrared background. These are used by the aerospace industry to simulate ballistic missiles in a cold space background. Activities have evolved from calibration of point-source cryogenic blackbodies at NIST to measurement of irradiance in off-site calibration chambers by a portable vacuum/cryogenic radiometer. Both areas of application required measurements on the cutting edge of what was technically feasible, thus compelling NIST to develop a state-of-the-art radiometric measurement infrastructure to meet the needs. This infrastructure has led to improved dissemination of the NIST spectroradiometric quantities.

Cultivating a Caring, Environmental Self: Using the Figured World Concept to Explore Children's Environmental Identity Production in a Public School Garden Space

NASA Astrophysics Data System (ADS)

Sulsberger, Megan Jane

This ethnographic case study investigates the diverse means and processes by which environmental identities were produced by five first grade students as they participated in an emergent, public school garden space. The children's histories, choices, personal and social experiences, expressions, and corresponding narratives are explored alongside the garden structure and social context to unpack the individualized and layered nature of children's environmental identity and care development. To locate and analyze children's engagements in the garden space, ethnographic, discourse, and narrative analysis methods are employed. The figured world concept is used to theorize and study the caring, environmental identities taken up and enacted by the children in this context. Through participation in emergent provocations, the creation and leveraging of garden artifacts, and investments in caring relationships, the children in this study shaped and cared for the garden space while it simultaneously shaped and cared for them. The environmental identity stories presented in this work broaden the definition of environmental identity to be more inclusive and less normalizing, thus, creating new spaces and moments for children to identify as environmentalists. The stories also raise implications for environmental education researchers to utilize more rigorous frameworks for investigating environmental care and identity development in the field. Findings from this research indicate that emergent garden spaces are potential sites for children to build relationships with nature in the public school. This is a significant practice for schools, as children today lack spaces in which to form environmental identities that implicate environmental care behaviors.

The Impact of Environmental Design on Doffing Personal Protective Equipment in a Healthcare Environment: A Formative Human Factors Trial.

PubMed

Herlihey, Tracey A; Gelmi, Stefano; Cafazzo, Joseph A; Hall, Trevor N T

2017-06-01

OBJECTIVE To explore the impact of environmental design on doffing personal protective equipment in a simulated healthcare environment. METHODS A mixed-methods approach was used that included human-factors usability testing and qualitative questionnaire responses. A patient room and connecting anteroom were constructed for testing purposes. This experimental doffing area was designed to overcome the environmental failures identified in a previous study and was not constructed based on any generalizable hospital standard. RESULTS In total, 72 healthcare workers from Ontario, Canada, took part in the study and tested the simulated doffing area. The following environmental design changes were tested and were deemed effective: increasing prominence of color-coded zones; securing disinfectant wipes and hand sanitizer; outlining disposal bins locations; providing mirrors to detect possible contamination; providing hand rails to assist with doffing; and restricting the space to doff. Further experimentation and iterative design are required with regard to several important features: positioning the disposal bins for safety, decreasing the risk of contamination and user accessibility; optimal positioning of mirrors for safety; communication within the team; and positioning the secondary team member for optimal awareness. Additional design suggestions also emerged during this study, and they require future investigation. CONCLUSIONS This study highlights the importance of the environment on doffing personal protective equipment in a healthcare setting. Iterative testing and modification of the design of the environment (doffing area) are important to enhancing healthcare worker safety. Infect Control Hosp Epidemiol 2017;38:712-717.

A Process for Comparing Dynamics of Distributed Space Systems Simulations

NASA Technical Reports Server (NTRS)

Cures, Edwin Z.; Jackson, Albert A.; Morris, Jeffery C.

2009-01-01

The paper describes a process that was developed for comparing the primary orbital dynamics behavior between space systems distributed simulations. This process is used to characterize and understand the fundamental fidelities and compatibilities of the modeling of orbital dynamics between spacecraft simulations. This is required for high-latency distributed simulations such as NASA s Integrated Mission Simulation and must be understood when reporting results from simulation executions. This paper presents 10 principal comparison tests along with their rationale and examples of the results. The Integrated Mission Simulation (IMSim) (formerly know as the Distributed Space Exploration Simulation (DSES)) is a NASA research and development project focusing on the technologies and processes that are related to the collaborative simulation of complex space systems involved in the exploration of our solar system. Currently, the NASA centers that are actively participating in the IMSim project are the Ames Research Center, the Jet Propulsion Laboratory (JPL), the Johnson Space Center (JSC), the Kennedy Space Center, the Langley Research Center and the Marshall Space Flight Center. In concept, each center participating in IMSim has its own set of simulation models and environment(s). These simulation tools are used to build the various simulation products that are used for scientific investigation, engineering analysis, system design, training, planning, operations and more. Working individually, these production simulations provide important data to various NASA projects.

Precision pointing compensation for DSN antennas with optical distance measuring sensors

NASA Technical Reports Server (NTRS)

Scheid, R. E.

1989-01-01

The pointing control loops of Deep Space Network (DSN) antennas do not account for unmodeled deflections of the primary and secondary reflectors. As a result, structural distortions due to unpredictable environmental loads can result in uncompensated boresight shifts which degrade pointing accuracy. The design proposed here can provide real-time bias commands to the pointing control system to compensate for environmental effects on pointing performance. The bias commands can be computed in real time from optically measured deflections at a number of points on the primary and secondary reflectors. Computer simulations with a reduced-order finite-element model of a DSN antenna validate the concept and lead to a proposed design by which a ten-to-one reduction in pointing uncertainty can be achieved under nominal uncertainty conditions.

78 FR 35087 - Office of Commercial Space Transportation; Notice of Extension of Comment Period for the Draft...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... Transportation; Notice of Extension of Comment Period for the Draft Environmental Impact Statement for the SpaceX... Notice of Availability (NOA) for the FAA's Draft Environmental Impact Statement for the SpaceX Texas... regarding the Draft EIS to Ms. Stacey M. Zee, FAA Environmental Specialist, SpaceX EIS c/o Cardno TEC Inc...

SEPAC data analysis in support of the environmental interaction program

NASA Technical Reports Server (NTRS)

Lin, Chin S.

1990-01-01

Injections of nonrelativistic electron beams from an isolated equipotential conductor into a uniform background of plasma and neutral gas were simulated using a two dimensional electrostatic particle code. The ionization effects of spacecraft charging are examined by including interactions of electrons with neutral gas. The simulations show that the conductor charging potential decreases with increasing neutral background density due to the production of secondary electrons near the conductor surface. In the spacecraft wake, the background electrons accelerated towards the charged space craft produced an enhancement of secondary electrons and ions. Simulations run for longer times indicate that the spacecraft potential is further reduced and short wavelength beam-plasma oscillations appear. The results are applied to explain the space craft charging potential measured during the SEPAC experiments from Spacelab 1. A second paper is presented in which a two dimensional electrostatic particle code was used to study the beam radial expansion of a nonrelativistic electron beam injected from an isolated equipotential conductor into a background plasma. The simulations indicate that the beam radius is generally proportional to the beam electron gyroradius when the conductor is charged to a large potential. The simulations also suggest that the charge buildup at the beam stagnation point causes the beam radial expansion. From a survey of the simulation results, it is found that the ratio of the beam radius to the beam electron gyroradius increases with the square root of beam density and decreases inversely with beam injection velocity. This dependence is explained in terms of the ratio of the beam electron Debye length to the ambient electron Debye length. These results are most applicable to the SEPAC electron beam injection experiments from Spacelab 1, where high charging potential was observed.

Precipitation From a Multiyear Database of Convection-Allowing WRF Simulations

NASA Astrophysics Data System (ADS)

Goines, D. C.; Kennedy, A. D.

2018-03-01

Convection-allowing models (CAMs) have become frequently used for operational forecasting and, more recently, have been utilized for general circulation model downscaling. CAM forecasts have typically been analyzed for a few case studies or over short time periods, but this limits the ability to judge the overall skill of deterministic simulations. Analysis over long time periods can yield a better understanding of systematic model error. Four years of warm season (April-August, 2010-2013)-simulated precipitation has been accumulated from two Weather Research and Forecasting (WRF) models with 4 km grid spacing. The simulations were provided by the National Center for Environmental Prediction (NCEP) and the National Severe Storms Laboratory (NSSL), each with different dynamic cores and parameterization schemes. These simulations are evaluated against the NCEP Stage-IV precipitation data set with similar 4 km grid spacing. The spatial distribution and diurnal cycle of precipitation in the central United States are analyzed using Hovmöller diagrams, grid point correlations, and traditional verification skill scoring (i.e., ETS; Equitable Threat Score). Although NCEP-WRF had a high positive error in total precipitation, spatial characteristics were similar to observations. For example, the spatial distribution of NCEP-WRF precipitation correlated better than NSSL-WRF for the Northern Plains. Hovmöller results exposed a delay in initiation and decay of diurnal precipitation by NCEP-WRF while both models had difficulty in reproducing the timing and location of propagating precipitation. ETS was highest for NSSL-WRF in all domains at all times. ETS was also higher in areas of propagating precipitation compared to areas of unorganized diurnal scattered precipitation. Monthly analysis identified unique differences between the two models in their abilities to correctly simulate the spatial distribution and zonal motion of precipitation through the warm season.

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 237

NASA Technical Reports Server (NTRS)

1982-01-01

A bibliography is given on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the Earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. In general, emphasis is placed on applied research, but references to fundamental studies and theoretical principles related to experimental development also qualify for inclusion.

Silver-Teflon coating improvement

NASA Technical Reports Server (NTRS)

Reed, M. W.

1976-01-01

Approximately forty adhesives were subjected to laboratory screening. Seven candidate adhesives were selected from the screening tests and evaluated in a thermal vacuum test on radiator panels similar to the anticipated flight hardware configuration. Several classes of adhesives based on epoxide, polyester, silicone, and urethane resin systems were tested. These included contact adhesives, heat cured adhesives, heat and pressure cured adhesives, pressure sensitive adhesives, and two part paint-on or spray-on adhesives. The panels were tested in a space environmental simulation laboratory chamber during the July 9-20, 1973 time span.

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 139

NASA Technical Reports Server (NTRS)

1975-01-01

The biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space are referenced. Similar effects on biological organisms of lower order are also included. Related topics such as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors are discussed. Applied research is emphasized, but references to fundamental studies and theoretical principles related to experimental development are also included. A total of 242 reports, articles, and other documents are listed.

Facility for generating crew waste water product for ECLSS testing

NASA Technical Reports Server (NTRS)

Buitekant, Alan; Roberts, Barry C.

1990-01-01

An End-use Equipment Facility (EEF) has been constructed which is used to simulate water interfaces between the Space Station Freedom Environmental Control and Life Support Systems (ECLSS) and man systems. The EEF is used to generate waste water to be treated by ECLSS water recovery systems. The EEF will also be used to close the water recovery loop by allowing test subjects to use recovered hygiene and potable water during several phases of testing. This paper describes the design and basic operation of the EEF.

Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication

NASA Technical Reports Server (NTRS)

Hickman, Robert; Broadway, Jeramie; Mireles, Omar; Webb, Jon; Qualls, Lou

2012-01-01

Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes these overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.

Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication

NASA Technical Reports Server (NTRS)

Hickman, Robert; Broadway, Jeramie; Mireles, Omar; Webb, Jon; Qualls, Lou

2012-01-01

Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes thses overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.

Dynamics Simulation Model for Space Tethers

NASA Technical Reports Server (NTRS)

Levin, E. M.; Pearson, J.; Oldson, J. C.

2006-01-01

This document describes the development of an accurate model for the dynamics of the Momentum Exchange Electrodynamic Reboost (MXER) system. The MXER is a rotating tether about 100-km long in elliptical Earth orbit designed to catch payloads in low Earth orbit and throw them to geosynchronous orbit or to Earth escape. To ensure successful rendezvous between the MXER tip catcher and a payload, a high-fidelity model of the system dynamics is required. The model developed here quantifies the major environmental perturbations, and can predict the MXER tip position to within meters over one orbit.

Structural dynamic analysis of the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Scott, L. P.; Jamison, G. T.; Mccutcheon, W. A.; Price, J. M.

1981-01-01

This structural dynamic analysis supports development of the SSME by evaluating components subjected to critical dynamic loads, identifying significant parameters, and evaluating solution methods. Engine operating parameters at both rated and full power levels are considered. Detailed structural dynamic analyses of operationally critical and life limited components support the assessment of engine design modifications and environmental changes. Engine system test results are utilized to verify analytic model simulations. The SSME main chamber injector assembly is an assembly of 600 injector elements which are called LOX posts. The overall LOX post analysis procedure is shown.

Mean Atlantic Meridional Overturning Circulation Across 26.5 degs N from Eddy-Resolving Simulations Compared to Observations

DTIC Science & Technology

2012-03-30

climatology, the Gen- eralized Digital Environmental Model ( GDEM [Carnes, 2009]), with an e-folding time of 5–60 days that increases with distance from the...after 10 years of integration due to an oversight. As a third change, E026 uses a new version of GDEM for initialization and buffer zone restor- ing...Carnes, M. R. (2009), Description and evaluation of GDEM -V3.0, Tech. Rep. NRL/ MR/7330–09-9165, 21 pp., Naval Res. Lab., Stennis Space Cent., Miss

Aerospace Medicine and Biology: A Continuing Bibliography. Supplement 483

NASA Technical Reports Server (NTRS)

1999-01-01

Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which humans are subjected during and following simulated or actual flight in the Earth's atmosphere or in interplanetary space. References describing similar effects on biological organisms of lower order are also included. Such related topics as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, exobiology, and personnel factors receive appropriate attention. Applied research receives the most emphasis, but references to fundamental studies and theoretical principles related to experimental development also qualify for inclusion.

X-Ray Imaging Study

NASA Technical Reports Server (NTRS)

OBrien, Susan K.; Workman, Gary L.

1996-01-01

The space environment in which the Space Station Freedom and other space platforms will orbit is truly a hostile environment. For example, the currently estimated integral fluence for electrons above 1 Mev at 2000 nautical miles is above 2 x 1O(exp 10) electrons/sq cm/day and the proton integral fluence is above 1 x 10(exp 9) protons/sq cm/day. At the 200 - 400 nautical miles, which is more representative of the altitude which will provide the environment for the Space Station, each of these fluences will be proportionally less; however, the data indicates that the radiation environment will obviously have an effect on structural materials exposed to the environment for long durations. The effects of this combined environment is the issue which needs to be understood for the long term exposure of structures in space. At the same time, there will be substantial potential for collisions between the space platforms and space debris. The current NASA catalogue contains over 4500 objects floating in space which are not considered payloads. This debris can have significant effects on collision with orbiting spacecraft. In order to better understand the effect of these hostile phenomena on spacecraft, several types of studies are being performed to simulate at some level the effect of the environment. In particular the study of debris clouds produced by hypervelocity impact on the various surfaces anticipated on the Space Station is very important at this point in time. The need to assess the threat of such debris clouds on space structures is an on-going activity. The Space Debris Impact facility in Building 4612 provides a test facility to monitor the types of damage produced with hypervelocity impact. These facilities are used to simulate space environmental effects from energetic particles. Flash radiography or x-ray imaging has traditionally provided such information and as such has been an important tool for recording damage in situ with the event. The proper operation of the system can provide much useful information with respect to parametric analysis of the hypervelocity experiment. The following report outlines the procedures developed to optimize the operation of the x-ray imaging system and its operational characteristics.

Configuration of the thermal landscape determines thermoregulatory performance of ectotherms

PubMed Central

Sears, Michael W.; Angilletta, Michael J.; Schuler, Matthew S.; Borchert, Jason; Dilliplane, Katherine F.; Stegman, Monica; Rusch, Travis W.; Mitchell, William A.

2016-01-01

Although most organisms thermoregulate behaviorally, biologists still cannot easily predict whether mobile animals will thermoregulate in natural environments. Current models fail because they ignore how the spatial distribution of thermal resources constrains thermoregulatory performance over space and time. To overcome this limitation, we modeled the spatially explicit movements of animals constrained by access to thermal resources. Our models predict that ectotherms thermoregulate more accurately when thermal resources are dispersed throughout space than when these resources are clumped. This prediction was supported by thermoregulatory behaviors of lizards in outdoor arenas with known distributions of environmental temperatures. Further, simulations showed how the spatial structure of the landscape qualitatively affects responses of animals to climate. Biologists will need spatially explicit models to predict impacts of climate change on local scales. PMID:27601639

Definition study for an extended manned test of a regenerative life support system

NASA Technical Reports Server (NTRS)

1971-01-01

A program was defined which consists of extended ground-based manned tests of regenerative life support systems. The tests are to evaluate prototypes of advanced life support systems under operational, integrated conditions, thus providing data for the design of efficient environmental control and life support systems for use in long-duration space missions. The requirements are defined for test operations to provide a simulation of an orbiting space laboratory. The features of Phase A and B programs are described. These tests use proven backup equipment to ensure successful evaluation of the advanced subsystems. A pre-tests all-systems checkout period is provided to minimize equipment problems during extended testing and to familiarize all crew and operating staff members with test equipment and procedures.

Webb's MIRI Shield Dropping in on Dropping Temperatures

NASA Image and Video Library

2013-12-04

Goddard Technicians Tony Kiem (left) and George Mooney (right) guide the craned structure holding the Webb telescope's Mid-Infrared Instrument or MIRI Shield Environmental Test Unit into place in a cryogenic (cooling) test chamber. This shield will be used to simulate the MIRI instrument during prelaunch testing to verify that the MIRI cooling system will function properly in space. Goddard Safety Engineer Richard Bowlan watches from above. Image Credit: NASA/Chris Gunn NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

CMIF ECLS system test findings

NASA Technical Reports Server (NTRS)

Schunk, Richard G.; Carrasquillo, Robyn L.; Ogle, Kathyrn Y.; Wieland, Paul O.; Bagdigian, Robert M.

1989-01-01

During 1987 three Space Station integrated Environmental Control and Life Support System (ECLSS) tests were conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) as part of the MSFC ECLSS Phase II test program. The three tests ranged in duration from 50 to 150 hours and were conducted inside of the CMIF module simulator. The Phase II partial integrated system test configuration consisted of four regenerative air revitalization subsystems and one regenerative water reclamation subsystem. This paper contains a discussion of results and lessons learned from the Phase II test program. The design of the Phase II test configuration and improvements made throughout the program are detailed. Future plans for the MSFC CMIF test program are provided, including an overview of planned improvements for the Phase III program.

High Pressure Quick Disconnect Particle Impact Tests

NASA Technical Reports Server (NTRS)

Rosales, Keisa R.; Stoltzfus, Joel M.

2009-01-01

NASA Johnson Space Center White Sands Test Facility (WSTF) performed particle impact testing to determine whether there is a particle impact ignition hazard in the quick disconnects (QDs) in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). Testing included standard supersonic and subsonic particle impact tests on 15-5 PH stainless steel, as well as tests performed on a QD simulator. This paper summarizes the particle impact tests completed at WSTF. Although there was an ignition in Test Series 4, it was determined the ignition was caused by the presence of a machining imperfection. The sum of all the test results indicates that there is no particle impact ignition hazard in the ISS ECLSS QDs. KEYWORDS: quick disconnect, high pressure, particle impact testing, stainless steel

High Pressure Quick Disconnect Particle Impact Tests

NASA Technical Reports Server (NTRS)

Peralta, Stephen; Rosales, Keisa; Smith, Sarah R.; Stoltzfus, Joel M.

2007-01-01

To determine whether there is a particle impact ignition hazard in the quick disconnects (QDs) in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS), NASA Johnson Space Center requested White Sands Test Facility (WSTF) to perform particle impact testing. Testing was performed from November 2006 through May 2007 and included standard supersonic and subsonic particle impact tests on 15-5 PH stainless steel, as well as tests performed on a QD simulator. This report summarizes the particle impact tests completed at WSTF. Although there was an ignition in Test Series 4, it was determined the ignition was caused by the presence of a machining imperfection. The sum of all the test results indicates that there is no particle impact ignition hazard in the ISS ECLSS QDs.

Appendices to the model description document for a computer program for the emulation/simulation of a space station environmental control and life support system

NASA Technical Reports Server (NTRS)

Yanosy, James L.

1988-01-01

A Model Description Document for the Emulation Simulation Computer Model was already published. The model consisted of a detailed model (emulation) of a SAWD CO2 removal subsystem which operated with much less detailed (simulation) models of a cabin, crew, and condensing and sensible heat exchangers. The purpose was to explore the utility of such an emulation simulation combination in the design, development, and test of a piece of ARS hardware, SAWD. Extensions to this original effort are presented. The first extension is an update of the model to reflect changes in the SAWD control logic which resulted from test. Also, slight changes were also made to the SAWD model to permit restarting and to improve the iteration technique. The second extension is the development of simulation models for more pieces of air and water processing equipment. Models are presented for: EDC, Molecular Sieve, Bosch, Sabatier, a new condensing heat exchanger, SPE, SFWES, Catalytic Oxidizer, and multifiltration. The third extension is to create two system simulations using these models. The first system presented consists of one air and one water processing system. The second consists of a potential air revitalization system.

The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

NASA Technical Reports Server (NTRS)

Mulugeta, Lealem; Myers, Jerry G.; Skytland, Nicholas G.; Platts, Steven H.

2010-01-01

With the ambitious goals to send manned missions to asteroids and onto Mars, substantial work will be required to ensure the well being of the men and women who will undertake these difficult missions. Unlike current International Space Station or Shuttle missions, astronauts will be required to endure long-term exposure to higher levels of radiation, isolation and reduced gravity. These new operation conditions will pose health risks that are currently not well understood and perhaps unanticipated. Therefore, it is essential to develop and apply advanced tools to predict, assess and mitigate potential hazards to astronaut health. NASA s Digital Astronaut Project (DAP) is working to develop and apply computational models of physiologic response to space flight operation conditions over various time periods and environmental circumstances. The collective application and integration of well vetted models assessing the physiology, biomechanics and anatomy is referred to as the Digital Astronaut. The Digital Astronaut simulation environment will serve as a practical working tool for use by NASA in operational activities such as the prediction of biomedical risks and functional capabilities of astronauts. In additional to space flight operation conditions, DAP s work has direct applicability to terrestrial biomedical research by providing virtual environments for hypothesis testing, experiment design, and to reduce animal/human testing. A practical application of the DA to assess pre and post flight responses to exercise is illustrated and the difficulty in matching true physiological responses is discussed.

DNA damage under simulated extraterrestrial conditions in bacteriophage T7

NASA Astrophysics Data System (ADS)

Fekete, A.; Módos, K.; Hegedüs, M.; Kovács, G.; Rontó, Gy.; Péter, Á.; Lammer, H.; Panitz, C.

The experiment "Phage and Uracil response" will be accommodated in the EXPOSE facility of the International Space Station. Its objective is to examine and quantify the effect of specific space conditions on nucleic acid models, especially on bacteriophage T7 and isolated T7 DNA thin films. In order to define the environmental and technical requirements of the EXPOSE, the samples were subjected to the experiment verification test (EVT). During EVT, the samples were exposed to vacuum (10 -4-10 -6 Pa) and polychromatic UV-radiation (200-400 nm) in air, in inert atmosphere, as well as in simulated space vacuum. The effect of extreme temperature in vacuum and the influence of temperature fluctuations around 0 °C were also studied. The total intraphage/isolated DNA damage was determined by quantitative PCR using 555 and 3826 bp fragments of T7 DNA. The type of the damage was resolved using a combination of enzymatic probes and neutral and alkaline agarose gel electrophoresis; the structural/chemical effects were analyzed by spectroscopic and microscopical methods. We obtained substantial evidence that DNA lesions accumulate throughout exposure, but the amount of damage depends on the thickness of the layers. According to our preliminary results, the damages by exposure to conditions of dehydration and UV-irradiation are larger than the sum of vacuum alone, or radiation alone case, suggesting a synergistic action of space vacuum and UV radiation with DNA being the critical target.

Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

NASA Astrophysics Data System (ADS)

Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

In addition to the several extreme environments on Earth, Space can be considered as just another exceptional environment with a unique mixture of stress factors comprising UV radiation, vacuum, desiccation, temperature, ionizing radiation and microgravity. Life that processes in these environments can depend on the life forms and their state of living. The question is whether there are different strategies for individual microorganisms compared to communities of the same organisms to cope with the different factors of their surroundings. Comparative studies of the survi-val of these communities called biofilms and planktonic cell samples of Deinococcus geothermalis stand at the focal point of the presented investigations. A biofilm is a structured community of microorganisms that live encapsulated in a matrix of extracellular polymeric substances on a surface. Microorganisms living in a biofilm usually have significantly different properties to cooperate than individually living microorganisms of the same species. An advantage of the biofilm is increased resistance to various chemical and physical effects, while the dense extracellular matrix and the outer layer of the cells protect the interior of the microbial consortium. The space experiment BOSS (Biofilm organisms surfing Space) as part the ESA experimental unit EXPOSE R-2 with a planned launch date in July 2014 will be subsequently mounted on the Russian Svesda module outside the ISS. An international team of scientists coordinated by Dr. P. Rettberg will investigate the hypothesis whether microorganisms organized as biofilm outmatch the same microorganisms exposed individually in the long-term survival of the harsh environmental conditions as they occur in space and on Mars. Another protective function in the samples could be dust par-ticles for instance Mars regolith simulant contained inside the biofilms or mixed with the planktonic cells, as additional shelter especially against the extraterrestrial UV radiation. D. geothermalis besides others, like co-cultures of Halomonas muralis and Halococcus morrhuae, Bacillus horneckiae, Chroococcidiopsis CCMEE 029 and Streptomyces + Polaromonas and Arthrobacter strains from volcanic rocks, was involved in the several preparatory test runs at the Planetary and Space Simulation facilities at the German Aerospace Center in Cologne. Results of the already carried out EVTs (Experiment Verification Test) and the SVT (Science verification test) as EXPOSE-R2 mission pre-paration tests, where investigated parameters like dehydration, temperature extremes, extraterrestrial UV radiation, simulated Martian atmosphere, and a Mars-like UV climate were tested individually as well as in combination will be presented. Following exposure to the parameters listed above, the survival of both biofilms and planktonic cells of D. geothermalis was assessed in terms of (i) culturability by colony counts on R2A medium, (ii) membrane integrity by using the Live/Dead differential staining kit, (iii) ATP content by using a commercial luminometric assay, and (iv) the presence of 16S rRNA by fluorescence in situ hybridization. So far, the results suggest that Deinococcus geothermalis remains viable in the desiccated state over weeks to months, whereas culturability, intracellular ATP levels, and membrane integrity were preserved in biofilm cells at a significantly higher level than in planktonic cells. Furthermore, cells of both sample types were able to survive simulated space and Martian conditions and showed high resistance after irradiation with monochromatic and polychromatic UV. The results will contribute to the fundamental understanding of the opportunities and limitations of viability of microorganisms organized in biofilms or as planktonic cells under the extreme environ-mental conditions of space or other planets.

Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

NASA Astrophysics Data System (ADS)

Emrich, William J.

2008-01-01

To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts.

Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.

2008-01-01

To support the eventual development of a nuclear thermal rocket engine, a state-of-the-art experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts.

2004 Space Report: Environment and Strategy for Space Research at NATO's Research and Technology Organisation (RTO)

NASA Technical Reports Server (NTRS)

Woods-Vedeler, Jessica A.

2007-01-01

This report describes the motivation for and a strategy to enhance the NATO Research and Technology Organisation's (RTO) current space research effort to reflect NATO's growing military dependence on space systems. Such systems and services provided by these systems are critical elements of military operations. NATO uses space systems for operational planning and support, communication, radio navigation, multi-sensor and multi-domain demonstrations. Such systems are also used to promote regional stability. A quantitative analysis of work related to space in the NATO RTO showed that during the period of 1998 - 2004, 5% of the research pursued in the NATO RTO has been clearly focused on space applications. Challenging environmental and organizational barriers for increasing RTO space research were identified. In part, these include lack of sufficient space expertise representation on panels, the military sensitivity of space, current panel work loads and the need for specific technical recommendations from peers. A strategy for enhancing space research in the RTO is to create a limited-life Space Advisory Group (SAG) composed of Space Expert Consultants who are panel members with appropriate expertise and additional expertise from the nations. The SAG will recommend and find support in the nations for specific technical activities related to space in the areas of Space Science, Remote Sensing Data Analysis, Spacecraft Systems, Surveillance and Early Warning, Training and Simulation and Policy. An RTO Space Advisory Group will provide an organizational mechanism to gain recognition of RTO as a forum for trans-Atlantic defence space research and to enhance space research activities.

Modeling Bird Migration in Changing Habitats: Space-based Ornithology using Satellites and GIS

NASA Technical Reports Server (NTRS)

Smith, James A.; Deppe, Jill L.

2008-01-01

Understanding bird migration and avian biodiversity is one of the most compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties presenting challenges in both geographic space and time. Space based technology, coupled with geographic information systems, yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At NASA, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. In our work, we use individual organism biophysical models and drive these models with satellite observations and numerical weather predictions of the spatio-temporal gradients in climate and habitat. Geographic information system technology comprises one component of our overall simulation framework, especially for characterizing the changing habitats and conditions encountered by en-route migratory birds. Simulation provides a tool for studying bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. We present examples of our simulation of shorebirds, principally, pectoral sandpipers, along the central flyways of the United States and Canada from the Gulf of Mexico to Alaska.

NASA GRC and MSFC Space-Plasma Arc Testing Procedures

NASA Technical Reports Server (NTRS)

Ferguson, Dale C.; Vayner, Boris V.; Galofaro, Joel T,; Hillard, G. Barry; Vaughn, Jason; Schneider, Todd

2005-01-01

Tests of arcing and current collection in simulated space plasma conditions have been performed at the NASA Glenn Research Center (GRC) in Cleveland, Ohio, for over 30 years and at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, for almost as long. During this period, proper test conditions for accurate and meaningful space simulation have been worked out, comparisons with actual space performance in spaceflight tests and with real operational satellites have been made, and NASA has achieved our own internal standards for test protocols. It is the purpose of this paper to communicate the test conditions, test procedures, and types of analysis used at NASA GRC and MSFC to the space environmental testing community at large, to help with international space-plasma arcing-testing standardization. To be discussed are: 1.Neutral pressures, neutral gases, and vacuum chamber sizes. 2. Electron and ion densities, plasma uniformity, sample sizes, and Debuy lengths. 3. Biasing samples versus self-generated voltages. Floating samples versus grounded. 4. Power supplies and current limits. Isolation of samples from power supplies during arcs. 5. Arc circuits. Capacitance during biased arc-threshold tests. Capacitance during sustained arcing and damage tests. Arc detection. Prevention sustained discharges during testing. 6. Real array or structure samples versus idealized samples. 7. Validity of LEO tests for GEO samples. 8. Extracting arc threshold information from arc rate versus voltage tests. 9. Snapover and current collection at positive sample bias. Glows at positive bias. Kapon (R) pyrolisis. 10. Trigger arc thresholds. Sustained arc thresholds. Paschen discharge during sustained arcing. 11. Testing for Paschen discharge threshold. Testing for dielectric breakdown thresholds. Testing for tether arcing. 12. Testing in very dense plasmas (ie thruster plumes). 13. Arc mitigation strategies. Charging mitigation strategies. Models. 14. Analysis of test results. Finally, the necessity of testing will be emphasized, not to the exclusion of modeling, but as part of a complete strategy for determining when and if arcs will occur, and preventing them from occurring in space.

NASA GRC and MSFC Space-Plasma Arc Testing Procedures

NASA Technical Reports Server (NTRS)

Ferguson, Dale C.a; Vayner, Boris V.; Galofaro, Joel T.; Hillard, G. Barry; Vaughn, Jason; Schneider, Todd

2005-01-01

Tests of arcing and current collection in simulated space plasma conditions have been performed at the NASA Glenn Research Center (GRC) in Cleveland, Ohio, for over 30 years and at the Marshall Space flight Center (MSFC) for almost as long. During this period, proper test conditions for accurate and meaningful space simulation have been worked out, comparisons with actual space performance in spaceflight tests and with real operational satellites have been made, and NASA has achieved our own internal standards for test protocols. It is the purpose of this paper to communicate the test conditions, test procedures, and types of analysis used at NASA GRC and MSFC to the space environmental testing community at large, to help with international space-plasma arcing testing standardization. To be discussed are: 1. Neutral pressures, neutral gases, and vacuum chamber sizes. 2. Electron and ion densities, plasma uniformity, sample sizes, and Debye lengths. 3. Biasing samples versus self-generated voltages. Floating samples versus grounded. 4. Power supplies and current limits. Isolation of samples from power supplies during arcs. Arc circuits. Capacitance during biased arc-threshold tests. Capacitance during sustained arcing and damage tests. Arc detection. Preventing sustained discharges during testing. 5. Real array or structure samples versus idealized samples. 6. Validity of LEO tests for GEO samples. 7. Extracting arc threshold information from arc rate versus voltage tests. 8 . Snapover and current collection at positive sample bias. Glows at positive bias. Kapton pyrolization. 9. Trigger arc thresholds. Sustained arc thresholds. Paschen discharge during sustained arcing. 10. Testing for Paschen discharge thresholds. Testing for dielectric breakdown thresholds. Testing for tether arcing. 11. Testing in very dense plasmas (ie thruster plumes). 12. Arc mitigation strategies. Charging mitigation strategies. Models. 13. Analysis of test results. Finally, the necessity of testing will be emphasized, not to the exclusion of modeling, but as part of a complete strategy for determining when and if arcs will occur, and preventing them from occurring in space.

Design, simulation and characterisation of integrated optics for a microfabricated flow cytometer

NASA Astrophysics Data System (ADS)

Barat, David; Benazzi, Giuseppe; Mowlem, Matthew Charles; Ruano, Jesus Miguel; Morgan, Hywel

2010-05-01

Flow cytometry is widely used for analyzing micro-particles such as cells and bacteria. Microfabricated flow cytometers promise reduced instrument size and cost with increased robustness and have application in medicine, life sciences and environmental metrology. Further miniaturisation and robustness can be achieved if integrated optics are used instead of traditional free space optics. We present designs simulation and experimental characterisation of integrated optics for a microfabricated cytometer made from SU-8 resin on a glass substrate. The optics constructed from combinations of optical fibres (positioned with microgrooves), waveguides, and microlenses enable analysis of scattered light and fluorescence from particles positioned near the centre of a microchannel using one dimensional sheath flow. Four different methods for directing the incident light onto the particles are examined and the optimum design discussed.

Measuring the spectral emissivity of thermal protection materials during atmospheric reentry simulation

NASA Technical Reports Server (NTRS)

Marble, Elizabeth

1996-01-01

Hypersonic spacecraft reentering the earth's atmosphere encounter extreme heat due to atmospheric friction. Thermal Protection System (TPS) materials shield the craft from this searing heat, which can reach temperatures of 2900 F. Various thermophysical and optical properties of TPS materials are tested at the Johnson Space Center Atmospheric Reentry Materials and Structures Evaluation Facility, which has the capability to simulate critical environmental conditions associated with entry into the earth's atmosphere. Emissivity is an optical property that determines how well a material will reradiate incident heat back into the atmosphere upon reentry, thus protecting the spacecraft from the intense frictional heat. This report describes a method of measuring TPS emissivities using the SR5000 Scanning Spectroradiometer, and includes system characteristics, sample data, and operational procedures developed for arc-jet applications.

Environmental Assessment, Balloon Launch and Landing Operations, Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico

DTIC Science & Technology

2012-06-01

Force Research Laboratory , Space Vehicles Directorate ( AFRL /RV) located at Kirtland Air Force Base is preparing an Environmental Assessment (EA) for...United States Air Force Research Laboratory , Space Vehicles Directorate ( AFRL /RV) located at Kirtland Air Force Base is preparing an Environmental...United States Air Force Research Laboratory , Space Vehicles Directorate ( AFRL

Space environmental effects on materials

NASA Technical Reports Server (NTRS)

Schwinghmaer, R. J.

1980-01-01

The design of long life platforms and structures for space is discussed in terms of the space environmental effects on the materials used. Vacuum, ultraviolet radiation, and charged particle radiation are among the factors considered. Research oriented toward the acquisition of long term environmental effects data needed to support the design and development of large low Earth orbit and geosynchronous Earth orbit space platforms and systems is described.

Semi-automated operation of Mars Climate Simulation chamber - MCSC modelled for biological experiments

NASA Astrophysics Data System (ADS)

Tarasashvili, M. V.; Sabashvili, Sh. A.; Tsereteli, S. L.; Aleksidze, N. D.; Dalakishvili, O.

2017-10-01

The Mars Climate Simulation Chamber (MCSC) (GEO PAT 12 522/01) is designed for the investigation of the possible past and present habitability of Mars, as well as for the solution of practical tasks necessary for the colonization and Terraformation of the Planet. There are specific tasks such as the experimental investigation of the biological parameters that allow many terrestrial organisms to adapt to the imitated Martian conditions: chemistry of the ground, atmosphere, temperature, radiation, etc. MCSC is set for the simulation of the conduction of various biological experiments, as well as the selection of extremophile microorganisms for the possible Settlement, Ecopoesis and/or Terraformation purposes and investigation of their physiological functions. For long-term purposes, it is possible to cultivate genetically modified organisms (e.g., plants) adapted to the Martian conditions for future Martian agriculture to sustain human Mars missions and permanent settlements. The size of the chamber allows preliminary testing of the functionality of space-station mini-models and personal protection devices such as space-suits, covering and building materials and other structures. The reliability of the experimental biotechnological materials can also be tested over a period of years. Complex and thorough research has been performed to acquire the most appropriate technical tools for the accurate engineering of the MCSC and precious programmed simulation of Martian environmental conditions. This paper describes the construction and technical details of the equipment of the MCSC, which allows its semi-automated, long-term operation.

Regional climate change predictions from the Goddard Institute for Space Studies high resolution GCM

NASA Technical Reports Server (NTRS)

Crane, Robert G.; Hewitson, Bruce

1990-01-01

Model simulations of global climate change are seen as an essential component of any program aimed at understanding human impact on the global environment. A major weakness of current general circulation models (GCMs), however, is their inability to predict reliably the regional consequences of a global scale change, and it is these regional scale predictions that are necessary for studies of human/environmental response. This research is directed toward the development of a methodology for the validation of the synoptic scale climatology of GCMs. This is developed with regard to the Goddard Institute for Space Studies (GISS) GCM Model 2, with the specific objective of using the synoptic circulation form a doubles CO2 simulation to estimate regional climate change over North America, south of Hudson Bay. This progress report is specifically concerned with validating the synoptic climatology of the GISS GCM, and developing the transfer function to derive grid-point temperatures from the synoptic circulation. Principal Components Analysis is used to characterize the primary modes of the spatial and temporal variability in the observed and simulated climate, and the model validation is based on correlations between component loadings, and power spectral analysis of the component scores. The results show that the high resolution GISS model does an excellent job of simulating the synoptic circulation over the U.S., and that grid-point temperatures can be predicted with reasonable accuracy from the circulation patterns.

KSC-2014-2900

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – From left, Jim Smodell, a technician with SGT, and George Guerra, a quality control engineer with QinetiQ North America, prepare to remove the plant pillows containing the outredgeous red lettuce leaves from the Veggie plant growth system inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

KSC-2014-2902

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Jim Smodell, a technician with SGT, moves the plant pillows containing the outredgeous red lettuce leaves outside of the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit for Veggie and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. In the background is Chuck Spern, lead project engineer with QinetiQ North America on the Engineering Services Contract. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

KSC-2014-2903

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – Jim Smodell, left, a technician with SGT, and Chuck Spern, lead project engineer with QinetiQ North America on the Engineering Services Contract, move the plant pillows containing the outredgeous red lettuce leaves outside of the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit for Veggie and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

KSC-2014-2899

NASA Image and Video Library

2014-06-11

CAPE CANAVERAL, Fla. – From left, Jim Smodell, a technician with SGT, and George Guerra, a quality control engineer with QinetiQ North America, review procedures for removing the plant pillows containing the outredgeous red lettuce leaves from the Veggie plant growth system inside the International Space Station Environmental Simulator chamber at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. The growth chamber was used as a control unit and procedures were followed identical to those being performed on Veggie and the Veg-01 experiment on the International Space Station. The chamber mimicked the temperature, relative humidity and carbon dioxide concentration of those in the Veggie unit on the space station. Veggie and Veg-01 were delivered to the space station aboard the SpaceX-3 mission. Veggie is the first fresh food production system delivered to the station. Six plant pillows, each containing outredgeous red romaine lettuce seeds and a root mat were inserted into Veggie. The plant chamber's red, blue and green LED lights were activated. The plant growth was monitored for 33 days. On June 10, at the end of the cycle, the plants were carefully harvested, frozen and stored for return to Earth by Expedition 39 flight engineer and NASA astronaut Steve Swanson. Photo credit: NASA/Frankie Martin

Launching a Dream. A Teachers Guide to a Simulated Space Shuttle Mission.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Cleveland, OH. Lewis Research Center.

This publication is about imagination, teamwork, creativity, and a host of other ingredients required to carry out a dream. It is about going into space--going into space as part of a simulated space shuttle mission. The publication highlights two simulated shuttle missions cosponsored by the National Aeronautics and Space Administration (NASA)…

The Structure of Vertical Wind Shear in Tropical Cyclone Environments: Implications for Forecasting and Predictability

NASA Astrophysics Data System (ADS)

Finocchio, Peter M.

The vertical wind shear measured between 200 and 850 hPa is commonly used to diagnose environmental interactions with a tropical cyclone (TC) and to forecast the storm's intensity and structural evolution. More often than not, stronger vertical shear within this deep layer prohibits the intensification of TCs and leads to predictable asymmetries in precipitation. But such bulk measures of vertical wind shear can occasionally mislead the forecaster. In the first part of this dissertation, we use a series of idealized numerical simulations to examine how a TC responds to changing the structure of unidirectional vertical wind shear while fixing the 200-850-hPa shear magnitude. These simulations demonstrate a significant intensity response, in which shear concentrated in shallow layers of the lower troposphere prevents vortex intensification. We attribute the arrested development of TCs in lower-level shear to the intrusion of mid-level environmental air over the surface vortex early in the simulations. Convection developing on the downshear side of the storm interacts with the intruding air so as to enhance the downward flux of low-entropy air into the boundary layer. We also construct a two-dimensional intensity response surface from a set of simulations that sparsely sample the joint shear height-depth parameter space. This surface reveals regions of the two-parameter space for which TC intensity is particularly sensitive. We interpret these parameter ranges as those which lead to reduced intensity predictability. Despite the robust response to changing the shape of a sheared wind profile in idealized simulations, we do not encounter such sensitivity within a large set of reanalyzed TCs in the Northern Hemisphere. Instead, there is remarkable consistency in the structure of reanalyzed wind profiles around TCs. This is evident in the distributions of two new parameters describing the height and depth of vertical wind shear, which highlight a clear preference for shallow layers of upper-level shear. Many of the wind profiles tested in the idealized simulations have shear height or depth values on the tails of these distributions, suggesting that the environmental wind profiles around real TCs do not exhibit enough structural variability to have the clear statistical relationship to intensity change that we expected. In the final part of this dissertation, we use the reanalyzed TC environments to initialize ensembles of idealized simulations. Using a new modeling technique that allows for time-varying environments, these simulations examine the predictability implications of exposing a TC to different structures and magnitudes of vertical wind shear during its life cycle. We find that TCs in more deeply distributed vertical wind shear environments have a more uncertain intensity evolution than TCs exposed to shallower layers of upper-level shear. This higher uncertainty arises from a more marginal boundary layer environment that the deeply distributed shear establishes, which enhances the TC sensitivity to the magnitude of deep-layer shear. Simulated radar reflectivity also appears to evolve in a more uncertain fashion in environments with deeply distributed vertical shear. However, structural predictability timescales, computed as the time it takes for errors in the amplitude or phase of azimuthal asymmetries of reflectivity to saturate, are similar for wind profiles with shallow upper-level shear and deeply distributed shear. Both ensembles demonstrate predictability timescales of two to three days for the lowest azimuthal wavenumbers of amplitude and phase. As the magnitude of vertical wind shear increases to universally destructive levels, structural and intensity errors begin to decrease. Shallow upper-level shear primes the TC for a more pronounced recovery in the predictability of the wavenumber-one precipitation structure in stronger shear. The recovered low-wavenumber predictability of TC precipitation structure and the collapse in intensity spread in strong shear suggests that vertical wind shear is most effective at reducing TC predictability when its magnitude is near the threshold between favorable and unfavorable values and when it is deeply distributed through the troposphere. By isolating the effect of the environmental flow, the simulations and analyses in this dissertation offer a unique understanding of how vertical wind shear affects TCs. In particular, the results have important implications for designing and implementing future environmental observing strategies that will be critical for improving forecasts of these destructive storms.

Optical design of space cameras for automated rendezvous and docking systems

NASA Astrophysics Data System (ADS)

Zhu, X.

2018-05-01

Visible cameras are essential components of a space automated rendezvous and docking (AR and D) system, which is utilized in many space missions including crewed or robotic spaceship docking, on-orbit satellite servicing, autonomous landing and hazard avoidance. Cameras are ubiquitous devices in modern time with countless lens designs that focus on high resolution and color rendition. In comparison, space AR and D cameras, while are not required to have extreme high resolution and color rendition, impose some unique requirements on lenses. Fixed lenses with no moving parts and separated lenses for narrow and wide field-of-view (FOV) are normally used in order to meet high reliability requirement. Cemented lens elements are usually avoided due to wide temperature swing and outgassing requirement in space environment. The lenses should be designed with exceptional straylight performance and minimum lens flare given intense sun light and lacking of atmosphere scattering in space. Furthermore radiation resistant glasses should be considered to prevent glass darkening from space radiation. Neptec has designed and built a narrow FOV (NFOV) lens and a wide FOV (WFOV) lens for an AR and D visible camera system. The lenses are designed by using ZEMAX program; the straylight performance and the lens baffles are simulated by using TracePro program. This paper discusses general requirements for space AR and D camera lenses and the specific measures for lenses to meet the space environmental requirements.

Space plasma simulations; Proceedings of the Second International School for Space Simulations, Kapaa, HI, February 4-15, 1985. Parts 1 & 2

NASA Technical Reports Server (NTRS)

Ashour-Abdalla, M. (Editor); Dutton, D. A. (Editor)

1985-01-01

Space plasma simulations, observations, and theories are discussed. Papers are presented on the capabilities of various types of simulation codes and simulation models. Consideration is given to plasma waves in the earth's magnetotail, outer planet magnetosphere, geospace, and the auroral and polar cap regions. Topics discussed include space plasma turbulent dissipation, the kinetics of plasma waves, wave-particle interactions, whistler mode propagation, global energy regulation, and auroral arc formation.

Limiting similarity and functional diversity along environmental gradients

USGS Publications Warehouse

Schwilk, D.W.; Ackerly, D.D.

2005-01-01

Recent developments in community models emphasize the importance of incorporating stochastic processes (e.g. ecological drift) in models of niche-structured community assembly. We constructed a finite, spatially explicit, lottery model to simulate the distribution of species in a one-dimensional landscape with an underlying gradient in environmental conditions. Our framework combines the potential for ecological drift with environmentally-mediated competition for space in a heterogeneous environment. We examined the influence of niche breadth, dispersal distances, community size (total number of individuals) and the breadth of the environmental gradient on levels of species and functional trait diversity (i.e. differences in niche optima). Three novel results emerge from this model: (1) niche differences between adjacent species (e.g. limiting similarity) increase in smaller communities, because of the interaction of competitive effects and finite population sizes; (2) immigration from a regional species pool, stochasticity and niche-assembly generate a bimodal distribution of species residence times ('transient' and 'resident') under a heterogeneous environment; and (3) the magnitude of environmental heterogeneity has a U-shaped effect on diversity, because of shifts in species richness of resident vs. transient species. These predictions illustrate the potential importance of stochastic (although not necessarily neutral) processes in community assembly. ??2005 Blackwell Publishing Ltd/CNRS.

[Research in space environmental medicine: review and future].

PubMed

Yu, Xue-jun; Qi, Zhang-nian; Chang, Shao-yong; Liang, Hong; Liu, Hong-tao

2003-01-01

The investigation progress of space environmental medicine in China is summarized. Then, the application of space environmental medicine to formulating medical requirements for the crew module design, and performing medical evaluation for Shenzhou spaceship are addressed. Additionally, the medical and engineering means for the protection from harmful agents during spaceflight is illustrated. Finally, the objective and challenge of space environment medicine faced in the future research in China are presented.

Polymethylmethacrylate combustion in a narrow channel apparatus simulating a microgravity environment

NASA Astrophysics Data System (ADS)

Bornand, Garrett Randall

Fire safety is an important part of engineering when human lives are at stake. From everyday homes to spacecraft that can cost hundreds of millions of dollars. The research in this thesis attempts to provide scientific evidence that the apparatus in question successfully simulates microgravity and can possibly replace NASA's current test method for spacecraft fire safety. Flame spread tests were conducted with thermally thick and thermally thin polymethylmethacrylate (PMMA) samples to study flame spread behavior in response to environmental changes. The tests were conducted using the San Diego State University Narrow Channel Apparatus (SDSU NCA) as well as within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS). The SDSU NCA can suppress buoyant flow in horizontally spreading flames, and is currently being investigated as a possible replacement or complement to NASA's current material flammability test standard for non-metallic solids, NASA-STD-(I)-6001B Test 1. The buoyant suppression attained in the NCA allows tests to be conducted in a simulated microgravity environment-a characteristic that NASA's Test 1 lacks since flames present in Test 1 are driven by buoyant flows. The SDSU NCA allows for tests to be conducted at various opposed flow oxidizer velocities, oxygen percent by volume, and total pressure to mimic various spacecraft and habitat atmospheres. Tests were conducted at 1 atm pressure, thin fuel thickness of 50 and 75 microns, thick fuel thickness ranging from 3 mm to 5.6 mm, opposed oxidizer velocity ranging from 10 to 25 cm/s, and oxygen concentration by volume at 21, 30, and 50 percent. The simulated microgravity flame spread results were then compared to true microgravity experiments including; testing conducted on the International Space Station (ISS) under the Burning and Suppression of Solids (BASS) research, NASA's 5.2 second Drop Tower, and Micro-Gravity Laboratory's (MGLAB) 4.5 second Drop Tower. Data was also compared to results found by Michigan State University's NCA. Flame spread results from the SDSU NCA compare closely to that of the other experimental techniques. Additionally, an infrared camera and species concentration sensors were added to the SDSU NCA and initial results are provided. Fire Dynamics Simulator (FDS) was used to model the combustion of PMMA within the SDSU NCA. Both thin and thick fuel beds were simulated and the numerical results were compared to experimental data. The simulation was then used to determine various results that cannot easily be found with experimentation, including how effectively the NCA simulates microgravity under certain environmental conditions, gas and fuel bed temperatures, heat fluxes, species concentrations, pyrolysis rate, and other various data. The simulation was found to give reasonable results and overall flame spread trends, but could be improved upon with further detailed kinetic parameter studies.

Evaluation of the effects of solar radiation on glass. [space environment simulation

NASA Technical Reports Server (NTRS)

Firestone, R. F.; Harada, Y.

1979-01-01

The degradation of glass used on space structures due to electromagnetic and particulate radiation in a space environment was evaluated. The space environment was defined and a simulated space exposure apparatus was constructed. Four optical materials were exposed to simulated solar and particulate radiation in a space environment. Sapphire and fused silica experienced little change in transmittance, while optical crown glass and ultra low expansion glass darkened appreciably. Specimen selection and preparation, exposure conditions, and the effect of simulated exposure are discussed. A selective bibliography of the effect of radiation on glass is included.

Future space development scenarios: Environmental considerations

NASA Technical Reports Server (NTRS)

Tangum, Richard

1992-01-01

The formation of positive attitudes and values concerning the environment of space, as the basis for assuming a wise stewardship role, is becoming increasingly important as many nations begin their journeys into space. A strong emphasis should be placed on fostering an international space environmental ethics. The object of environmental assessment and management in space should be to define what interplanetary regulatory procedures are needed to avoid unnecessary environmental damage and to monitor the effectiveness of such avoidance. The first requirement for research is to narrow the field of concern to areas where there could be an increased scale of development in space in the immediate future. Research needs to be focused on methodologies for defining the environmental systems involved (e.g., the lunar surface) and then recognizing key variables in the system that are fragile and need to be respected. Criteria for environmental quality should emerge which identify, in the case of lunar surface, how much mining activity can be safely undertaken and what quantity of exhaust gases can be released over a given period of time. Only then will humans be most able to evaluate the likely consequences of ventures into space.

Future perspectives on space psychology: Recommendations on psychosocial and neurobehavioural aspects of human spaceflight

NASA Astrophysics Data System (ADS)

De La Torre, Gabriel G.; van Baarsen, Berna; Ferlazzo, Fabio; Kanas, Nick; Weiss, Karine; Schneider, Stefan; Whiteley, Iya

2012-12-01

Recently the psychological effects of space flight have gained in attention. In uncovering the psychological challenges that individuals and teams can face, we need research options that integrate psychosocial aspects with behavioral, performance, technical and environmental issues. Future perspectives in Space Psychology and Human Spaceflight are reviewed in this paper. The topics covered include psychosocial and neurobehavioural aspects, neurocognitive testing tools, decision making, autonomy and delayed communications, well being, mental health, situational awareness, and methodology. Authors were members of a European Space Agency (ESA) Research Topical Team on Psychosocial and Behavioral Aspects of Human Spaceflight. They discuss the different topics under a common perspective of a theoretical and practical framework, showing interactions, relationships and possible solutions for the different aspects and variables in play. Recommendations for every topic are offered and summarized for future research in the field. The different proposed research ideas can be accomplished using analogs and simulation experiments, short- and long-duration bed rest, and in-flight microgravity studies. These topics are especially important for future Moon and Mars mission design and training.

A discrete-space urban model with environmental amenities

Treesearch

Liaila Tajibaeva; Robert G. Haight; Stephen Polasky

2008-01-01

This paper analyzes the effects of providing environmental amenities associated with open space in a discrete-space urban model and characterizes optimal provision of open space across a metropolitan area. The discrete-space model assumes distinct neighborhoods in which developable land is homogeneous within a neighborhood but heterogeneous across neighborhoods. Open...

LDEF polymeric materials: A summary of Langley characterization

NASA Technical Reports Server (NTRS)

Young, Philip R.; Slemp, Wayne S.; Whitley, Karen S.; Kalil, Carol R.; Siochi, Emilie J.; Shen, James Y.; Chang, A. C.

1995-01-01

The NASA Long Duration Exposure Facility (LDEF) enabled the exposure of a wide variety of materials to the low earth orbit (LEO) environment. This paper provides a summary of research conducted at the Langley Research Center into the response of selected LDEF polymers to this environment. Materials examined include graphite fiber reinforced epoxy, polysulfone, and additional polyimide matrix composites, films of FEP Teflon, Kapton, several experimental high performance polyimides, and films of more traditional polymers such as poly(vinyl toluene) and polystyrene. Exposure duration was either 10 months or 5.8 years. Flight and control specimens were characterized by a number of analytical techniques including ultraviolet-visible and infrared spectroscopy, thermal analysis, scanning electron and scanning tunneling microscopy, x-ray photoelectron spectroscopy, and, in some instances, selected solution property measurements. Characterized effects were found to be primarily surface phenomena. These effects included atomic oxygen-induced erosion of unprotected surfaces and ultraviolet-induced discoloration and changes in selected molecular level parameters. No gross changes in molecular structure or glass transition temperature were noted. The intent of this characterization is to increase our fundamental knowledge of space environmental effects as an aid in developing new and improved polymers for space application. A secondary objective is to develop benchmarks to enhance our methodology for the ground-based simulation of environmental effects so that polymer performance in space can be more reliably predicted.

Postnatal development under conditions of simulated weightlessness and space flight

NASA Technical Reports Server (NTRS)

Walton, K.

1998-01-01

The adaptability of the developing nervous system to environmental influences and the mechanisms underlying this plasticity has recently become a subject of interest in space neuroscience. Ground studies on neonatal rats using the tail suspension model of weightlessness have shown that the force of gravity clearly influences the events underlying the postnatal development of motor function. These effects depend on the age of the animal, duration of the perturbation and the motor function studied. A nine-day flight study has shown that a dam and neonates can develop under conditions of space flight. The motor function of the flight animals after landing was consistent with that seen in the tail suspension studies, being marked by limb joint extension. However, there were expected differences due to: (1) the unloading of the vestibular system in flight, which did not occur in the ground-based experiments; (2) differences between flight and suspension durations; and (3) the inability to evaluate motor function during the flight. The next step is to conduct experiments in space with the flexibility and rigor that is now limited to ground studies: an opportunity offered by the International Space Station. Copyright 1998 Published by Elsevier Science B.V.

Animal studies of life shortening and cancer risk from space radiation

NASA Astrophysics Data System (ADS)

Wood, D. H.; Yochmowitz, M. G.; Hardy, K. A.; Salmon, Y. L.

The U. S. Air Force study of the delayed effects of single, total body exposures to simulated space radiation in rhesus monkeys is now in its 21st year. Observations on 301 irradiated and 57 age-matched control animals indicate that life expectancy loss from exposure to protons in the energy range encountered in the Van Allen belts and solar proton events can be expressed as a logarithmic function of the dose. The primary causes of life shortening are cancer and endometriosis (an abnormal proliferation of the lining of the uterus in females). Life shortening estimates permit comparison of the risk associated with space radiation exposures to be compared with that of other occupational and environmental hazards, thereby facilitating risk/benefit decisions in the planning and operational phases of manned space missions. Calculations of the relative risk of fatal cancers in the irradiated subjects reveal that the total body surface dose required to double the risk of death from cancer over a 20-year post exposure period varies with the linear energy transfer (LET) of the radiation. The ability to determine the integrated dose and LET spectrum in space radiation exposures of human is, therefore, critical to the assessment of life-time cancer risk.

Space Station communications and tracking systems modeling and RF link simulation

NASA Technical Reports Server (NTRS)

Tsang, Chit-Sang; Chie, Chak M.; Lindsey, William C.

1986-01-01

In this final report, the effort spent on Space Station Communications and Tracking System Modeling and RF Link Simulation is described in detail. The effort is mainly divided into three parts: frequency division multiple access (FDMA) system simulation modeling and software implementation; a study on design and evaluation of a functional computerized RF link simulation/analysis system for Space Station; and a study on design and evaluation of simulation system architecture. This report documents the results of these studies. In addition, a separate User's Manual on Space Communications Simulation System (SCSS) (Version 1) documents the software developed for the Space Station FDMA communications system simulation. The final report, SCSS user's manual, and the software located in the NASA JSC system analysis division's VAX 750 computer together serve as the deliverables from LinCom for this project effort.

Development of Standardized Lunar Regolith Simulant Materials

NASA Technical Reports Server (NTRS)

Carpenter, P.; Sibille, L.; Meeker, G.; Wilson, S.

2006-01-01

Lunar exploration requires scientific and engineering studies using standardized testing procedures that ultimately support flight certification of technologies and hardware. It is necessary to anticipate the range of source materials and environmental constraints that are expected on the Moon and Mars, and to evaluate in-situ resource utilization (ISRU) coupled with testing and development. We describe here the development of standardized lunar regolith simulant (SLRS) materials that are traceable inter-laboratory standards for testing and technology development. These SLRS materials must simulate the lunar regolith in terms of physical, chemical, and mineralogical properties. A summary of these issues is contained in the 2005 Workshop on Lunar Regolith Simulant Materials [l]. Lunar mare basalt simulants MLS-1 and JSC-1 were developed in the late 1980s. MLS-1 approximates an Apollo 11 high-Ti basalt, and was produced by milling of a holocrystalline, coarse-grained intrusive gabbro (Fig. 1). JSC-1 approximates an Apollo 14 basalt with a relatively low-Ti content, and was obtained from a glassy volcanic ash (Fig. 2). Supplies of MLS-1 and JSC-1 have been exhausted and these materials are no longer available. No highland anorthosite simulant was previously developed. Upcoming lunar polar missions thus require the identification, assessment, and development of both mare and highland simulants. A lunar regolith simulant is manufactured from terrestrial components for the purpose of simulating the physical and chemical properties of the lunar regolith. Significant challenges exist in the identification of appropriate terrestrial source materials. Lunar materials formed under comparatively reducing conditions in the absence of water, and were modified by meteorite impact events. Terrestrial materials formed under more oxidizing conditions with significantly greater access to water, and were modified by a wide range of weathering processes. The composition space of lunar materials can be modeled by mixing programs utilizing a low-Ti basalt, ilmenite, KREEP component, high-Ca anorthosite, and meteoritic components. This approach has been used for genetic studies of lunar samples via chemical and modal analysis. A reduced composition space may be appropriate for simulant development, but it is necessary to determine the controlling properties that affect the physical, chemical and mineralogical components of the simulant.

Promoting Environmental Justice Through Urban Green Space Access: A Synopsis

Treesearch

Viniece Jennings; Cassandra Johnson Gaither; Richard Schulterbrandt Gragg

2012-01-01

This article reviews literature on the connection between urban green space access and environmental justice. It discusses the dynamics of the relationship as it relates to factors such as environmental quality, land use, and environmental health disparities. Urban development stresses the landscape and may compromise environmental quality. Since some communities are...

A Facility and Architecture for Autonomy Research

NASA Technical Reports Server (NTRS)

Pisanich, Greg; Clancy, Daniel (Technical Monitor)

2002-01-01

Autonomy is a key enabling factor in the advancement of the remote robotic exploration. There is currently a large gap between autonomy software at the research level and software that is ready for insertion into near-term space missions. The Mission Simulation Facility (MST) will bridge this gap by providing a simulation framework and suite of simulation tools to support research in autonomy for remote exploration. This system will allow developers of autonomy software to test their models in a high-fidelity simulation and evaluate their system's performance against a set of integrated, standardized simulations. The Mission Simulation ToolKit (MST) uses a distributed architecture with a communication layer that is built on top of the standardized High Level Architecture (HLA). This architecture enables the use of existing high fidelity models, allows mixing simulation components from various computing platforms and enforces the use of a standardized high-level interface among components. The components needed to achieve a realistic simulation can be grouped into four categories: environment generation (terrain, environmental features), robotic platform behavior (robot dynamics), instrument models (camera/spectrometer/etc.), and data analysis. The MST will provide basic components in these areas but allows users to plug-in easily any refined model by means of a communication protocol. Finally, a description file defines the robot and environment parameters for easy configuration and ensures that all the simulation models share the same information.

Overall Genomic Effects of the exposure to real and simulated gravity during Drosophila melanogaster metamorphosis

NASA Astrophysics Data System (ADS)

Marco, Roberto; Herranz, Raul; Lavan, David; Villa, Aida; Medina, Francisco Javier; van Loon, Jack W. A.

The availability of genomic information and of high through-put analysis techniques makes possible to investigate and understand the genetic basis of ecologically important traits, traits that could increase the fitness of the different organisms towards the different characteristics of the environment in which they are normally living and therefore are adapted. As recently discussed (1), it is not an easy task to identify among the global transcription response, the probably smaller group of genes with discernible relevance to the particular perturbation analyzed. The issue whether the challenge experienced by the biological systems is "familiar" or "evolutionary novel" is relevant to our experiments. Combining/modifying the type of environmental challenges and looking for the correlation among the genes responses is one way to substantiate the relevance of the results. Nevertheless, the more relevant genes involved in a particular response may not show the more important changes in expression levels as has been shown for hubs with high connectivity in interaction networks. To integrate the findings from gene expression changes with the experiments performed with more direct experimental approaches is a challenge for the immediate future. When we started our analysis, we were expecting to detect a relatively small group of gravity responding genes. On the other hand, we think now that the overall genome is responding to the evolutionary novel environment. The experiments on which we base our analysis are: a) experiments in the International Space Station, b) experiments performed on ground microgravity simulating equipment, mainly on the Random Position Machine and experiments under hypergravity, namely at 10g, well above the acceleration felt by the organisms during the launch of the space shifts that are used in the orbital experiments. The actual developmental process studied is the Drosophila metamorphosis. The pupae at the end of the developmental period where the adult flies are formed, starting from the larvae, provides an appropriated system where to answer the question, how general is the transcriptional response of a high organism such as Drosophila when exposed at unusual conditions such as those prevalent in Space and reproduced on the ground with more or less fidelity. Space experiments are always associated to strict experimental constraints caused by the specific requirements linked to this highly unusual environment. These constraints were partially introduced to make possible the fixation of our pupae in Space. The required levels of containment had the consequence of providing a limited amount of oxygen to the pupae inside the hermetic Type I container. Furthermore, it was necessary to cool down the early pupae to make possible that the majority of the pupal development occurred in Space. The compatibility of these constraints with the pupal development was tested. Furthermore, the ground control simulations could be run with or without the constraints. The results that will be reviewed in the presentation: metricconverterProductID1. A1. A large proportion of the genes responded to the Space conditions, very likely mostly to microgravity. 2. The constraints actually reinforced the gene response produced by the exposure to microgravity, making easier to detect the positive effect. 3. The Space results could be almost exactly reproduced on the ground simulation conditions. 5. Hypergravity although triggering a much less conspicuous response than microgravity, interestingly, changed the gene expression in an opposite directions to the one triggered by microgravity. The significance of these effects in long-term multigenerational experiments could provide the genetic basis for the adaptation to the new environmental parameters and indicate the way evolution could proceed. Manned space missions and the development of life support systems should take these findings into account. 1) Koonin, E. V. Chance and necessity in cellular response to challenge. Molecular Systems Biology (2007), 3

Environmental Controls on Space-Time Biodiversity Patterns in the Amazon

NASA Astrophysics Data System (ADS)

Porporato, A. M.; Bonetti, S.; Feng, X.

2014-12-01

The Amazon/Andes territory is characterized by the highest biodiversity on Earth and understanding how all these ecological niches and different species originated and developed is an open challenge. The niche perspective assumes that species have evolved and occupy deterministically different roles within its environment. This view differs from that of the neutral theories, which assume ecological equivalence between all species but incorporates stochastic demographic processes along with long-term migration and speciation rates. Both approaches have demonstrated tremendous power in predicting aspects species biodiversity. By combining tools from both approaches, we use modified birth and death processes to simulate plant species diversification in the Amazon/Andes and their space-time ecohydrological controls. By defining parameters related to births and deaths as functions of available resources, we incorporate the role of space-time resource variability on niche formation and community composition. We also explicitly include the role of a heterogeneous landscape and topography. The results are discussed in relation to transect datasets from neotropical forests.

Additive hazards regression and partial likelihood estimation for ecological monitoring data across space.

PubMed

Lin, Feng-Chang; Zhu, Jun

2012-01-01

We develop continuous-time models for the analysis of environmental or ecological monitoring data such that subjects are observed at multiple monitoring time points across space. Of particular interest are additive hazards regression models where the baseline hazard function can take on flexible forms. We consider time-varying covariates and take into account spatial dependence via autoregression in space and time. We develop statistical inference for the regression coefficients via partial likelihood. Asymptotic properties, including consistency and asymptotic normality, are established for parameter estimates under suitable regularity conditions. Feasible algorithms utilizing existing statistical software packages are developed for computation. We also consider a simpler additive hazards model with homogeneous baseline hazard and develop hypothesis testing for homogeneity. A simulation study demonstrates that the statistical inference using partial likelihood has sound finite-sample properties and offers a viable alternative to maximum likelihood estimation. For illustration, we analyze data from an ecological study that monitors bark beetle colonization of red pines in a plantation of Wisconsin.

Space Environment Stability and Physical Properties of New Materials for Space Power and Commercial Applications

NASA Technical Reports Server (NTRS)

Hambourger, Paul D.

1997-01-01

Useful and informative results were obtained on virtually all materials investigated. For example, the stability of ITO-based arc-proof transparent coatings was greatly improved by substitution of silicon oxide for magnesium fluoride as a dopant. Research on 'air-doped' ITO films has yielded new insight into their conduction mechanism which will help in further development of these coatings. Some air-doped films were found to be extremely pressure sensitive. This work may lead to improved, low-cost gas sensors and vacuum gauges. Work on another promising transparent arc-proof coating (titanium oxide) was initiated in collaboration with industry. Graphite oxide-like materials were synthesized and tested for possible use in high energy-density batteries and other applications. We also started a high-priority project to find the cause of unexpected environmental damage to the exterior of the Hubble Space Telescope (HST) discovered on a recent Shuttle mission. Materials were characterized before and after exposure to soft x-rays and other threats in ground-based simulators.

Evaluations of Silica Aerogel-Based Flexible Blanket as Passive Thermal Control Element for Spacecraft Applications

NASA Astrophysics Data System (ADS)

Hasan, Mohammed Adnan; Rashmi, S.; Esther, A. Carmel Mary; Bhavanisankar, Prudhivi Yashwantkumar; Sherikar, Baburao N.; Sridhara, N.; Dey, Arjun

2018-03-01

The feasibility of utilizing commercially available silica aerogel-based flexible composite blankets as passive thermal control element in applications such as extraterrestrial environments is investigated. Differential scanning calorimetry showed that aerogel blanket was thermally stable over - 150 to 126 °C. The outgassing behavior, e.g., total mass loss, collected volatile condensable materials, water vapor regained and recovered mass loss, was within acceptable range recommended for the space applications. ASTM tension and tear tests confirmed the material's mechanical integrity. The thermo-optical properties remained nearly unaltered in simulated space environmental tests such as relative humidity, thermal cycling and thermo-vacuum tests and confirmed the space worthiness of the aerogel. Aluminized Kapton stitched or anchored to the blanket could be used to control the optical transparency of the aerogel. These outcomes highlight the potential of commercial aerogel composite blankets as passive thermal control element in spacecraft. Structural and chemical characterization of the material was also done using scanning electron microscopy, Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy.

Hypervelocity Impact Test Facility: A gun for hire

NASA Technical Reports Server (NTRS)

Johnson, Calvin R.; Rose, M. F.; Hill, D. C.; Best, S.; Chaloupka, T.; Crawford, G.; Crumpler, M.; Stephens, B.

1994-01-01

An affordable technique has been developed to duplicate the types of impacts observed on spacecraft, including the Shuttle, by use of a certified Hypervelocity Impact Facility (HIF) which propels particulates using capacitor driven electric gun techniques. The fully operational facility provides a flux of particles in the 10-100 micron diameter range with a velocity distribution covering the space debris and interplanetary dust particle environment. HIF measurements of particle size, composition, impact angle and velocity distribution indicate that such parameters can be controlled in a specified, tailored test designed for or by the user. Unique diagnostics enable researchers to fully describe the impact for evaluating the 'targets' under full power or load. Users regularly evaluate space hardware, including solar cells, coatings, and materials, exposing selected portions of space-qualified items to a wide range of impact events and environmental conditions. Benefits include corroboration of data obtained from impact events, flight simulation of designs, accelerated aging of systems, and development of manufacturing techniques.

ASTAR Flight Test: Overview and Spacing Results

NASA Technical Reports Server (NTRS)

Roper, Roy D.; Koch, Michael R.

2016-01-01

The purpose of the NASA Langley Airborne Spacing for Terminal Arrival Routes (ASTAR) research aboard the Boeing ecoDemonstrator aircraft was to demonstrate the use of NASA's ASTAR algorithm using contemporary tools of the Federal Aviation Administration's Next Generation Air Transportation System (NEXTGEN). EcoDemonstrator is a Boeing test program which utilizes advanced experimental equipment to accelerate the science of aerospace and environmentally friendly technologies. The ASTAR Flight Test provided a proof-of-concept flight demonstration that exercised an algorithmic-based application in an actual aircraft. The test aircraft conducted Interval Management operations to provide time-based spacing off a target aircraft in non-simulator wind conditions. Work was conducted as a joint effort between NASA and Boeing to integrate ASTAR in a Boeing supplied B787 test aircraft while using a T-38 aircraft as the target. This demonstration was also used to identify operational risks to future flight trials for the NASA Air Traffic Management Technology Demonstration expected in 2017.

Alamos: An International Collaboration to Provide a Space Based Environmental Monitoring Solution for the Deep Space Network

NASA Astrophysics Data System (ADS)

Kennedy, S. O.; Dunn, A.; Lecomte, J.; Buchheim, K.; Johansson, E.; Berger, T.

2018-02-01

This abstract proposes the advantages of an externally mounted instrument in support of the human physiology, space biology, and human health and performance key science area. Alamos provides Space-Based Environmental Monitoring capabilities.

Advanced development receiver thermal vacuum tests with cold wall

NASA Technical Reports Server (NTRS)

Sedgwick, Leigh M.

1991-01-01

The first ever testing of a full size solar dynamic heat receiver using high temperature thermal energy storage was completed. The heat receiver was designed to meet the requirements for operation on the Space Station Freedom. The purpose of the test program was to quantify the receiver thermodynamic performance, its operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber with liquid nitrogen cold shrouds and an aperture cold plate to partially simulate a low Earth orbit environment. The cavity of the receiver was heated by an infrared quartz lamp heater with 30 independently controllable zones to produce flux distributions typical of candidate concentrators. A closed Brayton cycle engine simulator conditioned a helium xenon gas mixture to specific interface conditions to simulate various operational modes of the solar dynamic power module. Inlet gas temperature, pressure, and flow rate were independently varied. A total of 58 simulated orbital cycles were completed during the test conduct period. The test hardware, execution of testing, test data, and post test inspections are described.

Space stations: Living in zero gravity, developmental task for psychologists and space environmental experts

NASA Technical Reports Server (NTRS)

Ludwig, E.

1984-01-01

The recent advances in the psychological aspects of space station design are discussed, including the impact of the increase in awareness of both the public in general as well as space environmental experts of the importance of psychological factors when designing space stations and training astronauts.

A mechanistic model of environmental oxygen influence on the deterministic effects to human skin from space radiations

NASA Astrophysics Data System (ADS)

Flores-McLaughlin, John

During human spaceflight missions, controlled variation of atmospheric pressure and oxygen concentration from a sea-level based normal to hyperoxic levels may occur as part of operational procedure. This activity is of interest because it provides the relevant radiation exposure and dynamic oxygen concentration parameters that may lead to varying radiation sensitivity in the skin and other organs. Tumor hypoxia has been indicated as a primary factor in the decrease in efficacy of radiation therapy. These oxygen concentration effects have been largely demonstrated with low-LET radiations and to a lesser degree with high-LET primary radiations such as protons and heavy ions common in space exposure. In order to analyze the variation of oxygen concentration in human skin from spaceflight activities, a mathematical model of oxygen transport through the human cardiorespiratory system with pulmonary and cutaneous intake was implemented. Oxygen concentration was simulated at the various skin layers, from dermis to epidermis. Skin surface radiation doses and spectra from relatively high flux Solar Particle Events (SPEs) were calculated by the PHITS radiation transport code over a range of spacecraft and spacesuit thicknesses in terms of aluminum equivalence. A series of anatomical skin and shielding thicknesses were chosen to encompass the scope of radiation exposure levels as indicated by existing NASA skin phantom studies. To model the influence of oxygen with radiation exposure, microdosimetric oxygen fixation simulations were implemented using the Monte-Carlo-Damage-Simulation (MCDS) code. From these outputs, occurrence of DNA double strand breaks (DSBs) and relative biological effect (RBE) from radiation exposure with oxygen concentration dependence was established and correlated to spaceflight activities. It was determined that minimal but observable oxygen concentration transients occur in skin during environmental oxygen changes in spaceflight. The most significant transients occurred in the thickest epidermal layers with relatively high amounts of diffusion. Accordingly, these thickest epidermal layers also showed the greatest spaceflight induced transients of RBE relative to sea-level based atmosphere exposures.

NASA/SDIO Space Environmental Effects on Materials Workshop, part 1

NASA Technical Reports Server (NTRS)

Teichman, Louis A. (Compiler); Stein, Bland A. (Compiler)

1989-01-01

The present state of knowledge regarding space environmental effects on materials is described and the knowledge gaps that prevent informed decisions on the best use of advanced materials in space for long-duration NASA and Strategic Defense Initiative Organization (SDIO) missions are identified. Establishing priorities for future ground-based and space-based materials research was a major goal. The end product was an assessment of the current state-of-the-art in space environmental effects on materials in order to develop a national plan for spaceflight experiments.

The role of the Long Duration Exposure Facility in the development of space systems

NASA Technical Reports Server (NTRS)

Little, Sally A.

1992-01-01

The Long Duration Exposure Facility (LDEF) presents the international, aerospace community with an unprecedented opportunity to examine the synergistic, long term, space environmental effects on systems and materials. The analysis of the data within appropriate environmental contexts is essential to the overall process of advancing the understanding of space environmental effects needed for the continuing development of strategies to improve the reliability and durability of space systems and to effectively deal with the future challenges that new space initiatives will likely present.

Space Simulation, 7th. [facilities and testing techniques

NASA Technical Reports Server (NTRS)

1973-01-01

Space simulation facilities and techniques are outlined that encompass thermal scale modeling, computerized simulations, reentry materials, spacecraft contamination, solar simulation, vacuum tests, and heat transfer studies.

14 CFR 313.7 - Integration with environmental procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Integration with environmental procedures. 313.7 Section 313.7 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION....7 Integration with environmental procedures. (a) In proceedings in which an environmental impact...

Facility and Methods Developed for Simulated Space Vacuum Ultraviolet Exposure Testing of Polymer Films

NASA Technical Reports Server (NTRS)

Dever, Joyce A.; Pietromica, Anthony J.; Stueber, Thomas J.; Sechkar, Edward A.; Messer, Russell K.

2002-01-01

Vacuum ultraviolet (VUV) radiation of wavelengths between 115 and 200 nm produced by the Sun in the space environment can degrade polymer films, producing changes in their optical, mechanical, and chemical properties. These effects are particularly important for thin polymer films being considered for ultralightweight space structures, because, for most polymers, VUV radiation is absorbed in a thin surface layer. The NASA Glenn Research Center has developed facilities and methods for long-term ground testing of polymer films to evaluate space environmental VUV radiation effects. VUV exposure can also be used as part of combined or sequential simulated space environmental exposures to determine combined damaging effects with other aspects of the space environment, which include solar ultraviolet radiation, solar flare x-rays, electron and proton radiation, atomic oxygen (for low-Earth-orbit missions), and temperature effects. Because the wavelength sensitivity of VUV damage is not well known for most materials, Glenn's VUV facility uses a broad-spectrum deuterium lamp with a magnesium fluoride window that provides output between 115 and 200 nm. Deuterium lamps of this type were characterized by the National Institute of Standards and Technology and through measurements at Glenn. Spectral irradiance measurements show that from approximately 115 to 160 nm, deuterium lamp irradiance can be many times that of air mass zero solar irradiance, and as wavelength increases above approximately 160 nm, deuterium lamp irradiance decreases in comparison to the Sun. The facility is a cryopumped vacuum chamber that achieves a system pressure of approximately 5310(exp -6) torr. It contains four individual VUV-exposure compartments in vacuum, separated by water-cooled copper walls to minimize VUV radiation and any sample contamination cross interactions between compartments. Each VUV-exposure compartment contains a VUV deuterium lamp, a motor-controlled sample stage coupled with a moveable cesium iodide VUV phototube, and two thermocouples for temperature measurement. The vacuum chamber and exterior equipment is shown. Each VUV lamp is located at the top of the chamber with its projection-tube pushed through an O-ring compression fitting. The lamp assemblies are located on ports that can be isolated from the rest of the vacuum chamber, permitting maintenance or replacement of the lamps without breaking vacuum in the main chamber where the samples are located. A view of two of the four interior VUV-exposure compartments, including the moveable sample stages and detector holders is also shown. Glenn is using this facility to support testing of Next Generation Space Telescope sunshield materials that is being led by the NASA Goddard Space Flight Center and to develop an understanding of the wavelength, intensity, and temperature dependence of VUV-induced polymer degradation.

Application of virtual reality for crew mental health in extended-duration space missions

NASA Astrophysics Data System (ADS)

Salamon, Nick; Grimm, Jonathan M.; Horack, John M.; Newton, Elizabeth K.

2018-05-01

Human exploration of the solar system brings a host of environmental and engineering challenges. Among the most important factors in crew health and human performance is the preservation of mental health. The mental well-being of astronaut crews is a significant issue affecting the success of long-duration space missions, such as habitation on or around the Moon, Mars exploration, and eventual colonization of the solar system. If mental health is not properly addressed, these missions will be at risk. Upkeep of mental health will be especially difficult on long duration missions because many of the support systems available to crews on shorter missions will not be available. In this paper, we examine the use of immersive virtual reality (VR) simulations to maintain healthy mental states in astronaut crews who are removed from the essential comforts typically associated with terrestrial life. Various methods of simulations and their administration are analyzed in the context of current research and knowledge in the fields of psychology, medicine, and space sciences, with a specific focus on the environment faced by astronauts on long-term missions. The results of this investigation show that virtual reality should be considered a plausible measure in preventing mental state deterioration in astronauts, though more work is needed to provide a comprehensive view of the effectiveness and administration of VR methods.

Gravity of Living Systems: May the Force Be With You

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Holton, Emily M. (Technical Monitor)

1998-01-01

Gravity, the force which shapes the architecture of organisms from single cells to dinosaurs, has been the most constant environmental factor during the evolution of species on Earth. With long-duration space flight, an understanding of how gravity affects living systems gains greater urgency in order to maintain the health and performance of crews who will explore the solar system. For example, the cardiovascular and musculoskeletal systems are normally exposed to gravitational gradients of blood pressure and weight on Earth. Such gradients increase blood pressure and tissue weight in dependent tissues of the body. Thus, from a physiologic standpoint, these systems are greatly affected by altered gravity. Exposure to actual and simulated microgravity causes blood and tissue fluid to shift from the legs to the head. Studies of humans in space have documented facial edema, space adaptation syndrome, decreased plasma volume, muscle atrophy, and loss of bone strength. Return of astronauts to Earth is accompanied by orthostatic intolerance, decreased neuromuscular coordination, and reduced exercise capacity. These factors decrease performance during descent from orbit and increase risk during emergency egress from the space craft. Models of simulated microgravity include 60 head-down tilt, immersion, and prolonged horizontal bedrest. Head-down tilt and dry immersion are the most accepted models and studies using these models of up to one year have been performed in Russia. Sensitive animal models which offer clear insights into the role of gravity on structure and function include the developing giraffe and snakes from various habitats. Finally, possible countermeasures to speed readaptation of astronauts to gravity after prolonged space flight include exercise, lower body negative pressure, and centrifugation.

The Use of Microgravity Simulators for Space Research

NASA Technical Reports Server (NTRS)

Zhang, Ye; Richards, Stephanie E.; Richards, Jeffrey T.; Levine, Howard G.

2016-01-01

The spaceflight environment is known to influence biological processes ranging from stimulation of cellular metabolism to possible impacts on cellular damage repair, suppression of immune functions, and bone loss in astronauts. Microgravity is one of the most significant stress factors experienced by living organisms during spaceflight, and therefore, understanding cellular responses to altered gravity at the physiological and molecular level is critical for expanding our knowledge of life in space. Since opportunities to conduct experiments in space are scarce, various microgravity simulators and analogues have been widely used in space biology ground studies. Even though simulated microgravity conditions have produced some, but not all of the biological effects observed in the true microgravity environment, they provide test beds that are effective, affordable, and readily available to facilitate microgravity research. Kennedy Space Center (KSC) provides ground microgravity simulator support to offer a variety of microgravity simulators and platforms for Space Biology investigators. Assistance will be provided by both KSC and external experts in molecular biology, microgravity simulation, and engineering. Comparisons between the physical differences in microgravity simulators, examples of experiments using the simulators, and scientific questions regarding the use of microgravity simulators will be discussed.

The Use of Microgravity Simulators for Space Research

NASA Technical Reports Server (NTRS)

Zhang, Ye; Richards, Stephanie E.; Wade, Randall I.; Richards, Jeffrey T.; Fritsche, Ralph F.; Levine, Howard G.

2016-01-01

The spaceflight environment is known to influence biological processes ranging from stimulation of cellular metabolism to possible impacts on cellular damage repair, suppression of immune functions, and bone loss in astronauts. Microgravity is one of the most significant stress factors experienced by living organisms during spaceflight, and therefore, understanding cellular responses to altered gravity at the physiological and molecular level is critical for expanding our knowledge of life in space. Since opportunities to conduct experiments in space are scarce, various microgravity simulators and analogues have been widely used in space biology ground studies. Even though simulated microgravity conditions have produced some, but not all of the biological effects observed in the true microgravity environment, they provide test beds that are effective, affordable, and readily available to facilitate microgravity research. A Micro-g Simulator Center is being developed at Kennedy Space Center (KSC) to offer a variety of microgravity simulators and platforms for Space Biology investigators. Assistance will be provided by both KSC and external experts in molecular biology, microgravity simulation, and engineering. Comparisons between the physical differences in microgravity simulators, examples of experiments using the simulators, and scientific questions regarding the use of microgravity simulators will be discussed.

Unified Approach to Modeling and Simulation of Space Communication Networks and Systems

NASA Technical Reports Server (NTRS)

Barritt, Brian; Bhasin, Kul; Eddy, Wesley; Matthews, Seth

2010-01-01

Network simulator software tools are often used to model the behaviors and interactions of applications, protocols, packets, and data links in terrestrial communication networks. Other software tools that model the physics, orbital dynamics, and RF characteristics of space systems have matured to allow for rapid, detailed analysis of space communication links. However, the absence of a unified toolset that integrates the two modeling approaches has encumbered the systems engineers tasked with the design, architecture, and analysis of complex space communication networks and systems. This paper presents the unified approach and describes the motivation, challenges, and our solution - the customization of the network simulator to integrate with astronautical analysis software tools for high-fidelity end-to-end simulation. Keywords space; communication; systems; networking; simulation; modeling; QualNet; STK; integration; space networks

Using Data Warehouses to extract knowledge from Agro-Hydrological simulations

NASA Astrophysics Data System (ADS)

Bouadi, Tassadit; Gascuel-Odoux, Chantal; Cordier, Marie-Odile; Quiniou, René; Moreau, Pierre

2013-04-01

In recent years, simulation models have been used more and more in hydrology to test the effect of scenarios and help stakeholders in decision making. Agro-hydrological models have oriented agricultural water management, by testing the effect of landscape structure and farming system changes on water and chemical emission in rivers. Such models generate a large amount of data while few of them, such as daily concentrations at the outlet of the catchment, or annual budgets regarding soil, water and atmosphere emissions, are stored and analyzed. Thus, a great amount of information is lost from the simulation process. This is due to the large volumes of simulated data, but also to the difficulties in analyzing and transforming the data in an usable information. In this talk we illustrate a data warehouse which has been built to store and manage simulation data coming from the agro-hydrological model TNT (Topography-based nitrogen transfer and transformations, (Beaujouan et al., 2002)). This model simulates the transfer and transformation of nitrogen in agricultural catchments. TNT was used over 10 years on the Yar catchment (western France), a 50 km2 square area which present a detailed data set and have to facing to environmental issue (coastal eutrophication). 44 output key simulated variables are stored at a daily time step, i.e, 8 GB of storage size, which allows the users to explore the N emission in space and time, to quantify all the processes of transfer and transformation regarding the cropping systems, their location within the catchment, the emission in water and atmosphere, and finally to get new knowledge and help in making specific and detailed decision in space and time. We present the dimensional modeling process of the Nitrogen in catchment data warehouse (i.e. the snowflake model). After identifying the set of multileveled dimensions with complex hierarchical structures and relationships among related dimension levels, we chose the snowflake model to design our agri-environmental data warehouse. The snowflake schema is required for flexible querying complex dimension relationships. We have designed the Nitrogen in catchment data warehouse using the open source Business Intelligence Platform Pentaho Version 3.5. We use the online analytical processing (OLAP) to access and exploit, intuitively and quickly, the multidimensional and aggregated data from the Nitrogen in catchment data warehouse. We illustrate how the data warehouse can be efficiently used to explore spatio-temporal dimensions and to discover new knowledge and enrich the exploitation level of simulations. We show how the OLAP tool can be used to provide the user with the ability to synthesize environmental information and to understand nitrates emission in surface water by using comparative, personalized views on historical data. To perform advanced analyses that aim to find meaningful patterns and relationships in the data, the Nitrogen in catchment data warehouse should be extended with data mining or information retrieval methods as Skyline queries (Bouadi et al., 2012). (Beaujouan et al., 2002) Beaujouan, V., Durand, P., Ruiz, L., Aurousseau, P., and Cotteret, G. (2002). A hydrological model dedicated to topography-based simulation of nitrogen transfer and transformation: rationale and application to the geomorphology denitrification relationship. Hydrological Processes, pages 493-507. (Bouadi et al., 2012) Bouadi, T., Cordier, M., and Quiniou, R. (2012). Incremental computation of skyline queries with dynamic preferences. In DEXA (1), pages 219-233.

Older People’s Perceptions of Pedestrian Friendliness and Traffic Safety: An Experiment Using Computer-Simulated Walking Environments

PubMed Central

Kahlert, Daniela; Schlicht, Wolfgang

2015-01-01

Traffic safety and pedestrian friendliness are considered to be important conditions for older people’s motivation to walk through their environment. This study uses an experimental study design with computer-simulated living environments to investigate the effect of micro-scale environmental factors (parking spaces and green verges with trees) on older people’s perceptions of both motivational antecedents (dependent variables). Seventy-four consecutively recruited older people were randomly assigned watching one of two scenarios (independent variable) on a computer screen. The scenarios simulated a stroll on a sidewalk, as it is ‘typical’ for a German city. In version ‘A,’ the subjects take a fictive walk on a sidewalk where a number of cars are parked partially on it. In version ‘B’, cars are in parking spaces separated from the sidewalk by grass verges and trees. Subjects assessed their impressions of both dependent variables. A multivariate analysis of covariance showed that subjects’ ratings on perceived traffic safety and pedestrian friendliness were higher for Version ‘B’ compared to version ‘A’. Cohen’s d indicates medium (d = 0.73) and large (d = 1.23) effect sizes for traffic safety and pedestrian friendliness, respectively. The study suggests that elements of the built environment might affect motivational antecedents of older people’s walking behavior. PMID:26308026

Coherent quantum dynamics launched by incoherent relaxation in a quantum circuit simulator of a light-harvesting complex

NASA Astrophysics Data System (ADS)

Chin, A. W.; Mangaud, E.; Atabek, O.; Desouter-Lecomte, M.

2018-06-01

Engineering and harnessing coherent excitonic transport in organic nanostructures has recently been suggested as a promising way towards improving manmade light-harvesting materials. However, realizing and testing the dissipative system-environment models underlying these proposals is presently very challenging in supramolecular materials. A promising alternative is to use simpler and highly tunable "quantum simulators" built from programmable qubits, as recently achieved in a superconducting circuit by Potočnik et al. [A. Potočnik et al., Nat. Commun. 9, 904 (2018), 10.1038/s41467-018-03312-x]. We simulate the real-time dynamics of an exciton coupled to a quantum bath as it moves through a network based on the quantum circuit of Potočnik et al. Using the numerically exact hierarchical equations of motion to capture the open quantum system dynamics, we find that an ultrafast but completely incoherent relaxation from a high-lying "bright" exciton into a doublet of closely spaced "dark" excitons can spontaneously generate electronic coherences and oscillatory real-space motion across the network (quantum beats). Importantly, we show that this behavior also survives when the environmental noise is classically stochastic (effectively high temperature), as in present experiments. These predictions highlight the possibilities of designing matched electronic and spectral noise structures for robust coherence generation that do not require coherent excitation or cold environments.

Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey J.; Curley, Suzanne

2010-01-01

The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle s Environmental Control and Life Support System (ECLSS). Termed the Carbon Dioxide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were performed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic simulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

Marshall Space Flight Center Materials and Processes Laboratory

NASA Technical Reports Server (NTRS)

Tramel, Terri L.

2012-01-01

Marshall?s Materials and Processes Laboratory has been a core capability for NASA for over fifty years. MSFC has a proven heritage and recognized expertise in materials and manufacturing that are essential to enable and sustain space exploration. Marshall provides a "systems-wise" capability for applied research, flight hardware development, and sustaining engineering. Our history of leadership and achievements in materials, manufacturing, and flight experiments includes Apollo, Skylab, Mir, Spacelab, Shuttle (Space Shuttle Main Engine, External Tank, Reusable Solid Rocket Motor, and Solid Rocket Booster), Hubble, Chandra, and the International Space Station. MSFC?s National Center for Advanced Manufacturing, NCAM, facilitates major M&P advanced manufacturing partnership activities with academia, industry and other local, state and federal government agencies. The Materials and Processes Laborato ry has principal competencies in metals, composites, ceramics, additive manufacturing, materials and process modeling and simulation, space environmental effects, non-destructive evaluation, and fracture and failure analysis provide products ranging from materials research in space to fully integrated solutions for large complex systems challenges. Marshall?s materials research, development and manufacturing capabilities assure that NASA and National missions have access to cutting-edge, cost-effective engineering design and production options that are frugal in using design margins and are verified as safe and reliable. These are all critical factors in both future mission success and affordability.

Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

NASA Astrophysics Data System (ADS)

Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

2006-09-01

An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies an airflow rate of 5000lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

Low Earth orbital atomic oxygen and ultraviolet radiation effects on polymers

NASA Technical Reports Server (NTRS)

Dever, Joyce A.

1991-01-01

Because atomic oxygen and solar ultraviolet radiation present in the low earth orbital (LEO) environment can alter the chemistry of polymers resulting in degradation, their effects and mechanisms of degradation must be determined in order to determine the long term durability of polymeric surfaces to be exposed on missions such as Space Station Freedom. The effects of atomic oxygen on polymers which contain protective coatings must also be explored, since unique damage mechanisms can occur in areas where the protective coatings has failed. Mechanisms can be determined by utilizing results from previous LEO missions, by performing ground based LEO simulation tests and analysis, and by carrying out focussed space experiments. A survey is presented of the interactions and possible damage mechanisms for environmental atomic oxygen and UV radiation exposure of polymers commonly used in LEO.

Testimony to the House Science Space and Technology Committee.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Church, Michael Kenton; Tannenbaum, Benn

Chairman Smith, Ranking Member Johnson, and distinguished members of the Committee on Science, Space, and Technology, I thank you for the opportunity to testify today on the role of science, engineering, and research at Sandia National Laboratories, one of the nation’s premiere national labs and the nation’s largest Federally Funded Research and Development Center (FFRDC) laboratory. I am Dr. Susan Seestrom, Sandia’s Associate Laboratories Director for Advanced Science & Technology (AST) and Chief Research Officer (CRO). As CRO I am responsible for research strategy, Laboratory Directed Research & Development (LDRD), partnerships strategy, and technology transfer. As director and line managermore » for AST I manage capabilities and mission delivery across a variety of the physical and mathematical sciences and engineering disciplines, such as pulsed power, radiation effects, major environmental testing, high performance computing, and modeling and simulation.« less

Simulation of Martian surface-atmosphere interaction in a space-simulator: Technical considerations and feasibility

NASA Technical Reports Server (NTRS)

Moehlmann, D.; Kochan, H.

1992-01-01

The Space Simulator of the German Aerospace Research Establishment at Cologne, formerly used for testing satellites, is now, since 1987, the central unit within the research sub-program 'Comet-Simulation' (KOSI). The KOSI team has investigated physical processes relevant to comets and their surfaces. As a byproduct we gained experience in sample-handling under simulated space conditions. In broadening the scope of the research activities of the DLR Institute of Space Simulation an extension to 'Laboratory-Planetology' is planned. Following the KOSI-experiments a Mars Surface-Simulation with realistic minerals and surface soil in a suited environment (temperature, pressure, and CO2-atmosphere) is foreseen as the next step. Here, our main interest is centered on thermophysical properties of the Martian surface and energy transport (and related gas transport) through the surface. These laboratory simulation activities can be related to space missions as typical pre-mission and during-the-mission support of the experiments design and operations (simulation in parallel). Post mission experiments for confirmation and interpretation of results are of great value. The physical dimensions of the Space Simulator (cylinder of about 2.5 m diameter and 5 m length) allows for testing and qualification of experimental hardware under realistic Martian conditions.

SpaceNet: Modeling and Simulating Space Logistics

NASA Technical Reports Server (NTRS)

Lee, Gene; Jordan, Elizabeth; Shishko, Robert; de Weck, Olivier; Armar, Nii; Siddiqi, Afreen

2008-01-01

This paper summarizes the current state of the art in interplanetary supply chain modeling and discusses SpaceNet as one particular method and tool to address space logistics modeling and simulation challenges. Fundamental upgrades to the interplanetary supply chain framework such as process groups, nested elements, and cargo sharing, enabled SpaceNet to model an integrated set of missions as a campaign. The capabilities and uses of SpaceNet are demonstrated by a step-by-step modeling and simulation of a lunar campaign.

Convergence behavior of idealized convection-resolving simulations of summertime deep moist convection over land

NASA Astrophysics Data System (ADS)

Panosetti, Davide; Schlemmer, Linda; Schär, Christoph

2018-05-01

Convection-resolving models (CRMs) can explicitly simulate deep convection and resolve interactions between convective updrafts. They are thus increasingly used in numerous weather and climate applications. However, the truncation of the continuous energy cascade at scales of O (1 km) poses a serious challenge, as in kilometer-scale simulations the size and properties of the simulated convective cells are often determined by the horizontal grid spacing (Δ x ).In this study, idealized simulations of deep moist convection over land are performed to assess the convergence behavior of a CRM at Δ x = 8, 4, 2, 1 km and 500 m. Two types of convergence estimates are investigated: bulk convergence addressing domain-averaged and integrated variables related to the water and energy budgets, and structural convergence addressing the statistics and scales of individual clouds and updrafts. Results show that bulk convergence generally begins at Δ x =4 km, while structural convergence is not yet fully achieved at the kilometer scale, despite some evidence that the resolution sensitivity of updraft velocities and convective mass fluxes decreases at finer resolution. In particular, at finer grid spacings the maximum updraft velocity generally increases, and the size of the smallest clouds is mostly determined by Δ x . A number of different experiments are conducted, and it is found that the presence of orography and environmental vertical wind shear yields more energetic structures at scales much larger than Δ x , sometimes reducing the resolution sensitivity. Overall the results lend support to the use of kilometer-scale resolutions in CRMs, despite the inability of these models to fully resolve the associated cloud field.

The space transformation in the simulation of multidimensional random fields

USGS Publications Warehouse

Christakos, G.

1987-01-01

Space transformations are proposed as a mathematically meaningful and practically comprehensive approach to simulate multidimensional random fields. Within this context the turning bands method of simulation is reconsidered and improved in both the space and frequency domains. ?? 1987.

Characterizing the Survey Strategy and Initial Orbit Determination Abilities of the NASA MCAT Telescope for Geosynchronous Orbital Debris Environmental Studies

NASA Astrophysics Data System (ADS)

Frith, J.; Barker, E.; Cowardin, H.; Buckalew, B.; Anz-Meador, P.; Lederer, S.

The National Aeronautics and Space Administration (NASA) Orbital Debris Program Office (ODPO) recently commissioned the Meter Class Autonomous Telescope (MCAT) on Ascension Island with the primary goal of obtaining population statistics of the geosynchronous (GEO) orbital debris environment. To help facilitate this, studies have been conducted using MCAT’s known and projected capabilities to estimate the accuracy and timeliness in which it can survey the GEO environment, including collected weather data and the proposed observational data collection cadence. To optimize observing cadences and probability of detection, on-going work using a simulated GEO debris population sampled at various cadences are run through the Constrained Admissible Region Multi Hypotheses Filter (CAR-MHF). The orbits computed from the results are then compared to the simulated data to assess MCAT’s ability to determine accurately the orbits of debris at various sample rates. The goal of this work is to discriminate GEO and near-GEO objects from GEO transfer orbit objects that can appear as GEO objects in the environmental models due to the short arc observation and an assumed circular orbit. The specific methods and results are presented here.

Promoting A-Priori Interoperability of HLA-Based Simulations in the Space Domain: The SISO Space Reference FOM Initiative

NASA Technical Reports Server (NTRS)

Moller, Bjorn; Garro, Alfredo; Falcone, Alberto; Crues, Edwin Z.; Dexter, Daniel E.

2016-01-01

Distributed and Real-Time Simulation plays a key-role in the Space domain being exploited for missions and systems analysis and engineering as well as for crew training and operational support. One of the most popular standards is the 1516-2010 IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA). HLA supports the implementation of distributed simulations (called Federations) in which a set of simulation entities (called Federates) can interact using a Run-Time Infrastructure (RTI). In a given Federation, a Federate can publish and/or subscribes objects and interactions on the RTI only in accordance with their structures as defined in a FOM (Federation Object Model). Currently, the Space domain is characterized by a set of incompatible FOMs that, although meet the specific needs of different organizations and projects, increases the long-term cost for interoperability. In this context, the availability of a reference FOM for the Space domain will enable the development of interoperable HLA-based simulators for related joint projects and collaborations among worldwide organizations involved in the Space domain (e.g. NASA, ESA, Roscosmos, and JAXA). The paper presents a first set of results achieved by a SISO standardization effort that aims at providing a Space Reference FOM for international collaboration on Space systems simulations.

76 FR 71619 - Availability of the Final Environmental Assessment (EA) and Finding of No Significant Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... experimental permit from Space Exploration Technologies Corporation (SpaceX). Under the Proposed Action, the...); socioeconomics, environmental justice, and children's environmental health and safety; and secondary (induced...

Symposium keynote: Enduring the isolation of interplanetary travel. A personal account of the Mars500 mission

NASA Astrophysics Data System (ADS)

Urbina, Diego A.; Charles, Romain

2014-01-01

The Mars500 mission was a 520-day long simulation of a round trip to Mars. After going through an intense selection process, 6 individuals from various countries lived and worked for several months in a pressurized facility in Moscow, Russia, mimicking as close as possible the conditions of real space flight. The simulation concluded in November 2011 when the crew came out of the facility in seemingly good health and mood. A first person point of view description of daily life and activities is provided as well as the indication of the environmental factors that can act as stressors during such a mission as well as their change over the different periods of flight, including adaptation to the real world. Advice for the design and logistics of future exploration missions is given.

Posters: Environmental Effects on Space Optics and Technology

NASA Astrophysics Data System (ADS)

Cerutti-Maori, Guy

2018-04-01

This file includes abstracts for presentations given in the poster session on "Environmental Effects on Space Optics and Technology" as part of the International Conference on Space Optics—ICSO 1991, held in Toulouse, France.

Study of space shuttle environmental control and life support problems

NASA Technical Reports Server (NTRS)

Dibble, K. P.; Riley, F. E.

1971-01-01

Four problem areas were treated: (1) cargo module environmental control and life support systems; (2) space shuttle/space station interfaces; (3) thermal control considerations for payloads; and (4) feasibility of improving system reusability.

Evaluation of absorption cycle for space station environmental control system application

NASA Technical Reports Server (NTRS)

Sims, W. H.; Oneill, M. J.; Reid, H. C.; Bisenius, P. M.

1972-01-01

The study to evaluate an absorption cycle refrigeration system to provide environmental control for the space stations is reported. A zero-gravity liquid/vapor separator was designed and tested. The results were used to design a light-weight, efficient generator for the absorption refrigeration system. It is concluded that absorption cycle refrigeration is feasible for providing space station environmental control.

NASA’s Webb Telescope Completes Goddard Testing

NASA Image and Video Library

2017-12-08

NASA’s James Webb Space Telescope has successfully passed the center of curvature test, an important optical measurement of Webb’s fully assembled primary mirror prior to cryogenic testing, and the last test held at NASA's Goddard Space Flight Center in Greenbelt, Maryland, before the spacecraft is shipped to NASA’s Johnson Space Center in Houston for more testing. After undergoing rigorous environmental tests simulating the stresses of its rocket launch, the Webb telescope team at Goddard analyzed the results from this critical optical test and compared it to the pre-test measurements. The team concluded that the mirrors passed the test with the optical system unscathed. “The Webb telescope is about to embark on its next step in reaching the stars as it has successfully completed its integration and testing at Goddard. It has taken a tremendous team of talented individuals to get to this point from all across NASA, our industry and international partners, and academia,” said Bill Ochs, NASA’s Webb telescope project manager. “It is also a sad time as we say goodbye to the Webb Telescope at Goddard, but are excited to begin cryogenic testing at Johnson.” Rocket launches create high levels of vibration and noise that rattle spacecraft and telescopes. At Goddard, engineers tested the Webb telescope in vibration and acoustics test facilities that simulate the launch environment to ensure that functionality is not impaired by the rigorous ride on a rocket into space. Before and after these environmental tests took place, optical engineers set up an interferometer, the main device used to measure the shape of the Webb telescope’s mirror. An interferometer gets its name from the process of recording and measuring the ripple patterns that result when different beams of light mix and their waves combine or “interfere.” Waves of visible light are less than a thousandth of a millimeter long and optics on the Webb telescope need to be shaped and aligned even more accurately than that to work correctly. Making measurements of the mirror shape and position by lasers prevents physical contact and damage (scratches to the mirror). So, scientists use wavelengths of light to make tiny measurements. By measuring light reflected off the optics using an interferometer, they are able to measure extremely small changes in shape or position that may occur after exposing the mirror to a simulated launch or temperatures that simulate the subfreezing environment of space. During a test conducted by a team from Goddard, Ball Aerospace of Boulder, Colorado, and the Space Telescope Science Institute in Baltimore, temperature and humidity conditions in the clean room were kept incredibly stable to minimize fluctuations in the sensitive optical measurements over time. Even so, tiny vibrations are ever-present in the clean room that cause jitter during measurements, so the interferometer is a “high-speed” one, taking 5,000 “frames” every second, which is a faster rate than the background vibrations themselves. This allows engineers to subtract out jitter and get good, clean results on any changes to the mirror's shape. Credit: NASA/Goddard/Chris Gunn Read more: go.nasa.gov/2oPqHwR NASA’s Webb Telescope Completes Goddard Testing

NASA Space Shuttle Program: Shuttle Environmental Assurance (SEA) Initiative

NASA Technical Reports Server (NTRS)

Glover, Steve E.; McCool, Alex (Technical Monitor)

2002-01-01

The first Space Shuttle flight was in 1981 and the fleet was originally expected to be replaced with a new generation vehicle in the early 21st century. Space Shuttle Program (SSP) elements proactively address environmental and obsolescence concerns and continue to improve safety and supportability. The SSP manager created the Shuttle Environmental Assurance (SEA) Initiative in 2000. SEA is to provide an integrated approach for the SSP to promote environmental excellence, proactively manage materials obsolescence, and optimize associated resources.

Integrated Evaluation of Closed Loop Air Revitalization System Components

NASA Technical Reports Server (NTRS)

Murdock, K.

2010-01-01

NASA s vision and mission statements include an emphasis on human exploration of space, which requires environmental control and life support technologies. This Contractor Report (CR) describes the development and evaluation of an Air Revitalization System, modeling and simulation of the components, and integrated hardware testing with the goal of better understanding the inherent capabilities and limitations of this closed loop system. Major components integrated and tested included a 4-Bed Modular Sieve, Mechanical Compressor Engineering Development Unit, Temperature Swing Adsorption Compressor, and a Sabatier Engineering and Development Unit. The requisite methodolgy and technical results are contained in this CR.

Metabolic activity, experiment M171. [space flight effects on human metabolism

NASA Technical Reports Server (NTRS)

Michel, E. L.; Rummel, J. A.

1973-01-01

The Skylab metabolic activity experiment determines if man's metabolic effectiveness in doing mechanical work is progressively altered by a simulated Skylab environment, including environmental factors such as slightly increased pCO2. This test identified several hardware/procedural anomalies. The most important of these were: (1) the metabolic analyzer measured carbon dioxide production and expired water too high; (2) the ergometer load module failed under continuous high workload conditions; (3) a higher than desirable number of erroneous blood pressure measurements were recorded; (4) vital capacity measurements were unreliable; and (5) anticipated crew personal exercise needs to be more structured.

Coated columbium thermal protection systems: An assessment of technological readiness

NASA Technical Reports Server (NTRS)

Levine, S. R.; Grisaffe, S. J.

1973-01-01

Evaluation and development to date show that of the coated columbium alloys FS-85 coated with R512E shows significant promise for a reusable thermal protection system (TPS) as judged by environmental resistance and the retention of mechanical properties and structural integrity of panels upon repeated reentry simulation. Production of the alloy, the coating, and full-sized TPS panels is well within current manufacturing technology. Small defects which arise from impact damage or from local coating breakdown do not appear to have serious immediate consequences in the use environment anticipated for the space shuttle orbiter TPS.

Role of Oxygen Functionalities in Graphene Oxide Architectural Laminate Subnanometer Spacing and Water Transport.

PubMed

Amadei, Carlo Alberto; Montessori, Andrea; Kadow, Julian P; Succi, Sauro; Vecitis, Chad D

2017-04-18

Active research in nanotechnology contemplates the use of nanomaterials for environmental engineering applications. However, a primary challenge is understanding the effects of nanomaterial properties on industrial device performance and translating unique nanoscale properties to the macroscale. One emerging example consists of graphene oxide (GO) membranes for separation processes. Thus, here we investigate how individual GO properties can impact GO membrane characteristics and water permeability. GO chemistry and morphology were controlled with easy-to-implement photoreduction and sonication techniques and were quantitatively correlated, offering a valuable tool for accelerating characterization. Chemical GO modification allows for fine control of GO oxidation state, allowing control of GO architectural laminate (GOAL) spacing and permeability. Water permeability was measured for eight GOALs characterized by different GOAL chemistry and morphology and indicates that GOAL nanochannel height dictates water transport. The experimental outputs were corroborated with mesoscale water transport simulations of relatively large domains (thousands of square nanometers) and indicate a no-slip Darcy-like behavior inside the GOAL nanochannels. The experimental and simulation evidence presented in this study helps create a clearer picture of water transport in GOAL and can be used to rationally design more effective and efficient GO membranes.

Technology Readiness of the NEXT Ion Propulsion System

NASA Technical Reports Server (NTRS)

Benson, Scott W.; Patterson, Michael J.

2008-01-01

The NASA's Evolutionary Xenon Thruster (NEXT) ion propulsion system has been in advanced technology development under the NASA In-Space Propulsion Technology project. The highest fidelity hardware planned has now been completed by the government/industry team, including: a flight prototype model (PM) thruster, an engineering model (EM) power processing unit, EM propellant management assemblies, a breadboard gimbal, and control unit simulators. Subsystem and system level technology validation testing is in progress. To achieve the objective Technology Readiness Level 6, environmental testing is being conducted to qualification levels in ground facilities simulating the space environment. Additional tests have been conducted to characterize the performance range and life capability of the NEXT thruster. This paper presents the status and results of technology validation testing accomplished to date, the validated subsystem and system capabilities, and the plans for completion of this phase of NEXT development. The next round of competed planetary science mission announcements of opportunity, and directed mission decisions, are anticipated to occur in 2008 and 2009. Progress to date, and the success of on-going technology validation, indicate that the NEXT ion propulsion system will be a primary candidate for mission consideration in these upcoming opportunities.

Web-Based Toxic Gas Dispersion Model for Shuttle Launch Operations

NASA Technical Reports Server (NTRS)

Bardina, Jorge; Thirumalainambi, Rajkumar

2004-01-01

During the launch of the Space Shuttle vehicle, the burning of liquid hydrogen fuel with liquid oxygen at extreme high temperatures inside the three space shuttle main engines, and the burning of the solid propellant mixture of ammonium perchlorate oxidizer, aluminum fuel, iron oxide catalyst, polymer binder, and epoxy curing agent in the two solid rocket boosters result in the formation of a large cloud of hot, buoyant toxic exhaust gases near the ground level which subsequently rises and entrains into ambient air until the temperature and density of the cloud reaches an approximate equilibrium with ambient conditions. In this paper, toxic gas dispersion for various gases are simulated over the web for varying environmental conditions which is provided by rawinsonde data. The model simulates chemical concentration at ground level up to 10 miles (1 KM grids) in downrange up to an hour after launch. The ambient concentration of the gas dispersion and the deposition of toxic particles are used as inputs for a human health risk assessment model. The advantage of the present model is the accessibility and dissemination of model results to other NASA centers over the web. The model can be remotely operated and various scenarios can be analyzed.

DIRECT SIMULATION OF A-C MACHINERY.

DTIC Science & Technology

show the application of the simulation to both induction and synchronous machines. The fundamental space harmonic only, the fundamental and third ... space harmonic only, or all the space harmonics are considered. The report concludes that: (1) Successful direct simulation of the 2-phase induction

Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emrich, William J. Jr.

2008-01-21

To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowingmore » hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts.« less

Investigating the Effects of Simulated Space conditions on Novel Extremely Halophilic Archaea: Halovarius Luteus gen. nov., sp. nov.

NASA Astrophysics Data System (ADS)

Feshangsaz, Niloofar; Van Loon, ing.. Jack J. W. A.; Nazmi, Kamran; Semsarha, Farid

2016-07-01

Studying halophiles from different environments of Earth provide new insights into our search for life in the universe. Haloarchaea show some unique characteristics and physiological adaptations like acidic proteins against harsh environments such as natural brine with salt concentration approaching saturation (5 M) and regions with low active water. These properties make haloarchaea interesting candidate for astrobiological studies. Halovarius luteus gen. nov., sp. nov. a novel extremely halophilic archaeon from Urmia salt lake, in Iran has been chosen to explore its resistance against a series of extreme conditions. The aim of this study is to assess the resistance of strain DA50T under the effects of simulated space conditions like simulated microgravity, hypergravity, and desiccation. In this paper we will discuss the results of these studies where we specifically focus on changes in carotenoid pigments production and whole cell proteome. This is the first report of very novel Iranian archaea in response to extreme space conditions. The pigments were extracted by acetone and methanol. Pigments were analyzed by scanning the absorbance spectrum in the UV-VIS spectrophotometer. And they were separated by TLC. Whole protein from cell lysate supernatant was extracted after lysis with Bacterial Protein Extraction Reagent and fractionated by RP-HPLC using C18 column. Proteome analyzed by electrophoresis (SDS-PAGE), and MALDI-TOF. Carotenoid pigments are formed under different extreme conditions such as dry environment and gravitational changes. Also the protein composition exhibits alterations after exposure to the same conditions. Our conclusion is that pigments and proteins formation depend on the growth circumstances. Halophiles use this as an adaptation to survive under different environmental conditions.

Redesign of the Human Metabolic Simulator

NASA Technical Reports Server (NTRS)

Duffield, Bruce; Jeng, Frank; Lange, Kevin

2004-01-01

The National Aeronautics and Space Administration (NASA) is currently building a Human Metabolic Simulator (HMS) at the Johnson Space Center as part of the Advanced Life Support Air Revitalization Technology Evaluation Facility (ARTEF). The purpose of ARTEF is to evaluate Environmental Control and Life Support System Technologies for Advanced Missions. The HMS is needed to reproduce the primary metabolic effects of human respiration on an enclosed atmosphere when humans cannot be present and the impact of human presence on the system is required. A HMS was designed, built and successfully operated in 2000 but larger crew size requirements and the expense of upgrade of the current system necessitate redesign. This paper addresses the redesign. Several concepts were considered, ranging from chemical oxidation of a hydrocarbon like ethanol or ethyl acetate to carbon dioxide and water, oxidation of an iron-containing compound, or by using a fuel cell. For reasons of cost, simplicity, safety and other factors, the concept chosen includes: a molecular sieve packaged as an industrial oxygen concentrator to remove oxygen from the atmosphere, with direct carbon dioxide, water and heat injection. The water injection is done via heating water to steam with a heat exchanger and thermal effects are handled by directly adding heat to the air stream with a second heat exchanger. Both heat exchangers are supplied by a hot oil loop. The amount of oxygen removal, carbon dioxide addition, water addition and heat addition were calculated using metabolic profiles for respiration and heat, calculated using a series of empirical equations developed for International Space Station (ISS). Sketches of the Human Metabolic Simulator and the hot oil bath loop used to supply heat to the heat exchangers are included

[CFD numerical simulation onto the gas-liquid two-phase flow behavior during vehicle refueling process].

PubMed

Chen, Jia-Qing; Zhang, Nan; Wang, Jin-Hui; Zhu, Ling; Shang, Chao

2011-12-01

With the gradual improvement of environmental regulations, more and more attentions are attracted to the vapor emissions during the process of vehicle refueling. Research onto the vehicle refueling process by means of numerical simulation has been executed abroad since 1990s, while as it has never been involved so far domestically. Through reasonable simplification about the physical system of "Nozzle + filler pipe + gasoline storage tank + vent pipe" for vehicle refueling, and by means of volume of fluid (VOF) model for gas-liquid two-phase flow and Re-Normalization Group kappa-epsilon turbulence flow model provided in commercial computational fluid dynamics (CFD) software Fluent, this paper determined the proper mesh discretization scheme and applied the proper boundary conditions based on the Gambit software, then established the reasonable numerical simulation model for the gas-liquid two-phase flow during the refueling process. Through discussing the influence of refueling velocity on the static pressure of vent space in gasoline tank, the back-flowing phenomenon has been revealed in this paper. It has been demonstrated that, the more the flow rate and the refueling velocity of refueling nozzle is, the higher the gross static pressure in the vent space of gasoline tank. In the meanwhile, the variation of static pressure in the vent space of gasoline tank can be categorized into three obvious stages. When the refueling flow rate becomes higher, the back-flowing phenomenon of liquid gasoline can sometimes be induced in the head section of filler pipe, thus making the gasoline nozzle pre-shut-off. Totally speaking, the theoretical work accomplished in this paper laid some solid foundation for self-researching and self-developing the technology and apparatus for the vehicle refueling and refueling emissions control domestically.