Disequilibrium condensation environments in space - A frontier in thermodynamics

NASA Technical Reports Server (NTRS)

De, B. R.

1979-01-01

The thermal-disequilibrium aspect of the problem of dust-particle formation from a gas phase in an open space environment is discussed in an effort to draw attention to the space condensation environment as an interesting arena for application and extension of the ideas and formalisms of nonequilibrium thermodynamics. It is shown that quasi-steady states with a disequilibrium between the gas-phase kinetic temperature and the condensed-phase internal temperature appear to be the norm of condensation environments in space. Consideration of the case of condensation onto a bulk condensed phase indicates that these quasi-steady states may constitute Prigogine dissipative structures. It is suggested that a proper study of the process of condensation in a space environment should include any effects arising from thermal disequilibrium.

Phase space manipulation in high-brightness electron beams

NASA Astrophysics Data System (ADS)

Rihaoui, Marwan M.

Electron beams have a wide range of applications, including discovery science, medicine, and industry. Electron beams can also be used to power next-generation, high-gradient electron accelerators. The performances of some of these applications could be greatly enhanced by precisely tailoring the phase space distribution of the electron beam. The goal of this dissertation is to explore some of these phase space manipulations. We especially focus on transformations capable of tailoring the beam current distribution. Specifically, we investigate a beamline exchanging phase space coordinates between the horizontal and longitudinal degrees of freedom. The key components necessary for this beamline were constructed and tested. The preliminary beamline was used as a singleshot phase space diagnostics and to produce a train of picoseconds electron bunches. We also investigate the use of multiple electron beams to control the transverse focusing. Our numerical and analytical studies are supplemented with experiments performed at the Argonne Wakefield Accelerator.

A phase space approach to imaging from limited data

NASA Astrophysics Data System (ADS)

Testorf, Markus E.

2015-09-01

The optical instrument function is used as the basis to develop optical system theory for imaging applications. The detection of optical signals is conveniently described as the overlap integral of the Wigner distribution functions of instrument and optical signal. Based on this framework various optical imaging systems, including plenoptic cameras, phase-retrieval algorithms, and Shack-Hartman sensors are shown to acquire information about a domain in phase-space, with finite extension and finite resolution. It is demonstrated how phase space optics can be used both to analyze imaging systems, as well as for designing methods for image reconstruction.

Orbit transfer rocket engine technology program. Phase 2: Advanced engine study

NASA Technical Reports Server (NTRS)

Erickson, C.; Martinez, A.; Hines, B.

1987-01-01

In Phase 2 of the Advanced Engine Study, the Failure Modes and Effects Analysis (FMEA) maintenance-driven engine design, preliminary maintenance plan, and concept for space operable disconnects generated in Phase 1 were further developed. Based on the results of the vehicle contractors Orbit Transfer Vehicle (OTV) Concept Definition and System Analysis Phase A studies, minor revisions to the engine design were made. Additional refinements in the engine design were identified through further engine concept studies. These included an updated engine balance incorporating experimental heat transfer data from the Enhanced Heat Load Thrust Chamber Study and a Rao optimum nozzle contour. The preliminary maintenance plan of Phase 1 was further developed through additional studies. These included a compilation of critical component lives and life limiters and a review of the Space Shuttle Main Engine (SSME) operations and maintenance manual in order to begin outlining the overall maintenance procedures for the Orbit Transfer Vehicle Engine and identifying technology requirements for streamlining space-based operations. Phase 2 efforts also provided further definition to the advanced fluid coupling devices including the selection and preliminary design of a preferred concept and a preliminary test plan for its further development.

The U.S. Space Grant College and Fellowship Program

NASA Technical Reports Server (NTRS)

Dasch, E. Julius; Schwartz, Elaine T.; Keffer, Lynne

1990-01-01

The U.S. NASA Space Grant College and Fellowship Program, congressionally mandated in 1987, consists of two phases. Phase I consisted of the designation of 21 university consortia as 'Space Grant Colleges/Consortia' which received support from NASA to conduct programs to achieve, maintain, and advance a balanced program of research capability, curriculum, and public service. Program descriptions for phase II are given. This phase is designed to broaden participation in the Space Grant Program by targeting states that currently are not as involved in NASA programs as are the states for which phase I was constructed. Under phase II, states will compete in either the Programs Grants or the Capability Enhancement Grants category. Only one proposal per state will be accepted with the state determining in which category it will compete. The amount of total award, $150,000, is the same in both categories and includes funds for university-administered fellowship programs.

Space shuttle phase B wind tunnel model and test information. Volume 1: Booster configuration

NASA Technical Reports Server (NTRS)

Glynn, J. L.; Poucher, D. E.

1988-01-01

Archived wind tunnel test data are available for flyback booster or other alternative recoverable configurations as well as reusable orbiters studied during initial development (Phase B) of the Space Shuttle. Considerable wind tunnel data was acquired by the competing contractors and the NASA Centers for an extensive variety of configurations with an array of wing and body planforms. All contractor and NASA wind tunnel test data acquired in the Phase B development have been compiled into a database and are available for application to current winged flyback or recoverable booster aerodynamic studies. The Space Shuttle Phase B Wind Tunnel Database is structured by vehicle component and configuration type. Basic components include the booster, the orbiter, and the launch vehicle. Booster configuration types include straight and delta wings, canard, cylindrical, retroglide and twin body. Orbiter configuration types include straight and delta wings, lifting body, drop tanks and double delta wings. Launch configurations include booster and orbiter components in various stacked and tandem combinations. This is Volume 1 (Part 2) of the report -- Booster Configuration.

Space shuttle phase B wind tunnel model and test information. Volume 1: Booster configuration

NASA Technical Reports Server (NTRS)

Glynn, J. L.; Poucher, D. E.

1988-01-01

Archived wind tunnel test data are available for flyback booster or other alternative recoverable configurations as well as reusable orbiters studied during initial development (Phase B) of the Space Shuttle. Considerable wind tunnel data was acquired by the competing contractors and the NASA Centers for an extensive variety of configurations with an array of wing and body planforms. All contractor and NASA wind tunnel test data acquired in the Phase B development have been compiled into a database and are available for application to current winged flyback or recoverable booster aerodynamic studies. The Space Shuttle Phase B Wind Tunnel Database is structured by vehicle component and configuration type. Basic components include the booster, the orbiter and the launch vehicle. Booster configuration types include straight and delta wings, canard, cylindrical, retroglide and twin body. Orbiter configuration types include straight and delta wings, lifting body, drop tanks, and double delta wings. Launch configurations include booster and orbiter components in various stacked and tandem combinations. This is Volume 1 (Part 1) of the report -- Booster Configuration.

Thermal Technology Development Activities at the Goddard Space Flight Center - 2001

NASA Technical Reports Server (NTRS)

Butler, Dan

2002-01-01

This presentation provides an overview of thermal technology development activities carried out at NASA's Goddard Space Flight Center during 2001. Specific topics covered include: two-phase systems (heat pipes, capillary pumped loops, vapor compression systems and phase change materials), variable emittance systems, advanced coatings, high conductivity materials and electrohydrodynamic (EHD) thermal coatings. The application of these activities to specific space missions is also discussed.

Space Station Freedom environmental control and life support system phase 3 simplified integrated test detailed report

NASA Technical Reports Server (NTRS)

Roberts, B. C.; Carrasquillo, R. L.; Dubiel, M. Y.; Ogle, K. Y.; Perry, J. L.; Whitley, K. M.

1990-01-01

A description of the phase 3 simplified integrated test (SIT) conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) in 1989 is presented. This was the first test in the phase 3 series integrated environmental control and life support systems (ECLSS) tests. The basic goal of the SIT was to achieve full integration of the baseline air revitalization (AR) subsystems for Space Station Freedom. Included is a description of the SIT configuration, a performance analysis of each subsystem, results from air and water sampling, and a discussion of lessons learned from the test. Also included is a full description of the preprototype ECLSS hardware used in the test.

Space cryogenics components based on the thermomechanical effect - Vapor-liquid phase separation

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Frederking, T. H. K.

1989-01-01

Applications of the thermomechanical effect has been qualified including incorporation in large-scale space systems in the area of vapor-liquid phase separation (VLPS). The theory of the porous-plug phase separator is developed for the limit of a high thermal impedance of the solid-state grains. Extensions of the theory of nonlinear turbulent flow are presented based on experimental results.

Space shuttle phase B wind tunnel model and test information. Volume 3: Launch configuration

NASA Technical Reports Server (NTRS)

Glynn, J. L.; Poucher, D. E.

1988-01-01

Archived wind tunnel test data are available for flyback booster or other alternate recoverable configuration as well as reusable orbiters studied during initial development (Phase B) of the Space Shuttle, including contractor data for an extensive variety of configurations with an array of wing and body planforms. The test data have been compiled into a database and are available for application to current winged flyback or recoverable booster aerodynamic studies. The Space Shuttle Phase B Wind Tunnel Database is structured by vehicle component and configuration. Basic components include booster, orbiter, and launch vehicle. Booster configuration types include straight and delta wings, canard, cylindrical, retroglide and twin body. Orbiter configurations include straight and delta wings, lifting body, drop tanks and double delta wings. Launch configurations include booster and orbiter components in various stacked and tandem combinations. The digital database consists of 220 files containing basic tunnel data. Database structure is documented in a series of reports which include configuration sketches for the various planforms tested. This is Volume 3 -- launch configurations.

Multiplexed phase-space imaging for 3D fluorescence microscopy.

PubMed

Liu, Hsiou-Yuan; Zhong, Jingshan; Waller, Laura

2017-06-26

Optical phase-space functions describe spatial and angular information simultaneously; examples of optical phase-space functions include light fields in ray optics and Wigner functions in wave optics. Measurement of phase-space enables digital refocusing, aberration removal and 3D reconstruction. High-resolution capture of 4D phase-space datasets is, however, challenging. Previous scanning approaches are slow, light inefficient and do not achieve diffraction-limited resolution. Here, we propose a multiplexed method that solves these problems. We use a spatial light modulator (SLM) in the pupil plane of a microscope in order to sequentially pattern multiplexed coded apertures while capturing images in real space. Then, we reconstruct the 3D fluorescence distribution of our sample by solving an inverse problem via regularized least squares with a proximal accelerated gradient descent solver. We experimentally reconstruct a 101 Megavoxel 3D volume (1010×510×500µm with NA 0.4), demonstrating improved acquisition time, light throughput and resolution compared to scanning aperture methods. Our flexible patterning scheme further allows sparsity in the sample to be exploited for reduced data capture.

Microwave performance characterization of large space antennas

NASA Technical Reports Server (NTRS)

Bathker, D. A. (Editor)

1977-01-01

Performance capabilities of large microwave space antenna configurations with apertures generally from 100 wavelengths upwards are discussed. Types of antennas considered include: phased arrays, lenses, reflectors, and hybrid combinations of phased arrays with reflectors or lenses. The performance characteristics of these broad classes of antennas are examined and compared in terms of applications.

Uncovering the nonadiabatic response of geosynchronous electrons to geomagnetic disturbance

USGS Publications Warehouse

Gannon, Jennifer; Elkington, Scot R.; Onsager, Terrance G.

2012-01-01

We describe an energy spectrum method for scaling electron integral flux, which is measured at a constant energy, to phase space density at a constant value of the first adiabatic invariant which removes much of the variation due to reversible adiabatic effects. Applying this method to nearly a solar cycle (1995 - 2006) of geosynchronous electron integral flux (E>2.0MeV) from the GOES satellites, we see that much of the diurnal variation in electron phase space density at constant energy can be removed by the transformation to phase space density at constant μ (4000 MeV/G). This allows us a clearer picture of underlying non-adiabatic electron population changes due to geomagnetic activity. Using scaled phase space density, we calculate the percentage of geomagnetic storms resulting in an increase, decrease or no change in geosynchronous electrons as 38%, 7%, and 55%, respectively. We also show examples of changes in the electron population that may be different than the unscaled fluxes alone suggest. These examples include sudden electron enhancements during storms which appear during the peak of negative Dst for μ-scaled phase space density, contrary to the slow increase seen during the recovery phase for unscaled phase space density for the same event.

Transverse Phase Space Reconstruction and Emittance Measurement of Intense Electron Beams using a Tomography Technique

NASA Astrophysics Data System (ADS)

Stratakis, D.; Kishek, R. A.; Li, H.; Bernal, S.; Walter, M.; Tobin, J.; Quinn, B.; Reiser, M.; O'Shea, P. G.

2006-11-01

Tomography is the technique of reconstructing an image from its projections. It is widely used in the medical community to observe the interior of the human body by processing multiple x-ray images taken at different angles, A few pioneering researchers have adapted tomography to reconstruct detailed phase space maps of charged particle beams. Some questions arise regarding the limitations of tomography technique for space charge dominated beams. For instance is the linear space charge force a valid approximation? Does tomography equally reproduce phase space for complex, experimentally observed, initial particle distributions? Does tomography make any assumptions about the initial distribution? This study explores the use of accurate modeling with the particle-in-cell code WARP to address these questions, using a wide range of different initial distributions in the code. The study also includes a number of experimental results on tomographic phase space mapping performed on the University of Maryland Electron Ring (UMER).

Phase C/D program development plan. Volume 1: Program plan

NASA Technical Reports Server (NTRS)

1971-01-01

The Phase C/D definition of the Modular Space Station has been developed. The modular approach selected during the option period was evaluated, requirements were defined, and program definition and preliminary design were accomplished. The Space Station Project is covered in depth, the research applications module is limited to a project-level definition, and the shuttle operations are included for interface requirements identification, scheduling, and costing. Discussed in detail are: (1) baseline program and project descriptions; (2) phase project planning; (3) modular space station program schedule; (4) program management plan; (5) operations; (6) facilities; (7) logistics; and (8) manpower.

Positive phase space distributions and uncertainty relations

NASA Technical Reports Server (NTRS)

Kruger, Jan

1993-01-01

In contrast to a widespread belief, Wigner's theorem allows the construction of true joint probabilities in phase space for distributions describing the object system as well as for distributions depending on the measurement apparatus. The fundamental role of Heisenberg's uncertainty relations in Schroedinger form (including correlations) is pointed out for these two possible interpretations of joint probability distributions. Hence, in order that a multivariate normal probability distribution in phase space may correspond to a Wigner distribution of a pure or a mixed state, it is necessary and sufficient that Heisenberg's uncertainty relation in Schroedinger form should be satisfied.

Quantum Optics in Phase Space

NASA Astrophysics Data System (ADS)

Schleich, Wolfgang P.

2001-04-01

Quantum Optics in Phase Space provides a concise introduction to the rapidly moving field of quantum optics from the point of view of phase space. Modern in style and didactically skillful, Quantum Optics in Phase Space prepares students for their own research by presenting detailed derivations, many illustrations and a large set of workable problems at the end of each chapter. Often, the theoretical treatments are accompanied by the corresponding experiments. An exhaustive list of references provides a guide to the literature. Quantum Optics in Phase Space also serves advanced researchers as a comprehensive reference book. Starting with an extensive review of the experiments that define quantum optics and a brief summary of the foundations of quantum mechanics the author Wolfgang P. Schleich illustrates the properties of quantum states with the help of the Wigner phase space distribution function. His description of waves ala WKB connects semi-classical phase space with the Berry phase. These semi-classical techniques provide deeper insight into the timely topics of wave packet dynamics, fractional revivals and the Talbot effect. Whereas the first half of the book deals with mechanical oscillators such as ions in a trap or atoms in a standing wave the second half addresses problems where the quantization of the radiation field is of importance. Such topics extensively discussed include optical interferometry, the atom-field interaction, quantum state preparation and measurement, entanglement, decoherence, the one-atom maser and atom optics in quantized light fields. Quantum Optics in Phase Space presents the subject of quantum optics as transparently as possible. Giving wide-ranging references, it enables students to study and solve problems with modern scientific literature. The result is a remarkably concise yet comprehensive and accessible text- and reference book - an inspiring source of information and insight for students, teachers and researchers alike.

In-space experiment on thermoacoustic convection heat transfer phenomenon-experiment definition

NASA Technical Reports Server (NTRS)

Parang, M.; Crocker, D. S.

1991-01-01

The definition phase of an in-space experiment in thermoacoustic convection (TAC) heat transfer phenomenon is completed and the results are presented and discussed in some detail. Background information, application and potential importance of TAC in heat transfer processes are discussed with particular focus on application in cryogenic fluid handling and storage in microgravity space environment. Also included are the discussion on TAC space experiment objectives, results of ground support experiments, hardware information, and technical specifications and drawings. The future plans and a schedule for the development of experiment hardware (Phase 1) and flight tests and post-flight analysis (Phase 3/4) are also presented. The specific experimental objectives are rapid heating of a compressible fluid and the measurement of the fluid temperature and pressure and the recording and analysis of the experimental data for the establishment of the importance of TAC heat transfer process. The ground experiments that were completed in support of the experiment definition included fluid temperature measurement by a modified shadowgraph method, surface temperature measurements by thermocouples, and fluid pressure measurements by strain-gage pressure transducers. These experiments verified the feasibility of the TAC in-space experiment, established the relevance and accuracy of the experimental results, and specified the nature of the analysis which will be carried out in the post-flight phase of the report.

Shuttle free-flying teleoperator system experiment definition. Volume 3: program development requirements

NASA Technical Reports Server (NTRS)

1972-01-01

The planning data are presented for subsequent phases of free-flying teleoperator program (FFTO) and includes costs, schedules and supporting research and technology activities required to implement the free-flying teleoperator system and associated flight equipment. The purpose of the data presented is to provide NASA with the information needed to continue development of the FFTO and integrate it into the space shuttle program. The planning data describes three major program phases consisting of activities and events scheduled to effect integrated design, development, fabrication and operation of an FFTO system. Phase A, Concept Generation, represents a study effort directed toward generating and evaluating a number of feasible FFTO experiment system concepts. Phase B, Definition, will include preliminary design and supporting analysis of the FFTO, the shuttle based equipment and ground support equipment. Phase C/D, Design, Development and Operations will include detail design of the operational FFTO, its integration into the space shuttle, hardware fabrication and testing, delivery of flight hardware and support of flight operations. Emphasis is placed on the planning for Phases A and B since these studies will be implemented early in the development cycle. Phase C/D planning is more general and subject to refinement during the definition phase.

Phase-space foundations of electron holography

NASA Astrophysics Data System (ADS)

Lubk, A.; Röder, F.

2015-09-01

We present a unified formalism for describing various forms of electron holography in quantum mechanical phase space including their extensions to quantum-state reconstructions. The phase-space perspective allows for taking into account partial coherence as well as the quantum mechanical detection process typically hampering the unique reconstruction of a wave function. We elaborate on the limitations imposed by the electron optical elements of the transmission electron microscope as well as the scattering at the target. The results provide the basis for vastly extending the scope of electron holographic techniques towards analyzing partially coherent signals such as inelastically scattered electrons or electron pulses used in ultrafast transmission electron microscopy.

Phase-space methods for the spin dynamics in condensed matter systems

PubMed Central

Hurst, Jérôme; Manfredi, Giovanni

2017-01-01

Using the phase-space formulation of quantum mechanics, we derive a four-component Wigner equation for a system composed of spin- fermions (typically, electrons) including the Zeeman effect and the spin–orbit coupling. This Wigner equation is coupled to the appropriate Maxwell equations to form a self-consistent mean-field model. A set of semiclassical Vlasov equations with spin effects is obtained by expanding the full quantum model to first order in the Planck constant. The corresponding hydrodynamic equations are derived by taking velocity moments of the phase-space distribution function. A simple closure relation is proposed to obtain a closed set of hydrodynamic equations. This article is part of the themed issue ‘Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces’. PMID:28320903

Classical phase space and Hadamard states in the BRST formalism for gauge field theories on curved spacetime

NASA Astrophysics Data System (ADS)

Wrochna, Michał; Zahn, Jochen

We investigate linearized gauge theories on globally hyperbolic spacetimes in the BRST formalism. A consistent definition of the classical phase space and of its Cauchy surface analogue is proposed. We prove that it is isomorphic to the phase space in the ‘subsidiary condition’ approach of Hack and Schenkel in the case of Maxwell, Yang-Mills, and Rarita-Schwinger fields. Defining Hadamard states in the BRST formalism in a standard way, their existence in the Maxwell and Yang-Mills case is concluded from known results in the subsidiary condition (or Gupta-Bleuler) formalism. Within our framework, we also formulate criteria for non-degeneracy of the phase space in terms of BRST cohomology and discuss special cases. These include an example in the Yang-Mills case, where degeneracy is not related to a non-trivial topology of the Cauchy surface.

Augmenting Phase Space Quantization to Introduce Additional Physical Effects

NASA Astrophysics Data System (ADS)

Robbins, Matthew P. G.

Quantum mechanics can be done using classical phase space functions and a star product. The state of the system is described by a quasi-probability distribution. A classical system can be quantized in phase space in different ways with different quasi-probability distributions and star products. A transition differential operator relates different phase space quantizations. The objective of this thesis is to introduce additional physical effects into the process of quantization by using the transition operator. As prototypical examples, we first look at the coarse-graining of the Wigner function and the damped simple harmonic oscillator. By generalizing the transition operator and star product to also be functions of the position and momentum, we show that additional physical features beyond damping and coarse-graining can be introduced into a quantum system, including the generalized uncertainty principle of quantum gravity phenomenology, driving forces, and decoherence.

WFL: Microwave Applications of Thin Ferroelectric Films

NASA Technical Reports Server (NTRS)

Romanofsky, Robert

2013-01-01

We have developed a family of tunable microwave circuits, operating from X- through Ka-band, based on laser ablated BaxSr1-xTiO films on lanthanum aluminate and magnesium oxide substrates. Circuits include voltage controlled oscillators, filters, phase shifters and antennas. A review of the basic theory of operation of these devices will be presented along with measured performance. Emphasis has been on low-loss phase shifters to enable a new phased array architecture. The critical role of phase shifter loss and transient response in reflectarray antennas will be discussed. The Ferroelectric Reflectarray Critical Components Space Experiment was launched on the penultimate Space Shuttle, STS-134, in May of 2011. It included a bank of ferroelectric phase shifters with two different stoichiometries as well as ancillary electronics. The experiment package and status will be reported. In addition, unusual results of a Van der Pauw measurement involving a ferroelectric film grown on buffered high resisitivity silicon will be discussed.

Tracking and data systems support for the Helios project. Volume 1: Project development through end of mission, phase 2

NASA Technical Reports Server (NTRS)

Goodwin, P. S.; Traxler, M. R.; Meeks, W. G.; Flanagan, F. M.

1976-01-01

The overall evolution of the Helios Project is summarized from its conception through to the completion of the Helios-1 mission phase 2. Beginning with the project objectives and concluding with the Helios-1 spacecraft entering its first superior conjunction (end of mission phase 2), descriptions of the project, the mission and its phases, international management and interfaces, and Deep Space Network-spacecraft engineering development in telemetry, tracking, and command systems to ensure compatibility between the U.S. Deep Space Network and the German-built spacecraft are included.

Integrated optic single-ring filter for narrowband phase demodulation

NASA Astrophysics Data System (ADS)

Madsen, C. K.

2017-05-01

Integrated optic notch filters are key building blocks for higher-order spectral filter responses and have been demonstrated in many technology platforms from dielectrics (such as Si3N4) to semiconductors (Si photonics). Photonic-assisted RF processing applications for notch filters include identifying and filtering out high-amplitude, narrowband signals that may be interfering with the desired signal, including undesired frequencies detected in radar and free-space optical links. The fundamental tradeoffs for bandwidth and rejection depth as a function of the roundtrip loss and coupling coefficient are investigated along with the resulting spectral phase response for minimum-phase and maximum-phase responses compared to the critical coupling condition and integration within a Mach Zehnder interferometer. Based on a full width at half maximum criterion, it is shown that maximum-phase responses offer the smallest bandwidths for a given roundtrip loss. Then, a new role for passive notch filters in combination with high-speed electro-optic phase modulation is explored around narrowband phase-to-amplitude demodulation using a single ring operating on one sideband. Applications may include microwave processing and instantaneous frequency measurement (IFM) for radar, space and defense applications.

Flow Pattern Phenomena in Two-Phase Flow in Microchannels

NASA Astrophysics Data System (ADS)

Keska, Jerry K.; Simon, William E.

2004-02-01

Space transportation systems require high-performance thermal protection and fluid management techniques for systems ranging from cryogenic fluid management devices to primary structures and propulsion systems exposed to extremely high temperatures, as well as for other space systems such as cooling or environment control for advanced space suits and integrated circuits. Although considerable developmental effort is being expended to bring potentially applicable technologies to a readiness level for practical use, new and innovative methods are still needed. One such method is the concept of Advanced Micro Cooling Modules (AMCMs), which are essentially compact two-phase heat exchangers constructed of microchannels and designed to remove large amounts of heat rapidly from critical systems by incorporating phase transition. The development of AMCMs requires fundamental technological advancement in many areas, including: (1) development of measurement methods/systems for flow-pattern measurement/identification for two-phase mixtures in microchannels; (2) development of a phenomenological model for two-phase flow which includes the quantitative measure of flow patterns; and (3) database development for multiphase heat transfer/fluid dynamics flows in microchannels. This paper focuses on the results of experimental research in the phenomena of two-phase flow in microchannels. The work encompasses both an experimental and an analytical approach to incorporating flow patterns for air-water mixtures flowing in a microchannel, which are necessary tools for the optimal design of AMCMs. Specifically, the following topics are addressed: (1) design and construction of a sensitive test system for two-phase flow in microchannels, one which measures ac and dc components of in-situ physical mixture parameters including spatial concentration using concomitant methods; (2) data acquisition and analysis in the amplitude, time, and frequency domains; and (3) analysis of results including evaluation of data acquisition techniques and their validity for application in flow pattern determination.

Optical properties monitor: Experiment definition phase

NASA Technical Reports Server (NTRS)

Wilkes, Donald R.; Bennett, Jean M.; Hummer, Leigh L.; Chipman, Russell A.; Hadaway, James B.; Pezzaniti, Larry

1990-01-01

The stability of materials used in the space environment will continue to be a limiting technology for space missions. The Optical Properties Monitor (OPM) Experiment provides a comprehensive space research program to study the effects of the space environment (both natural and induced) on optical, thermal and space power materials. The OPM Experiment was selected for definition under the NASA/OAST In-Space Technology Experiment Program. The results of the OPM Definition Phase are presented. The OPM experiment will expose selected materials to the space environment and measure the effects with in-space optical measurements. In-space measurements include total hemispherical reflectance total integrated scatter and VUV reflectance/transmittance. The in-space measurements will be augmented with extensive pre- and post-flight sample measurements to determine other optical, mechanical, electrical, chemical or surface effects of space exposure. Environmental monitors will provide the amount and time history of the sample exposure to solar irradiation, atomic oxygen and molecular contamination.

Optical properties monitor: Experiment definition phase

NASA Technical Reports Server (NTRS)

Wilkes, Donald R.; Bennett, Jean M.; Hummer, Leigh L.; Chipman, Russell A.; Hadaway, James B.; Pezzaniti, Larry

1989-01-01

The stability of materials used in the space environment will continue to be a limiting technology for space missions. The Optical Properties Monitor (OPM) Experiment provides a comprehensive space research program to study the effects of the space environment-both natural and induced-on optical, thermal and space power materials. The OPM Experiment was selected for definition under the NASA/OAST In-Space Technology Experiment Program. The results of the OPM Definition Phase are presented. The OPM Experiment will expose selected materials to the space environment and measure the effects with in-space optical measurements. In-space measurements include total hemispherical reflectance total integrated scatter and VUV reflectance/transmittance. The in-space measurements will be augmented with extensive pre- and post-flight sample measurements to determine other optical, mechanical, electrical, chemical or surface effects of space exposure. Environmental monitors will provide the amount and time history of the sample exposure to solar irradiation, atomic oxygen and molecular contamination.

Microbiological Tests Performed During the Design of the International Space Station ECLSS: Part 1, Bulk Phase Water and Wastewater

NASA Technical Reports Server (NTRS)

Roman, Monsi C.; Mittelman, Marc W.

2010-01-01

This slide presentation summarizes the studies performed to assess the bulk phase microbial community during the Space Station Water Recover Tests (WRT) from 1990-1998. These tests show that it is possible to recycle water from different sources including urine, and produce water that can exceed the quality of municpally produced tap water.

Model Transformation for a System of Systems Dependability Safety Case

NASA Technical Reports Server (NTRS)

Murphy, Judy; Driskell, Steve

2011-01-01

The presentation reviews the dependability and safety effort of NASA's Independent Verification and Validation Facility. Topics include: safety engineering process, applications to non-space environment, Phase I overview, process creation, sample SRM artifact, Phase I end result, Phase II model transformation, fault management, and applying Phase II to individual projects.

Performance of a Ka-band transponder breadboard for deep-space applications

NASA Technical Reports Server (NTRS)

Mysoor, N. R.; Lane, J. P.; Kayalar, S.; Kermode, A. W.

1995-01-01

This article summarizes the design concepts applied in the development of and advanced Ka-band (34.4 GHz/32 GHz) transponder breadboard for the next generation of space communications systems applications. The selected architecture upgrades the X-band (7.2 GHz/8.4 GHz) deep-space transponder (DST) to provide Da-band up/Ka- and X-band down capability. The Ka-band transponder breadboard incorporates several state-of-the-art components, including sampling mixers, a Ka-band dielectric resonator oscillator, and microwave monolithic integrated circuits (MMICs). The MMICs that were tested in the breadboard include upconverters, downconverters, automatic gain control circuits, mixers, phase modulators, and amplifiers. The measured receiver dynamic range, tracking range, acquisition rate, static phase error, and phase jitter characteristics of the Ka-band breadboard interfaced to the advanced engineering model X-band DST are in good agreement with the expected performance. The results show a receiver tracking threshold of -149 dBm with a dynamic range of 80 dB and a downlink phase jitter of 7 deg rms. The analytical results of phase noise and Allan standard deviation are in good agreement with the experimental results.

Radiation Hardness Assurance (RHA) for Space Systems

NASA Technical Reports Server (NTRS)

Poivey, Christian; Buchner, Stephen

2007-01-01

This presentation discusses radiation hardness assurance (RHA) for space systems, providing both the programmatic aspects of RHA and the RHA procedure. RHA consists of all activities undertaken to ensure that the electronics and materials of a space system perform to their design specifications after exposure to the space radiation environment. RHA also pertains to environment definition, part selection, part testing, spacecraft layout, radiation tolerant design, and mission/system/subsystems requirements. RHA procedure consists of establishing mission requirements, defining and evaluating the radiation hazard, selecting and categorizing the appropriate parts, and evaluating circuit response to hazard. The RHA approach is based on risk management and is confined only to parts, it includes spacecraft layout, system/subsystem/circuit design, and system requirements and system operations. RHA should be taken into account in the early phases of a program including the proposal and feasibility analysis phases.

Combining states without scale hierarchies with ordered parton showers

DOE PAGES

Fischer, Nadine; Prestel, Stefan

2017-09-12

Here, we present a parameter-free scheme to combine fixed-order multi-jet results with parton-shower evolution. The scheme produces jet cross sections with leading-order accuracy in the complete phase space of multiple emissions, resumming large logarithms when appropriate, while not arbitrarily enforcing ordering on momentum configurations beyond the reach of the parton-shower evolution equation. This then requires the development of a matrix-element correction scheme for complex phase-spaces including ordering conditions as well as a systematic scale-setting procedure for unordered phase-space points. Our algorithm does not require a merging-scale parameter. We implement the new method in the Vincia framework and compare to LHCmore » data.« less

Closed Cycle Magnetohydrodynamic Nuclear Space Power Generation Using Helium/Xenon Working Plasma

NASA Technical Reports Server (NTRS)

Litchford, R. J.; Harada, N.

2005-01-01

A multimegawatt-class nuclear fission powered closed cycle magnetohydrodynamic space power plant using a helium/xenon working gas has been studied, to include a comprehensive system analysis. Total plant efficiency was expected to be 55.2 percent including pre-ionization power. The effects of compressor stage number, regenerator efficiency, and radiation cooler temperature on plant efficiency were investigated. The specific mass of the power generation plant was also examined. System specific mass was estimated to be 3 kg/kWe for a net electrical output power of 1 MWe, 2-3 kg/kWe at 2 MWe, and approx.2 kg/KWe at >3 MWe. Three phases of research and development plan were proposed: (1) Phase I-proof of principle, (2) Phase II-demonstration of power generation, and (3) Phase III-prototypical closed loop test.

Diffeomorphisms as symplectomorphisms in history phase space: Bosonic string model

NASA Astrophysics Data System (ADS)

Kouletsis, I.; Kuchař, K. V.

2002-06-01

The structure of the history phase space G of a covariant field system and its history group (in the sense of Isham and Linden) is analyzed on an example of a bosonic string. The history space G includes the time map T from the spacetime manifold (the two-sheet) Y to a one-dimensional time manifold T as one of its configuration variables. A canonical history action is posited on G such that its restriction to the configuration history space yields the familiar Polyakov action. The standard Dirac-ADM action is shown to be identical with the canonical history action, the only difference being that the underlying action is expressed in two different coordinate charts on G. The canonical history action encompasses all individual Dirac-ADM actions corresponding to different choices T of foliating Y. The history Poisson brackets of spacetime fields on G induce the ordinary Poisson brackets of spatial fields in the instantaneous phase space G0 of the Dirac-ADM formalism. The canonical history action is manifestly invariant both under spacetime diffeomorphisms Diff Y and temporal diffeomorphisms Diff T. Both of these diffeomorphisms are explicitly represented by symplectomorphisms on the history phase space G. The resulting classical history phase space formalism is offered as a starting point for projection operator quantization and consistent histories interpretation of the bosonic string model.

Space Station Furnace Facility. Volume 2: Requirements definition and conceptual design study

NASA Technical Reports Server (NTRS)

1992-01-01

The Space Station Freedom Furnace (SSFF) Project is divided into two phases: phase 1, a definition study phase, and phase 2, a design and development phase. TBE was awarded a research study entitled, 'Space Station Furnace Facility Requirements Definition and Conceptual Design Study' on June 2, 1989. This report addresses the definition study phase only. Phase 2 is to be complete after completion of phase 1. The contract encompassed a requirements definition study and culminated in hardware/facility conceptual designs and hardware demonstration development models to test these conceptual designs. The study was divided into two parts. Part 1 (the basic part of the effort) encompassed preliminary requirements definition and assessment; conceptional design of the SSFF Core; fabrication of mockups; and preparation for the support of a conceptional design review (CoDR). Part 2 (the optional part of the effort) included detailed definition of the engineering and design requirements, as derived from the science requirements; refinement of the conceptual design of the SSFF Core; fabrication and testing of the 'breadboards' or development models; and preparation for and support of a requirements definition review.

Gas-Liquid Flows and Phase Separation

NASA Technical Reports Server (NTRS)

McQuillen, John

2004-01-01

Common issues for space system designers include:Ability to Verify Performance in Normal Gravity prior to Deployment; System Stability; Phase Accumulation & Shedding; Phase Separation; Flow Distribution through Tees & Manifolds Boiling Crisis; Heat Transfer Coefficient; and Pressure Drop.The report concludes:Guidance similar to "A design that operates in a single phase is less complex than a design that has two-phase flow" is not always true considering the amount of effort spent on pressurizing, subcooling and phase separators to ensure single phase operation. While there is still much to learn about two-phase flow in reduced gravity, we have a good start. Focus now needs to be directed more towards system level problems .

Renovating and Reconstructing in Phases--Specifying Phased Construction.

ERIC Educational Resources Information Center

Bunzick, John

2002-01-01

Discusses planning for phased school construction projects, including effects on occupancy (for example, construction adjacent to occupied space, construction procedure safety zones near occupied areas, and code-complying means of egress), effects on building systems (such as heating and cooling equipment and power distribution), and contract…

Multipurpose exciter with low phase noise

NASA Technical Reports Server (NTRS)

Conroy, B.; Le, D.

1989-01-01

Results of an effort to develop a lower-cost exciter with high stability, low phase noise, and controllable phase and frequency for use in Deep Space Network and Goldstone Solar System Radar applications are discussed. Included is a discussion of the basic concept, test results, plans, and concerns.

DTN Implementation and Utilization Options on the International Space Station

NASA Technical Reports Server (NTRS)

Nichols, Kelvin; Holbrook, Mark; Pitts, Lee; Gifford, Kevin; Jenkins, Andrew; Kuzminsky, Sebastian

2010-01-01

This slide presentation reviews the implementation and future uses of Delay/Disruption Tolerant Networking (DTN) for space communication, using the International Space Station as the primary example. The presentation includes: (1) A brief introduction of the current communications architecture of the ISS (2) How current payload operations are handled in the non-DTN environment (3) Making the case to implement DTN into the current payload science operations model (4) Phase I DTN Operations: early implementation with BioServe's CGBA Payload (5) Phase II DTN Operations: Developing the HOSC DTN Gateway

GSFC contamination monitors for Space Station

NASA Technical Reports Server (NTRS)

Carosso, P. A.; Tveekrem, J. L.; Coopersmith, J. D.

1988-01-01

This paper describes the Work Package 3 activities in the area of neutral contamination monitoring for the Space Station. Goddard Space Flight Center's responsibilities include the development of the Attached Payload Accommodations Equipment (APAE), the Polar Orbiting Platform (POP), and the Flight Telerobotic Servicer (FTS). GSFC will also develop the Customer Servicing Facility (CSF) in Phase 2 of the Space Station.

Space transportation system payload interface verification

NASA Technical Reports Server (NTRS)

Everline, R. T.

1977-01-01

The paper considers STS payload-interface verification requirements and the capability provided by STS to support verification. The intent is to standardize as many interfaces as possible, not only through the design, development, test and evaluation (DDT and E) phase of the major payload carriers but also into the operational phase. The verification process is discussed in terms of its various elements, such as the Space Shuttle DDT and E (including the orbital flight test program) and the major payload carriers DDT and E (including the first flights). Five tools derived from the Space Shuttle DDT and E are available to support the verification process: mathematical (structural and thermal) models, the Shuttle Avionics Integration Laboratory, the Shuttle Manipulator Development Facility, and interface-verification equipment (cargo-integration test equipment).

Application of modern tools and techniques to maximize engineering productivity in the development of orbital operations plans for the space station progrm

NASA Technical Reports Server (NTRS)

Manford, J. S.; Bennett, G. R.

1985-01-01

The Space Station Program will incorporate analysis of operations constraints and considerations in the early design phases to avoid the need for later modifications to the Space Station for operations. The application of modern tools and administrative techniques to minimize the cost of performing effective orbital operations planning and design analysis in the preliminary design phase of the Space Station Program is discussed. Tools and techniques discussed include: approach for rigorous analysis of operations functions, use of the resources of a large computer network, and providing for efficient research and access to information.

Langley's CSI evolutionary model: Phase O

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Elliott, Kenny B.; Horta, Lucas G.; Bailey, Jim P.; Bruner, Anne M.; Sulla, Jeffrey L.; Won, John; Ugoletti, Roberto M.

1991-01-01

A testbed for the development of Controls Structures Interaction (CSI) technology to improve space science platform pointing is described. The evolutionary nature of the testbed will permit the study of global line-of-sight pointing in phases 0 and 1, whereas, multipayload pointing systems will be studied beginning with phase 2. The design, capabilities, and typical dynamic behavior of the phase 0 version of the CSI evolutionary model (CEM) is documented for investigator both internal and external to NASA. The model description includes line-of-sight pointing measurement, testbed structure, actuators, sensors, and real time computers, as well as finite element and state space models of major components.

Teaching Science. A Weighty Gravity Lesson.

ERIC Educational Resources Information Center

Leyden, Michael B.

1996-01-01

Describes an activity that uses a candle, a scale, and an elevator to demonstrate the concept of weightlessness in space, showing that astronauts are not truly weightless. Activity includes an exploration phase, a concept introduction phase, and a concept application phase. Provides guidelines and safety measures for conducting the activity. (JW)

48 CFR 1852.217-72 - Phased acquisition using progressive competition down-selection procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND... Phase 2 proposals, including the final evaluation criteria and factors, will be provided at that time... award. (g) The following draft Phase 2 evaluation factors are provided for your information. Please note...

Space Station Human Factors Research Review. Volume 1: EVA Research and Development

NASA Technical Reports Server (NTRS)

Cohen, Marc M. (Editor); Vykukal, H. C. (Editor)

1988-01-01

An overview is presented of extravehicular activity (EVA) research and development activities at Ames. The majority of the program was devoted to presentations by the three contractors working in parallel on the EVA System Phase A Study, focusing on Implications for Man-Systems Design. Overhead visuals are included for a mission results summary, space station EVA requirements and interface accommodations summary, human productivity study cross-task coordination, and advanced EVAS Phase A study implications for man-systems design. Articles are also included on subsea approach to work systems development and advanced EVA system design requirements.

Halo density profiles and baryon physics

NASA Astrophysics Data System (ADS)

Del Popolo, A.; Li, Xi-Guo

2017-08-01

The radial dependence of the pseudo phase-space density, ρ( r)/ σ 3( r) is studied. We find that the pseudo phase-space density for halos consisting both of dark matter and baryons is approximately a power-law only down to 0.1% of the virial radius while it has a non-power law behavior below the quoted scale, with inner profiles changing with mass. Halos consisting just of dark matter, as the one in dark matter only simulations, are characterized by an approximately power-law behavior. The results argue against universality of the pseudo phase-space density, when the baryons effect are included, and as a consequence argue against universality of density profiles constituted by dark matter and baryons as also discussed in [1].

Microgravity Research Results and Experiences from the NASA Mir Space Station Program

NASA Technical Reports Server (NTRS)

Schagheck, R. A.; Trach, B.

2000-01-01

The Microgravity Research Program Office (MRPO) participated aggressively in Phase I of the International Space Station Program using the Russian Mir Space Station. The Mir Station offered an otherwise unavailable opportunity to explore the advantages and challenges to long duration microgravity space research. Payloads with both NASA and commercial backing were included as well as cooperative research with the Canadian Space Agency (CSA). From this experience, much was learned about dealing with long duration on orbit science utilization and developing new working relationships with our Russian partner to promote efficient planning, operations, and integration to solve complexities associated with a multiple partner program. Microgravity participation in the NASA Mir Program began with the first joint NASA Mir flight to the Mir Space Station. The earliest participation setup acceleration measurement capabilities that were used throughout the Program. Research, conducted by all Microgravity science disciplines, continued on each subsequent increment for the entire three-year duration of the Program. The Phase I Program included the Microgravity participation of over 30 Fluids, Combustion, Materials, and Biotechnology Sciences and numerous commercially sponsored research payloads. In addition to the research gained from Microgravity investigations, long duration operation of facility hardware was tested. Microgravity facilities operated on Mir included the Space Acceleration Measurement System (SAMS), the Microgravity Glovebox (MGBX), the Biotechnology System (BTS) and the Canadian Space Agency sponsored Microgravity Isolation Mount (MIM). The Russian OPTIZONE Furnace was also incorporated into our material science research. All of these efforts yielded significant and useful scientific research data. This paper focuses on the microgravity research conducted onboard the Mir space station. It includes the Program preparation and planning necessary to support this type of cross increment research experience; the payloads which were flown; and summaries of significant microgravity science findings. Most importantly this paper highlights the various disciplines of microgravity research conducted during the International Space Station, Phase 1 Program onboard the Mir Station. A capsulation of significant research and the applicability of our findings are provided. In addition, a brief discussion of how future microgravity science gathering capabilities, hardware development and payload operations techniques have enhanced our ability to conduct long duration microgravity research.

Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 3: Project cost estimates

NASA Technical Reports Server (NTRS)

1990-01-01

The laser atmospheric wind sounder (LAWS) cost modeling activities were initiated in phase 1 to establish the ground rules and cost model that would apply to both phase 1 and phase 2 cost analyses. The primary emphasis in phase 1 was development of a cost model for a LAWS instrument for the Japanese Polar Orbiting Platform (JPOP). However, the Space Station application was also addressed in this model, and elements were included, where necessary, to account for Space Station unique items. The cost model presented in the following sections defines the framework for all LAWS cost modeling. The model is consistent with currently available detail, and can be extended to account for greater detail as the project definition progresses.

Development of control systems for space shuttle vehicles. Volume 2: Appendixes

NASA Technical Reports Server (NTRS)

Stone, C. R.; Chase, T. W.; Kiziloz, B. M.; Ward, M. D.

1971-01-01

A launch phase random normal wind model is presented for delta wing, two-stage, space shuttle control system studies. Equations, data, and simulations for conventional launch studies are given as well as pitch and lateral equations and data for covariance analyses of the launch phase of MSFC vehicle B. Lateral equations and data for North American 130G and 134D are also included along with a high-altitude abort simulation.

Reducing environmental risk associated with laboratory decommissioning and property transfer.

PubMed

Dufault, R; Abelquist, E; Crooks, S; Demers, D; DiBerardinis, L; Franklin, T; Horowitz, M; Petullo, C; Sturchio, G

2000-12-01

The need for more or less space is a common laboratory problem. Solutions may include renovating existing space, leaving or demolishing old space, or acquiring new space or property for building. All of these options carry potential environmental risk. Such risk can be the result of activities related to the laboratory facility or property (e.g., asbestos, underground storage tanks, lead paint), or the research associated with it (e.g., radioactive, microbiological, and chemical contamination). Regardless of the option chosen to solve the space problem, the potential environmental risk must be mitigated and the laboratory space and/or property must be decommissioned or rendered safe prior to any renovation, demolition, or property transfer activities. Not mitigating the environmental risk through a decommissioning process can incur significant financial liability for any costs associated with future decommissioning cleanup activities. Out of necessity, a functioning system, environmental due diligence auditing, has evolved over time to assess environmental risk and reduce associated financial liability. This system involves a 4-phase approach to identify, document, manage, and clean up areas of environmental concern or liability, including contamination. Environmental due diligence auditing includes a) historical site assessment, b) characterization assessment, c) remedial effort and d) final status survey. General practice standards from the American Society for Testing and Materials are available for conducting the first two phases. However, standards have not yet been developed for conducting the third and final phases of the environmental due diligence auditing process. Individuals involved in laboratory decommissioning work in the biomedical research industry consider this a key weakness.

Reducing environmental risk associated with laboratory decommissioning and property transfer.

PubMed Central

Dufault, R; Abelquist, E; Crooks, S; Demers, D; DiBerardinis, L; Franklin, T; Horowitz, M; Petullo, C; Sturchio, G

2000-01-01

The need for more or less space is a common laboratory problem. Solutions may include renovating existing space, leaving or demolishing old space, or acquiring new space or property for building. All of these options carry potential environmental risk. Such risk can be the result of activities related to the laboratory facility or property (e.g., asbestos, underground storage tanks, lead paint), or the research associated with it (e.g., radioactive, microbiological, and chemical contamination). Regardless of the option chosen to solve the space problem, the potential environmental risk must be mitigated and the laboratory space and/or property must be decommissioned or rendered safe prior to any renovation, demolition, or property transfer activities. Not mitigating the environmental risk through a decommissioning process can incur significant financial liability for any costs associated with future decommissioning cleanup activities. Out of necessity, a functioning system, environmental due diligence auditing, has evolved over time to assess environmental risk and reduce associated financial liability. This system involves a 4-phase approach to identify, document, manage, and clean up areas of environmental concern or liability, including contamination. Environmental due diligence auditing includes a) historical site assessment, b) characterization assessment, c) remedial effort and d) final status survey. General practice standards from the American Society for Testing and Materials are available for conducting the first two phases. However, standards have not yet been developed for conducting the third and final phases of the environmental due diligence auditing process. Individuals involved in laboratory decommissioning work in the biomedical research industry consider this a key weakness. PMID:11121365

Phase space effects on fast ion distribution function modeling in tokamaks

NASA Astrophysics Data System (ADS)

Podestà, M.; Gorelenkova, M.; Fredrickson, E. D.; Gorelenkov, N. N.; White, R. B.

2016-05-01

Integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities, ad-hoc models can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. The kick model implemented in the tokamak transport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.

Phase space effects on fast ion distribution function modeling in tokamaks

DOE Data Explorer

White, R. B. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Podesta, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkova, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fredrickson, E. D. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkov, N. N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2016-06-01

Integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities, ad-hoc models can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. The kick model implemented in the tokamak transport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.

Numerical Studies of High-Intensity Injection Painting for Project X

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

Drozhdin, A.I.; Vorobiev, L.G.; Johnson, D.E.

Injection phase space painting enables the mitigation of space charge and stability issues, and will be indispensable for the Project-X at Fermilab [1], delivering high-intensity proton beams to HEP experiments. Numerical simulations of multi-turn phase space painting have been performed for the FNAL Recycler Ring, including a self-consistent space charge model. The goal of our studies was to study the injection painting with inclusion of 3D space charge, using the ORBIT tracking code. In a current scenario the painting lasts for 110 turns, twice faster, than we considered in this paper. The optimal wave-forms for painting kickers, which ensure themore » flatter phase distributions, should be found. So far we used a simplified model for painting kicker strength (implemented as the 'ideal bump' in ORBIT). We will include a more realistic field map for the chicane magnets. Additional stripping simulations will be combined. We developed a block for longitudinal painting, which works with arbitrary notches in incoming micro-bunch buckets. The appropriate choice of the amplitude of the second harmonic of RF field will help to flatten the RF-bucket contours, as was demonstrated in 1D simulations. Non-linear lattice issue will be also addressed.« less

Manned spacecraft electrical power systems

NASA Technical Reports Server (NTRS)

Simon, William E.; Nored, Donald L.

1987-01-01

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

Developmental Cryogenic Active Telescope Testbed, a Wavefront Sensing and Control Testbed for the Next Generation Space Telescope

NASA Technical Reports Server (NTRS)

Leboeuf, Claudia M.; Davila, Pamela S.; Redding, David C.; Morell, Armando; Lowman, Andrew E.; Wilson, Mark E.; Young, Eric W.; Pacini, Linda K.; Coulter, Dan R.

1998-01-01

As part of the technology validation strategy of the next generation space telescope (NGST), a system testbed is being developed at GSFC, in partnership with JPL and Marshall Space Flight Center (MSFC), which will include all of the component functions envisioned in an NGST active optical system. The system will include an actively controlled, segmented primary mirror, actively controlled secondary, deformable, and fast steering mirrors, wavefront sensing optics, wavefront control algorithms, a telescope simulator module, and an interferometric wavefront sensor for use in comparing final obtained wavefronts from different tests. The developmental. cryogenic active telescope testbed (DCATT) will be implemented in three phases. Phase 1 will focus on operating the testbed at ambient temperature. During Phase 2, a cryocapable segmented telescope will be developed and cooled to cryogenic temperature to investigate the impact on the ability to correct the wavefront and stabilize the image. In Phase 3, it is planned to incorporate industry developed flight-like components, such as figure controlled mirror segments, cryogenic, low hold power actuators, or different wavefront sensing and control hardware or software. A very important element of the program is the development and subsequent validation of the integrated multidisciplinary models. The Phase 1 testbed objectives, plans, configuration, and design will be discussed.

Phase A conceptual design study of the Atmospheric, Magnetospheric and Plasmas in Space (AMPS) payload

NASA Technical Reports Server (NTRS)

1974-01-01

The 12 month Phase A Conceptual Design Study of the Atmospheric, Magnetospheric and Plasmas in Space (AMPS) payload performed within the Program Development Directorate of the Marshall Space Flight Center is presented. The AMPS payload makes use of the Spacelab pressurized module and pallet, is launched by the space shuttle, and will have initial flight durations of 7 days. Scientific instruments including particle accelerators, high power transmitters, optical instruments, and chemical release devices are mounted externally on the Spacelab pallet and are controlled by the experimenters from within the pressurized module. The capability of real-time scientist interaction on-orbit with the experiment is a major characteristic of AMPS.

Phase-Retrieval Uncertainty Estimation and Algorithm Comparison for the JWST-ISIM Test Campaign

NASA Technical Reports Server (NTRS)

Aronstein, David L.; Smith, J. Scott

2016-01-01

Phase retrieval, the process of determining the exitpupil wavefront of an optical instrument from image-plane intensity measurements, is the baseline methodology for characterizing the wavefront for the suite of science instruments (SIs) in the Integrated Science Instrument Module (ISIM) for the James Webb Space Telescope (JWST). JWST is a large, infrared space telescope with a 6.5-meter diameter primary mirror. JWST is currently NASA's flagship mission and will be the premier space observatory of the next decade. ISIM contains four optical benches with nine unique instruments, including redundancies. ISIM was characterized at the Goddard Space Flight Center (GSFC) in Greenbelt, MD in a series of cryogenic vacuum tests using a telescope simulator. During these tests, phase-retrieval algorithms were used to characterize the instruments. The objective of this paper is to describe the Monte-Carlo simulations that were used to establish uncertainties (i.e., error bars) for the wavefronts of the various instruments in ISIM. Multiple retrieval algorithms were used in the analysis of ISIM phase-retrieval focus-sweep data, including an iterativetransform algorithm and a nonlinear optimization algorithm. These algorithms emphasize the recovery of numerous optical parameters, including low-order wavefront composition described by Zernike polynomial terms and high-order wavefront described by a point-by-point map, location of instrument best focus, focal ratio, exit-pupil amplitude, the morphology of any extended object, and optical jitter. The secondary objective of this paper is to report on the relative accuracies of these algorithms for the ISIM instrument tests, and a comparison of their computational complexity and their performance on central and graphical processing unit clusters. From a phase-retrieval perspective, the ISIM test campaign includes a variety of source illumination bandwidths, various image-plane sampling criteria above and below the Nyquist- Shannon critical sampling value, various extended object sizes, and several other impactful effects.

Future utilization of space: Silverton Conference on material science and phase transformations in zero-gravity, summary of proceeding

NASA Technical Reports Server (NTRS)

Eisner, M. (Editor)

1975-01-01

The importance of zero gravity environment in the development and production of new and improved materials is considered along with the gravitational effects on phase changes or critical behavior in a variety of materials. Specific experiments discussed include: fine scale phase separation in zero gravity; glass formation in zero gravity; effects of gravitational perturbations on determination of critical exponents; and light scattering from long wave fluctuations in liquids in zero gravity. It is concluded that the space shuttle/spacelab system is applicable to various fields of interest.

Mixed Integer Programming and Heuristic Scheduling for Space Communication Networks

NASA Technical Reports Server (NTRS)

Lee, Charles H.; Cheung, Kar-Ming

2012-01-01

In this paper, we propose to solve the constrained optimization problem in two phases. The first phase uses heuristic methods such as the ant colony method, particle swarming optimization, and genetic algorithm to seek a near optimal solution among a list of feasible initial populations. The final optimal solution can be found by using the solution of the first phase as the initial condition to the SQP algorithm. We demonstrate the above problem formulation and optimization schemes with a large-scale network that includes the DSN ground stations and a number of spacecraft of deep space missions.

Implementation of a production Ada project: The GRODY study

NASA Technical Reports Server (NTRS)

Godfrey, Sara; Brophy, Carolyn Elizabeth

1989-01-01

The use of the Ada language and design methodologies that encourage full use of its capabilities have a strong impact on all phases of the software development project life cycle. At the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC), the Software Engineering Laboratory (SEL) conducted an experiment in parallel development of two flight dynamics systems in FORTRAN and Ada. The differences observed during the implementation, unit testing, and integration phases of the two projects are described and the lessons learned during the implementation phase of the Ada development are outlined. Included are recommendations for future Ada development projects.

Autonomous Satellite Command and Control Through the World Wide Web. Phase 3

NASA Technical Reports Server (NTRS)

Cantwell, Brian; Twiggs, Robert

1998-01-01

The Automated Space System Experimental Testbed (ASSET) system is a simple yet comprehensive real-world operations network being developed. Phase 3 of the ASSET Project was January-December 1997 and is the subject of this report. This phase permitted SSDL and its project partners to expand the ASSET system in a variety of ways. These added capabilities included the advancement of ground station capabilities, the adaptation of spacecraft on-board software, and the expansion of capabilities of the ASSET management algorithms. Specific goals of Phase 3 were: (1) Extend Web-based goal-level commanding for both the payload PI and the spacecraft engineer. (2) Support prioritized handling of multiple (PIs) Principle Investigators as well as associated payload experimenters. (3) Expand the number and types of experiments supported by the ASSET system and its associated spacecraft. (4) Implement more advanced resource management, modeling and fault management capabilities that integrate the space and ground segments of the space system hardware. (5) Implement a beacon monitoring test. (6) Implement an experimental blackboard controller for space system management. (7) Further define typical ground station developments required for Internet-based remote control and for full system automation of the PI-to-spacecraft link. Each of those goals are examined. Significant sections of this report were also published as a conference paper. Several publications produced in support of this grant are included as attachments. Titles include: 1) Experimental Initiatives in Space System Operations; 2) The ASSET Client Interface: Balancing High Level Specification with Low Level Control; 3) Specifying Spacecraft Operations At The Product/Service Level; 4) The Design of a Highly Configurable, Reusable Operating System for Testbed Satellites; 5) Automated Health Operations For The Sapphire Spacecraft; 6) Engineering Data Summaries for Space Missions; and 7) Experiments In Automated Health Assessment And Notification For The Sapphire Microsatellite.

Methyl Chloroform Elimination from the Production of Space Shuttle Sold Rocket Motors

NASA Technical Reports Server (NTRS)

Golde, Rick P.; Burt, Rick; Key, Leigh

1997-01-01

Thiokol Space Operations manufactures the Reusable Solid Rocket Motors used to launch America's fleet of Space Shuttles. In 1989, Thiokol used more than 1.4 Mlb of methyl chloroform to produce rocket motors. The ban placed by the Environmental Protection Agency on the sale of methyl chloroform had a significant effect on future Reusable Solid Rocket Motor production. As a result, changes in the materials and processes became necessary. A multiphased plan was established by Thiokol in partnership with NASA's Marshall Space Flight Center to eliminate the use of methyl chloroform in the Reusable Solid Rocket Motor production process. Because of the extensive scope of this effort, the plan was phased to target the elimination of the majority of methyl chloroform use (90 percent) by January 1, 1996, the 3 Environmental Protection Agency deadline. Referred to as Phase I, this effort includes the elimination of two large vapor degreasers, grease diluent processes, and propellant tooling handcleaning using methyl chloroform. Meanwhile, a request was made for an essential use exemption to allow the continued use of the remaining 10 percent of methyl chloroform after the 1996 deadline, while total elimination was pursued for this final, critical phase (Phase II). This paper provides an update to three previous presentations prepared for the 1993, 1994, and 1995 CFC/Halon Alternative Conferences, and will outline the overall Ozone Depleting Compounds Elimination Program from the initial phases through the final testing and implementation phases, including facility and equipment development. Processes and materials to be discussed include low-pressure aqueous wash systems, high-pressure water blast systems- environmental shipping containers, aqueous and semi-aqueous cleaning solutions, and bond integrity and inspection criteria. Progress toward completion of facility implementation and lessons learned during the scope of the program, as well as the current development efforts and basic requirements of future methyl chloroform handcleaning elimination, will also be outlined.

Phase 111A Crew Interface Specifications Development for Inflight Maintenance and Stowage Functions

NASA Technical Reports Server (NTRS)

Carl, John G.

1973-01-01

This report presents the findings and data products developed during the Phase IIIA Crew Interface Specification Study for Inflight Maintenance and Stowage Functions, performed by General Electric for the NASA, Johnson Space Center with a set of documentation that can be used as definitive guidelines to improve the present process of defining, controlling and managing flight crew interface requirements that are related to inflight maintenance (including assembly and servicing) and stowage functions. During the Phase IIIA contract period, the following data products were developed: 1) Projected NASA Crew Procedures/Flight Data File Development Process. 2) Inflight Maintenance Management Process Description. 3) Preliminary Draft, General Specification, Inflight Maintenance Management Requirements. 4) Inflight Maintenance Operational Process Description. 5) Preliminary Draft, General Specification, Inflight Maintenance Task and Support Requirements Analysis. 6) Suggested IFM Data Processing Reports for Logistics Management The above Inflight Maintenance data products have been developed during the Phase IIIA study after review of Space Shuttle Program Documentation, including the Level II Integrated Logistics Requirements and other DOD and NASA data relative to Payloads Accommodations and Satellite On-Orbit Servicing. These Inflight Maintenance data products were developed to be in consonance with Space Shuttle Program technical and management requirements.

Space Debris: Its Causes and Management

NASA Technical Reports Server (NTRS)

Johnson, Nicholas L.

2002-01-01

Orbital debris is internationally recognized as an environmental issue which needs to be addressed today to preserve near-Earth space for future generations. All major space agencies are committed to mitigating the growth of the debris environment. Many commercial space system operators have responded positively to orbital debris mitigation principles and recommendations. Orbital debris mitigation measures are most cost-effective if included in the design development phase.

Phase 3 study of selected tether applications in space, mid-term review

NASA Technical Reports Server (NTRS)

1986-01-01

Topics addressed include: guidelines for the Space Transportation System (STS) payload deployer design; mini-orbital maneuvering vehicle (MOMV) design: shuttle tether deployer systems (STEDS); cost modeling; tethered platform analysis; fuel savings analysis; and STEDS control simulation.

Toward large space systems. [Space Construction Base development from shuttles

NASA Technical Reports Server (NTRS)

Daros, C. J.; Freitag, R. F.; Kline, R. L.

1977-01-01

The design of the Space Transportation System, consisting of the Space Shuttle, Spacelab, and upper stages, provides experience for the development of more advanced space systems. The next stage will involve space stations in low earth orbit with limited self-sufficiency, characterized by closed ecological environments, space-generated power, and perhaps the first use of space materials. The third phase would include manned geosynchronous space-station activity and a return to lunar operations. Easier access to space will encourage the use of more complex, maintenance-requiring satellites than those currently used. More advanced space systems could perform a wide range of public services such as electronic mail, personal and police communication, disaster control, earthquake detection/prediction, water availability indication, vehicle speed control, and burglar alarm/intrusion detection. Certain products, including integrated-circuit chips and some enzymes, can be processed to a higher degree of purity in space and might eventually be manufactured there. Hardware including dishes, booms, and planar surfaces necessary for advanced space systems and their development are discussed.

Long-term memory, sleep, and the spacing effect.

PubMed

Bell, Matthew C; Kawadri, Nader; Simone, Patricia M; Wiseheart, Melody

2014-01-01

Many studies have shown that memory is enhanced when study sessions are spaced apart rather than massed. This spacing effect has been shown to have a lasting benefit to long-term memory when the study phase session follows the encoding session by 24 hours. Using a spacing paradigm we examined the impact of sleep and spacing gaps on long-term declarative memory for Swahili-English word pairs by including four spacing delay gaps (massed, 12 hours same-day, 12 hours overnight, and 24 hours). Results showed that a 12-hour spacing gap that includes sleep promotes long-term memory retention similar to the 24-hour gap. The findings support the importance of sleep to the long-term benefit of the spacing effect.

Quantum work in the Bohmian framework

NASA Astrophysics Data System (ADS)

Sampaio, R.; Suomela, S.; Ala-Nissila, T.; Anders, J.; Philbin, T. G.

2018-01-01

At nonzero temperature classical systems exhibit statistical fluctuations of thermodynamic quantities arising from the variation of the system's initial conditions and its interaction with the environment. The fluctuating work, for example, is characterized by the ensemble of system trajectories in phase space and, by including the probabilities for various trajectories to occur, a work distribution can be constructed. However, without phase-space trajectories, the task of constructing a work probability distribution in the quantum regime has proven elusive. Here we use quantum trajectories in phase space and define fluctuating work as power integrated along the trajectories, in complete analogy to classical statistical physics. The resulting work probability distribution is valid for any quantum evolution, including cases with coherences in the energy basis. We demonstrate the quantum work probability distribution and its properties with an exactly solvable example of a driven quantum harmonic oscillator. An important feature of the work distribution is its dependence on the initial statistical mixture of pure states, which is reflected in higher moments of the work. The proposed approach introduces a fundamentally different perspective on quantum thermodynamics, allowing full thermodynamic characterization of the dynamics of quantum systems, including the measurement process.

NASA's In-Space Manufacturing Project: Materials and Manufacturing Process Development Update

NASA Technical Reports Server (NTRS)

Prater, Tracie; Bean, Quincy; Werkheiser, Niki; Ledbetter, Frank

2017-01-01

The mission of NASA's In-Space Manufacturing (ISM) project is to identify, design, and implement on-demand, sustainable manufacturing solutions for fabrication, maintenance and repair during exploration missions. ISM has undertaken a phased strategy of incrementally increasing manufacturing capabilities to achieve this goal. The ISM project began with the development of the first 3D printer for the International Space Station. To date, the printer has completed two phases of flight operations. Results from phase I specimens indicated some differences in material properties between ground-processed and ISS-processed specimens, but results of follow-on analyses of these parts and a ground-based study with an equivalent printer strongly indicate that this variability is likely attributable to differences in manufacturing process settings between the ground and flight prints rather than microgravity effects on the fused deposition modeling (FDM) process. Analysis of phase II specimens from the 3D Printing in Zero G tech demo, which shed further light on the sources of material variability, will be presented. The ISM project has also developed a materials characterization plan for the Additive Manufacturing Facility, the follow-on commercial multimaterial 3D printing facility developed for ISS by Made in Space. This work will yield a suite of characteristic property values that can inform use of AMF by space system designers. Other project activities include development of an integrated 3D printer and recycler, known as the Refabricator, by Tethers Unlimited, which will be operational on ISS in 2018. The project also recently issued a broad area announcement for a multimaterial fabrication laboratory, which may include in-space manufacturing capabilities for metals, electronics, and polymeric materials, to be deployed on ISS in the 2022 timeframe.

Research planning criteria for regenerative life-support systems applicable to space habitats

NASA Technical Reports Server (NTRS)

Spurlock, J.; Cooper, W.; Deal, P.; Harlan, A.; Karel, M.; Modell, M.; Moe, P.; Phillips, J.; Putnam, D.; Quattrone, P.

1979-01-01

The second phase of analyses that were conducted by the Life Support Systems Group of the 1977 NASA Ames Summer Study is described. This phase of analyses included a preliminary review of relevant areas of technology that can contribute to the development of closed life-support systems for space habitats, the identification of research options in these areas of technology, and the development of guidelines for an effective research program. The areas of technology that were studied included: (1) nutrition, diet, and food processing; (2) higher plant agriculture; (3) animal agriculture; (4) waste conversion and resource recovery; and (5) system stability and safety. Results of these analyses, including recommended research options and criteria for establishing research priorities among these many options, are discussed.

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.

Manipulation of Liquids Using Phased Array Generation of Acoustic Radiation Pressure

NASA Technical Reports Server (NTRS)

Oeftering, Richard C. (Inventor)

2000-01-01

A phased array of piezoelectric transducers is used to control and manipulate contained as well as uncontained fluids in space and earth applications. The transducers in the phased array are individually activated while being commonly controlled to produce acoustic radiation pressure and acoustic streaming. The phased array is activated to produce a single pulse, a pulse burst or a continuous pulse to agitate, segregate or manipulate liquids and gases. The phased array generated acoustic radiation pressure is also useful in manipulating a drop, a bubble or other object immersed in a liquid. The transducers can be arranged in any number of layouts including linear single or multi- dimensional, space curved and annular arrays. The individual transducers in the array are activated by a controller, preferably driven by a computer.

Great Explorations in Math and Science[R] (GEMS[R]) Space Science. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

"Great Explorations in Math and Science[R] (GEMS[R]) Space Science" is an instructional sequence for grades 3-5 that covers fundamental concepts, including planetary sizes and distance, the Earth's shape and movement, gravity, and moon phases and eclipses. Part of the "GEMS"[R] core curriculum, "GEMS[R] Space Science"…

NASA's commercial research plans and opportunities

NASA Technical Reports Server (NTRS)

Arnold, Ray J.

1992-01-01

One of the primary goals of the National Aeronautics and Space Administration's (NASA) commercial space development plan is to encourage the development of space-based products and markets, along with the infrastructure and transportation that will support those products and markets. A three phased program has been instituted to carry out this program. The first phase utilizes government grants through the Centers for the Commercial Development of Space (CCDS) for space-related, industry driven research; the development of a technology data base; and the development of commercial space transportation and infrastructure. The second phase includes the development of these technologies by industry for new commercial markets, and features unique industry/government collaborations such as Joint Endeavor Agreements. The final phase will feature technical applications actually brought to the marketplace. The government's role will be to support industry required infrastructure to encourage start-up markets and industries through follow-on development agreements such as the Space Systems Development Agreement. The Office of Commercial Programs has an aggressive flight program underway on the Space Shuttle, suborbital rockets, orbital expendable launch vehicles, and the Commercial Middeck Accommodation Module with SPACEHAB Inc. The Office of Commercial Program's has been allocated 35 percent of the U.S. share of the Space Station Freedom resources for 1997 utilization. A utilization plan has been developed with the Centers for the Commercial Development of Space and has identified eleven materials processing and biotechnology payloads occupying 5 double racks in the pressurized module as well as two payloads external to the module in materials exposure and environment monitoring. The Office of Commercial Programs will rely on the Space Station Freedom to provide the long duration laboratory component for space-based commercial research.

NASA's commercial research plans and opportunities

NASA Astrophysics Data System (ADS)

Arnold, Ray J.

One of the primary goals of the National Aeronautics and Space Administration's (NASA) commercial space development plan is to encourage the development of space-based products and markets, along with the infrastructure and transportation that will support those products and markets. A three phased program has been instituted to carry out this program. The first phase utilizes government grants through the Centers for the Commercial Development of Space (CCDS) for space-related, industry driven research; the development of a technology data base; and the development of commercial space transportation and infrastructure. The second phase includes the development of these technologies by industry for new commercial markets, and features unique industry/government collaborations such as Joint Endeavor Agreements. The final phase will feature technical applications actually brought to the marketplace. The government's role will be to support industry required infrastructure to encourage start-up markets and industries through follow-on development agreements such as the Space Systems Development Agreement. The Office of Commercial Programs has an aggressive flight program underway on the Space Shuttle, suborbital rockets, orbital expendable launch vehicles, and the Commercial Middeck Accommodation Module with SPACEHAB Inc. The Office of Commercial Program's has been allocated 35 percent of the U.S. share of the Space Station Freedom resources for 1997 utilization. A utilization plan has been developed with the Centers for the Commercial Development of Space and has identified eleven materials processing and biotechnology payloads occupying 5 double racks in the pressurized module as well as two payloads external to the module in materials exposure and environment monitoring. The Office of Commercial Programs will rely on the Space Station Freedom to provide the long duration laboratory component for space-based commercial research.

Modular space station phase B extension preliminary system design. Volume 5: configuration analyses

NASA Technical Reports Server (NTRS)

Stefan, A. J.; Goble, G. J.

1972-01-01

The initial and growth modular space station configurations are described, and the evolutionary steps arriving at the final configuration are outlined. Supporting tradeoff studies and analyses such as stress, radiation dosage, and micrometeoroid and thermal protection are included.

Flat space (higher spin) gravity with chemical potentials

NASA Astrophysics Data System (ADS)

Gary, Michael; Grumiller, Daniel; Riegler, Max; Rosseel, Jan

2015-01-01

We introduce flat space spin-3 gravity in the presence of chemical potentials and discuss some applications to flat space cosmology solutions, their entropy, free energy and flat space orbifold singularity resolution. Our results include flat space Einstein gravity with chemical potentials as special case. We discover novel types of phase transitions between flat space cosmologies with spin-3 hair and show that the branch that continuously connects to spin-2 gravity becomes thermodynamically unstable for sufficiently large temperature or spin-3 chemical potential.

Constitutive Relationships and Models in Continuum Theories of Multiphase Flows. [conferences

NASA Technical Reports Server (NTRS)

Decker, Rand (Editor)

1989-01-01

In April, 1989, a workshop on constitutive relationships and models in continuum theories of multiphase flows was held at NASA's Marshall Space Flight Center. Topics of constitutive relationships for the partial or per phase stresses, including the concept of solid phase pressure are discussed. Models used for the exchange of mass, momentum, and energy between the phases in a multiphase flow are also discussed. The program, abstracts, and texts of the presentations from the workshop are included.

An Analytical Singularity-Free Solution to the J2 Perturbation Problem

NASA Technical Reports Server (NTRS)

Bond, V. R.

1979-01-01

The development of a singularity-free solution of the J2 problem in satellite theory is presented. The procedure resembles that of Lyndane who rederives Brouwer's satellite theory using Poincare elements. A comparable procedure is used in this report in which the satellite theory of Scheifele, who used elements similar to the Delaunay elements but in the extended phase space, is rederived using Poincare elements also in the extended phase space. Only the short-period effects due to J2 are included.

Radiation reaction in fusion plasmas.

PubMed

Hazeltine, R D; Mahajan, S M

2004-10-01

The effects of a radiation reaction on thermal electrons in a magnetically confined plasma, with parameters typical of planned burning plasma experiments, are studied. A fully relativistic kinetic equation that includes the radiation reaction is derived. The associated rate of phase-space contraction is computed and the relative importance of the radiation reaction in phase space is estimated. A consideration of the moments of the radiation reaction force show that its effects are typically small in reactor-grade confined plasmas, but not necessarily insignificant.

Space station operations task force. Panel 3 report: User development and integration

NASA Technical Reports Server (NTRS)

1987-01-01

The User Development and Integration Panel of the Space Station Operations Task Force was chartered to develop concepts relating to the operations of the Space Station manned base and the platforms, user accommodation and integration activities. The needs of the user community are addressed in the context with the mature operations phase of the Space Station. Issues addressed include space station pricing options, marketing strategies, payload selection and resource allocation options, and manifesting techniques.

GaAs MMIC elements in phased-array antennas

NASA Technical Reports Server (NTRS)

Leonard, Regis F.

1988-01-01

Over the last six years NASA Lewis Research Center has carried out a program aimed at the development of advanced monolithic microwave integrated circuit technology, principally for use in phased-array antenna applications. Arising out of the Advanced Communications Technology Satellite (ACTS) program, the initial targets of the program were chips which operated at 30 and 20 GHz. Included in this group of activities were monolithic power modules with an output of 2 watts at GHz, variable phase shifters at both 20 and 30 GHz, low noise technology at 30 GHz, and a fully integrated (phase shifter, variable gain amplifier, power amplifier) transmit module at 20 GHz. Subsequent developments are centered on NASA mission requirements, particularly Space Station communications systems and deep space data communications.

The Capabilities of Space Stations

NASA Technical Reports Server (NTRS)

1995-01-01

Over the past two years the U.S. space station program has evolved to a three-phased international program, with the first phase consisting of the use of the U.S. Space Shuttle and the upgrading and use of the Russian Mir Space Station, and the second and third phases consisting of the assembly and use of the new International Space Station. Projected capabilities for research, and plans for utilization, have also evolved and it has been difficult for those not directly involved in the design and engineering of these space stations to learn and understand their technical details. The Committee on the Space Station of the National Research Council, with the concurrence of NASA, undertook to write this short report in order to provide concise and objective information on space stations and platforms -- with emphasis on the Mir Space Station and International Space Station -- and to supply a summary of the capabilities of previous, existing, and planned space stations. In keeping with the committee charter and with the task statement for this report, the committee has summarized the research capabilities of five major space platforms: the International Space Station, the Mir Space Station, the Space Shuttle (with a Spacelab or Spacehab module in its cargo bay), the Space Station Freedom (which was redesigned to become the International Space Station in 1993 and 1994), and Skylab. By providing the summary, together with brief descriptions of the platforms, the committee hopes to assist interested readers, including scientists and engineers, government officials, and the general public, in evaluating the utility of each system to meet perceived user needs.

Space Station Freedom electrical power system hardware commonality with the United States Polar Platform

NASA Technical Reports Server (NTRS)

Rieker, Lorra L.; Haraburda, Francis M.

1989-01-01

Information is presented on how the concept of commonality is being implemented with respect to electric power system hardware for the Space Station Freedom and the U.S. Polar Platform. Included is a historical account of the candidate common items which have the potential to serve the same power system functions on both Freedom and the Polar Platform. The Space Station program and objectives are described, focusing on the test and development responsibilities. The program definition and preliminary design phase and the design and development phase are discussed. The goal of this work is to reduce the program cost.

Bound-Preserving Discontinuous Galerkin Methods for Conservative Phase Space Advection in Curvilinear Coordinates

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

Mezzacappa, Anthony; Endeve, Eirik; Hauck, Cory D.

We extend the positivity-preserving method of Zhang & Shu [49] to simulate the advection of neutral particles in phase space using curvilinear coordinates. The ability to utilize these coordinates is important for non-equilibrium transport problems in general relativity and also in science and engineering applications with specific geometries. The method achieves high-order accuracy using Discontinuous Galerkin (DG) discretization of phase space and strong stabilitypreserving, Runge-Kutta (SSP-RK) time integration. Special care in taken to ensure that the method preserves strict bounds for the phase space distribution function f; i.e., f ϵ [0, 1]. The combination of suitable CFL conditions and themore » use of the high-order limiter proposed in [49] is su cient to ensure positivity of the distribution function. However, to ensure that the distribution function satisfies the upper bound, the discretization must, in addition, preserve the divergencefree property of the phase space ow. Proofs that highlight the necessary conditions are presented for general curvilinear coordinates, and the details of these conditions are worked out for some commonly used coordinate systems (i.e., spherical polar spatial coordinates in spherical symmetry and cylindrical spatial coordinates in axial symmetry, both with spherical momentum coordinates). Results from numerical experiments - including one example in spherical symmetry adopting the Schwarzschild metric - demonstrate that the method achieves high-order accuracy and that the distribution function satisfies the maximum principle.« less

Large space telescope, phase A. Volume 4: Scientific instrument package

NASA Technical Reports Server (NTRS)

1972-01-01

The design and characteristics of the scientific instrument package for the Large Space Telescope are discussed. The subjects include: (1) general scientific objectives, (2) package system analysis, (3) scientific instrumentation, (4) imaging photoelectric sensors, (5) environmental considerations, and (6) reliability and maintainability.

Phase space effects on fast ion distribution function modeling in tokamaks

DOE PAGES

Podesta, M.; Gorelenkova, M.; Fredrickson, E. D.; ...

2016-04-14

Here, integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities,ad-hocmodels can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. Themore » kick model implemented in the tokamaktransport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.« less

Center for Space Telemetering and Telecommunications Systems, New Mexico State University

NASA Technical Reports Server (NTRS)

Horan, Stephen; DeLeon, Phillip; Borah, Deva; Lyman, Ray

2002-01-01

This viewgraph presentation gives an overview of the Center for Space Telemetering and Telecommunications Systems activities at New Mexico State University. Presentations cover the following topics: (1) small satellite communications, including nanosatellite radio and virtual satellite development; (2) modulation and detection studies, including details on smooth phase interpolated keying (SPIK) spectra and highlights of an adaptive turbo multiuser detector; (3) decoupled approaches to nonlinear ISI compensation; (4) space internet testing; (4) optical communication; (5) Linux-based receiver for lightweight optical communications without a laser in space, including software design, performance analysis, and the receiver algorithm; (6) carrier tracking hardware; and (7) subband transforms for adaptive direct sequence spread spectrum receivers.

Viking Mars encounter

NASA Technical Reports Server (NTRS)

1976-01-01

Various phases of planetary operations related to the Viking mission to Mars are described. Topics discussed include: approach phase, Mars orbit insertion, prelanding orbital activities, separation, descent and landing, surface operations, surface sampling and operations starting, orbiter science and radio science, Viking 2, Deep Space Network and data handling.

Two-phase adiabatic pressure drop experiments and modeling under micro-gravity conditions

NASA Astrophysics Data System (ADS)

Longeot, Matthieu J.; Best, Frederick R.

1995-01-01

Thermal systems for space applications based on two phase flow have several advantages over single phase systems. Two phase thermal energy management and dynamic power conversion systems have the capability of achieving high specific power levels. However, before two phase systems for space applications can be designed effectively, knowledge of the flow behavior in a ``0-g'' acceleration environment is necessary. To meet this need, two phase flow experiments were conducted by the Interphase Transport Phenomena Laboratory Group (ITP) aboard the National Aeronautics and Space Administration's (NASA) KC-135, using R12 as the working fluid. The present work is concerned with modeling of two-phase pressure drop under 0-g conditions, for bubbly and slug flow regimes. The set of data from the ITP group includes 3 bubbly points, 9 bubbly/slug points and 6 slug points. These two phase pressure drop data were collected in 1991 and 1992. A methodology to correct and validate the data was developed to achieve high levels of confidence. A homogeneous model was developed to predict the pressure drop for particular flow conditions. This model, which uses the Blasius Correlation, was found to be accurate for bubbly and bubbly/slug flows, with errors not larger than 28%. For slug flows, however, the errors are greater, attaining values up to 66%.

Application of Fourier-wavelet regularized deconvolution for improving image quality of free space propagation x-ray phase contrast imaging.

PubMed

Zhou, Zhongxing; Gao, Feng; Zhao, Huijuan; Zhang, Lixin

2012-11-21

New x-ray phase contrast imaging techniques without using synchrotron radiation confront a common problem from the negative effects of finite source size and limited spatial resolution. These negative effects swamp the fine phase contrast fringes and make them almost undetectable. In order to alleviate this problem, deconvolution procedures should be applied to the blurred x-ray phase contrast images. In this study, three different deconvolution techniques, including Wiener filtering, Tikhonov regularization and Fourier-wavelet regularized deconvolution (ForWaRD), were applied to the simulated and experimental free space propagation x-ray phase contrast images of simple geometric phantoms. These algorithms were evaluated in terms of phase contrast improvement and signal-to-noise ratio. The results demonstrate that the ForWaRD algorithm is most appropriate for phase contrast image restoration among above-mentioned methods; it can effectively restore the lost information of phase contrast fringes while reduce the amplified noise during Fourier regularization.

Modular space station phase B extension period executive summary

NASA Technical Reports Server (NTRS)

Tischler, A. A.; Could, C. L.

1972-01-01

A narrative summary is presented of technical, programmatic, and planning information developed during the space station definition study extension period. The modular space station is emphasized, but tasks pertaining to shuttle sorties missions and information management advanced development are included. A series of program options considering technical, schedule, and programmatic alternatives to the baseline program are defined and evaluated.

The ESA Space Weather Applications Pilot Project

NASA Astrophysics Data System (ADS)

Glover, A.; Hilgers, A.; Daly, E.

Following the completion in 2001 of two parallel studies to consider the feasibility of a European Space Weather Programme ESA embarked upon a space weather pilot study with the goal of prototyping European space weather services and assessing the overall market for such within Europe This pilot project centred on a number of targeted service development activities supported by a common infrastructure and making use of only existing space weather assets Each service activity included clear participation from at least one identified service user who was requested to provide initial requirements and regular feedback during the operational phase of the service These service activities are now reaching the end of their 2-year development and testing phase and are now accessible each with an element of the service in the public domain see http www esa-spaceweathet net swenet An additional crucial element of the study was the inclusion of a comprehensive and independent analysis of the benefits both economic and strategic of embarking on a programme which would include the deployment of an infrastructure with space-based elements The results of this study will be reported together with their implication for future coordinated European activities in this field

Manned Mars mission accommodation: Sprint mission

NASA Technical Reports Server (NTRS)

Cirillo, William M.; Kaszubowski, Martin J.; Ayers, J. Kirk; Llewellyn, Charles P.; Weidman, Deene J.; Meredith, Barry D.

1988-01-01

The results of a study conducted at the NASA-LaRC to assess the impacts on the Phase 2 Space Station of Accommodating a Manned Mission to Mars are documented. In addition, several candidate transportation node configurations are presented to accommodate the assembly and verification of the Mars Mission vehicles. This study includes an identification of a life science research program that would need to be completed, on-orbit, prior to mission departure and an assessment of the necessary orbital technology development and demonstration program needed to accomplish the mission. Also included is an analysis of the configuration mass properties and a preliminary analysis of the Space Station control system sizing that would be required to control the station. Results of the study indicate the Phase 2 Space Station can support a manned mission to Mars with the addition of a supporting infrastructure that includes a propellant depot, assembly hangar, and a heavy lift launch vehicle to support the large launch requirements.

Workshop on Two-Phase Fluid Behavior in a Space Environment

NASA Technical Reports Server (NTRS)

Swanson, Theodore D. (Editor); Juhasz, AL (Editor); Long, W. Russ (Editor); Ottenstein, Laura (Editor)

1989-01-01

The Workshop was successful in achieving its main objective of identifying a large number of technical issues relating to the design of two-phase systems for space applications. The principal concern expressed was the need for verified analytical tools that will allow an engineer to confidently design a system to a known degree of accuracy. New and improved materials, for such applications as thermal storage and as heat transfer fluids, were also identified as major needs. In addition to these research efforts, a number of specific hardware needs were identified which will require development. These include heat pumps, low weight radiators, advanced heat pipes, stability enhancement devices, high heat flux evaporators, and liquid/vapor separators. Also identified was the need for a centralized source of reliable, up-to-date information on two-phase flow in a space environment.

Numerical simulation of phase transition problems with explicit interface tracking

DOE PAGES

Hu, Yijing; Shi, Qiangqiang; de Almeida, Valmor F.; ...

2015-12-19

Phase change is ubiquitous in nature and industrial processes. Started from the Stefan problem, it is a topic with a long history in applied mathematics and sciences and continues to generate outstanding mathematical problems. For instance, the explicit tracking of the Gibbs dividing surface between phases is still a grand challenge. Our work has been motivated by such challenge and here we report on progress made in solving the governing equations of continuum transport in the presence of a moving interface by the front tracking method. The most pressing issue is the accounting of topological changes suffered by the interfacemore » between phases wherein break up and/or merge takes place. The underlying physics of topological changes require the incorporation of space-time subscales not at reach at the moment. Therefore we use heuristic geometrical arguments to reconnect phases in space. This heuristic approach provides new insight in various applications and it is extensible to include subscale physics and chemistry in the future. We demonstrate the method on applications such as simulating freezing, melting, dissolution, and precipitation. The later examples also include the coupling of the phase transition solution with the Navier-Stokes equations for the effect of flow convection.« less

Dead space and slope indices from the expiratory carbon dioxide tension-volume curve.

PubMed

Kars, A H; Bogaard, J M; Stijnen, T; de Vries, J; Verbraak, A F; Hilvering, C

1997-08-01

The slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate (PIE), were investigated in 28 healthy control subjects, 12 asthma and 29 emphysema patients (20 severely obstructed and nine moderately obstructed) with the aim to establish diagnostic value. Because breath volume and frequency are closely related to CO2 elimination, the recording procedures included varying breath volumes in all subjects during self-chosen/natural breathing frequency, and fixed frequencies of 10, 15 and 20 breaths x min(-1) with varying breath volumes only in the healthy controls. From the relationships of the variables with tidal volume (VT), the values at 1 L were estimated to compare the groups. The slopes of phase 3 and VD,Bohr at 1 L VT showed the most significant difference between controls and patients with asthma or emphysema, compared to the other two dead space estimates, and were related to the degree of airways obstruction. Discrimination between no-emphysema (asthma and controls) and emphysema patients was possible on the basis of a plot of intercept and slope of the relationship between VD,Bohr and VT. A combination of both the slope of phase 3 and VD,Bohr of a breath of 1 L was equally discriminating. The influence of fixed frequencies in the controls did not change the results. The conclusion is that Bohr dead space in relation to tidal volume seems to have diagnostic properties separating patients with asthma from patients with emphysema with the same degree of airways obstruction. Equally discriminating was a combination of both phase 3 and Bohr dead space of a breath of 1 L. The different pathophysiological mechanisms in asthma and emphysema leading to airways obstruction are probably responsible for these results.

CTS/Comstar communications link characterization experiment

NASA Technical Reports Server (NTRS)

Hodge, D. B.; Taylor, R. C.

1980-01-01

Measurements of angle of arrival and amplitude fluctuations on millimeter wavelength Earth-space communication links are described. Measurement of rainfall attenuation and radiometric temperature statistics and the assessment of the performance of a self-phased array as a receive antenna on an Earth-space link are also included.

Space Shuttle aerothermodynamic data report, phase C

NASA Technical Reports Server (NTRS)

1985-01-01

Space shuttle aerothermodynamic data, collected from a continuing series of wind tunnel tests, are permanently stored with the Data Management Services (DMS) system. Information pertaining to current baseline configuration definition is also stored. Documentation of DMS processed data arranged sequentially and by space shuttle configuration are included. An up-to-date record of all applicable aerothermodynamic data collected, processed, or summarized during the space shuttle program is provided. Tables are designed to provide suvery information to the various space shuttle managerial and technical levels.

Reference earth orbital research and applications investigations (blue book). Volume 1: Summary

NASA Technical Reports Server (NTRS)

1971-01-01

The criteria, guidelines, and an organized approach for use in the space station and space shuttle program definition phase are presented. Subjects discussed are: (1) background information and evolution of the studies, (2) definition of terms used, (3) concepts of the space shuttle, space station, experiment modules, shuttle-sortie operations and modular space station, and (4) summary of functional program element (FPE) requirements. Diagrams of the various configurations and the experimental equipment to be installed in the structures are included.

LCA in space - current status and future development

NASA Astrophysics Data System (ADS)

Ko, Nathanael; Betten, Thomas; Schestak, Isabel; Gantner, Johannes

2018-06-01

This paper represents the first stage of extending the scope of LCA to space and is intended as a discussion starter. Based on the assumption, that the future and outlast of humanity lies within the exploration and colonisation of space, the LCA methodology as of today, is discussed with regards to its capabilities to cover the impact of human activities in space. Based on this assessment, ideas whether and how LCA can be extended are outlined. Initially, an understanding of additional environmental impacts which occur in space compared to Earth is built up by the means of literature research. The state of the art of space regulations and availability of LCAs in space and for astronautics is clarified as well. Further literature research was conducted on the LCA subtopic of regionalization. Based on this and assumptions regarding future space travel, the suitability of LCA as an assessment method is validated. Afterwards, different potential development phases of LCA towards its applicability in space are defined. For activities in space, the regarded environmental impacts have to be expanded (e.g. space debris, extra-terrestrial life toxicity, etc.). Space regulations, if in place, cover only impacts of space activities on Earth so far. LCAs for space activities are not widespread yet. One reason for this is that the state of the art LCA methodology has not been expanded and existing regionalisation approaches are not easily transferable to space. Critical issues are faced in all phases of an LCA and include widening of boundaries, definition of space regions, finding suitable reference units and ethical problems. As a result, four LCA development phases are suggested: Earth-bound, solar system-bound, transition phase and intergalactic. Each phase involves different activities and goals, which result in different system boundaries and impact categories and widen the scope of LCA subsequently. It is a long way for humanity to populate space and so, it is for enabling LCA to assess these activities. The methodology of LCA is flexible and capable to make this adaptation. This paper can be seen as a starting point of a discussion opening up many questions. Some of these questions can only be answered in the future with more certainty about the development of space colonialization.

The eigenvalue problem in phase space.

PubMed

Cohen, Leon

2018-06-30

We formulate the standard quantum mechanical eigenvalue problem in quantum phase space. The equation obtained involves the c-function that corresponds to the quantum operator. We use the Wigner distribution for the phase space function. We argue that the phase space eigenvalue equation obtained has, in addition to the proper solutions, improper solutions. That is, solutions for which no wave function exists which could generate the distribution. We discuss the conditions for ascertaining whether a position momentum function is a proper phase space distribution. We call these conditions psi-representability conditions, and show that if these conditions are imposed, one extracts the correct phase space eigenfunctions. We also derive the phase space eigenvalue equation for arbitrary phase space distributions functions. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Gouy phase for relativistic quantum particles

NASA Astrophysics Data System (ADS)

Ducharme, R.; da Paz, I. G.

2015-08-01

Exact Hermite-Gaussian solutions to the Klein-Gordon equation for particle beams are obtained here that depend on the 4-position of the beam waist. These are Bateman-Hillion solutions that are shown to include Gouy phase and preserve their forms under Lorentz transformations. As the wave function contains two time coordinates, the particle current must be interpreted in a constraint space to reduce the number of independent coordinates. The form of the constraint space is not certain except in the nonrelativistic limit, but a trial form is proposed, enabling the observable properties of the beam to be calculated for future comparison to experiment. These results can be relevant in the theoretical development of singular electron optics since it was shown that the Gouy phase is crucial in this field as well as to investigate a possible Gouy phase effect in Zitterbewegung phenomenon of spin-zero particles. Additionally, the traditional argument that beam solutions belong to a complex shifted spacetime is shown to necessitate a corresponding Born reciprocal shift in 4-momentum space.

Shuttle considerations for the design of large space structures

NASA Technical Reports Server (NTRS)

Roebuck, J. A., Jr.

1980-01-01

Shuttle related considerations (constraints and guidelines) are compiled for use by designers of a potential class of large space structures which are transported to orbit and, deployed, fabricated or assembled in space using the Space Shuttle Orbiter. Considerations of all phases of shuttle operations from launch to ground turnaround operations are presented. Design of large space structures includes design of special construction fixtures and support equipment, special stowage cradles or pallets, special checkout maintenance, and monitoring equipment, and planning for packaging into the orbiter of all additional provisions and supplies chargeable to payload. Checklists of design issues, Shuttle capabilities constraints and guidelines, as well as general explanatory material and references to source documents are included.

Analysis of remote operating systems for space-based servicing operations. Volume 2: Study results

NASA Technical Reports Server (NTRS)

1985-01-01

The developments in automation and robotics have increased the importance of applications for space based servicing using remotely operated systems. A study on three basic remote operating systems (teleoperation, telepresence and robotics) was performed in two phases. In phase one, requirements development, which consisted of one three-month task, a group of ten missions were selected. These included the servicing of user equipment on the station and the servicing of the station itself. In phase two, concepts development, which consisted of three tasks, overall system concepts were developed for the selected missions. These concepts, which include worksite servicing equipment, a carrier system, and payload handling equipment, were evaluated relative to the configurations of the overall worksite. It is found that the robotic/teleoperator concepts are appropriate for relatively simple structured tasks, while the telepresence/teleoperator concepts are applicable for missions that are complex, unstructured tasks.

New physics in the visible final states of B → D(*) τν

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

Ligeti, Zoltan; Papucci, Michele; Robinson, Dean J.

We derive compact expressions for the helicity amplitudes of the many-body B → D (*) (→ DY)τ(→ Xν)ν decays, specifically for X = ℓν or π and Y = π or γ. We include contributions from all ten possible new physics four-Fermi operators with arbitrary couplings. Our results capture interference effects in the full phase space of the visible τ and D * decay products which are missed in analyses that treat the τ or D * or both as stable. The τ interference effects are sizable, formally of order m τ/m B for the standard model, and may bemore » of order unity in the presence of new physics. Treating interference correctly is essential when considering kinematic distributions of the τ or D * decay products, and when including experimentally unavoidable phase space cuts. Our amplitude-level results also allow for efficient exploration of new physics effects in the fully differential phase space, by enabling experiments to perform such studies on fully simulated Monte Carlo datasets via efficient event reweighing. As an example, we explore a class of new physics interactions that can fit the observed R(D (*) ) ratios, and show that analyses including more differential kinematic information can provide greater discriminating power for new physics, than single kinematic variables alone.« less

New physics in the visible final states of B → D(*) τν

DOE PAGES

Ligeti, Zoltan; Papucci, Michele; Robinson, Dean J.

2017-01-18

We derive compact expressions for the helicity amplitudes of the many-body B → D (*) (→ DY)τ(→ Xν)ν decays, specifically for X = ℓν or π and Y = π or γ. We include contributions from all ten possible new physics four-Fermi operators with arbitrary couplings. Our results capture interference effects in the full phase space of the visible τ and D * decay products which are missed in analyses that treat the τ or D * or both as stable. The τ interference effects are sizable, formally of order m τ/m B for the standard model, and may bemore » of order unity in the presence of new physics. Treating interference correctly is essential when considering kinematic distributions of the τ or D * decay products, and when including experimentally unavoidable phase space cuts. Our amplitude-level results also allow for efficient exploration of new physics effects in the fully differential phase space, by enabling experiments to perform such studies on fully simulated Monte Carlo datasets via efficient event reweighing. As an example, we explore a class of new physics interactions that can fit the observed R(D (*) ) ratios, and show that analyses including more differential kinematic information can provide greater discriminating power for new physics, than single kinematic variables alone.« less

Pre-Launch Risk Reduction Activities Conducted at KSC for the International Space Station

NASA Technical Reports Server (NTRS)

Kirkpatrick, Paul

2011-01-01

In the development of any large scale space-based multi-piece assembly effort, planning must include provisions for testing and verification; not only of the individual pieces but also of the pieces together. Without such testing on the ground, the risk to cost, schedule and technical performance increases substantially. This paper will review the efforts undertaken by the International Space Station (ISS), including the International Partners, during the pre-launch phase, primarily at KSC, to reduce the risks associated with the on-orbit assembly and operation of the ISS.

Architectural Design for European SST System

NASA Astrophysics Data System (ADS)

Utzmann, Jens; Wagner, Axel; Blanchet, Guillaume; Assemat, Francois; Vial, Sophie; Dehecq, Bernard; Fernandez Sanchez, Jaime; Garcia Espinosa, Jose Ramon; Agueda Mate, Alberto; Bartsch, Guido; Schildknecht, Thomas; Lindman, Niklas; Fletcher, Emmet; Martin, Luis; Moulin, Serge

2013-08-01

The paper presents the results of a detailed design, evaluation and trade-off of a potential European Space Surveillance and Tracking (SST) system architecture. The results have been produced in study phase 1 of the on-going "CO-II SSA Architectural Design" project performed by the Astrium consortium as part of ESA's Space Situational Awareness Programme and are the baseline for further detailing and consolidation in study phase 2. The sensor network is comprised of both ground- and space-based assets and aims at being fully compliant with the ESA SST System Requirements. The proposed ground sensors include a surveillance radar, an optical surveillance system and a tracking network (radar and optical). A space-based telescope system provides significant performance and robustness for the surveillance and tracking of beyond-LEO target objects.

Solar power satellite system definition study. Volume 3: Reference system description, phase 1

NASA Technical Reports Server (NTRS)

1979-01-01

An analysis of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed including the structure, power distribution, thermal control, and energy storage. Space construction and support systems are described including the work support facilities and construction equipment. An assessment of the space transportation system for the satellite and the ground receiving station is presented.

Fluid Studies on the International Space Station

NASA Technical Reports Server (NTRS)

Motil, Brian J.

2016-01-01

Will discuss the recent activities on the international space station, including the adiabatic two phase flow, capillary flow and interfacial phenomena, and boiling and condensation. Will also give a historic introduction to Microgravity Studies at Glenn Research Center. Talk will be given to students and faculty at University of Louisville.

JPL space station telerobotic engineering prototype development FY 91 status/achievements

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne

1991-01-01

The topics covered are presented in view graph form and include: (1) streamlining intravehicular activity (IVA) teleoperation activities on the Space Station Freedom (SSF); (2) enhancing SSF utilization during the man-tended phase; (3) telerobotic ground remote operations (TGRO); and (4) advanced telerobotics system technology (shared control).

Large space telescope, phase A. Volume 5: Support systems module

NASA Technical Reports Server (NTRS)

1972-01-01

The development and characteristics of the support systems module for the Large Space Telescope are discussed. The following systems and described: (1) thermal control, (2) electrical, (3) communication and data landing, (4) attitude control system, and (5) structural features. Analyses of maintainability and reliability considerations are included.

Space Solar Power Management and Distribution (PMAD)

NASA Technical Reports Server (NTRS)

Lynch, Thomas H.

2000-01-01

This paper presents, in viewgraph form, SSP PMAD (Space Solar Power Management and Distribution). The topics include: 1) Architecture; 2) Backside Thermal View; 3) Solar Array Interface; 4) Transformer design and risks; 5) Twelve phase rectifier; 6) Antenna (80V) Converters; 7) Distribution Cables; 8) Weight Analysis; and 9) PMAD Summary.

Science with the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2012-01-01

The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. The science goals for JWST include the formation of the first stars and galaxies in the early universe; the chemical, morphological and dynamical buildup of galaxies and the formation of stars and planetary systems. Recently, the goals have expanded to include studies of dark energy, dark matter, active galactic nuclei, exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitiess Spectrograph will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory is confirmed for launch in 2018; the design is complete and it is in its construction phase. Recent progress includes the completion of the mirrors, the delivery of the first flight instrument(s) and the start of the integration and test phase.

The James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2012-01-01

The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (SDK) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. The science goals for JWST include the formation of the first stars and galaxies in the early universe; the chemical, morphological and dynamical buildup of galaxies and the formation of stars and planetary systems. Recently, the goals have expanded to include studies of dark energy, dark matter, active galactic nuclei, exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to S microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory is confirmed for launch in 2018; the design is complete and it is in its construction phase. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.

A control approach for robots with flexible links and rigid end-effectors

NASA Technical Reports Server (NTRS)

Barbieri, Enrique; Ozguner, Umit

1989-01-01

Multiarm flexible robots with dexterous end effectors are currently being considered in such tasks as satellite retrieval, servicing and repair where a two phase problem can be identified: Phase 1, robot positioning in space; Phase 2, object retrieval. Some issues in Phase 1 regarding modelling and control strategies for a robotic system comprised of along flexible arm and a rigid three-link end effector are presented. The control objective is to maintain the last (rigid) link stationary in space in the presence of an additive disturbance caused by the flexible energy in the first link after a positioning maneuver has been accomplished. Several configuration strategies can be considered, and optimal decentralized servocompensators can be designed. Preliminary computer simulations are included for a simple proportional controller to illustrate the approach.

An investigation of two phase flow pressure drops in a reduced acceleration environment

NASA Astrophysics Data System (ADS)

Wheeler, Montgomery W.; Best, Frederick R.; Reinarts, Thomas R.

1993-01-01

Thermal systems for space applications based on two phase flow have several advantages over single phase systems. Two phase thermal energy management and dynamic power conversion system advantages include the capability of achieving high specific power levels. Before two phase systems for space applications can be designed effectively, knowledge of the flow behavior in a reduced acceleration environment is necessary. To meet these needs, two phase flow experiments were conducted aboard the National Aeronautic and Space Administration's KC-135 using R12 as the working fluid. Annular flow two phase pressure drops were measured through 10.41-mm ID 1.251-m long glass tubing during periods with acceleration levels in the range ±0.05 G. The experiments were conducted with emphasis on achieving data with a high level of accuracy. The reduced acceleration annular flow pressure drops were compred with pressure drops measured in a 1-G environment for similar flow conditions. The reduced acceleration pressure drops were found to be 45% greater than the 1-G pressure drops. In addition, the reduced acceleration annular flow interfacial friction factors were compared with models for vertical up-flow in a 1-G environment. The reduced acceleration interfacial friction factor data was not predicted by the 1-G models.

MSFC Sortie Laboratory Environmental Control System (ECS) phase B design study results

NASA Technical Reports Server (NTRS)

Ignatonis, A. J.; Mitchell, K. L.

1974-01-01

Phase B effort of the Sortie Lab program has concluded. Results of that effort are presented which pertain to the definitions of the environmental control system (ECS). Numerous design studies were performed in Phase B to investigate system feasibility, complexity, weight, and cost. The results and methods employed for these design studies are included. An autonomous Sortie Lab ECS was developed which utilizes a deployed space radiator. Total system weight was projected to be 1814.4 kg including the radiator and fluids. ECS power requirements were estimated at 950 watts.

Anharmonic quantum mechanical systems do not feature phase space trajectories

NASA Astrophysics Data System (ADS)

Oliva, Maxime; Kakofengitis, Dimitris; Steuernagel, Ole

2018-07-01

Phase space dynamics in classical mechanics is described by transport along trajectories. Anharmonic quantum mechanical systems do not allow for a trajectory-based description of their phase space dynamics. This invalidates some approaches to quantum phase space studies. We first demonstrate the absence of trajectories in general terms. We then give an explicit proof for all quantum phase space distributions with negative values: we show that the generation of coherences in anharmonic quantum mechanical systems is responsible for the occurrence of singularities in their phase space velocity fields, and vice versa. This explains numerical problems repeatedly reported in the literature, and provides deeper insight into the nature of quantum phase space dynamics.

Multiphase Flow Technology Impacts on Thermal Control Systems for Exploration

NASA Technical Reports Server (NTRS)

McQuillen, John; Sankovic, John; Lekan, Jack

2006-01-01

The Two-Phase Flow Facility (TPHIFFy) Project focused on bridging the critical knowledge gap by developing and demonstrating critical multiphase fluid products for advanced life support, thermal management and power conversion systems that are required to enable the Vision for Space Exploration. Safety and reliability of future systems will be enhanced by addressing critical microgravity fluid physics issues associated with flow boiling, condensation, phase separation, and system stability. The project included concept development, normal gravity testing, and reduced gravity aircraft flight campaigns, in preparation for the development of a space flight experiment implementation. Data will be utilized to develop predictive models that could be used for system design and operation. A single fluid, two-phase closed thermodynamic loop test bed was designed, assembled and tested. The major components in this test bed include: a boiler, a condenser, a phase separator and a circulating pump. The test loop was instrumented with flow meters, thermocouples, pressure transducers and both high speed and normal speed video cameras. A low boiling point surrogate fluid, FC-72, was selected based on scaling analyses using preliminary designs for operational systems. Preliminary results are presented which include flow regime transitions and some observations regarding system stability.

Space station wardroom habitability and equipment study

NASA Technical Reports Server (NTRS)

Nixon, David; Miller, Christopher; Fauquet, Regis

1989-01-01

Experimental designs in life-size mock-up form for the wardroom facility for the Space Station Habitability Module are explored and developed. In Phase 1, three preliminary concepts for the wardroom configuration are fabricated and evaluated. In Phase 2, the results of Phase 1 are combined with a specific range of program design requirements to provide the design criteria for the fabrication of an innovative medium-fidelity mock-up of a wardrobe configuration. The study also focuses on the design and preliminary prototyping of selected equipment items including crew exercise compartments, a meal/meeting table and a portable workstation. Design criteria and requirements are discussed and documented. Preliminary and final mock-ups and equipment prototypes are described and illustrated.

Experimental evaluation of a new form of M-ary (M = 8) phase shift keying including design of the transmitter and receiver

NASA Astrophysics Data System (ADS)

Thompson, G. E.

1984-12-01

For transmitting digital information over bandpass channels, M-ary Phase Shift Keying 8(PSK) schemes are used to conserve bandwidth at the expense of signal power. A block of k bits is used to change the phase of the carrier. These k bits represent M possible phase shifts since M = 2. Common forms of M-ary PSK use equally spaced phase angles. For example, if M = 8 and k=3, 8-ary PSK uses eight phase angles spaced 45 degrees apart. This thesis considers a hybrid form of PSK when M = 8 and k = 3. Each of eight blocks of data with three bits per block are represented by different phase shifts of the carrier. The phase angles are chosen to give an equal distance between states (symbols) when projected onto the sine axis and the cosine axis of a phasor diagram. Thus, when the three bits are recovered, using two coherent phase detectors, the separation of the decision regions (voltage levels) are equal.

Single phase four pole/six pole motor

DOEpatents

Kirschbaum, Herbert S.

1984-01-01

A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils.

Space station WP-04 power system. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Hallinan, G. J.

1987-01-01

Major study activities and results of the phase B study contract for the preliminary design of the space station Electrical Power System (EPS) are summarized. The areas addressed include the general system design, man-tended option, automation and robotics, evolutionary growth, software development environment, advanced development, customer accommodations, operations planning, product assurance, and design and development phase planning. The EPS consists of a combination photovoltaic and solar dynamic power generation subsystem and a power management and distribution (PMAD) subsystem. System trade studies and costing activities are also summarized.

2 Tbit/s free-space data transmission on two orthogonal orbital-angular-momentum beams each carrying 25 WDM channels.

PubMed

Fazal, Irfan M; Ahmed, Nisar; Wang, Jian; Yang, Jeng-Yuan; Yan, Yan; Shamee, Bishara; Huang, Hao; Yue, Yang; Dolinar, Sam; Tur, Moshe; Willner, Alan E

2012-11-15

We demonstrate a 2 Tbit/s free-space data link using two orthogonal orbital angular momentum beams each carrying 25 different wavelength-division-multiplexing channels. We measure the performance for different modulation formats, including directly detected 40 Gbit/s nonreturn-to-zero (NRZ) differential phase-shift keying, 40 Gbit/s NRZ on-off keying, and coherently-detected 10 Gbaud NRZ quadrature phase-shift keying, and achieve low bit error rates with penalties less than 5 dB.

Massless spinning particle and null-string on AdS d : projective-space approach

NASA Astrophysics Data System (ADS)

Uvarov, D. V.

2018-07-01

The massless spinning particle and the tensionless string models on an AdS d background in the projective-space realization are proposed as constrained Hamiltonian systems. Various forms of particle and string Lagrangians are derived and classical mechanics is studied including the Lax-type representation of the equations of motion. After that, the transition to the quantum theory is discussed. The analysis of potential anomalies in the tensionless string model necessitates the introduction of ghosts and BRST charge. It is shown that a quantum BRST charge is nilpotent for any d if coordinate-momentum ordering for the phase-space bosonic variables, Weyl ordering for the fermions and cb () ordering for the ghosts is chosen, while conformal reparametrizations and space-time dilatations turn out to be anomalous for ordering in terms of positive and negative Fourier modes of the phase-space variables and ghosts.

Heat transfer in space systems; Proceedings of the Symposium, AIAA/ASME Thermophysics and Heat Transfer Conference, Seattle, WA, June 18-20, 1990

NASA Technical Reports Server (NTRS)

Chan, S. H. (Editor); Anderson, E. E. (Editor); Simoneau, R. J. (Editor); Chan, C. K. (Editor); Pepper, D. W. (Editor)

1990-01-01

Theoretical and experimental studies of heat-tranfer in a space environment are discussed in reviews and reports. Topics addressed include a small-scale two-phase thermosiphon to cool high-power electronics, a low-pressure-drop heat exchanger with integral heat pipe, an analysis of the thermal performance of heat-pipe radiators, measurements of temperature and concentration fields in a rectangular heat pipe, and a simplified aerothermal heating method for axisymmetric blunt bodies. Consideration is given to entropy production in a shock wave, bubble-slug transition in a two-phase liquid-gas flow under microgravity, plasma arc welding under normal and zero gravity, the Microgravity Thaw Experiment, the flow of a thin film on stationary and rotating disks, an advanced ceramic fabric body-mounted radiator for Space Station Freedom phase 0 design, and lunar radiators with specular reflectors.

Digital signal processing in the radio science stability analyzer

NASA Technical Reports Server (NTRS)

Greenhall, C. A.

1995-01-01

The Telecommunications Division has built a stability analyzer for testing Deep Space Network installations during flight radio science experiments. The low-frequency part of the analyzer operates by digitizing wave signals with bandwidths between 80 Hz and 45 kHz. Processed outputs include spectra of signal, phase, amplitude, and differential phase; time series of the same quantities; and Allan deviation of phase and differential phase. This article documents the digital signal-processing methods programmed into the analyzer.

Invulnerability, coping, salutogenesis, integration: four phases of space psychology.

PubMed

Suedfeld, Peter

2005-06-01

The relationship between NASA and the psychological research community has progressed through a number of phases during the past four decades. This paper summarizes how the relationship has developed as data have accumulated and space missions and crews have changed. In the beginning, most NASA astronauts and staff considered possible psychological problems during space missions to be a non-issue. It was assumed that people with "the right stuff" would not experience any such problems. A more realistic recognition of stress and its consequences has led to a concern with prevention and countermeasures, a concern that has come to dominate NASA's involvement with psychology. Very recently, space psychologists have started to import the concepts of positive psychology, and consider the benefits of participation in the space program, including the self-enhancing aspects of stressful experiences (salutogenesis). Both the agency and psychologists now need to broaden their thinking and their research to cover the gamut of empirical data and theoretical concepts. These include human strengths as well as vulnerabilities, both negative and positive impacts of spaceflight, long- as well as short-term effects, and the reactions not only of the astronauts themselves but also of ground personnel and the families of both groups.

Analyzing the Impacts of Natural Environments on Launch and Landing Availability for NASA's Eploration Systems Development Programs

NASA Technical Reports Server (NTRS)

Altino, Karen M.; Burns, K. Lee; Barbre, Robert E.; Leahy, Frank B.

2014-01-01

NASA is developing new capabilities for human and scientific exploration beyond Earth orbit. Natural environments information is an important asset for NASA's development of the next generation space transportation system as part of the Exploration Systems Development Program, which includes the Space Launch System (SLS) and MultiPurpose Crew Vehicle (MPCV) Programs. Natural terrestrial environment conditions - such as wind, lightning and sea states - can affect vehicle safety and performance during multiple mission phases ranging from prelaunch ground processing to landing and recovery operations, including all potential abort scenarios. Space vehicles are particularly sensitive to these environments during the launch/ascent and the entry/landing phases of mission operations. The Marshall Space Flight Center (MSFC) Natural Environments Branch provides engineering design support for NASA space vehicle projects and programs by providing design engineers and mission planners with natural environments definitions as well as performing custom analyses to help characterize the impacts the natural environment may have on vehicle performance. One such analysis involves assessing the impact of natural environments to operational availability. Climatological time series of operational surface weather observations are used to calculate probabilities of meeting or exceeding various sets of hypothetical vehicle-specific parametric constraint thresholds.

Phase-space networks of geometrically frustrated systems.

PubMed

Han, Yilong

2009-11-01

We illustrate a network approach to the phase-space study by using two geometrical frustration models: antiferromagnet on triangular lattice and square ice. Their highly degenerated ground states are mapped as discrete networks such that the quantitative network analysis can be applied to phase-space studies. The resulting phase spaces share some comon features and establish a class of complex networks with unique Gaussian spectral densities. Although phase-space networks are heterogeneously connected, the systems are still ergodic due to the random Poisson processes. This network approach can be generalized to phase spaces of some other complex systems.

Liquid Phase Sintering

NASA Technical Reports Server (NTRS)

2004-01-01

Industry spends billions of dollars each year on machine tools to manufacture products out of metal. This includes tools for cutting every kind of metal part from engine blocks to Shuttle main engine components. Cutting tool tips often break because of weak spots or defects in their composition. Based on a new concept called defect trapping, space offers a novel environment to study defect formation in molten metal materials as they solidify. After the return of these materials from space, researchers can evaluate the source of the defect and seek ways to eliminate them in products prepared on Earth. A widely used process for cutting tip manufacturing is liquid phase sintering. Compared to Earth-sintered samples which slump due to buoyancy induced by gravity, space samples are uniformly shaped and defects remain where they are formed. By studying metals sintered in space the US tool industry can potentially enhance its worldwide competitiveness. The Consortium for Materials Development in Space along with Wyle Labs, Teledyne Advanced Materials, and McDornell Douglas have conducted experiments in space.

Technology assessment of advanced automation for space missions

NASA Technical Reports Server (NTRS)

1982-01-01

Six general classes of technology requirements derived during the mission definition phase of the study were identified as having maximum importance and urgency, including autonomous world model based information systems, learning and hypothesis formation, natural language and other man-machine communication, space manufacturing, teleoperators and robot systems, and computer science and technology.

Neurodynamics With Spatial Self-Organization

NASA Technical Reports Server (NTRS)

Zak, Michail A.

1993-01-01

Report presents theoretical study of dynamics of neural network organizing own response in both phase space and in position space. Postulates several mathematical models of dynamics including spatial derivatives representing local interconnections among neurons. Shows how neural responses propagate via these interconnections and how spatial pattern of neural responses formed in homogeneous biological neural network.

KSC-08pd1384

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- A support boat from a rescue training exercise, known as Mode VIII, returns to the ship off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1374

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- An HH-60G helicopter flies overhead of a rescue boat during a training exercise, known as Mode VIII, off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1381

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Participants in a rescue training exercise, known as Mode VIII, wait for a support boat off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1382

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Support boats connect off Florida's central east coast during a rescue training exercise, known as Mode VIII. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

Alkaline static feed electrolyzer based oxygen generation system

NASA Technical Reports Server (NTRS)

Noble, L. D.; Kovach, A. J.; Fortunato, F. A.; Schubert, F. H.; Grigger, D. J.

1988-01-01

In preparation for the future deployment of the Space Station, an R and D program was established to demonstrate integrated operation of an alkaline Water Electrolysis System and a fuel cell as an energy storage device. The program's scope was revised when the Space Station Control Board changed the energy storage baseline for the Space Station. The new scope was aimed at the development of an alkaline Static Feed Electrolyzer for use in an Environmental Control/Life Support System as an oxygen generation system. As a result, the program was divided into two phases. The phase 1 effort was directed at the development of the Static Feed Electrolyzer for application in a Regenerative Fuel Cell System. During this phase, the program emphasized incorporation of the Regenerative Fuel Cell System design requirements into the Static Feed Electrolyzer electrochemical module design and the mechanical components design. The mechanical components included a Pressure Control Assembly, a Water Supply Assembly and a Thermal Control Assembly. These designs were completed through manufacturing drawing during Phase 1. The Phase 2 effort was directed at advancing the Alkaline Static Feed Electrolyzer database for an oxygen generation system. This development was aimed at extending the Static Feed Electrolyzer database in areas which may be encountered from initial fabrication through transportation, storage, launch and eventual Space Station startup. During this Phase, the Program emphasized three major areas: materials evaluation, electrochemical module scaling and performance repeatability and Static Feed Electrolyzer operational definition and characterization.

Research Objectives for Human Missions in the Proving Ground of Cis-Lunar Space

NASA Technical Reports Server (NTRS)

Niles, P. B.; Eppler, D. B.; Kennedy, K. J.; Lewis, R.; Spann, J. F.; Sullivan, T. A.

2016-01-01

Beginning in as early as 2023, crewed missions beyond low Earth orbit will begin enabled by the new capabilities of the SLS and Orion vehicles. This will initiate the "Proving Ground" phase of human exploration with Mars as an ultimate destination. The primary goal of the Proving Ground is to demonstrate the capability of suitably long duration spaceflight without need of continuous support from Earth, i.e. become Earth Independent. A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fundamental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fundamental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In Situ Resource Utilization. Mapping and prioritizing the most important objectives from these disciplines will provide a strong foundation for establishing the architecture to be utilized in the Proving Ground.

Clock Technology Development in the Laser Cooling and Atomic Physics (LCAP) Program

NASA Technical Reports Server (NTRS)

Seidel, Dave; Thompson, R. J.; Klipstein, W. M.; Kohel, J.; Maleki, L.

2000-01-01

This paper presents the Laser Cooling and Atomic Physics (LCAP) program. It focuses on clock technology development. The topics include: 1) Overview of LCAP Flight Projects; 2) Space Clock 101; 3) Physics with Clocks in microgravity; 4) Space Clock Challenges; 5) LCAP Timeline; 6) International Space Station (ISS) Science Platforms; 7) ISS Express Rack; 8) Space Qualification of Components; 9) Laser Configuration; 10) Clock Rate Comparisons: GPS Carrier Phase Frequency Transfer; and 11) ISS Model Views. This paper is presented in viewgraph form.

Robotics and telepresence for moon missions

NASA Technical Reports Server (NTRS)

Sallaberger, Christian

1994-01-01

An integrated moon program has often been proposed as a logical next step for today's space efforts. In the context of preparing for the possibility of launching a moon program, the European Space Agency is currently conducting an internal study effort which is focusing on the assessment of key technologies. Current thinking has this moon program organized into four phases. Phase 1 will deal with lunar resource exploration. The goal would be to produce a complete chemical inventory of the moon, including oxygen, water, other volatiles, carbon, silicon, and other resources. Phase 2 will establish a permanent robotic presence on the moon via a number of landers and surface rovers. Phase 3 will extend the second phase and concentrate on the use and exploitation of local lunar resources. Phase 4 will be the establishment of a first human outpost. Some preliminary work such as the building of the outpost and the installation of scientific equipment will be done by unmanned systems before a human crew is sent to the moon.

Illustration of microphysical processes in Amazonian deep convective clouds in the gamma phase space: introduction and potential applications

NASA Astrophysics Data System (ADS)

Cecchini, Micael A.; Machado, Luiz A. T.; Wendisch, Manfred; Costa, Anja; Krämer, Martina; Andreae, Meinrat O.; Afchine, Armin; Albrecht, Rachel I.; Artaxo, Paulo; Borrmann, Stephan; Fütterer, Daniel; Klimach, Thomas; Mahnke, Christoph; Martin, Scot T.; Minikin, Andreas; Molleker, Sergej; Pardo, Lianet H.; Pöhlker, Christopher; Pöhlker, Mira L.; Pöschl, Ulrich; Rosenfeld, Daniel; Weinzierl, Bernadett

2017-12-01

The behavior of tropical clouds remains a major open scientific question, resulting in poor representation by models. One challenge is to realistically reproduce cloud droplet size distributions (DSDs) and their evolution over time and space. Many applications, not limited to models, use the gamma function to represent DSDs. However, even though the statistical characteristics of the gamma parameters have been widely studied, there is almost no study dedicated to understanding the phase space of this function and the associated physics. This phase space can be defined by the three parameters that define the DSD intercept, shape, and curvature. Gamma phase space may provide a common framework for parameterizations and intercomparisons. Here, we introduce the phase space approach and its characteristics, focusing on warm-phase microphysical cloud properties and the transition to the mixed-phase layer. We show that trajectories in this phase space can represent DSD evolution and can be related to growth processes. Condensational and collisional growth may be interpreted as pseudo-forces that induce displacements in opposite directions within the phase space. The actually observed movements in the phase space are a result of the combination of such pseudo-forces. Additionally, aerosol effects can be evaluated given their significant impact on DSDs. The DSDs associated with liquid droplets that favor cloud glaciation can be delimited in the phase space, which can help models to adequately predict the transition to the mixed phase. We also consider possible ways to constrain the DSD in two-moment bulk microphysics schemes, in which the relative dispersion parameter of the DSD can play a significant role. Overall, the gamma phase space approach can be an invaluable tool for studying cloud microphysical evolution and can be readily applied in many scenarios that rely on gamma DSDs.

Space station needs, attributes, and architectural options. Volume 1. Executive summary

NASA Technical Reports Server (NTRS)

Pritchard, E. B.

1983-01-01

The initial space station should be manned, placed in 28.5 deg orbit, and provide substantial economic, performance, and social benefits. The most beneficial space station capabilities include: a space test facility; a transport harbor; satellite servicing and assembly; and an observatory. A space industrial park could be added once further development effort validates the cost and expanding commercial market for space processed materials. The potential accrued gross mission model benefit derived from these capabilities is $5.9B without the industrial park, and $9.3B with it. An unclassified overview of all phases of the study is presented.

Low-cost Active Structural Control Space Experiment (LASC)

NASA Technical Reports Server (NTRS)

Robinett, Rush; Bukley, Angelia P.

1992-01-01

The DOE Lab Director's Conference identified the need for the DOE National Laboratories to actively and aggressively pursue ways to apply DOE technology to problems of national need. Space structures are key elements of DOD and NASA space systems and a space technology area in which DOE can have a significant impact. LASC is a joint agency space technology experiment (DOD Phillips, NASA Marshall, and DOE Sandia). The topics are presented in viewgraph form and include the following: phase 4 investigator testbed; control of large flexible structures in orbit; INFLEX; Controls, Astrophysics; and structures experiments in space; SARSAT; and LASC mission objectives.

Deep Space Habitat Team: HEFT Phase 2 Effects

NASA Technical Reports Server (NTRS)

Toups, Larry D.; Smitherman, David; Shyface, Hilary; Simon, Matt; Bobkill, Marianne; Komar, D. R.; Guirgis, Peggy; Bagdigian, Bob; Spexarth, Gary

2011-01-01

HEFT was a NASA-wide team that performed analyses of architectures for human exploration beyond LEO, evaluating technical, programmatic, and budgetary issues to support decisions at the highest level of the agency in HSF planning. HEFT Phase I (April - September, 2010) and Phase II (September - December, 2010) examined a broad set of Human Exploration of Near Earth Objects (NEOs) Design Reference Missions (DRMs), evaluating such factors as elements, performance, technologies, schedule, and cost. At end of HEFT Phase 1, an architecture concept known as DRM 4a represented the best available option for a full capability NEO mission. Within DRM4a, the habitation system was provided by Deep Space Habitat (DSH), Multi-Mission Space Exploration Vehicle (MMSEV), and Crew Transfer Vehicle (CTV) pressurized elements. HEFT Phase 2 extended DRM4a, resulting in DRM4b. Scrubbed element-level functionality assumptions and mission Concepts of Operations. Habitation Team developed more detailed concepts of the DSH and the DSH/MMSEV/CTV Conops, including functionality and accommodations, mass & volume estimates, technology requirements, and DDT&E costs. DRM 5 represented an effort to reduce cost by scaling back on technologies and eliminating the need for the development of an MMSEV.

WISPER: Wirless Space Power Experiment

NASA Technical Reports Server (NTRS)

Hawkins, Joseph

1993-01-01

The 1993 Advanced Design Project at the University of Alaska Fairbanks was to design a spacecraft as a technology demonstration of wireless power transmission (WPT). With cost effectiveness as a design constraint, a micro-satellite in low earth orbit (LEO) was chosen for the mission. Existing and near term technologies were analyzed and selected for the project. In addition to the conceptual design of the payload, support systems, and structure, the analysis included attention to safety, environmental impact, cost, and schedule for construction and operation. Wireless power beaming is not a new concept. Experimental demonstrations and study efforts have continued since the early 1960's. With the latest progress in transmitter and receiver technology, the next natural step is to beam power from earth to space. This proposed flight demonstration will advance the science of power beaming and prove the viability of various applications of WPT in space. Two methods of power beaming will be examined during the two separate phases of the spacecraft life. The first phase will demonstrate the technology and examine the theory of microwave power transmission at a high frequency. Special aspects of the first phase will include a highly accurate attitude control system and a 14 m inflatable parabolic antenna. The second phase will investigate the utilization of high intensity laser power using modified photovoltaic arrays. Special instrumentation on the spacecraft will measure the conversion efficiency from the received microwave or laser power to direct current power.

The NASA Space Radiobiology Risk Assessment Project

NASA Astrophysics Data System (ADS)

Cucinotta, Francis A.; Huff, Janice; Ponomarev, Artem; Patel, Zarana; Kim, Myung-Hee

The current first phase (2006-2011) has the three major goals of: 1) optimizing the conventional cancer risk models currently used based on the double-detriment life-table and radiation quality functions; 2) the integration of biophysical models of acute radiation syndromes; and 3) the development of new systems radiation biology models of cancer processes. The first-phase also includes continued uncertainty assessment of space radiation environmental models and transport codes, and relative biological effectiveness factors (RBE) based on flight data and NSRL results, respectively. The second phase of the (2012-2016) will: 1) develop biophysical models of central nervous system risks (CNS); 2) achieve comphrensive systems biology models of cancer processes using data from proton and heavy ion studies performed at NSRL; and 3) begin to identify computational models of biological countermeasures. Goals for the third phase (2017-2021) include: 1) the development of a systems biology model of cancer risks for operational use at NASA; 2) development of models of degenerative risks, 2) quantitative models of counter-measure impacts on cancer risks; and 3) indiviudal based risk assessments. Finally, we will support a decision point to continue NSRL research in support of NASA's exploration goals beyond 2021, and create an archival of NSRL research results for continued analysis. Details on near term goals, plans for a WEB based data resource of NSRL results, and a space radiation Wikepedia are described.

First-principles study on the phase transitions, crystal stabilities and thermodynamic properties of TiN under high pressure

NASA Astrophysics Data System (ADS)

Sun, Xinjun; Liu, Changdong; Guo, Yongliang; Sun, Deyan; Ke, Xuezhi

2018-03-01

The structural and thermodynamic properties of titanium nitride (TiN) have been investigated by merging first-principles calculations and particle-swarm algorithm. The three phases are identified for TiN, including the B1, the P63 / mmc, and the B2 phases. A new phase of anti-TiP structure with the space group P63 / mmc has been predicted. The calculated phase transition from the B1 to the P63 / mmc occurs at 270 GPa. The vibrational, elastic, and thermodynamic properties for the three phases have been calculated and discussed.

The Astrophysics of Visible-light Orbital Phase Curves in the Space Age

NASA Astrophysics Data System (ADS)

Shporer, Avi

2017-07-01

The field of visible-light continuous time series photometry is now at its golden age, manifested by the continuum of past (CoRoT, Kepler), present (K2), and future (TESS, PLATO) space-based surveys delivering high precision data with a long baseline for a large number of stars. The availability of the high-quality data has enabled astrophysical studies not possible before, including, for example, detailed asteroseismic investigations and the study of the exoplanet census including small planets. This has also allowed to study the minute photometric variability following the orbital motion in stellar binaries and star-planet systems which is the subject of this review. We focus on systems with a main sequence primary and a low-mass secondary, from a small star to a massive planet. The orbital modulations are induced by a combination of gravitational and atmospheric processes, including the beaming effect, tidal ellipsoidal distortion, reflected light, and thermal emission. Therefore, the phase curve shape contains information about the companion’s mass and atmospheric characteristics, making phase curves a useful astrophysical tool. For example, phase curves can be used to detect and measure the mass of short-period low-mass companions orbiting hot fast-rotating stars out of reach of other detection methods. Another interesting application of phase curves is using the orbital phase modulations to look for non-transiting systems, which comprise the majority of stellar binary and star-planet systems. We discuss the science done with phase curves, the first results obtained so far, and the current difficulties and open questions related to this young and evolving subfield.

Generalized Kapchinskij-Vladimirskij Distribution and Beam Matrix for Phase-Space Manipulations of High-Intensity Beams

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

Chung, Moses; Qin, Hong; Davidson, Ronald C.

In an uncoupled linear lattice system, the Kapchinskij-Vladimirskij (KV) distribution formulated on the basis of the single-particle Courant-Snyder invariants has served as a fundamental theoretical basis for the analyses of the equilibrium, stability, and transport properties of high-intensity beams for the past several decades. Recent applications of high-intensity beams, however, require beam phase-space manipulations by intentionally introducing strong coupling. Here in this Letter, we report the full generalization of the KV model by including all of the linear (both external and space-charge) coupling forces, beam energy variations, and arbitrary emittance partition, which all form essential elements for phase-space manipulations. Themore » new generalized KV model yields spatially uniform density profiles and corresponding linear self-field forces as desired. Finally, the corresponding matrix envelope equations and beam matrix for the generalized KV model provide important new theoretical tools for the detailed design and analysis of high-intensity beam manipulations, for which previous theoretical models are not easily applicable.« less

Generalized Kapchinskij-Vladimirskij Distribution and Beam Matrix for Phase-Space Manipulations of High-Intensity Beams

DOE PAGES

Chung, Moses; Qin, Hong; Davidson, Ronald C.; ...

2016-11-23

In an uncoupled linear lattice system, the Kapchinskij-Vladimirskij (KV) distribution formulated on the basis of the single-particle Courant-Snyder invariants has served as a fundamental theoretical basis for the analyses of the equilibrium, stability, and transport properties of high-intensity beams for the past several decades. Recent applications of high-intensity beams, however, require beam phase-space manipulations by intentionally introducing strong coupling. Here in this Letter, we report the full generalization of the KV model by including all of the linear (both external and space-charge) coupling forces, beam energy variations, and arbitrary emittance partition, which all form essential elements for phase-space manipulations. Themore » new generalized KV model yields spatially uniform density profiles and corresponding linear self-field forces as desired. Finally, the corresponding matrix envelope equations and beam matrix for the generalized KV model provide important new theoretical tools for the detailed design and analysis of high-intensity beam manipulations, for which previous theoretical models are not easily applicable.« less

Gas-Liquid Two-Phase Flows Through Packed Bed Reactors in Microgravity

NASA Technical Reports Server (NTRS)

Motil, Brian J.; Balakotaiah, Vemuri

2001-01-01

The simultaneous flow of gas and liquid through a fixed bed of particles occurs in many unit operations of interest to the designers of space-based as well as terrestrial equipment. Examples include separation columns, gas-liquid reactors, humidification, drying, extraction, and leaching. These operations are critical to a wide variety of industries such as petroleum, pharmaceutical, mining, biological, and chemical. NASA recognizes that similar operations will need to be performed in space and on planetary bodies such as Mars if we are to achieve our goals of human exploration and the development of space. The goal of this research is to understand how to apply our current understanding of two-phase fluid flow through fixed-bed reactors to zero- or partial-gravity environments. Previous experiments by NASA have shown that reactors designed to work on Earth do not necessarily function in a similar manner in space. Two experiments, the Water Processor Assembly and the Volatile Removal Assembly have encountered difficulties in predicting and controlling the distribution of the phases (a crucial element in the operation of this type of reactor) as well as the overall pressure drop.

An Overview of the Space Environments and Spacecraft Effects Organization Concept

NASA Technical Reports Server (NTRS)

Edwards, David L.; Burns, Howard D.; Garrett, Henry B.; Miller, Sharon K.; Peddie, Darilyn; Porter Ron; Spann, James F.; Xapsos, Michael A.

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore our Earth, and the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge on the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments fields that will serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environment and spacecraft effects (SESE) organization. This SESE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems, and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Environment effects focuses on the material, component, sub-system, and system-level response to the space environment and include the selection and testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA, other federal government agencies, and the commercial sector to ensure that communications are well established and the needs of the programs are being met. The programmatic support function also includes working in coordination with the program in anomaly resolution and generation of lessons learned documentation. The goal of this space environment and spacecraft effects organization is to develop decision-making tools and engineering products to support all mission phases from mission concept through operations by focusing on transitioning research to application. Products generated by this space environments and effects application are suitable for use in anomaly investigations. This paper will describe the scope and purpose of the space environments and spacecraft effects organization and describe the TWG's and their relationship to the functional areas.

Phase Space Exchange in Thick Wedge Absorbers

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

Neuffer, David

The problem of phase space exchange in wedge absorbers with ionization cooling is discussed. The wedge absorber exchanges transverse and longitudinal phase space by introducing a position-dependent energy loss. In this paper we note that the wedges used with ionization cooling are relatively thick, so that single wedges cause relatively large changes in beam phase space. Calculation methods adapted to such “thick wedge” cases are presented, and beam phase-space transformations through such wedges are discussed.

Phase-space topography characterization of nonlinear ultrasound waveforms.

PubMed

Dehghan-Niri, Ehsan; Al-Beer, Helem

2018-03-01

Fundamental understanding of ultrasound interaction with material discontinuities having closed interfaces has many engineering applications such as nondestructive evaluation of defects like kissing bonds and cracks in critical structural and mechanical components. In this paper, to analyze the acoustic field nonlinearities due to defects with closed interfaces, the use of a common technique in nonlinear physics, based on a phase-space topography construction of ultrasound waveform, is proposed. The central idea is to complement the "time" and "frequency" domain analyses with the "phase-space" domain analysis of nonlinear ultrasound waveforms. A nonlinear time series method known as pseudo phase-space topography construction is used to construct equivalent phase-space portrait of measured ultrasound waveforms. Several nonlinear models are considered to numerically simulate nonlinear ultrasound waveforms. The phase-space response of the simulated waveforms is shown to provide different topographic information, while the frequency domain shows similar spectral behavior. Thus, model classification can be substantially enhanced in the phase-space domain. Experimental results on high strength aluminum samples show that the phase-space transformation provides a unique detection and classification capabilities. The Poincaré map of the phase-space domain is also used to better understand the nonlinear behavior of ultrasound waveforms. It is shown that the analysis of ultrasound nonlinearities is more convenient and informative in the phase-space domain than in the frequency domain. Copyright © 2017 Elsevier B.V. All rights reserved.

Phase-space evolution of x-ray coherence in phase-sensitive imaging.

PubMed

Wu, Xizeng; Liu, Hong

2008-08-01

X-ray coherence evolution in the imaging process plays a key role for x-ray phase-sensitive imaging. In this work we present a phase-space formulation for the phase-sensitive imaging. The theory is reformulated in terms of the cross-spectral density and associated Wigner distribution. The phase-space formulation enables an explicit and quantitative account of partial coherence effects on phase-sensitive imaging. The presented formulas for x-ray spectral density at the detector can be used for performing accurate phase retrieval and optimizing the phase-contrast visibility. The concept of phase-space shearing length derived from this phase-space formulation clarifies the spatial coherence requirement for phase-sensitive imaging with incoherent sources. The theory has been applied to x-ray Talbot interferometric imaging as well. The peak coherence condition derived reveals new insights into three-grating-based Talbot-interferometric imaging and gratings-based x-ray dark-field imaging.

Detection and Imaging of Moving Targets with LiMIT SAR Data

DTIC Science & Technology

2017-03-03

include space time adaptive processing (STAP) or displaced phase center antenna (DPCA) [4]–[7]. Page et al. combined constant acceleration target...motion focusing with space-time adaptive processing (STAP), and included the refocusing parameters in the STAP steering vector. Due to inhomogenous...wavelength λ and slow time t, of a moving target after matched filter and passband equalization processing can be expressed as: P (t) = exp ( −j 4π λ ||~rp

Higher order explicit symmetric integrators for inseparable forms of coordinates and momenta

NASA Astrophysics Data System (ADS)

Liu, Lei; Wu, Xin; Huang, Guoqing; Liu, Fuyao

2016-06-01

Pihajoki proposed the extended phase-space second-order explicit symmetric leapfrog methods for inseparable Hamiltonian systems. On the basis of this work, we survey a critical problem on how to mix the variables in the extended phase space. Numerical tests show that sequent permutations of coordinates and momenta can make the leapfrog-like methods yield the most accurate results and the optimal long-term stabilized error behaviour. We also present a novel method to construct many fourth-order extended phase-space explicit symmetric integration schemes. Each scheme represents the symmetric production of six usual second-order leapfrogs without any permutations. This construction consists of four segments: the permuted coordinates, triple product of the usual second-order leapfrog without permutations, the permuted momenta and the triple product of the usual second-order leapfrog without permutations. Similarly, extended phase-space sixth, eighth and other higher order explicit symmetric algorithms are available. We used several inseparable Hamiltonian examples, such as the post-Newtonian approach of non-spinning compact binaries, to show that one of the proposed fourth-order methods is more efficient than the existing methods; examples include the fourth-order explicit symplectic integrators of Chin and the fourth-order explicit and implicit mixed symplectic integrators of Zhong et al. Given a moderate choice for the related mixing and projection maps, the extended phase-space explicit symplectic-like methods are well suited for various inseparable Hamiltonian problems. Samples of these problems involve the algorithmic regularization of gravitational systems with velocity-dependent perturbations in the Solar system and post-Newtonian Hamiltonian formulations of spinning compact objects.

Closed-form solution for the Wigner phase-space distribution function for diffuse reflection and small-angle scattering in a random medium.

PubMed

Yura, H T; Thrane, L; Andersen, P E

2000-12-01

Within the paraxial approximation, a closed-form solution for the Wigner phase-space distribution function is derived for diffuse reflection and small-angle scattering in a random medium. This solution is based on the extended Huygens-Fresnel principle for the optical field, which is widely used in studies of wave propagation through random media. The results are general in that they apply to both an arbitrary small-angle volume scattering function, and arbitrary (real) ABCD optical systems. Furthermore, they are valid in both the single- and multiple-scattering regimes. Some general features of the Wigner phase-space distribution function are discussed, and analytic results are obtained for various types of scattering functions in the asymptotic limit s > 1, where s is the optical depth. In particular, explicit results are presented for optical coherence tomography (OCT) systems. On this basis, a novel way of creating OCT images based on measurements of the momentum width of the Wigner phase-space distribution is suggested, and the advantage over conventional OCT images is discussed. Because all previous published studies regarding the Wigner function are carried out in the transmission geometry, it is important to note that the extended Huygens-Fresnel principle and the ABCD matrix formalism may be used successfully to describe this geometry (within the paraxial approximation). Therefore for completeness we present in an appendix the general closed-form solution for the Wigner phase-space distribution function in ABCD paraxial optical systems for direct propagation through random media, and in a second appendix absorption effects are included.

A tale of two theories: How the adiabatic response and ULF waves affect relativistic electrons

NASA Astrophysics Data System (ADS)

Green, J. C.; Kivelson, M. G.

2001-11-01

Using data from the Comprehensive Energetic Particle and Pitch Angle Distribution (CEPPAD)-High Sensitivity Telescope (HIST) instrument on the Polar spacecraft and ground magnetometer data from the 210 meridian magnetometer chain, we test the ULF wave drift resonance theory proposed to explain relativistic electron phase space density enhancements. We begin by investigating changes in electron flux due to the ``Dst effect.'' The Dst effect refers to the adiabatic response of relativistic electrons to changes in the magnetic field characterized by the Dst index. The Dst effect, assuming no loss or addition of new electrons, produces reversible order of magnitude changes in relativistic electrons flux measured at fixed energy, but it cannot account for the flux enhancement that occurs in the recovery phase of most storms. Liouville's theorem states that phase space density expressed in terms of constant adiabatic invariants is unaffected by adiabatic field changes and thus is insensitive to the Dst effect. It is therefore useful to express flux measurements in terms of phase space densities at constant first, second and third adiabatic invariants. The phase space density is determined from the CEPPAD-HIST electron detector that measures differential directional flux of electrons from 0.7 to 9 MeV and the Tsyganenko 96 field model. The analysis is done for January to June 1997. The ULF wave drift resonance theory that we test proposes that relativistic electrons are accelerated by an m=2 toroidal or poloidal mode wave whose frequency equals the drift frequency of the electron. The theory is tested by comparing the relativistic electron phase space densities to wave power determined at three ground stations with L* values of 4.0, 5.7 and 6.2. Comparison of the wave data to the phase space densities shows that five out of nine storm events are consistent with the ULF wave drift resonance mechanism, three out of nine give ambiguous support to the model, and one event has high ULF wave power at the drift frequency of the electrons but no corresponding phase space density enhancement suggesting that ULF wave power alone is not sufficient to cause an electron response. Two explanations of the anomalous event are investigated including excessive loss of electrons to the magnetopause and wave duration.

Thermal management system options for high power space platforms

NASA Technical Reports Server (NTRS)

Sadunas, J. A.; Lehtinen, A.; Parish, R.

1985-01-01

Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

Space shuttle orbiter mechanical refrigeration system

NASA Technical Reports Server (NTRS)

Williams, J. L.

1974-01-01

A radiator/condenser was designed which is efficient in both condensation (refrigeration) and liquid phase (radiator) operating modes, including switchover from the refrigeration mode to the radiator mode and vice versa. A method for predicting the pressure drop of a condensing two-phase flow in zero-gravity was developed along with a method for predicting the flow regime which would prevail along the condensation path. The hybrid refrigeration system was assembled with the two radiator/condenser panels installed in a space environment simulator. The system was tested under both atmospheric and vacuum conditions. Results of the tests are presented.

Adiabatic description of long range frequency sweeping

NASA Astrophysics Data System (ADS)

Breizman, Boris; Nyqvist, Robert; Lilley, Matthew

2012-10-01

A theoretical framework is developed to describe long range frequency sweeping events in the 1D electrostatic bump-on-tail model with fast particle sources and collisions. The model includes three collision operators (Krook, drag (dynamical friction) and velocity space diffusion), and allows for a general shape of the fast particle distribution function. The behavior of phase space holes and clumps is analyzed, and the effect of particle trapping due to separatrix expansion is discussed. With a fast particle distribution function whose slope decays above the resonant phase velocity, hooked frequency sweeping is found for holes in the presence of drag collisions alone.

MIT Space Engineering Research Center

NASA Technical Reports Server (NTRS)

Crawley, Edward F.; Miller, David W.

1990-01-01

The Space Engineering Research Center (SERC) at MIT, started in Jul. 1988, has completed two years of research. The Center is approaching the operational phase of its first testbed, is midway through the construction of a second testbed, and is in the design phase of a third. We presently have seven participating faculty, four participating staff members, ten graduate students, and numerous undergraduates. This report reviews the testbed programs, individual graduate research, other SERC activities not funded by the Center, interaction with non-MIT organizations, and SERC milestones. Published papers made possible by SERC funding are included at the end of the report.

Single phase four pole/six pole motor

DOEpatents

Kirschbaum, H.S.

1984-10-09

A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils. 10 figs.

Hubble Space Telescope cycle 5. Phase 1: Proposal instructions, version 4.0

NASA Technical Reports Server (NTRS)

Madau, Piero (Editor)

1994-01-01

This document has the following purposes: it describes the information that must be submitted to the Space Telescope Science Institute by Phase 1 proposers, both electronically and on paper, and describes how to submit it; it describes how to fill out the proposal LATEX templates; it describes how to estimate the number of spacecraft orbits that the proposed observations will require; it provides detailed information about the parameters that are used in the forms to describe the requested observations; and it provides information about the preparation and electronic submission of proposal files. Examples of completed proposal forms are included.

BUDHIES II: a phase-space view of H I gas stripping and star formation quenching in cluster galaxies

NASA Astrophysics Data System (ADS)

Jaffé, Yara L.; Smith, Rory; Candlish, Graeme N.; Poggianti, Bianca M.; Sheen, Yun-Kyeong; Verheijen, Marc A. W.

2015-04-01

We investigate the effect of ram-pressure from the intracluster medium on the stripping of H I gas in galaxies in a massive, relaxed, X-ray bright, galaxy cluster at z = 0.2 from the Blind Ultra Deep H I Environmental Survey (BUDHIES). We use cosmological simulations, and velocity versus position phase-space diagrams to infer the orbital histories of the cluster galaxies. In particular, we embed a simple analytical description of ram-pressure stripping in the simulations to identify the regions in phase-space where galaxies are more likely to have been sufficiently stripped of their H I gas to fall below the detection limit of our survey. We find a striking agreement between the model predictions and the observed location of H I-detected and non-detected blue (late-type) galaxies in phase-space, strongly implying that ram-pressure plays a key role in the gas removal from galaxies, and that this can happen during their first infall into the cluster. However, we also find a significant number of gas-poor, red (early-type) galaxies in the infall region of the cluster that cannot easily be explained with our model of ram-pressure stripping alone. We discuss different possible additional mechanisms that could be at play, including the pre-processing of galaxies in their previous environment. Our results are strengthened by the distribution of galaxy colours (optical and UV) in phase-space, that suggests that after a (gas-rich) field galaxy falls into the cluster, it will lose its gas via ram-pressure stripping, and as it settles into the cluster, its star formation will decay until it is completely quenched. Finally, this work demonstrates the utility of phase-space diagrams to analyse the physical processes driving the evolution of cluster galaxies, in particular H I gas stripping.

Urban greenspace for resilient city in the future: Case study of Yogyakarta City

NASA Astrophysics Data System (ADS)

Ni'mah, N. M.; Lenonb, S.

2017-06-01

The capacity of adaptation is essential elements towards urban resilience. One adaptation that can be done is to consider the provision of open space and public space in the city. Yogyakarta City development which focused on the built area and negates the open space has blurred the characteristics of the city. Efforts in increasing the availability of public space is one of the seven priorities of the programs included in the environmental and the utilization of space in Yogyakarta City. An understanding of the provision of public green open spaces in Yogyakarta is important because the products and processes that take place in a development will determine the successful implementation of the development plan. The objectives of this study are as follows: (1) to identify the provision green space in Yogyakarta City from the aspects of product and procedure; and (2) to identify the role of green space to build resilient city. This study is used descriptive qualitative approach with in-depth interview, literature review, and triangulation as the method for data collection. Yogyakarta has had instruments for public green open spaces provision called Masterplan Ruang Terbuka Hijau (RTH) Up-Scaling Yogyakarta 2013-2032 which govern the typologies and criteria for green open space development in the city.Public green open spaces development mechanism can be grouped into the planning phase, the utilization phase, and the control phase of each consisting of legal and regulatory aspects, institutional aspects, financial aspects, and technical aspects. The mechanism of green open space provision should regard the need of advocacy for “urban green commons” (UGCs) development as a systematic approach of collective-participatory for urban land management.

KSC-08pd1383

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Off Florida's central east coast, a support boat from a rescue training exercise, known as Mode VIII, returns to the Freedom Star, one of NASA's solid rocket booster retrieval ships from NASA's Kennedy Space Center. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

Space station data flow

NASA Technical Reports Server (NTRS)

1972-01-01

The results of the space station data flow study are reported. Conceived is a low cost interactive data dissemination system for space station experiment data that includes facility and personnel requirements and locations, phasing requirements and implementation costs. Each of the experiments identified by the operating schedule is analyzed and the support characteristics identified in order to determine data characteristics. Qualitative and quantitative comparison of candidate concepts resulted in a proposed data system configuration baseline concept that includes a data center which combines the responsibility of reprocessing, archiving, and user services according to the various agencies and their responsibility assignments. The primary source of data is the space station complex which provides through the Tracking Data Relay Satellite System (TDRS) and by space shuttle delivery data from experiments in free flying modules and orbiting shuttles as well as from the experiments in the modular space station itself.

Space telescope optical telescope assembly/scientific instruments. Phase B: -Preliminary design and program definition study; Volume 2A: Planetary camera report

NASA Technical Reports Server (NTRS)

1976-01-01

Development of the F/48, F/96 Planetary Camera for the Large Space Telescope is discussed. Instrument characteristics, optical design, and CCD camera submodule thermal design are considered along with structural subsystem and thermal control subsystem. Weight, electrical subsystem, and support equipment requirements are also included.

Space radiation hazards to Project Skylab photographic film, phase 2

NASA Technical Reports Server (NTRS)

Hill, C. W.; Neville, C. F.

1971-01-01

The results of a study of space radiation hazards to Project Skylab photographic film are presented. Radiation components include trapped protons, trapped electrons, bremsstrahlung, and galactic cosmic radiation. The shielding afforded by the Skylab cluster is taken into account with a 5000 volume element mathematical model. A preliminary survey of expected proton spectrometer data is reported.

Study of solid rocket motors for a space shuttle booster. Volume 3: Program acquisition planning

NASA Technical Reports Server (NTRS)

Vonderesch, A. H.

1972-01-01

Plans for conducting Phase C/D for a solid rocket motor booster vehicle are presented. Methods for conducting this program with details of scheduling, testing, and program management and control are included. The requirements of the space shuttle program to deliver a minimum cost/maximum reliability booster vehicle are examined.

Solar power satellite system definition study. Volume 2, phase 1: Systems analyses tradeoffs.

NASA Technical Reports Server (NTRS)

1979-01-01

A systems definition study of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed. Space construction and support systems are examined including a series construction and equipment characteristics analysis. Space transportation for the satellite and the ground receiving station are assessed.

Candidate space processing techniques for biomaterials other than preparative electrophoresis

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1976-01-01

The advantages of performing the partition and countercurrent distribution (CCD) of cells in phase separated aqueous polymer systems under reduced gravity were assessed. Other possible applications considered for the space processing program include the freezing front separation of cells, adsorption of cells at the air-water interface, and the macrophage electrophoretic mobility test for cancer.

Autonomous rendezvous and docking operations of unmanned expendable cargo transfer vehicles (e.g. Centaur) with Space Station Freedom

NASA Technical Reports Server (NTRS)

Emmet, Brian R.

1991-01-01

This paper describes the results of the feasibility study using Centaur or other CTV's to deliver payloads to the Space Station Freedom (SSF). During this study was examined the requirements upon unmanned cargo transfer stages (including Centaur) for phasing, rendezvous, proximity operations and docking/berthing (capture).

Grassmann phase space theory and the Jaynes–Cummings model

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

Dalton, B.J., E-mail: bdalton@swin.edu.au; Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne, Victoria 3122; Garraway, B.M.

2013-07-15

The Jaynes–Cummings model of a two-level atom in a single mode cavity is of fundamental importance both in quantum optics and in quantum physics generally, involving the interaction of two simple quantum systems—one fermionic system (the TLA), the other bosonic (the cavity mode). Depending on the initial conditions a variety of interesting effects occur, ranging from ongoing oscillations of the atomic population difference at the Rabi frequency when the atom is excited and the cavity is in an n-photon Fock state, to collapses and revivals of these oscillations starting with the atom unexcited and the cavity mode in a coherentmore » state. The observation of revivals for Rydberg atoms in a high-Q microwave cavity is key experimental evidence for quantisation of the EM field. Theoretical treatments of the Jaynes–Cummings model based on expanding the state vector in terms of products of atomic and n-photon states and deriving coupled equations for the amplitudes are a well-known and simple method for determining the effects. In quantum optics however, the behaviour of the bosonic quantum EM field is often treated using phase space methods, where the bosonic mode annihilation and creation operators are represented by c-number phase space variables, with the density operator represented by a distribution function of these variables. Fokker–Planck equations for the distribution function are obtained, and either used directly to determine quantities of experimental interest or used to develop c-number Langevin equations for stochastic versions of the phase space variables from which experimental quantities are obtained as stochastic averages. Phase space methods have also been developed to include atomic systems, with the atomic spin operators being represented by c-number phase space variables, and distribution functions involving these variables and those for any bosonic modes being shown to satisfy Fokker–Planck equations from which c-number Langevin equations are often developed. However, atomic spin operators satisfy the standard angular momentum commutation rules rather than the commutation rules for bosonic annihilation and creation operators, and are in fact second order combinations of fermionic annihilation and creation operators. Though phase space methods in which the fermionic operators are represented directly by c-number phase space variables have not been successful, the anti-commutation rules for these operators suggest the possibility of using Grassmann variables—which have similar anti-commutation properties. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of phase space methods in quantum optics to treat fermionic systems by representing fermionic annihilation and creation operators directly by Grassmann phase space variables is rather rare. This paper shows that phase space methods using a positive P type distribution function involving both c-number variables (for the cavity mode) and Grassmann variables (for the TLA) can be used to treat the Jaynes–Cummings model. Although it is a Grassmann function, the distribution function is equivalent to six c-number functions of the two bosonic variables. Experimental quantities are given as bosonic phase space integrals involving the six functions. A Fokker–Planck equation involving both left and right Grassmann differentiations can be obtained for the distribution function, and is equivalent to six coupled equations for the six c-number functions. The approach used involves choosing the canonical form of the (non-unique) positive P distribution function, in which the correspondence rules for the bosonic operators are non-standard and hence the Fokker–Planck equation is also unusual. Initial conditions, such as those above for initially uncorrelated states, are discussed and used to determine the initial distribution function. Transformations to new bosonic variables rotating at the cavity frequency enable the six coupled equations for the new c-number functions–that are also equivalent to the canonical Grassmann distribution function–to be solved analytically, based on an ansatz from an earlier paper by Stenholm. It is then shown that the distribution function is exactly the same as that determined from the well-known solution based on coupled amplitude equations. In quantum–atom optics theories for many atom bosonic and fermionic systems are needed. With large atom numbers, treatments must often take into account many quantum modes—especially for fermions. Generalisations of phase space distribution functions of phase space variables for a few modes to phase space distribution functionals of field functions (which represent the field operators, c-number fields for bosons, Grassmann fields for fermions) are now being developed for large systems. For the fermionic case, the treatment of the simple two mode problem represented by the Jaynes–Cummings model is a useful test case for the future development of phase space Grassmann distribution functional methods for fermionic applications in quantum–atom optics. -- Highlights: •Novel phase space theory of the Jaynes–Cummings model using Grassmann variables. •Fokker–Planck equations solved analytically. •Results agree with the standard quantum optics treatment. •Grassmann phase space theory applicable to fermion many-body problems.« less

Microgravity research results and experiences from the NASA/MIR space station program.

PubMed

Schlagheck, R A; Trach, B L

2003-12-01

The Microgravity Research Program (MRP) participated aggressively in Phase 1 of the International Space Station Program using the Russian Mir Space Station. The Mir Station offered an otherwise unavailable opportunity to explore the advantages and challenges of long duration microgravity space research. Payloads with both National Aeronautics and Space Agency (NASA) and commercial backing were included as well as cooperative research with the Canadian Space Agency (CSA). From this experience, much was learned about long-duration on-orbit science utilization and developing new working relationships with our Russian partner to promote efficient planning, operations, and integration to solve complexities associated with a multiple partner program. This paper focuses on the microgravity research conducted onboard the Mir space station. It includes the Program preparation and planning necessary to support this type of cross increment research experience; the payloads which were flown; and summaries of significant microgravity science findings. Published by Elsevier Ltd.

Design of a surface-based factory for the production of life support and technology support products. Phase 2: Integrated water system for a space colony

NASA Technical Reports Server (NTRS)

1989-01-01

Phase 2 of a conceptual design of an integrated water treatment system to support a space colony is presented. This includes a breathable air manufacturing system, a means of drilling for underground water, and storage of water for future use. The system is to supply quality water for biological consumption, farming, residential and industrial use and the water source is assumed to be artesian or subsurface and on Mars. Design criteria and major assumptions are itemized. A general block diagram of the expected treatment system is provided. The design capacity of the system is discussed, including a summary of potential users and the level of treatment required; and, finally, various treatment technologies are described.

KSC-08pd1364

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a U.S. Coast Guard rescue boat off Florida's central east coast, participants in a rescue training exercise, known as Mode VIII, put on astronauts' launch-and-entry suits. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1387

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Off Florida's central east coast, support boats from a training exercise, known as Mode VIII, return to the U.S. Coast Guard cutter Kingfisher, from Port Canaveral, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1367

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Participants in a rescue training exercise, known as Mode VIII, are successfully launched from a U.S. Coast Guard rescue boat off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1378

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a rescue training exercise, known as Mode VIII, off Florida's central east coast, an HH-60G helicopter lifts the stretcher bearing a participant. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1366

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Participants in a rescue training exercise, known as Mode VIII, are successfully launched from a U.S. Coast Guard rescue boat off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1368

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Participants in a rescue training exercise, known as Mode VIII, are successfully launched from a U.S. Coast Guard rescue boat off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1371

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- An Air Force HC-130 rescue tanker flies over the target area off Florida's central east coast during a rescue training exercise, known as Mode VIII. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1373

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- A U.S. Coast Guard HU-25 Falcon jet flies over a rescue boat during a training exercise, known as Mode VIII, off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1372

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- A U.S. Coast Guard HU-25 Falcon jet flies overhead during a rescue training exercise, known as Mode VIII, off Florida's central east coast. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1370

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Participants take part in a rescue training exercise, known as Mode VIII, off Florida's central east coast while a U.S. Coast Guard HU-25 Falcon jet flies overhead. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1379

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a rescue training exercise, known as Mode VIII, off Florida's central east coast, a participant is lifted out of the water with a harness from an HH-60G helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1386

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Off Florida's central east coast, members of the rescue team in a training exercise, known as Mode VIII, stay alert aboard the U.S. Coast Guard cutter Kingfisher, from Port Canaveral, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1377

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a rescue training exercise, known as Mode VIII, off Florida's central east coast, an HH-60G helicopter lifts the stretcher bearing a participant. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1376

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a training exercise, known as Mode VIII, off Florida's central east coast, an HH-60G helicopter rescues a participant from the Atlantic Ocean. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1375

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a training exercise, known as Mode VIII, off Florida's central east coast, an HH-60G helicopter executes a rescue maneuver of a participant. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1365

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a U.S. Coast Guard rescue boat off Florida's central east coast, participants in a rescue training exercise, known as Mode VIII, are ready to be launched into the Atlantic Ocean. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1363

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a U.S. Coast Guard rescue boat off Florida's central east coast, participants in a rescue training exercise, known as Mode VIII, put on astronauts' launch-and-entry suits. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1380

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a rescue training exercise, known as Mode VIII, off Florida's central east coast, a participant is lifted out of the water with a harness from an HH-60G helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1369

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- An Air Force HC-130 rescue tanker flies over the target area off Florida's central east coast during a rescue training exercise, known as Mode VIII. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

Integrated optical phased arrays for quasi-Bessel-beam generation.

PubMed

Notaros, Jelena; Poulton, Christopher V; Byrd, Matthew J; Raval, Manan; Watts, Michael R

2017-09-01

Integrated optical phased arrays for generating quasi-Bessel beams are proposed and experimentally demonstrated in a CMOS-compatible platform. Owing to their elongated central beams, Bessel beams have applications in a range of fields, including multiparticle trapping and laser lithography. In this Letter, continuous Bessel theory is manipulated to formulate the phase and amplitude conditions necessary for generating free-space-propagating Bessel-Gauss beams using on-chip optical phased arrays. Discussion of the effects of select phased array parameters on the generated beam's figures of merit is included. A one-dimensional splitter-tree-based phased array architecture is modified to enable arbitrary passive control of the array's element phase and amplitude distributions. This architecture is used to experimentally demonstrate on-chip quasi-Bessel-beam generation with a ∼14  mm Bessel length and ∼30  μm power full width at half maximum.

Method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam

DOEpatents

Hannon, Fay

2016-08-02

A method for maximizing the brightness of the bunches in a particle injector by converting a highly space-charged beam to a relativistic and emittance-dominated beam. The method includes 1) determining the bunch charge and the initial kinetic energy of the highly space-charge dominated input beam; 2) applying the bunch charge and initial kinetic energy properties of the highly space-charge dominated input beam to determine the number of accelerator cavities required to accelerate the bunches to relativistic speed; 3) providing the required number of accelerator cavities; and 4) setting the gradient of the radio frequency (RF) cavities; and 5) operating the phase of the accelerator cavities between -90 and zero degrees of the sinusoid of phase to simultaneously accelerate and bunch the charged particles to maximize brightness, and until the beam is relativistic and emittance-dominated.

Space transportation nodes assumptions and requirements: Lunar base systems study task 2.1

NASA Technical Reports Server (NTRS)

Kahn, Taher Ali; Simonds, Charles H.; Stump, William R.

1988-01-01

The Space Transportation Nodes Assumptions and Requirements task was performed as part of the Advanced Space Transportation Support Contract, a NASA Johnson Space Center (JSC) study intended to provide planning for a Lunar Base near the year 2000. The original task statement has been revised to satisfy the following queries: (1) What vehicles are to be processed at the transportation node; (2) What is the flow of activities involved in a vehicle passing through the node; and (3) What node support resources are necessary to support a lunar scenario traffic model composed of a mix of vehicles in an active flight schedule. The Lunar Base Systems Study is concentrating on the initial years of the Phase 2 Lunar Base Scenario. The study will develop the first five years of that phase in order to define the transportation and surface systems (including mass, volumes, power requirements, and designs).

Grassmann phase space theory and the Jaynes-Cummings model

NASA Astrophysics Data System (ADS)

Dalton, B. J.; Garraway, B. M.; Jeffers, J.; Barnett, S. M.

2013-07-01

The Jaynes-Cummings model of a two-level atom in a single mode cavity is of fundamental importance both in quantum optics and in quantum physics generally, involving the interaction of two simple quantum systems—one fermionic system (the TLA), the other bosonic (the cavity mode). Depending on the initial conditions a variety of interesting effects occur, ranging from ongoing oscillations of the atomic population difference at the Rabi frequency when the atom is excited and the cavity is in an n-photon Fock state, to collapses and revivals of these oscillations starting with the atom unexcited and the cavity mode in a coherent state. The observation of revivals for Rydberg atoms in a high-Q microwave cavity is key experimental evidence for quantisation of the EM field. Theoretical treatments of the Jaynes-Cummings model based on expanding the state vector in terms of products of atomic and n-photon states and deriving coupled equations for the amplitudes are a well-known and simple method for determining the effects. In quantum optics however, the behaviour of the bosonic quantum EM field is often treated using phase space methods, where the bosonic mode annihilation and creation operators are represented by c-number phase space variables, with the density operator represented by a distribution function of these variables. Fokker-Planck equations for the distribution function are obtained, and either used directly to determine quantities of experimental interest or used to develop c-number Langevin equations for stochastic versions of the phase space variables from which experimental quantities are obtained as stochastic averages. Phase space methods have also been developed to include atomic systems, with the atomic spin operators being represented by c-number phase space variables, and distribution functions involving these variables and those for any bosonic modes being shown to satisfy Fokker-Planck equations from which c-number Langevin equations are often developed. However, atomic spin operators satisfy the standard angular momentum commutation rules rather than the commutation rules for bosonic annihilation and creation operators, and are in fact second order combinations of fermionic annihilation and creation operators. Though phase space methods in which the fermionic operators are represented directly by c-number phase space variables have not been successful, the anti-commutation rules for these operators suggest the possibility of using Grassmann variables—which have similar anti-commutation properties. However, in spite of the seminal work by Cahill and Glauber and a few applications, the use of phase space methods in quantum optics to treat fermionic systems by representing fermionic annihilation and creation operators directly by Grassmann phase space variables is rather rare. This paper shows that phase space methods using a positive P type distribution function involving both c-number variables (for the cavity mode) and Grassmann variables (for the TLA) can be used to treat the Jaynes-Cummings model. Although it is a Grassmann function, the distribution function is equivalent to six c-number functions of the two bosonic variables. Experimental quantities are given as bosonic phase space integrals involving the six functions. A Fokker-Planck equation involving both left and right Grassmann differentiations can be obtained for the distribution function, and is equivalent to six coupled equations for the six c-number functions. The approach used involves choosing the canonical form of the (non-unique) positive P distribution function, in which the correspondence rules for the bosonic operators are non-standard and hence the Fokker-Planck equation is also unusual. Initial conditions, such as those above for initially uncorrelated states, are discussed and used to determine the initial distribution function. Transformations to new bosonic variables rotating at the cavity frequency enable the six coupled equations for the new c-number functions-that are also equivalent to the canonical Grassmann distribution function-to be solved analytically, based on an ansatz from an earlier paper by Stenholm. It is then shown that the distribution function is exactly the same as that determined from the well-known solution based on coupled amplitude equations. In quantum-atom optics theories for many atom bosonic and fermionic systems are needed. With large atom numbers, treatments must often take into account many quantum modes—especially for fermions. Generalisations of phase space distribution functions of phase space variables for a few modes to phase space distribution functionals of field functions (which represent the field operators, c-number fields for bosons, Grassmann fields for fermions) are now being developed for large systems. For the fermionic case, the treatment of the simple two mode problem represented by the Jaynes-Cummings model is a useful test case for the future development of phase space Grassmann distribution functional methods for fermionic applications in quantum-atom optics.

Measuring quality progress

NASA Astrophysics Data System (ADS)

Lambert, Larry D.

The study by the American Productivity & Quality Center (APQC) was commissioned by Loral Space Information Systems, Inc. and the National Aeronautics and Space Administration (NASA) to evaluate internal assessment systems. APQC benchmarked approaches to the internal assessment of quality management systems in three phases. The first phase included work conducted for the International Benchmarking Clearinghouse (IBC) and consisted of an in-depth analysis of the 1991 Malcolm Baldrige National Quality Award criteria. The second phase was also performed for the IBC and compared the 1991 award criteria among the following quality awards: Deming Prize, Malcolm Baldrige National Quality Award, The President's Award for Quality and Productivity Improvement, The NASA Excellence Award (The George M. Lowe Trophy) for Quality and Productivity Improvement and the Shigeo Shingo Award for Excellence in Manufacturing. The third phase compared the internal implementation approaches of 23 companies selected from American industry for their recognized, formal assessment systems.

Measuring quality progress

NASA Technical Reports Server (NTRS)

Lambert, Larry D.

1992-01-01

The study by the American Productivity & Quality Center (APQC) was commissioned by Loral Space Information Systems, Inc. and the National Aeronautics and Space Administration (NASA) to evaluate internal assessment systems. APQC benchmarked approaches to the internal assessment of quality management systems in three phases. The first phase included work conducted for the International Benchmarking Clearinghouse (IBC) and consisted of an in-depth analysis of the 1991 Malcolm Baldrige National Quality Award criteria. The second phase was also performed for the IBC and compared the 1991 award criteria among the following quality awards: Deming Prize, Malcolm Baldrige National Quality Award, The President's Award for Quality and Productivity Improvement, The NASA Excellence Award (The George M. Lowe Trophy) for Quality and Productivity Improvement and the Shigeo Shingo Award for Excellence in Manufacturing. The third phase compared the internal implementation approaches of 23 companies selected from American industry for their recognized, formal assessment systems.

Phase transition and entropy inequality of noncommutative black holes in a new extended phase space

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

Miao, Yan-Gang; Xu, Zhen-Ming, E-mail: miaoyg@nankai.edu.cn, E-mail: xuzhenm@mail.nankai.edu.cn

We analyze the thermodynamics of the noncommutative high-dimensional Schwarzschild-Tangherlini AdS black hole with the non-Gaussian smeared matter distribution by regarding a noncommutative parameter as an independent thermodynamic variable named as the noncommutative pressure . In the new extended phase space that includes this noncommutative pressure and its conjugate variable, we reveal that the noncommutative pressure and the original thermodynamic pressure related to the negative cosmological constant make the opposite effects in the phase transition of the noncommutative black hole, i.e. the former dominates the UV regime while the latter does the IR regime, respectively. In addition, by means of themore » reverse isoperimetric inequality, we indicate that only the black hole with the Gaussian smeared matter distribution holds the maximum entropy for a given thermodynamic volume among the noncommutative black holes with various matter distributions.« less

Symplectic multiparticle tracking model for self-consistent space-charge simulation

DOE PAGES

Qiang, Ji

2017-01-23

Symplectic tracking is important in accelerator beam dynamics simulation. So far, to the best of our knowledge, there is no self-consistent symplectic space-charge tracking model available in the accelerator community. In this paper, we present a two-dimensional and a three-dimensional symplectic multiparticle spectral model for space-charge tracking simulation. This model includes both the effect from external fields and the effect of self-consistent space-charge fields using a split-operator method. Such a model preserves the phase space structure and shows much less numerical emittance growth than the particle-in-cell model in the illustrative examples.

Symplectic multiparticle tracking model for self-consistent space-charge simulation

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

Qiang, Ji

Symplectic tracking is important in accelerator beam dynamics simulation. So far, to the best of our knowledge, there is no self-consistent symplectic space-charge tracking model available in the accelerator community. In this paper, we present a two-dimensional and a three-dimensional symplectic multiparticle spectral model for space-charge tracking simulation. This model includes both the effect from external fields and the effect of self-consistent space-charge fields using a split-operator method. Such a model preserves the phase space structure and shows much less numerical emittance growth than the particle-in-cell model in the illustrative examples.

Partners in Progress: A Responsible Approach.

ERIC Educational Resources Information Center

Davis, Bob A.; Wallace, William H., Jr.

1983-01-01

The financial plan for the Alabama Space and Rocket Center's $16-million expansion program, including the recreational-educational complex, involved funding from state, city, county, regional, federal, and private sources. The plan's three phases encompass planning (including environmental impacts and necessary support items) and present and…

A general formalism for phase space calculations

NASA Technical Reports Server (NTRS)

Norbury, John W.; Deutchman, Philip A.; Townsend, Lawrence W.; Cucinotta, Francis A.

1988-01-01

General formulas for calculating the interactions of galactic cosmic rays with target nuclei are presented. Methods for calculating the appropriate normalization volume elements and phase space factors are presented. Particular emphasis is placed on obtaining correct phase space factors for 2-, and 3-body final states. Calculations for both Lorentz-invariant and noninvariant phase space are presented.

General phase spaces: from discrete variables to rotor and continuum limits

NASA Astrophysics Data System (ADS)

Albert, Victor V.; Pascazio, Saverio; Devoret, Michel H.

2017-12-01

We provide a basic introduction to discrete-variable, rotor, and continuous-variable quantum phase spaces, explaining how the latter two can be understood as limiting cases of the first. We extend the limit-taking procedures used to travel between phase spaces to a general class of Hamiltonians (including many local stabilizer codes) and provide six examples: the Harper equation, the Baxter parafermionic spin chain, the Rabi model, the Kitaev toric code, the Haah cubic code (which we generalize to qudits), and the Kitaev honeycomb model. We obtain continuous-variable generalizations of all models, some of which are novel. The Baxter model is mapped to a chain of coupled oscillators and the Rabi model to the optomechanical radiation pressure Hamiltonian. The procedures also yield rotor versions of all models, five of which are novel many-body extensions of the almost Mathieu equation. The toric and cubic codes are mapped to lattice models of rotors, with the toric code case related to U(1) lattice gauge theory.

WAKES: Wavelet Adaptive Kinetic Evolution Solvers

NASA Astrophysics Data System (ADS)

Mardirian, Marine; Afeyan, Bedros; Larson, David

2016-10-01

We are developing a general capability to adaptively solve phase space evolution equations mixing particle and continuum techniques in an adaptive manner. The multi-scale approach is achieved using wavelet decompositions which allow phase space density estimation to occur with scale dependent increased accuracy and variable time stepping. Possible improvements on the SFK method of Larson are discussed, including the use of multiresolution analysis based Richardson-Lucy Iteration, adaptive step size control in explicit vs implicit approaches. Examples will be shown with KEEN waves and KEEPN (Kinetic Electrostatic Electron Positron Nonlinear) waves, which are the pair plasma generalization of the former, and have a much richer span of dynamical behavior. WAKES techniques are well suited for the study of driven and released nonlinear, non-stationary, self-organized structures in phase space which have no fluid, limit nor a linear limit, and yet remain undamped and coherent well past the drive period. The work reported here is based on the Vlasov-Poisson model of plasma dynamics. Work supported by a Grant from the AFOSR.

Lead Paint Exposure Assessment in High Bays of Johnson Space Center

NASA Technical Reports Server (NTRS)

Stanch, Penney; Plaza, Angel; Keprta, Sean

2008-01-01

This slide presentation reviews the program to assess the possibility of lead paint exposure in the high bays of some of the Johnson Space Center buildings. Some of the buildings in the Manned Space Flight Center (MSC) were built in 1962 and predate any considerations to reduce lead in paints and coatings. There are many of these older buildings that contain open shops and work areas that have open ceilings, These shops include those that had operations that use leaded gasoline, batteries, and lead based paints. Test were planned to be conducted in three phases: (1) Surface Dust sampling, (2) personal exposure montioring, and (3) Ceiling paint Sampling. The results of the first two phases were reviewed. After considering the results of the first two phases, and the problems associated with the retrieval of samples from high ceilings, it was determined that the evaluation of ceiling coatings would be done on a project by project and in response to a complaint.

Neurons with hysteresis form a network that can learn without any changes in synaptic connection strengths

NASA Astrophysics Data System (ADS)

Hoffmann, Geoffrey W.; Benson, Maurice W.

1986-08-01

A neural network concept derived from an analogy between the immune system and the central nerous system is outlined. The theory is based on a nervous that is slightly more complicated than the conventional McCullogh-Pitts type of neuron, in that it exhibits hysteresis at the single cell level. This added complication is compensated by the fact that a network of such neurons is able to learn without the necessity for any changes in synaptic connection strengths. The learning occurs as a natural consequence of interactions between the network and its enviornment, with environmental stimuli moving the system around in an N-dimensional phase space, until a point in phase space is reached such that the system's responses are appropriate for dealing with the stimuli. Due to the hysteresis associated with each neuron, the system tends to stay in the region of phase space where it is located. The theory includes a role for sleep in learning.

Quantum and Ecosystem Entropies

NASA Astrophysics Data System (ADS)

Kirwan, A. D.

2008-06-01

Ecosystems and quantum gases share a number of superficial similarities including enormous numbers of interacting elements and the fundamental role of energy in such interactions. A theory for the synthesis of data and prediction of new phenomena is well established in quantum statistical mechanics. The premise of this paper is that the reason a comparable unifying theory has not emerged in ecology is that a proper role for entropy has yet to be assigned. To this end, a phase space entropy model of ecosystems is developed. Specification of an ecosystem phase space cell size based on microbial mass, length, and time scales gives an ecosystem uncertainty parameter only about three orders of magnitude larger than Planck’s constant. Ecosystem equilibria is specified by conservation of biomass and total metabolic energy, along with the principle of maximum entropy at equilibria. Both Bose - Einstein and Fermi - Dirac equilibrium conditions arise in ecosystems applications. The paper concludes with a discussion of some broader aspects of an ecosystem phase space.

Nonequilibrium life-cycles in Ocean Heat Content

NASA Astrophysics Data System (ADS)

Weiss, Jeffrey B.; Fox-Kemper, Baylor; Mandal, Dibyendu; Zia, Royce K. P.

2014-03-01

Natural climate variability can be considered as fluctuations in a nonequilibrium steady state. A fundamental property of nonequilibrium steady states is the phase space current which provides a preferred direction for fluctuations, and is manifested as preferred life-cycles for climate fluctuations. We propose a new quantity, the phase space angular momentum, to quantify the phase space rotation. In analogy with traditional angular momentum, which quantifies the rotation of mass in physical space, the phase space angular momentum quantifies the rotation of probability in phase space. It has the additional advantage that it is straightforward to calculate from a time series. We investigate the phase space angular momentum for fluctuations in ocean heat content in both observations and ocean general circulation models. We gratefully acknowledge financial support from the National Science Foundation (USA) under grant OCE 1245944.

Quantum mechanics on phase space: The hydrogen atom and its Wigner functions

NASA Astrophysics Data System (ADS)

Campos, P.; Martins, M. G. R.; Fernandes, M. C. B.; Vianna, J. D. M.

2018-03-01

Symplectic quantum mechanics (SQM) considers a non-commutative algebra of functions on a phase space Γ and an associated Hilbert space HΓ, to construct a unitary representation for the Galilei group. From this unitary representation the Schrödinger equation is rewritten in phase space variables and the Wigner function can be derived without the use of the Liouville-von Neumann equation. In this article the Coulomb potential in three dimensions (3D) is resolved completely by using the phase space Schrödinger equation. The Kustaanheimo-Stiefel(KS) transformation is applied and the Coulomb and harmonic oscillator potentials are connected. In this context we determine the energy levels, the amplitude of probability in phase space and correspondent Wigner quasi-distribution functions of the 3D-hydrogen atom described by Schrödinger equation in phase space.

Quantization of Space-like States in Lorentz-Violating Theories

NASA Astrophysics Data System (ADS)

Colladay, Don

2018-01-01

Lorentz violation frequently induces modified dispersion relations that can yield space-like states that impede the standard quantization procedures. In certain cases, an extended Hamiltonian formalism can be used to define observer-covariant normalization factors for field expansions and phase space integrals. These factors extend the theory to include non-concordant frames in which there are negative-energy states. This formalism provides a rigorous way to quantize certain theories containing space-like states and allows for the consistent computation of Cherenkov radiation rates in arbitrary frames and avoids singular expressions.

Dredging Research Program. Dredge Mooring Study, Recommended Design, Phase 2 Report

DTIC Science & Technology

1992-05-01

describes the amount of dock space and staging area required (250 ft by 300 ft of dock space), crane requirements (a 50- to 60-ton crane ), and time and...including a diver) in 1 week or less (5 days minimum). With the addition of a second crane and second anchor handling vessel, the assembly and installation...describes the amount of dock space and staging area required (250 ft by 300 ft of dock space), crane requirements (a 50- to 60-ton crane ), and time and

Fifteen-foot diameter modular space station Kennedy Space Center launch site support definition (space station program Phase B extension definition)

NASA Technical Reports Server (NTRS)

Bjorn, L. C.; Martin, M. L.; Murphy, C. W.; Niebla, J. F., V

1971-01-01

This document defines the facilities, equipment, and operational plans required to support the MSS Program at KSC. Included is an analysis of KSC operations, a definition of flow plans, facility utilization and modifications, test plans and concepts, activation, and tradeoff studies. Existing GSE and facilities that have a potential utilization are identified, and new items are defined where possible. The study concludes that the existing facilities are suitable for use in the space station program without major modification from the Saturn-Apollo configuration.

Space station MSFC-DPD-235/DR no. MA-05 phase C/D program development plan. Volume 2: Phase C/D, programmatic requirements

NASA Technical Reports Server (NTRS)

1971-01-01

The design plan requirements define the design implementation and control requirements for Phase C/D of the Modular Space Station Project and specifically address the Initial Space Station phase of the Space Station Program (modular). It is based primarily on the specific objective of translating the requirements of the Space Station Program, Project, Interface, and Support Requirements and preliminary contract end x item specifications into detail design of the operational systems which comprise the initial space station. This document is designed to guide aerospace contractors in the planning and bidding for Phase C/D.

User assembly and servicing system for Space Station, an evolving architecture approach

NASA Technical Reports Server (NTRS)

Lavigna, Thomas A.; Cline, Helmut P.

1988-01-01

On-orbit assembly and servicing of a variety of scientific and applications hardware systems is expected to be one of the Space Station's primary functions. The hardware to be serviced will include the attached payloads resident on the Space Station, the free-flying satellites and co-orbiting platforms brought to the Space Station, and the polar orbiting platforms. The requirements for assembly and servicing such a broad spectrum of missions have led to the development of an Assembly and Servicing System Architecture that is composed of a complex array of support elements. This array is comprised of US elements, both Space Station and non-Space Station, and elements provided by Canada to the Space Station Program. For any given servicing or assembly mission, the necessary support elements will be employed in an integrated manner to satisfy the mission-specific needs. The structure of the User Assembly and Servicing System Architecture and the manner in which it will evolved throughout the duration of the phased Space Station Program are discussed. Particular emphasis will be placed upon the requirements to be accommodated in each phase, and the development of a logical progression of capabilities to meet these requirements.

Space Environments and Spacecraft Effects Concept: Transitioning Research to Operations and Applications

NASA Technical Reports Server (NTRS)

Edwards, D. L.; Burns, H. D.; Clinton, R. G.; Schumacher, D.; Spann, J. F.

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. NASA has established numerous organizations specializing in specific space environments disciplines that will serve to enable these missions. To complement these existing discipline organizations, a concept is presented focusing on the development of a space environment and spacecraft effects organization. This includes space climate, space weather, natural and induced space environments, and effects on spacecraft materials and systems. This space environment and spacecraft effects organization would be comprised of Technical Working Groups (TWG) focusing on, for example: a) Charged Particles (CP), b) Space Environmental Effects (SEE), and c) Interplanetary and Extraterrestrial Environments (IEE). These technical working groups will generate products and provide knowledge supporting four functional areas: design environments, environment effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Environment effects focuses on the material, component, sub-system and system-level selection and the testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather observations to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA and other federal agencies to ensure that communications are well established and the needs of the programs are being met. The programmatic support function also includes working in coordination with the program in anomaly resolution and generation of lesson learned documentation. The goal of this space environment and spacecraft effects organization is to develop decision-making tools and engineering products to support the mission phases of mission concept through operations by focusing on transitioning research to application. Products generated by this space environments and spacecraft effects organization are suitable for use in anomaly investigations. This paper will describe the organizational structure for this space environments and spacecraft effects organization, and outline the scope of conceptual TWG's and their relationship to the functional areas.

TU-AB-BRC-05: Creation of a Monte Carlo TrueBeam Model by Reproducing Varian Phase Space Data

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

O’Grady, K; Davis, S; Seuntjens, J

Purpose: To create a Varian TrueBeam 6 MV FFF Monte Carlo model using BEAMnrc/EGSnrc that accurately reproduces the Varian representative dataset, followed by tuning the model’s source parameters to accurately reproduce in-house measurements. Methods: A BEAMnrc TrueBeam model for 6 MV FFF has been created by modifying a validated 6 MV Varian CL21EX model. Geometric dimensions and materials were adjusted in a trial and error approach to match the fluence and spectra of TrueBeam phase spaces output by the Varian VirtuaLinac. Once the model’s phase space matched Varian’s counterpart using the default source parameters, it was validated to match 10more » × 10 cm{sup 2} Varian representative data obtained with the IBA CC13. The source parameters were then tuned to match in-house 5 × 5 cm{sup 2} PTW microDiamond measurements. All dose to water simulations included detector models to include the effects of volume averaging and the non-water equivalence of the chamber materials, allowing for more accurate source parameter selection. Results: The Varian phase space spectra and fluence were matched with excellent agreement. The in-house model’s PDD agreement with CC13 TrueBeam representative data was within 0.9% local percent difference beyond the first 3 mm. Profile agreement at 10 cm depth was within 0.9% local percent difference and 1.3 mm distance-to-agreement in the central axis and penumbra regions, respectively. Once the source parameters were tuned, PDD agreement with microDiamond measurements was within 0.9% local percent difference beyond 2 mm. The microDiamond profile agreement at 10 cm depth was within 0.6% local percent difference and 0.4 mm distance-to-agreement in the central axis and penumbra regions, respectively. Conclusion: An accurate in-house Monte Carlo model of the Varian TrueBeam was achieved independently of the Varian phase space solution and was tuned to in-house measurements. KO acknowledges partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant number: 432290).« less

A digitally implemented phase-locked loop detection scheme for analysis of the phase and power stability of a calibration tone

NASA Technical Reports Server (NTRS)

Densmore, A. C.

1988-01-01

A digital phase-locked loop (PLL) scheme is described which detects the phase and power of a high SNR calibration tone. The digital PLL is implemented in software directly from the given description. It was used to evaluate the stability of the Goldstone Deep Space Station open loop receivers for Radio Science. Included is a derivative of the Allan variance sensitivity of the PLL imposed by additive white Gaussian noise; a lower limit is placed on the carrier frequency.

Lattice modeling and calibration with turn-by-turn orbit data

NASA Astrophysics Data System (ADS)

Huang, Xiaobiao; Sebek, Jim; Martin, Don

2010-11-01

A new method that explores turn-by-turn beam position monitor (BPM) data to calibrate lattice models of accelerators is proposed. The turn-by-turn phase space coordinates at one location of the ring are first established using data from two BPMs separated by a simple section with a known transfer matrix, such as a drift space. The phase space coordinates are then tracked with the model to predict positions at other BPMs, which can be compared to measurements. The model is adjusted to minimize the difference between the measured and predicted orbit data. BPM gains and rolls are included as fitting variables. This technique can be applied to either the entire or a section of the ring. We have tested the method experimentally on a part of the SPEAR3 ring.

Advanced space power requirements and techniques. Task 1: Mission projections and requirements. Volume 1: Technical report

NASA Technical Reports Server (NTRS)

Wolfe, M. G.

1978-01-01

The objectives of this study were to: (1) develop projections of the NASA, DoD, and civil space power requirements for the 1980-1995 time period; (2) identify specific areas of application and space power subsystem type needs for each prospective user; (3) document the supporting and historical base, including relevant cost related measures of performance; and (4) quantify the benefits of specific technology projection advancements. The initial scope of the study included: (1) construction of likely models for NASA, DoD, and civil space systems; (2) generation of a number of future scenarios; (3) extraction of time phased technology requirements based on the scenarios; and (4) cost/benefit analyses of some of the technologies identified.

Effects of upstream-biased third-order space correction terms on multidimensional Crowley advection schemes

NASA Technical Reports Server (NTRS)

Schlesinger, R. E.

1985-01-01

The impact of upstream-biased corrections for third-order spatial truncation error on the stability and phase error of the two-dimensional Crowley combined advective scheme with the cross-space term included is analyzed, putting primary emphasis on phase error reduction. The various versions of the Crowley scheme are formally defined, and their stability and phase error characteristics are intercompared using a linear Fourier component analysis patterned after Fromm (1968, 1969). The performances of the schemes under prototype simulation conditions are tested using time-dependent numerical experiments which advect an initially cone-shaped passive scalar distribution in each of three steady nondivergent flows. One such flow is solid rotation, while the other two are diagonal uniform flow and a strongly deformational vortex.

A generic multi-flex-body dynamics, controls simulation tool for space station

NASA Technical Reports Server (NTRS)

London, Ken W.; Lee, John F.; Singh, Ramen P.; Schubele, Buddy

1991-01-01

An order (n) multiflex body Space Station simulation tool is introduced. The flex multibody modeling is generic enough to model all phases of Space Station from build up through to Assembly Complete configuration and beyond. Multibody subsystems such as the Mobile Servicing System (MSS) undergoing a prescribed translation and rotation are also allowed. The software includes aerodynamic, gravity gradient, and magnetic field models. User defined controllers can be discrete or continuous. Extensive preprocessing of 'body by body' NASTRAN flex data is built in. A significant aspect, too, is the integrated controls design capability which includes model reduction and analytic linearization.

Three-phase Four-leg Inverter LabVIEW FPGA Control Code

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

In the area of power electronics control, Field Programmable Gate Arrays (FPGAs) have the capability to outperform their Digital Signal Processor (DSP) counterparts due to the FPGA’s ability to implement true parallel processing and therefore facilitate higher switching frequencies, higher control bandwidth, and/or enhanced functionality. National Instruments (NI) has developed two platforms, Compact RIO (cRIO) and Single Board RIO (sbRIO), which combine a real-time processor with an FPGA. The FPGA can be programmed with a subset of the well-known LabVIEW graphical programming language. The use of cRIO and sbRIO for power electronics control has developed over the last few yearsmore » to include control of three-phase inverters. Most three-phase inverter topologies include three switching legs. The addition of a fourth-leg to natively generate the neutral connection allows the inverter to serve single-phase loads in a microgrid or stand-alone power system and to balance the three-phase voltages in the presence of significant load imbalance. However, the control of a four-leg inverter is much more complex. In particular, instead of standard two-dimensional space vector modulation (SVM), the inverter requires three-dimensional space vector modulation (3D-SVM). The candidate software implements complete control algorithms in LabVIEW FPGA for a three-phase four-leg inverter. The software includes feedback control loops, three-dimensional space vector modulation gate-drive algorithms, advanced alarm handling capabilities, contactor control, power measurements, and debugging and tuning tools. The feedback control loops allow inverter operation in AC voltage control, AC current control, or DC bus voltage control modes based on external mode selection by a user or supervisory controller. The software includes the ability to synchronize its AC output to the grid or other voltage-source before connection. The software also includes provisions to allow inverter operation in parallel with other voltage regulating devices on the AC or DC buses. This flexibility allows the Inverter to operate as a stand-alone voltage source, connected to the grid, or in parallel with other controllable voltage sources as part of a microgrid or remote power system. In addition, as the inverter is expected to operate under severe unbalanced conditions, the software includes algorithms to accurately compute real and reactive power for each phase based on definitions provided in the IEEE Standard 1459: IEEE Standard Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions. Finally, the software includes code to output analog signals for debugging and for tuning of control loops. The software fits on the Xilinx Virtex V LX110 FPGA embedded in the NI cRIO-9118 FPGA chassis, and with a 40 MHz base clock, supports a modulation update rate of 40 MHz, user-settable switching frequencies and synchronized control loop update rates of tens of kHz, and reference waveform generation, including Phase Lock Loop (PLL), update rate of 100 kHz.« less

Quantization of simple parametrized systems

NASA Astrophysics Data System (ADS)

Ruffini, G.

2005-11-01

I study the canonical formulation and quantization of some simple parametrized systems, including the non-relativistic parametrized particle and the relativistic parametrized particle. Using Dirac's formalism I construct for each case the classical reduced phase space and study the dependence on the gauge fixing used. Two separate features of these systems can make this construction difficult: the actions are not invariant at the boundaries, and the constraints may have disconnected solution spaces. The relativistic particle is affected by both, while the non-relativistic particle displays only by the first. Analyzing the role of canonical transformations in the reduced phase space, I show that a change of gauge fixing is equivalent to a canonical transformation. In the relativistic case, quantization of one branch of the constraint at the time is applied and I analyze the electromagenetic backgrounds in which it is possible to quantize simultaneously both branches and still obtain a covariant unitary quantum theory. To preserve unitarity and space-time covariance, second quantization is needed unless there is no electric field. I motivate a definition of the inner product in all these cases and derive the Klein-Gordon inner product for the relativistic case. I construct phase space path integral representations for amplitudes for the BFV and the Faddeev path integrals, from which the path integrals in coordinate space (Faddeev-Popov and geometric path integrals) are derived.

Tracking and data system support for the Mariner Mars 1971 mission. Prelaunch phase through first trajectory correction maneuver, volume 1

NASA Technical Reports Server (NTRS)

Laeser, R. P.; Textor, G. P.; Kelly, L. B.; Kelly, M.

1972-01-01

The DSN command system provided the capability to enter commands in a computer at the deep space stations for transmission to the spacecraft. The high-rate telemetry system operated at 16,200 bits/sec. This system will permit return to DSS 14 of full-resolution television pictures from the spacecraft tape recorder, plus the other science experiment data, during the two playback periods of each Goldstone pass planned for each corresponding orbit. Other features included 4800 bits/sec modem high-speed data lines from all deep space stations to Space Flight Operations Facility (SFOF) and the Goddard Space Flight Center, as well as 50,000 bits/sec wideband data lines from DSS 14 to the SFOF, thus providing the capability for data flow of two 16,200 bits/sec high-rate telemetry data streams in real time. The TDS performed prelaunch training and testing and provided support for the Mariner Mars 1971/Mission Operations System training and testing. The facilities of the ETR, DSS 71, and stations of the MSFN provided flight support coverage at launch and during the near-earth phase. The DSSs 12, 14, 41, and 51 of the DSN provided the deep space phase support from 30 May 1971 through 4 June 1971.

Orbital transfer vehicle concept definition and system analysis study. Volume 1A: Executive summary. Phase 2

NASA Technical Reports Server (NTRS)

Ketchum, W. J.

1986-01-01

The objectives of the Phase 2 study were to improve the orbit transfer vehicle (OTV) concept definition by focusing on the following issues: the impact of mission requirements on OTV system design; OTV basing concepts on the Space Shuttle, separate platforms, and/or remote locations; cost reduction of an OTV program to improve its economic benefits and support its acquisition. The OTV mission scenario includes a wide range of missions the main drivers of which are manned GEO servicing, mid-inclination/polar DOD, and lunar/planetary projects. A mission model is presented which includes the type and number of missions per year and the estimated propellant requirements. To accomplish the missions, many OTV concepts were defined including ground-based OTVs launched either in the STS orbiter, the aft cargo carrier, or a heavy lift launch vehicle, and a space-based OTV. System and program trade studies were conducted using performance, cost, safety/risk, and operations/growth criteria. The study shows that mission requirements and substantial economic benefits justify a reusable, cryogenic (H2/O2) space-based OTV. Such a system would not be subjected to Earth-to-orbit launch loads and would not be constained in size or weight. Safety is enhanced by the fact that the system components are launched unfueled. Its inherent reusability and ability to be refueled in space make the space-based OTV very economical to operate.

The Effect of Boron and Zirconium on the Structure and Tensile Properties of the Cast Nickel-Based Superalloy ATI 718Plus

NASA Astrophysics Data System (ADS)

Hosseini, Seyed Ali; Abbasi, Seyed Mehdi; Madar, Karim Zangeneh

2018-04-01

The effects of boron and zirconium on cast structure, hardness, and tensile properties of the nickel-based superalloy 718Plus were investigated. For this purpose, five alloys with different contents of boron and zirconium were cast via vacuum induction melting and then purified via vacuum arc remelting. Microstructural analysis by light-optical microscope and scanning electron microscope equipped with energy-dispersive x-ray spectroscopy and phase studies by x-ray diffraction analysis were performed. The results showed that boron and zirconium tend to significantly reduce dendritic arm spacing and increase the amount of Laves, Laves/gamma eutectic, and carbide phases. It was also found that boron led to the formation of B4C and (Cr, Fe, Mo, Ni, Ti)3B2 phases and zirconium led to the formation of intermetallic phases and ZrC carbide. In the presence of boron and zirconium, the hardness and its difference between dendritic branches and inter-dendritic spaces increased by concentrating such phases as Laves in the inter-dendritic spaces. These elements had a negative effect on tensile properties of the alloy, including ductility and strength, mainly because of the increase in the Laves phase. It should be noted that the largest degradation of the tensile properties occurred in the alloys containing the maximum amount of zirconium.

Texas A&M vortex type phase separator

NASA Astrophysics Data System (ADS)

Best, Frederick

2000-01-01

Phase separation is required for regenerative biological and chemical process systems as well as thermal transport and rejection systems. Liquid and gas management requirements for future spacecraft will demand small, passive systems able to operate over wide ranges of inlet qualities. Conservation and recycling of air and water is a necessary part of the construction and operation of the International Space Station as well as future long duration space missions. Space systems are sensitive to volume, mass, and power. Therefore, it is necessary to develop a method to recycle wastewater with minimal power consumption. Regenerative life support systems currently being investigated require phase separation to separate the liquid from the gas produced. The microgravity phase separator designed and fabricated at Texas A&M University relies on centripetal driven buoyancy forces to form a gas-liquid vortex within a fixed, right-circular cylinder. Two-phase flow is injected tangentially along the inner wall of this cylinder producing a radial acceleration gradient. The gradient produced from the intrinsic momentum of the injected mixture results in a rotating flow that drives the buoyancy process by the production of a hydrostatic pressure gradient. Texas A&M has flown several KC-135 flights with separator. These flights have included scaling studies, stability and transient investigations, and tests for inventory instrumentation. Among the hardware tested have been passive devices for separating mixed vapor/liquid streams into single-phase streams of vapor only and liquid only. .

Large space telescope, phase A. Volume 3: Optical telescope assembly

NASA Technical Reports Server (NTRS)

1972-01-01

The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

High Energy Astronomy Observatory, Mission C, Phase A. Volume 2: Preliminary analyses and conceptual design

NASA Technical Reports Server (NTRS)

1972-01-01

An analysis and conceptual design of a baseline mission and spacecraft are presented. Aspects of the HEAO-C discussed include: baseline experiments with X-ray observations of space, analysis of mission requirements, observatory design, structural analysis, thermal control, attitude sensing and control system, communication and data handling, and space shuttle launch and retrieval of HEAO-C.

Electrical Power Systems for NASA's Space Transportation Program

NASA Technical Reports Server (NTRS)

Lollar, Louis F.; Maus, Louis C.

1998-01-01

Marshall Space Flight Center (MSFC) is the National Aeronautics and Space Administration's (NASA) lead center for space transportation systems development. These systems include earth to orbit launch vehicles, as well as vehicles for orbital transfer and deep space missions. The tasks for these systems include research, technology maturation, design, development, and integration of space transportation and propulsion systems. One of the key elements in any transportation system is the electrical power system (EPS). Every transportation system has to have some form of electrical power and the EPS for each of these systems tends to be as varied and unique as the missions they are supporting. The Preliminary Design Office (PD) at MSFC is tasked to perform feasibility analyses and preliminary design studies for new projects, particularly in the space transportation systems area. All major subsystems, including electrical power, are included in each of these studies. Three example systems being evaluated in PD at this time are the Liquid Fly Back Booster (LFBB) system, the Human Mission to Mars (HMM) study, and a tether based flight experiment called the Propulsive Small Expendable Deployer System (ProSEDS). These three systems are in various stages of definition in the study phase.

Communication: importance sampling including path correlation in semiclassical initial value representation calculations for time correlation functions.

PubMed

Pan, Feng; Tao, Guohua

2013-03-07

Full semiclassical (SC) initial value representation (IVR) for time correlation functions involves a double phase space average over a set of two phase points, each of which evolves along a classical path. Conventionally, the two initial phase points are sampled independently for all degrees of freedom (DOF) in the Monte Carlo procedure. Here, we present an efficient importance sampling scheme by including the path correlation between the two initial phase points for the bath DOF, which greatly improves the performance of the SC-IVR calculations for large molecular systems. Satisfactory convergence in the study of quantum coherence in vibrational relaxation has been achieved for a benchmark system-bath model with up to 21 DOF.

Phases of unstable conifolds

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

Narayan, K.

2007-03-15

We explore the phase structure induced by closed string tachyon condensation of toric nonsupersymmetric conifold-like singularities described by an integral charge matrix Q=(n{sub 1}n{sub 2}-n{sub 3}-n{sub 4}), n{sub i}>0, iQ{sub i}{ne}0, initiated by Narayan [J. High Energy Phys. 03 (2006) 036]. Using gauged linear sigma model renormalization group flows and toric geometry techniques, we see a cascadelike phase structure containing decays to lower order conifold-like singularities, including, in particular, the supersymmetric conifold and the Y{sup pq} spaces. This structure is consistent with the Type II GSO projection obtained previously for these singularities. Transitions between the various phases of these geometriesmore » include flips and flops.« less

Advances in Scanning Reflectarray Antennas Based on Ferroelectric Thin Film Phase Shifters for Deep Space Communications

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.

2007-01-01

Though there are a few examples of scanning phased array antennas that have flown successfully in space, the quest for low-cost, high-efficiency, large aperture microwave phased arrays continues. Fixed and mobile applications that may be part of a heterogeneous exploration communication architecture will benefit from the agile (rapid) beam steering and graceful degradation afforded by phased array antennas. The reflectarray promises greater efficiency and economy compared to directly-radiating varieties. Implementing a practical scanning version has proven elusive. The ferroelectric reflectarray, under development and described herein, involves phase shifters based on coupled microstrip patterned on Ba(x)Sr(1-x)TiO3 films, that were laser ablated onto LaAlO3 substrates. These devices outperform their semiconductor counterparts from X- through and K-band frequencies. There are special issues associated with the implementation of a scanning reflectarray antenna, especially one realized with thin film ferroelectric phase shifters. This paper will discuss these issues which include: relevance of phase shifter loss; modulo 2(pi) effects and phase shifter transient effects on bit error rate; scattering from the ground plane; presentation of a novel hybrid ferroelectric-semiconductor phase shifter; and the effect of mild radiation exposure on phase shifter performance.

Measurement of the Shear Lift Force on a Bubble in a Channel Flow

NASA Technical Reports Server (NTRS)

Nahra, Henry K.; Motil, Brian; Skor, Mark

2005-01-01

Two-phase flow systems play vital roles in the design of some current and anticipated space applications of two-phase systems which include: thermal management systems, transfer line flow in cryogenic storage, space nuclear power facilities, design and operation of thermal bus, life support systems, propulsion systems, In Situ Resource Utilization (ISRU), and space processes for pharmaceutical applications. The design of two-phase flow systems for space applications requires a clear knowledge of the behaviors of the dispersed phase (bubble), its interaction with the continuous phase (liquid) and its effect on heat and mass transfer processes, The need to understand the bubble generation process arises from the fact that for all space applications, the size and distribution of bubbles are extremely crucial for heat and mass transfer control. One important force in two-phase flow systems is the lift force on a bubble or particle in a liquid shear flow. The shear lift is usually overwhelmed by buoyancy in normal gravity, but it becomes an important force in reduced gravity. Since the liquid flow is usually sheared because of the confining wall, the trajectories of bubbles and particles injected into the liquid flow are affected by the shear lift in reduced gravity. A series of experiments are performed to investigate the lift force on a bubble in a liquid shear flow and its effect on the detachment of a bubble from a wall under low gravity conditions. Experiments are executed in a Poiseuille flow in a channel. An air-water system is used in these experiments that are performed in the 2.2 second drop tower. A bubble is injected into the shear flow from a small injector and the shear lift is measured while the bubble is held stationary relative to the fluid. The trajectory of the bubble prior, during and after its detachment from the injector is investigated. The measured shear lift force is calculated from the trajectory of the bubble at the detachment point. These values for the shear lift are then compared with the theoretical predictions from various published works on shear lift in the open literature, which include asymptotic solutions at low bubble Reynolds number, potential flow predictions and numerical studies that deal with intermediate bubble Reynolds numbers.

Capabilities of the Materials Contamination Team at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burns, H. D.; Finckenor, M. M.; Boothe, R. E.; Albyn, K. C.; Finchum, C. A.

2003-01-01

The Materials Contamination Team of the Environmental Effects Group, Materials, Processes, and Manufacturing Department, has been recognized for its contribution to space flight, including space transportation, space science and flight projects, such as the reusable solid rocket motor, Chandra X-Ray Observatory, and the International Space Station. The Materials Contamination Team s realm of responsibility encompasses all phases of hardware development including design, manufacturing, assembly, test, transportation, launch-site processing, on-orbit exposure, return, and refurbishment if required. Contamination is a concern in the Space Shuttle with sensitivity bondlines and reactive fluid (liquid oxygen) compatibility as well as for sensitive optics, particularly spacecraft 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 team of engineers and technicians also develop and evaluates new surface cleanliness inspection technologies. Databases are maintained by the team for proces! materials as well as outgassing and optical compatibility test results for specific environments.

Internet Technology on Spacecraft

NASA Technical Reports Server (NTRS)

Rash, James; Parise, Ron; Hogie, Keith; Criscuolo, Ed; Langston, Jim; Powers, Edward I. (Technical Monitor)

2000-01-01

The Operating Missions as Nodes on the Internet (OMNI) project has shown that Internet technology works in space missions through a demonstration using the UoSAT-12 spacecraft. An Internet Protocol (IP) stack was installed on the orbiting UoSAT-12 spacecraft and tests were run to demonstrate Internet connectivity and measure performance. This also forms the basis for demonstrating subsequent scenarios. This approach provides capabilities heretofore either too expensive or simply not feasible such as reconfiguration on orbit. The OMNI project recognized the need to reduce the risk perceived by mission managers and did this with a multi-phase strategy. In the initial phase, the concepts were implemented in a prototype system that includes space similar components communicating over the TDRS (space network) and the terrestrial Internet. The demonstration system includes a simulated spacecraft with sample instruments. Over 25 demonstrations have been given to mission and project managers, National Aeronautics and Space Administration (NASA), Department of Defense (DoD), contractor technologists and other decisions makers, This initial phase reached a high point with an OMNI demonstration given from a booth at the Johnson Space Center (JSC) Inspection Day 99 exhibition. The proof to mission managers is provided during this second phase with year 2000 accomplishments: testing the use of Internet technologies onboard an actual spacecraft. This was done with a series of tests performed using the UoSAT-12 spacecraft. This spacecraft was reconfigured on orbit at very low cost. The total period between concept and the first tests was only 6 months! On board software was modified to add an IP stack to support basic IP communications. Also added was support for ping, traceroute and network timing protocol (NTP) tests. These tests show that basic Internet functionality can be used onboard spacecraft. The performance of data was measured to show no degradation from current approaches. The cost to implement is much less than current approaches due to the availability of highly reliable and standard Internet tools. Use of standard Internet applications onboard reduces the risk of obsolescence inherent in custom protocols due to extremely wide use across all domains. These basic building blocks provide the framework for building onboard software to support direct user communication with payloads including payload control. Other benefits are payload to payload communication from dissimilar spacecraft, constellations of spacecraft, and reconfigurability on orbit. This work is funded through contract with the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC).

The Ongoing Assembly of a Central Cluster Galaxy: Phase-space Substructures in the Halo of M87

NASA Astrophysics Data System (ADS)

Romanowsky, Aaron J.; Strader, Jay; Brodie, Jean P.; Mihos, J. Christopher; Spitler, Lee R.; Forbes, Duncan A.; Foster, Caroline; Arnold, Jacob A.

2012-03-01

The halos of galaxies preserve unique records of their formation histories. We carry out the first combined observational and theoretical study of phase-space halo substructure in an early-type galaxy: M87, the central galaxy in the Virgo cluster. We analyze an unprecedented wide-field, high-precision photometric and spectroscopic data set for 488 globular clusters (GCs), which includes new, large-radius Subaru/Suprime-Cam and Keck/DEIMOS observations. We find signatures of two substructures in position-velocity phase space. One is a small, cold stream associated with a known stellar filament in the outer halo; the other is a large shell-like pattern in the inner halo that implies a massive, hitherto unrecognized accretion event. We perform extensive statistical tests and independent metallicity analyses to verify the presence and characterize the properties of these features, and to provide more general methodologies for future extragalactic studies of phase-space substructure. The cold outer stream is consistent with a dwarf galaxy accretion event, while for the inner shell there is tension between a low progenitor mass implied by the cold velocity dispersion, and a high mass from the large number of GCs, which might be resolved by a ~0.5 L* E/S0 progenitor. We also carry out proof-of-principle numerical simulations of the accretion of smaller galaxies in an M87-like gravitational potential. These produce analogous features to the observed substructures, which should have observable lifetimes of ~1 Gyr. The shell and stream GCs together support a scenario where the extended stellar envelope of M87 has been built up by a steady rain of material that continues until the present day. This phase-space method demonstrates unique potential for detailed tests of galaxy formation beyond the Local Group.

Attractors, universality, and inflation

NASA Astrophysics Data System (ADS)

Downes, Sean; Dutta, Bhaskar; Sinha, Kuver

2012-11-01

Studies of the initial conditions for inflation have conflicting predictions from exponential suppression to inevitability. At the level of phase space, this conflict arises from the competing intuitions of CPT invariance and thermodynamics. After reviewing this conflict, we enlarge the ensemble beyond phase space to include scalar potential data. We show how this leads to an important contribution from inflection point inflation, enhancing the likelihood of inflation to a power law, 1/Ne3. In the process, we emphasize the attractor dynamics of the gravity-scalar system and the existence of universality classes from inflection point inflation. Finally, we comment on the predictivity of inflation in light of these results.

The Simpsons program 6-D phase space tracking with acceleration

NASA Astrophysics Data System (ADS)

Machida, S.

1993-12-01

A particle tracking code, Simpsons, in 6-D phase space including energy ramping has been developed to model proton synchrotrons and storage rings. We take time as the independent variable to change machine parameters and diagnose beam quality in a quite similar way as real machines, unlike existing tracking codes for synchrotrons which advance a particle element by element. Arbitrary energy ramping and rf voltage curves as a function of time are read as an input file for defining a machine cycle. The code is used to study beam dynamics with time dependent parameters. Some of the examples from simulations of the Superconducting Super Collider (SSC) boosters are shown.

International Space Station Environmental Control and Life Support System Status: 2006 - 2007

NASA Technical Reports Server (NTRS)

Williams, David E.; Gentry, Gregory J.

2007-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2006 and February 2007. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence. Work continued on the Phase 3 pressurized elements and the continued manufacturing and testing of the regenerative ECLS equipment.

International Space Station Environmental Control and Life Support System Status: 2008 - 2009

NASA Technical Reports Server (NTRS)

Williams, David E.; Gentry, Gregory J.; Gentry, Gregory J.

2009-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2008 and February 2009. The ISS continued permanent crew operations, with the continuation of Phase 3 of the ISS Assembly Sequence. Work continues on the last of the Phase 3 pressurized elements and the continued manufacturing and testing of the regenerative ECLS equipment.

International Space Station Environmental Control and Life Support System Status: 2005 - 2006

NASA Technical Reports Server (NTRS)

Williams, David E.; Gentry, Gregory J.

2006-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2005 and February 2006. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence. Work continued on the Phase 3 pressurized elements and the continued manufacturing and testing of the regenerative ECLS equipment.

International Space Station (ISS) Environmental Control and Life Support System Status: 2003-2004

NASA Technical Reports Server (NTRS)

Williams, David E.; Gentry, Gregory

2004-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between April 2003 and March 2004. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence. Work continued on the Phase 3 pressurized elements and the continued manufacturing and testing of the regenerative ECLS equipment.

International Space Station Environmental Control and Life Support System Status: 2009 - 2010

NASA Technical Reports Server (NTRS)

Williams, David E.; Dake, Jason R.; Gentry, Gregory J.

2010-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non -regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2009 and February 2010. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence and an increase of the ISS crew size from three to six. Work continues on the last of the Phase 3 pressurized elements.

KSC-2013-2916

NASA Image and Video Library

2013-06-27

CAPE CANAVERAL, Fla. - NASA's Commercial Crew Program Manager Ed Mango and astronaut Mike Good media on the progress of American human spaceflight development at Kennedy Space Center in Florida. At right is NASA Public Affairs Officer Gregory Harland. They also discussed the future steps the program will take to certify crew transportation systems for missions to the International Space Station. The program is working toward the next phase of certification, which will be called Commercial Crew Transportation Capability, or CCtCap. That phase will include a joint test concept in which NASA astronauts will play a role in flight testing the systems. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: Jim Grossmann

KSC-2013-2914

NASA Image and Video Library

2013-06-27

CAPE CANAVERAL, Fla. - NASA's Commercial Crew Program Manager Ed Mango and astronaut Mike Good media on the progress of American human spaceflight development at Kennedy Space Center in Florida. At right is NASA Public Affairs Officer Gregory Harland. They also discussed the future steps the program will take to certify crew transportation systems for missions to the International Space Station. The program is working toward the next phase of certification, which will be called Commercial Crew Transportation Capability, or CCtCap. That phase will include a joint test concept in which NASA astronauts will play a role in flight testing the systems. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: Jim Grossmann

Adiabatic description of long range frequency sweeping

NASA Astrophysics Data System (ADS)

Nyqvist, R. M.; Lilley, M. K.; Breizman, B. N.

2012-09-01

A theoretical framework is developed to describe long range frequency sweeping events in the 1D electrostatic bump-on-tail model with fast particle sources and collisions. The model includes three collision operators (Krook, drag (dynamical friction) and velocity space diffusion), and allows for a general shape of the fast particle distribution function. The behaviour of phase space holes and clumps is analysed in the absence of diffusion, and the effect of particle trapping due to separatrix expansion is discussed. With a fast particle distribution function whose slope decays above the resonant phase velocity, hooked frequency sweeping is found for holes in the presence of drag collisions alone.

International Space Station Environmental Control and Life Support System Status: 2009 - 2010

NASA Technical Reports Server (NTRS)

Williams, David E.; Dake, Jason R.; Gentry, Gregory J.

2009-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2009 and February 2010. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence and an increase of the ISS crew size from three to six. Work continues on the last of the Phase 3 pressurized elements.

Tracking and data system support for the Viking 1975 mission to Mars. Volume 2: Launch through landing of Viking 1

NASA Technical Reports Server (NTRS)

Mudgway, D. J.; Traxler, M. R.

1977-01-01

Problems inherent in the deployment and management of a worldwide tracking and data acquisition network to support the two Viking Orbiters and two Viking Landers simultaneously over 320 million kilometers (200 million miles) of deep space are discussed. Activities described include tracking coverage of the launch phase, the deep space operations during the long cruise phase that occupied approximately 11 months, and the implementation of the a vast worldwide network of tracking sttions and global communications systems. The performance of the personnel, hardware, and software involved in this vast undertaking are evaluated.

TU-AB-BRC-07: Efficiency of An IAEA Phase-Space Source for a Low Energy X-Ray Tube Using Egs++

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

Watson, PGF; Renaud, MA; Seuntjens, J

Purpose: To extend the capability of the EGSnrc C++ class library (egs++) to write and read IAEA phase-space files as a particle source, and to assess the relative efficiency gain in dose calculation using an IAEA phase-space source for modelling a miniature low energy x-ray source. Methods: We created a new ausgab object to score particles exiting a user-defined geometry and write them to an IAEA phase-space file. A new particle source was created to read from IAEA phase-space data. With these tools, a phase-space file was generated for particles exiting a miniature 50 kVp x-ray tube (The INTRABEAM System,more » Carl Zeiss). The phase-space source was validated by comparing calculated PDDs with a full electron source simulation of the INTRABEAM. The dose calculation efficiency gain of the phase-space source was determined relative to the full simulation. The efficiency gain as a function of i) depth in water, and ii) job parallelization was investigated. Results: The phase-space and electron source PDDs were found to agree to 0.5% RMS, comparable to statistical uncertainties. The use of a phase-space source for the INTRABEAM led to a relative efficiency gain of greater than 20 over the full electron source simulation, with an increase of up to a factor of 196. The efficiency gain was found to decrease with depth in water, due to the influence of scattering. Job parallelization (across 2 to 256 cores) was not found to have any detrimental effect on efficiency gain. Conclusion: A set of tools has been developed for writing and reading IAEA phase-space files, which can be used with any egs++ user code. For simulation of a low energy x-ray tube, the use of a phase-space source was found to increase the relative dose calculation efficiency by factor of up to 196. The authors acknowledge partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant No. 432290).« less

KSC-08pd1342

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- Participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla., get instruction about the rescue equipment they will be working with. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1362

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- In a U.S. Coast Guard boat off Florida's central east coast, astronaut Richard Mastracchio adjusts his launch-and-entry suit to participate in a rescue training exercise, known as Mode VIII. Behind him is astronaut Paulo Nespoli. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

KSC-08pd1385

NASA Image and Video Library

2008-05-14

CAPE CANAVERAL, Fla. -- Off Florida's central east coast, a member of the rescue team in a training exercise, known as Mode VIII, keeps watch for the returning support crew from the U.S. Coast Guard cutter Kingfisher, from Port Canaveral, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. Photo credit: NASA/Dimitri Gerondidakis

Phase space methods for Majorana fermions

NASA Astrophysics Data System (ADS)

Rushin Joseph, Ria; Rosales-Zárate, Laura E. C.; Drummond, Peter D.

2018-06-01

Fermionic phase space representations are a promising method for studying correlated fermion systems. The fermionic Q-function and P-function have been defined using Gaussian operators of fermion annihilation and creation operators. The resulting phase-space of covariance matrices belongs to the symmetry class D, one of the non-standard symmetry classes. This was originally proposed to study mesoscopic normal-metal-superconducting hybrid structures, which is the type of structure that has led to recent experimental observations of Majorana fermions. Under a unitary transformation, it is possible to express these Gaussian operators using real anti-symmetric matrices and Majorana operators, which are much simpler mathematical objects. We derive differential identities involving Majorana fermion operators and an antisymmetric matrix which are relevant to the derivation of the corresponding Fokker–Planck equations on symmetric space. These enable stochastic simulations either in real or imaginary time. This formalism has direct relevance to the study of fermionic systems in which there are Majorana type excitations, and is an alternative to using expansions involving conventional Fermi operators. The approach is illustrated by showing how a linear coupled Hamiltonian as used to study topological excitations can be transformed to Fokker–Planck and stochastic equation form, including dissipation through particle losses.

Active control of bright electron beams with RF optics for femtosecond microscopy

DOE PAGES

Williams, J.; Zhou, F.; Sun, T.; ...

2017-08-01

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. In this paper, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the design of ultrafast electron microscopy. Through the introduction of a novel atomic grating approach for characterization of electron bunch phase space and control optics, we elucidate the principles for predicting and controlling the phase space dynamics to reach optimalmore » compressions at various electron densities and generating conditions. We provide strategies to identify high-brightness modes, achieving ~100 fs and ~1 eV resolutions with 10 6 electrons per bunch, and establish the scaling of performance for different bunch charges. These results benchmark the sensitivity and resolution from the fundamental beam brightness perspective and also validate the adaptive optics concept to enable delicate control of the density-dependent phase space structures to optimize the performance, including delivering ultrashort, monochromatic, high-dose, or coherent electron bunches.« less

Active control of bright electron beams with RF optics for femtosecond microscopy

PubMed Central

Williams, J.; Zhou, F.; Sun, T.; Tao, Z.; Chang, K.; Makino, K.; Berz, M.; Duxbury, P. M.; Ruan, C.-Y.

2017-01-01

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. Here, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the design of ultrafast electron microscopy. Through the introduction of a novel atomic grating approach for characterization of electron bunch phase space and control optics, we elucidate the principles for predicting and controlling the phase space dynamics to reach optimal compressions at various electron densities and generating conditions. We provide strategies to identify high-brightness modes, achieving ∼100 fs and ∼1 eV resolutions with 106 electrons per bunch, and establish the scaling of performance for different bunch charges. These results benchmark the sensitivity and resolution from the fundamental beam brightness perspective and also validate the adaptive optics concept to enable delicate control of the density-dependent phase space structures to optimize the performance, including delivering ultrashort, monochromatic, high-dose, or coherent electron bunches. PMID:28868325

Modeling of two-phase flow in membranes and porous media in microgravity as applied to plant irrigation in space

NASA Technical Reports Server (NTRS)

Scovazzo, P.; Illangasekare, T. H.; Hoehn, A.; Todd, P.

2001-01-01

In traditional applications in soil physics it is convention to scale porous media properties, such as hydraulic conductivity, soil water diffusivity, and capillary head, with the gravitational acceleration. In addition, the Richards equation for water flux in partially saturated porous media also contains a gravity term. With the plans to develop plant habitats in space, such as in the International Space Station, it becomes necessary to evaluate these properties and this equation under conditions of microgravitational acceleration. This article develops models for microgravity steady state two-phase flow, as found in irrigation systems, that addresses critical design issues. Conventional dimensionless groups in two-phase mathematical models are scaled with gravity, which must be assigned a value of zero for microgravity modeling. The use of these conventional solutions in microgravity, therefore, is not possible. This article therefore introduces new dimensionless groups for two-phase models. The microgravity models introduced here determined that in addition to porous media properties, important design factors for microgravity systems include applied water potential and the ratio of inner to outer radii for cylindrical and spherical porous media systems.

A Local Condensation Analysis Representing Two-phase Annular Flow in Condenser/radiator Capillary Tubes

NASA Technical Reports Server (NTRS)

Karimi, Amir

1991-01-01

NASA's effort for the thermal environmental control of the Space Station Freedom is directed towards the design, analysis, and development of an Active Thermal Control System (ATCS). A two phase, flow through condenser/radiator concept was baselined, as a part of the ATCS, for the radiation of space station thermal load into space. The proposed condenser rejects heat through direct condensation of ATCS working fluid (ammonia) in the small diameter radiator tubes. Analysis of the condensation process and design of condenser tubes are based on the available two phase flow models for the prediction of flow regimes, heat transfer, and pressure drops. The prediction formulas use the existing empirical relationships of friction factor at gas-liquid interface. An attempt is made to study the stability of interfacial waves in two phase annular flow. The formulation is presented of a stability problem in cylindrical coordinates. The contribution of fluid viscosity, surface tension, and transverse radius of curvature to the interfacial surface is included. A solution is obtained for Kelvin-Helmholtz instability problem which can be used to determine the critical and most dangerous wavelengths for interfacial waves.

Shuttle communications design study

NASA Technical Reports Server (NTRS)

Cartier, D. E.

1975-01-01

The design and development of a space shuttle communication system are discussed. The subjects considered include the following: (1) Ku-band satellite relay to shuttle, (2) phased arrays, (3) PN acquisition, (4) quadriplexing of direct link ranging and telemetry, (5) communications blackout on launch and reentry, (6) acquisition after blackout on reentry, (7) wideband communications interface with the Ku-Band rendezvous radar, (8) aeroflight capabilities of the space shuttle, (9) a triple multiplexing scheme equivalent to interplex, and (10) a study of staggered quadriphase for use on the space shuttle.

Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22.

PubMed

Silva, H G; Lopes, I

Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

KSC-2011-2278

NASA Image and Video Library

2011-03-14

CAPE CANAVERAL, Fla. -- Land clearing and construction of a new road at the Exploration Park site begins outside of the Space Life Sciences Laboratory (SLSL) at NASA's Kennedy Space Center in Florida. The fill dirt being used to develop the first phase was donated by Port Canaveral as part of an agreement between the port and Space Florida, the park’s partner developer. The first phase will encompass 60 acres just outside Kennedy’s security gates. Nine buildings will provide 350,000-square feet of work space, including educational, office, research and lab, and high-bay facilities. Each building is expected to be certified in the U.S. Green Building Council’s Leadership in Environmental and Energy Design (LEED).Exploration Park is designed to be a strategically located complex, adjacent to the SLSL, for servicing diverse tenants and uses that will engage in activities to support space-related activities of NASA, other government agencies and the U.S. commercial space industry. It also is expected to bring new aerospace work to the Space Coast. The SLSL will be the anchor facility for the park, which is expected to open its first new facility in early 2012. Photo credit: NASA/Jim Grossmann

KSC-2011-2279

NASA Image and Video Library

2011-03-14

CAPE CANAVERAL, Fla. -- Land clearing and construction of a new road at the Exploration Park site begins outside of the Space Life Sciences Laboratory (SLSL) at NASA's Kennedy Space Center in Florida. The fill dirt being used to develop the first phase was donated by Port Canaveral as part of an agreement between the port and Space Florida, the park’s partner developer. The first phase will encompass 60 acres just outside Kennedy’s security gates. Nine buildings will provide 350,000-square feet of work space, including educational, office, research and lab, and high-bay facilities. Each building is expected to be certified in the U.S. Green Building Council’s Leadership in Environmental and Energy Design (LEED).Exploration Park is designed to be a strategically located complex, adjacent to the SLSL, for servicing diverse tenants and uses that will engage in activities to support space-related activities of NASA, other government agencies and the U.S. commercial space industry. It also is expected to bring new aerospace work to the Space Coast. The SLSL will be the anchor facility for the park, which is expected to open its first new facility in early 2012. Photo credit: NASA/Jim Grossmann

KSC-2011-2277

NASA Image and Video Library

2011-03-14

CAPE CANAVERAL, Fla. -- Land clearing and construction of a new road at the Exploration Park site begins outside of the Space Life Sciences Laboratory (SLSL) at NASA's Kennedy Space Center in Florida. The fill dirt being used to develop the first phase was donated by Port Canaveral as part of an agreement between the port and Space Florida, the park’s partner developer. The first phase will encompass 60 acres just outside Kennedy’s security gates. Nine buildings will provide 350,000-square feet of work space, including educational, office, research and lab, and high-bay facilities. Each building is expected to be certified in the U.S. Green Building Council’s Leadership in Environmental and Energy Design (LEED).Exploration Park is designed to be a strategically located complex, adjacent to the SLSL, for servicing diverse tenants and uses that will engage in activities to support space-related activities of NASA, other government agencies and the U.S. commercial space industry. It also is expected to bring new aerospace work to the Space Coast. The SLSL will be the anchor facility for the park, which is expected to open its first new facility in early 2012. Photo credit: NASA/Jim Grossmann

Application of System Operational Effectiveness Methodology to Space Launch Vehicle Development and Operations

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Kelley, Gary W.

2012-01-01

The Department of Defense (DoD) defined System Operational Effectiveness (SOE) model provides an exceptional framework for an affordable approach to the development and operation of space launch vehicles and their supporting infrastructure. The SOE model provides a focal point from which to direct and measure technical effectiveness and process efficiencies of space launch vehicles. The application of the SOE model to a space launch vehicle's development and operation effort leads to very specific approaches and measures that require consideration during the design phase. This paper provides a mapping of the SOE model to the development of space launch vehicles for human exploration by addressing the SOE model key points of measurement including System Performance, System Availability, Technical Effectiveness, Process Efficiency, System Effectiveness, Life Cycle Cost, and Affordable Operational Effectiveness. In addition, the application of the SOE model to the launch vehicle development process is defined providing the unique aspects of space launch vehicle production and operations in lieu of the traditional broader SOE context that examines large quantities of fielded systems. The tailoring and application of the SOE model to space launch vehicles provides some key insights into the operational design drivers, capability phasing, and operational support systems.

Gas-phase chemistry in dense interstellar clouds including grain surface molecular depletion and desorption

NASA Technical Reports Server (NTRS)

Bergin, E. A.; Langer, W. D.; Goldsmith, P. F.

1995-01-01

We present time-dependent models of the chemical evolution of molecular clouds which include depletion of atoms and molecules onto grain surfaces and desorption, as well as gas-phase interactions. We have included three mechanisms to remove species from the grain mantles: thermal evaporation, cosmic-ray-induced heating, and photodesorption. A wide range of parameter space has been explored to examine the abundance of species present both on the grain mantles and in the gas phase as a function of both position in the cloud (visual extinction) and of evolutionary state (time). The dominant mechanism that removes molecules from the grain mantles is cosmic-ray desorption. At times greater than the depletion timescale, the abundances of some simple species agree with abundances observed in the cold dark cloud TMC-1. Even though cosmic-ray desorption preserves the gas-phase chemistry at late times, molecules do show significant depletions from the gas phase. Examination of the dependence of depletion as a function of density shows that when the density increases from 10(exp 3)/cc to 10(exp 5)/cc several species including HCO(+), HCN, and CN show gas-phase abundance reductions of over an order of magnitude. The CO: H2O ratio in the grain mantles for our standard model is on the order of 10:1, in reasonable agreement with observations of nonpolar CO ice features in rho Ophiuchus and Serpens. We have also examined the interdependence of CO depletion with the space density of molecular hydrogen and binding energy to the grain surface. We find that the observed depletion of CO in Taurus in inconsistent with CO bonding in an H2O rich mantle, in agreement with observations. We suggest that if interstellar grains consist of an outer layer of CO ice, then the binding energies for many species to the grain mantle may be lower than commonly used, and a significant portion of molecular material may be maintained in the gas phase.

Novel phases and superconductivity of tin sulfide compounds

NASA Astrophysics Data System (ADS)

Gonzalez, Joseph M.; Nguyen-Cong, Kien; Steele, Brad A.; Oleynik, Ivan I.

2018-05-01

Tin sulfides, SnxSy, are an important class of materials that are actively investigated as novel photovoltaic and water splitting materials. A first-principles evolutionary crystal structure search is performed with the goal of constructing the complete phase diagram of SnxSy and discovering new phases as well as new compounds of varying stoichiometry at ambient conditions and pressures up to 100 GPa. The ambient phase of SnS2 with P 3 ¯ m 1 symmetry remains stable up to 28 GPa. Another ambient phase, SnS, experiences a series of phase transformations including α-SnS to β-SnS at 9 GPa, followed by β-SnS to γ-SnS at 40 GPa. γ-SnS is a new high-pressure metallic phase with P m 3 ¯ m space group symmetry stable up to 100 GPa, which becomes a superconductor with a maximum Tc = 9.74 K at 40 GPa. Another new metallic compound, Sn3S4 with I 4 ¯ 3 d space group symmetry, is predicted to be stable at pressures above 15 GPa, which also becomes a superconductor with relatively high Tc = 21.9 K at 30 GPa.

Phase portraits of general f(T) cosmology

NASA Astrophysics Data System (ADS)

Awad, A.; El Hanafy, W.; Nashed, G. G. L.; Saridakis, Emmanuel N.

2018-02-01

We use dynamical system methods to explore the general behaviour of f(T) cosmology. In contrast to the standard applications of dynamical analysis, we present a way to transform the equations into a one-dimensional autonomous system, taking advantage of the crucial property that the torsion scalar in flat FRW geometry is just a function of the Hubble function, thus the field equations include only up to first derivatives of it, and therefore in a general f(T) cosmological scenario every quantity is expressed only in terms of the Hubble function. The great advantage is that for one-dimensional systems it is easy to construct the phase space portraits, and thus extract information and explore in detail the features and possible behaviours of f(T) cosmology. We utilize the phase space portraits and we show that f(T) cosmology can describe the universe evolution in agreement with observations, namely starting from a Big Bang singularity, evolving into the subsequent thermal history and the matter domination, entering into a late-time accelerated expansion, and resulting to the de Sitter phase in the far future. Nevertheless, f(T) cosmology can present a rich class of more exotic behaviours, such as the cosmological bounce and turnaround, the phantom-divide crossing, the Big Brake and the Big Crunch, and it may exhibit various singularities, including the non-harmful ones of type II and type IV. We study the phase space of three specific viable f(T) models offering a complete picture. Moreover, we present a new model of f(T) gravity that can lead to a universe in agreement with observations, free of perturbative instabilities, and applying the Om(z) diagnostic test we confirm that it is in agreement with the combination of SNIa, BAO and CMB data at 1σ confidence level.

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

Akkelin, S.V.; Sinyukov, Yu.M.

A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase-space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate thatmore » multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase-space density at each space point decreases rapidly during the system's expansion. We found that, unlike the particle density, the average phase-space density has no direct link to the freeze-out criterion and final thermodynamic parameters, being connected rather to the initial phase-space density of hadronic matter formed in relativistic nucleus-nucleus collisions.« less

Prospects for tracking spacecrafts within 2 million Km of Earth with phased array antennas

NASA Technical Reports Server (NTRS)

Amoozegar, F.; Jamnejad, V.; Cesarone, R.

2003-01-01

Recent advances in space technology for Earth observations, global communications, and positioning systems have created heavy traffic at a variety of orbits. These include smart sensors in low Earth orbits (LEO), internet satellites in LEO and GEO orbits, Earth observing satellites in high Earth orbits (HEO), observatory class satellites at Lagrangian libration points, and those heading for deep space.

Landing and Rollout STS-135 Crew Training on the Vertical Motion Simulator (VMS) at NASA Ames (Reporter Pkg)

NASA Image and Video Library

2011-07-05

Every Space Shuttle flight crew has trained for the final phase of a Shuttle mission, landing and rollout, using the VMS at NASA Ames. This story follows at the crew of STS-135, the final Space Shuttle mission, as they train on the VMS. Includes an interview with Chris Ferguson, the STS-135 mission commander.

Disentangling the Cosmic Web with Lagrangian Submanifold

NASA Astrophysics Data System (ADS)

Shandarin, Sergei F.; Medvedev, Mikhail V.

2016-10-01

The Cosmic Web is a complicated highly-entangled geometrical object. Remarkably it has formed from practically Gaussian initial conditions, which may be regarded as the simplest departure from exactly uniform universe in purely deterministic mapping. The full complexity of the web is revealed neither in configuration no velocity spaces considered separately. It can be fully appreciated only in six-dimensional (6D) phase space. However, studies of the phase space is complicated by the fact that every projection of it on a three-dimensional (3D) space is multivalued and contained caustics. In addition phase space is not a metric space that complicates studies of geometry. We suggest to use Lagrangian submanifold i.e., x = x(q), where both x and q are 3D vectors instead of the phase space for studies the complexity of cosmic web in cosmological N-body dark matter simulations. Being fully equivalent in dynamical sense to the phase space it has an advantage of being a single valued and also metric space.

Advanced launch system. Advanced development oxidizer turbopump program

NASA Technical Reports Server (NTRS)

1993-01-01

On May 19, 1989, Pratt & Whitney was awarded contract NAS8-37595 by the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville Alabama for an Advanced Development Program (ADP) to design, develop and demonstrate a highly reliable low cost, liquid oxygen turbopump for the Advanced Launch System (ALS). The ALS had an overall goal of reducing the cost of placing payloads in orbit by an order of magnitude. This goal would require a substantial reduction in life cycle costs, with emphasis on recurring costs, compared to current launch vehicles. Engine studies supporting these efforts were made for the Space Transportation Main Engine (STME). The emphasis on low cost required design simplification of components and subsystems such that the ground maintenance and test operations was minimized. The results of the Oxygen Turbopump ADP technology effort would provide data to be used in the STME. Initially the STME baseline was a gas generator cycle engine with a vacuum thrust level of 580,000 lbf. This was later increased to 650,000 lbf and the oxygen turbopump design approach was changed to reflect the new thrust level. It was intended that this ADP program be conducted in two phases. Phase 1, a basic phase, would encompass the preliminary design effort, and Phase II, an optional contract phase to cover design, fabrication and test evaluation of an oxygen turbopump at a component test facility at the NASA John C. Stennis Space Center in Mississippi. The basic phase included preliminary design and analysis, evaluation of low cost concepts, and evaluation of fabrication techniques. The option phase included design of the pump and support hardware, analysis of the final configuration to ensure design integrity, fabrication of hardware to demonstrate low cost, DVS Testing of hardware to verify the design, assembly of the turbopump and full scale turbopump testing. In December 1990, the intent of this ADP to support the design and development was changed. The design effort for the oxygen turbopump became part of the STME Phase B contract. The status of the pump design funded through this ADP was presented at the Preliminary Design Review (PDR) at the MSFC on October 24, 1990. Advancements in the design of the pump were subsequently continued under the Phase B Contract. The emphasis of this ADP became the demonstration of individual technologies that would have the greatest potential for reducing the recurring cost and increasing reliability. In October of 1992, overall program funding was reduced and work on this ADP was terminated.

Advanced launch system. Advanced development oxidizer turbopump program

NASA Astrophysics Data System (ADS)

1993-10-01

On May 19, 1989, Pratt & Whitney was awarded contract NAS8-37595 by the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville Alabama for an Advanced Development Program (ADP) to design, develop and demonstrate a highly reliable low cost, liquid oxygen turbopump for the Advanced Launch System (ALS). The ALS had an overall goal of reducing the cost of placing payloads in orbit by an order of magnitude. This goal would require a substantial reduction in life cycle costs, with emphasis on recurring costs, compared to current launch vehicles. Engine studies supporting these efforts were made for the Space Transportation Main Engine (STME). The emphasis on low cost required design simplification of components and subsystems such that the ground maintenance and test operations was minimized. The results of the Oxygen Turbopump ADP technology effort would provide data to be used in the STME. Initially the STME baseline was a gas generator cycle engine with a vacuum thrust level of 580,000 lbf. This was later increased to 650,000 lbf and the oxygen turbopump design approach was changed to reflect the new thrust level. It was intended that this ADP program be conducted in two phases. Phase 1, a basic phase, would encompass the preliminary design effort, and Phase II, an optional contract phase to cover design, fabrication and test evaluation of an oxygen turbopump at a component test facility at the NASA John C. Stennis Space Center in Mississippi. The basic phase included preliminary design and analysis, evaluation of low cost concepts, and evaluation of fabrication techniques. The option phase included design of the pump and support hardware, analysis of the final configuration to ensure design integrity, fabrication of hardware to demonstrate low cost, DVS Testing of hardware to verify the design, assembly of the turbopump and full scale turbopump testing. In December 1990, the intent of this ADP to support the design and development was changed. The design effort for the oxygen turbopump became part of the STME Phase B contract. The status of the pump design funded through this ADP was presented at the Preliminary Design Review (PDR) at the MSFC on October 24, 1990. Advancements in the design of the pump were subsequently continued under the Phase B Contract. The emphasis of this ADP became the demonstration of individual technologies that would have the greatest potential for reducing the recurring cost and increasing reliability. In October of 1992, overall program funding was reduced and work on this ADP was terminated.

Space station experiment definition: Advanced power system test bed

NASA Technical Reports Server (NTRS)

Pollard, H. E.; Neff, R. E.

1986-01-01

A conceptual design for an advanced photovoltaic power system test bed was provided and the requirements for advanced photovoltaic power system experiments better defined. Results of this study will be used in the design efforts conducted in phase B and phase C/D of the space station program so that the test bed capabilities will be responsive to user needs. Critical PV and energy storage technologies were identified and inputs were received from the idustry (government and commercial, U.S. and international) which identified experimental requirements. These inputs were used to develop a number of different conceptual designs. Pros and cons of each were discussed and a strawman candidate identified. A preliminary evolutionary plan, which included necessary precursor activities, was established and cost estimates presented which would allow for a successful implementation to the space station in the 1994 time frame.

Recent Applications of Space Weather Research to NASA Space Missions

NASA Technical Reports Server (NTRS)

Willis, Emily M.; Howard, James W., Jr.; Miller, J. Scott; Minow, Joseph I.; NeergardParker, L.; Suggs, Robert M.

2013-01-01

Marshall Space Flight Center s Space Environments Team is committed to applying the latest research in space weather to NASA programs. We analyze data from an extensive set of space weather satellites in order to define the space environments for some of NASA s highest profile programs. Our goal is to ensure that spacecraft are designed to be successful in all environments encountered during their missions. We also collaborate with universities, industry, and other federal agencies to provide analysis of anomalies and operational impacts to current missions. This presentation is a summary of some of our most recent applications of space weather data, including the definition of the space environments for the initial phases of the Space Launch System (SLS), acquisition of International Space Station (ISS) frame potential variations during geomagnetic storms, and Nascap-2K charging analyses.

Atmosphere, Magnetosphere and Plasmas in Space (AMPS). Spacelab payload definition study. Volume 7, book 2: AMPS phase C/D analysis and planning document

NASA Technical Reports Server (NTRS)

1976-01-01

The results are presented of the AMPS Phase C/D (Design, Development, and Operations) program analysis and planning effort. Cost and schedule estimates are included. Although the AMPS program has been specifically addressed, these task descriptions are basically adaptable to a broader-based program incorporating additional or different Spacelab/orbiter payloads.

Level 3 material characterization of NARC HRPF, HRHU, HRHF, and HRPU

NASA Technical Reports Server (NTRS)

Tobias, Mark E.

1993-01-01

The North American Rayon Corporation (NARC) precursor was developed, qualified, and characterized for Space Shuttle nozzle carbon-cloth phenolic ablative materials in three distinct phases. The characterization phase includes thermal and structural material property analysis and comparisons. This report documents the thermal and structural material property characterization performed by Southern Research Institute (SRI) on the two NARC baseline and two crossover materials.

Space station needs, attributes, and architectural options study

NASA Technical Reports Server (NTRS)

1983-01-01

The top level, time-phased total space program support system architecture is described including progress from the use of ground-based space shuttle, teleoperator system, extended duration orbiter, and multimission spacecraft, to an initial 4-man crew station at 29 deg inclination in 1991, to a growth station with an 8-man crew with capabilities for OTV high energy orbit payload placement and servicing, assembly, and construction of mission payloads in 1994. System Z, proposed for Earth observation missions in high inclination orbit, can be accommodated in 1993 using a space station derivative platform. Mission definition, system architecture, and benefits are discussed.

Space Shuttle Reusable Solid Rocket Motor (RSRM) Hand Cleaning Solvent Replacement at Kennedy Space Center (KSC)

NASA Technical Reports Server (NTRS)

Keen, Jill M.; DeWeese, Darrell C.; Key, Leigh W.

1997-01-01

At Kennedy Space Center (KSC), Thiokol Corporation provides the engineering to assemble and prepare the Space Shuttle Reusable Solid Rocket Motor (RSRM) for launch. This requires hand cleaning over 86 surfaces including metals, adhesives, rubber and electrical insulations, various painted surfaces and thermal protective materials. Due to the phase-out of certain ozone depleting chemical (ODC) solvents, all RSRM hand wipe operations being performed at KSC using l,l,1-trichloroethane (TCA) were eliminated. This presentation summarizes the approach used and the data gathered in the effort to eliminate TCA from KSC hand wipe operations.

Asymmetrical booster ascent guidance and control system design study. Volume 5: Space shuttle powered explicit guidance. [space shuttle development

NASA Technical Reports Server (NTRS)

Jaggers, R. F.

1974-01-01

An optimum powered explicit guidance algorithm capable of handling all space shuttle exoatospheric maneuvers is presented. The theoretical and practical basis for the currently baselined space shuttle powered flight guidance equations and logic is documented. Detailed flow diagrams for implementing the steering computations for all shuttle phases, including powered return to launch site (RTLS) abort, are also presented. Derivation of the powered RTLS algorithm is provided, as well as detailed flow diagrams for implementing the option. The flow diagrams and equations are compatible with the current powered flight documentation.

Selected tether applications in space: Phase 2. Executive summary

NASA Technical Reports Server (NTRS)

Thorson, M. H.; Lippy, L. J.

1985-01-01

The application of tether technology has the potential to increase the overall performance efficiency and capability of the integrated space operations and transportation systems through the decade of the 90s. The primary concepts for which significant economic benefits were identified are dependent on the space station as a storage device for angular momentum and as an operating base for the tether system. Concepts examined include: (1) tether deorbit of shuttle from space station; (2) tethered orbit insertion of a spacecraft from shuttle; (3) tethered platform deployed from space station; (4) tether-effected rendezvous of an OMV with a returning OTV; (5) electrodynamic tether as an auxiliary power source for space station; and (6) tether assisted launch of an OTV mission from space station.

Phase space methods in HMD systems

NASA Astrophysics Data System (ADS)

Babington, James

2017-06-01

We consider using phase space techniques and methods in analysing optical ray propagation in head mounted display systems. Two examples are considered that illustrate the concepts and methods. Firstly, a shark tooth freeform geometry, and secondly, a waveguide geometry that replicates a pupil in one dimension. Classical optics and imaging in particular provide a natural stage to employ phase space techniques, albeit as a constrained system. We consider how phase space provides a global picture of the physical ray trace data. As such, this gives a complete optical world history of all of the rays propagating through the system. Using this data one can look at, for example, how aberrations arise on a surface by surface basis. These can be extracted numerically from phase space diagrams in the example of a freeform imaging prism. For the waveguide geometry, phase space diagrams provide a way of illustrating how replicated pupils behave and what these imply for design considerations such as tolerances.

Purification of biomaterials by phase partitioning

NASA Technical Reports Server (NTRS)

Harris, J. M.

1984-01-01

A technique which is particularly suited to microgravity environments and which is potentially more powerful than electrophoresis is phase partitioning. Phase partitioning is purification by partitioning between the two immiscible aqueous layers formed by solution of the polymers poly(ethylene glycol) and dextran in water. This technique proved to be very useful for separations in one-g but is limited for cells because the cells are more dense than the phase solutions thus tend to sediment to the bottom of the container before reaching equilibrium with the preferred phase. There are three phases to work in this area: synthesis of new polymers for affinity phase partitioning; development of automated apparatus for ground-based separations; and design of apparatus for performing simple phase partitioning space experiments, including examination of mechanisms for separating phases in the absence of gravity.

Nonvolatile Memory Technology for Space Applications

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

2010-01-01

This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

Analyzing the Impacts of Natural Environments on Launch and Landing Availability for NASA's Exploration Systems Development Programs

NASA Technical Reports Server (NTRS)

Altino, Karen M.; Burns, K. Lee; Barbre, Robert E., Jr.; Leahy, Frank B.

2014-01-01

The National Aeronautics and Space Administration (NASA) is developing new capabilities for human and scientific exploration beyond Earth orbit. Natural environments information is an important asset for NASA's development of the next generation space transportation system as part of the Exploration Systems Development (ESD) Programs, which includes the Space Launch System (SLS) and Multi-Purpose Crew Vehicle (MPCV) Programs. Natural terrestrial environment conditions - such as wind, lightning and sea states - can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing to landing and recovery operations, including all potential abort scenarios. Space vehicles are particularly sensitive to these environments during the launch/ascent and the entry/landing phases of mission operations. The Marshall Space Flight Center (MSFC) Natural Environments Branch provides engineering design support for NASA space vehicle projects and programs by providing design engineers and mission planners with natural environments definitions as well as performing custom analyses to help characterize the impacts the natural environment may have on vehicle performance. One such analysis involves assessing the impact of natural environments to operational availability. Climatological time series of operational surface weather observations are used to calculate probabilities of meeting/exceeding various sets of hypothetical vehicle-specific parametric constraint thresholds. Outputs are tabulated by month and hour of day to show both seasonal and diurnal variation. This paper will discuss how climate analyses are performed by the MSFC Natural Environments Branch to support the ESD Launch Availability (LA) Technical Performance Measure (TPM), the SLS Launch Availability due to Natural Environments TPM, and several MPCV (Orion) launch and landing availability analyses - including the 2014 Orion Exploration Flight Test 1 (EFT-1) mission.

Phase 1 research program overview

NASA Technical Reports Server (NTRS)

Uri, J. J.; Lebedev, O. N.

2001-01-01

The Phase 1 research program was unprecedented in its scope and ambitious in its objectives. The National Aeronautics and Space Administration committed to conducting a multidisciplinary long-duration research program on a platform whose capabilities were not well known, not to mention belonging to another country. For the United States, it provided the first opportunity to conduct research in a long-duration space flight environment since the Skylab program in the 1970's. Multiple technical as well as cultural challenges were successfully overcome through the dedicated efforts of a relatively small cadre of individuals. The program developed processes to successfully plan, train for and execute research in a long-duration environment, with significant differences identified from short-duration space flight science operations. Between August 1994 and June 1998, thousands of kilograms of research hardware was prepared and launched to Mir, and thousands of kilograms of hardware and data products were returned to Earth. More than 150 Principal Investigators from eight countries were involved in the program in seven major research disciplines: Advanced Technology; Earth Sciences; Fundamental Biology; Human Life Sciences; International Space Station Risk Mitigation; Microgravity; and Space Sciences. Approximately 75 long-duration investigations were completed on Mir, with additional investigations performed on the Shuttle flights that docked with Mir. The flight phase included the participation of seven US astronauts and 20 Russian cosmonauts. The successful completion of the Phase 1 research program not only resulted in high quality science return but also in numerous lessons learned to make the ISS experience more productive. The cooperation developed during the program was instrumental in its success. c2001 AIAA. Published by Elsevier Science Ltd.

Phase 1 research program overview.

PubMed

Uri, J J; Lebedev, O N

2001-01-01

The Phase 1 research program was unprecedented in its scope and ambitious in its objectives. The National Aeronautics and Space Administration committed to conducting a multidisciplinary long-duration research program on a platform whose capabilities were not well known, not to mention belonging to another country. For the United States, it provided the first opportunity to conduct research in a long-duration space flight environment since the Skylab program in the 1970's. Multiple technical as well as cultural challenges were successfully overcome through the dedicated efforts of a relatively small cadre of individuals. The program developed processes to successfully plan, train for and execute research in a long-duration environment, with significant differences identified from short-duration space flight science operations. Between August 1994 and June 1998, thousands of kilograms of research hardware was prepared and launched to Mir, and thousands of kilograms of hardware and data products were returned to Earth. More than 150 Principal Investigators from eight countries were involved in the program in seven major research disciplines: Advanced Technology; Earth Sciences; Fundamental Biology; Human Life Sciences; International Space Station Risk Mitigation; Microgravity; and Space Sciences. Approximately 75 long-duration investigations were completed on Mir, with additional investigations performed on the Shuttle flights that docked with Mir. The flight phase included the participation of seven US astronauts and 20 Russian cosmonauts. The successful completion of the Phase 1 research program not only resulted in high quality science return but also in numerous lessons learned to make the ISS experience more productive. The cooperation developed during the program was instrumental in its success. c2001 AIAA. Published by Elsevier Science Ltd.

The Seasat surface truth experiments

NASA Technical Reports Server (NTRS)

Shemdin, O. H.

1976-01-01

A surface truth program for Seasat A is formulated in two phases: pre- and post-launch. The pre-launch phase (which includes the Marineland experiments, the JONSWAP-75 experiment, the West Coast experiment, and the altimeter experiment) is designed to provide data from aircraft over instrumented ocean sites during desirable geophysical events. The objective is to gather sufficient data for the development of algorithms which transfer space data into geophysical variables useful for applications. In the post-launch phase, the surface truth program is designed to verify and improve the algorithms developed in the pre-launch phase and also to evaluate the performance of spaceborne sensors.

Impact: a low cost, reconfigurable, digital beamforming common module building block for next generation phased arrays

NASA Astrophysics Data System (ADS)

Paulsen, Lee; Hoffmann, Ted; Fulton, Caleb; Yeary, Mark; Saunders, Austin; Thompson, Dan; Chen, Bill; Guo, Alex; Murmann, Boris

2015-05-01

Phased array systems offer numerous advantages to the modern warfighter in multiple application spaces, including Radar, Electronic Warfare, Signals Intelligence, and Communications. However, a lack of commonality in the underlying technology base for DoD Phased Arrays has led to static systems with long development cycles, slow technology refreshes in response to emerging threats, and expensive, application-specific sub-components. The IMPACT module (Integrated Multi-use Phased Array Common Tile) is a multi-channel, reconfigurable, cost-effective beamformer that provides a common building block for multiple, disparate array applications.

Constructing a modern cytology laboratory: A toolkit for planning and design.

PubMed

Roberson, Janie; Wrenn, Allison; Poole, John; Jaeger, Andrew; Eltoum, Isam A

2013-01-01

Constructing or renovating a laboratory can be both challenging and rewarding. UAB Cytology (UAB CY) recently undertook a project to relocate from a building constructed in 1928 to new space. UAB CY is part of an academic center that provides service to a large set of patients, support training of one cytotechnology program and one cytopathology fellowship training program and involve actively in research and scholarly activity. Our objectives were to provide a safe, aesthetically pleasing space and gain efficiencies through lean processes. The phases of any laboratory design project are Planning, Schematic Design (SD), Design Development (DD), Construction Documents (CD) and Construction. Lab personnel are most critical in the Planning phase. During this time stakeholders, relationships, budget, square footage and equipment were identified. Equipment lists, including what would be relocated, purchased new and projected for future growth ensure that utilities were matched to expected need. A chemical inventory was prepared and adequate storage space was planned. Regulatory and safety requirements were discussed. Tours and high level process flow diagrams helped architects and engineers understand the laboratory daily work. Future needs were addressed through a questionnaire which identified potential areas of growth and technological change. Throughout the project, decisions were driven by data from the planning phase. During the SD phase, objective information from the first phase was used by architects and planners to create a general floor plan. This was the basis of a series of meetings to brainstorm and suggest modifications. DD brings more detail to the plans with engineering, casework, equipment specifics, finishes. Design changes should be completed at this phase. The next phase, CD took the project from the lab purview into purely technical mode. Construction documents were used by the contractor for the bidding process and ultimately the Construction phase. The project fitted out a total of 9,000 square feet; 4,000 laboratory and 5,000 office/support. Lab space includes areas for Prep, CT screening, sign out and Imaging. Adjacent space houses faculty offices and conferencing facilities. Transportation time was reduced (waste removal) by a Pneumatic Tube System, specimen drop window to Prep Lab and a pass thru window to the screening area. Open screening and prep areas allow visual management control. Efficiencies were gained by ergonomically placing CT Manual and Imaging microscopes and computers in close proximity, also facilitating a paperless workflow for additional savings. Logistically, closer proximity to Surgical Pathology maximized the natural synergies between the areas. Lab construction should be a systematic process based on sound principles for safety, high quality testing, and finance. Our detailed planning and design process can be a model for others undertaking similar projects.

Constructing a modern cytology laboratory: A toolkit for planning and design

PubMed Central

Roberson, Janie; Wrenn, Allison; Poole, John; Jaeger, Andrew; Eltoum, Isam A.

2013-01-01

Introduction: Constructing or renovating a laboratory can be both challenging and rewarding. UAB Cytology (UAB CY) recently undertook a project to relocate from a building constructed in 1928 to new space. UAB CY is part of an academic center that provides service to a large set of patients, support training of one cytotechnology program and one cytopathology fellowship training program and involve actively in research and scholarly activity. Our objectives were to provide a safe, aesthetically pleasing space and gain efficiencies through lean processes. Methods: The phases of any laboratory design project are Planning, Schematic Design (SD), Design Development (DD), Construction Documents (CD) and Construction. Lab personnel are most critical in the Planning phase. During this time stakeholders, relationships, budget, square footage and equipment were identified. Equipment lists, including what would be relocated, purchased new and projected for future growth ensure that utilities were matched to expected need. A chemical inventory was prepared and adequate storage space was planned. Regulatory and safety requirements were discussed. Tours and high level process flow diagrams helped architects and engineers understand the laboratory daily work. Future needs were addressed through a questionnaire which identified potential areas of growth and technological change. Throughout the project, decisions were driven by data from the planning phase. During the SD phase, objective information from the first phase was used by architects and planners to create a general floor plan. This was the basis of a series of meetings to brainstorm and suggest modifications. DD brings more detail to the plans with engineering, casework, equipment specifics, finishes. Design changes should be completed at this phase. The next phase, CD took the project from the lab purview into purely technical mode. Construction documents were used by the contractor for the bidding process and ultimately the Construction phase. Results: The project fitted out a total of 9,000 square feet; 4,000 laboratory and 5,000 office/support. Lab space includes areas for Prep, CT screening, sign out and Imaging. Adjacent space houses faculty offices and conferencing facilities. Transportation time was reduced (waste removal) by a Pneumatic Tube System, specimen drop window to Prep Lab and a pass thru window to the screening area. Open screening and prep areas allow visual management control. Efficiencies were gained by ergonomically placing CT Manual and Imaging microscopes and computers in close proximity, also facilitating a paperless workflow for additional savings. Logistically, closer proximity to Surgical Pathology maximized the natural synergies between the areas. Conclusions: Lab construction should be a systematic process based on sound principles for safety, high quality testing, and finance. Our detailed planning and design process can be a model for others undertaking similar projects PMID:23599722

Flow induced vibrations in the SSME injector heads

NASA Technical Reports Server (NTRS)

Lepore, Frank A.

1991-01-01

A description is given of the flowfield in the Space Shuttle Main Engine (SSME) powerhead, the mechanisms which control flow-induced vibrations, and previous experimental work. An in-depth description is given of the development phase of the program , which includes the analysis, design, and fabrication of liquid oxygen (LOX) posts models used in the experimental phase, as well as test facilities, equipment, and procedures used. Also covered is the experimental data analysis, which includes overall steady state powerhead flowfield as well as the high frequency response of the LOX posts.

Vertebrate development in the environment of space: models, mechanisms, and use of the medaka

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Herrada, G.; Kiss, S.; Cannon, T.; Forsstrom, C.; Pranger, L. A.; Weismann, W. P.; Pearce, L.; Whalon, B.; Phillips, C. R.

1997-01-01

With the advent of space travel, it is of immediate interest and importance to study the effects of exposure to various aspects of the altered environment of space, including microgravity, on Earth-based life forms. Initial studies of space travel have focused primarily on the short-term effects of radiation and microgravity on adult organisms. However, with the potential for increased lengths of time in space, it is critical to now address the effects of space on all phases of an organism's life cycle, from embryogenesis to post-natal development to reproduction. It is already possible for certain species to undergo multiple generations within the confines of the Mir Space Station. The possibility now exists for scientists to consider the consequences of even potentially subtle defects in development through multiple phases of an organism's life cycle, or even through multiple generations. In this discussion, we highlight a few of the salient observations on the effects of the space environment on vertebrate development and reproductive function. We discuss some of the many unanswered questions, in particular, in the context of the choice of appropriate models in which to address these questions, as well as an assessment of the availability of hardware already existing or under development which would be useful in addressing these questions.

Husimi function and phase-space analysis of bilayer quantum Hall systems at ν = 2/λ

NASA Astrophysics Data System (ADS)

Calixto, M.; Peón-Nieto, C.

2018-05-01

We propose localization measures in phase space of the ground state of bilayer quantum Hall systems at fractional filling factors , to characterize the three quantum phases (shortly denoted by spin, canted and ppin) for arbitrary -isospin λ. We use a coherent state (Bargmann) representation of quantum states, as holomorphic functions in the 8-dimensional Grassmannian phase-space (a higher-dimensional generalization of the Haldane’s 2-dimensional sphere ). We quantify the localization (inverse volume) of the ground state wave function in phase-space throughout the phase diagram (i.e. as a function of Zeeman, tunneling, layer distance, etc, control parameters) with the Husimi function second moment, a kind of inverse participation ratio that behaves as an order parameter. Then we visualize the different ground state structure in phase space of the three quantum phases, the canted phase displaying a much higher delocalization (a Schrödinger cat structure) than the spin and ppin phases, where the ground state is highly coherent. We find a good agreement between analytic (variational) and numeric diagonalization results.

Study of selected tether applications in space, phase 3, volume 2

NASA Technical Reports Server (NTRS)

1986-01-01

The results of a Phase 3 study of two Selected Tether Applications in Space (STAIS); deorbit of a Shuttle and launch of an Orbital Transfer Vehicle (OTV), both from the space station using a tether were examined. The study objectives were to: perform a preliminary engineering design, define operational scenarios, develop a common cost model, perform cost benefits analyses, and develop a Work Breakdown Structure (WBS). Key features of the performance analysis were to identify the net increases in effective Shuttle cargo capability if tethers are used to assist in the deorbit of Shuttles and the launching of the OTVs from the space station and to define deployer system designs required to accomplish these tasks. Deployer concepts were designed and discussed. Operational scenarios, including timelines, for both tethered and nontethered Shuttle and OTV operations at the space station were evaluated. A summary discussion of the Selected Tether Applications Cost Model (STACOM) and the results of the cost benefits analysis are presented. Several critical technologies needed to implement tether assisted deployment of payloads are also discussed. Conclusions and recommendations are presented.

KSC-08pd1345

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron demonstrates rescue equipment that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In the background is an HH-60G helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1351

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- Representatives of the 301st Rescue Squadron demonstrate the use of rescue equipment on the HH-60G helicopter that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1350

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron demonstrates rescue equipment on the HH-60G helicopter that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1349

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- Representatives of the 301st Rescue Squadron demonstrate the use of rescue equipment on the HH-60G helicopter that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1344

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron demonstrates rescue equipment that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In the background is an HH-60G helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1341

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- Participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla., are introduced to the equipment they will be working with. In the foreground is an HH-60 helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1343

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron familiarizes participants in the Mode VIII exercise with the HH-60G helicopter that will play a part. The Mode VIII is being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1346

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron demonstrates rescue equipment that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

Natural orbital environment definition guidelines for use in aerospace vehicle development

NASA Technical Reports Server (NTRS)

Anderson, B. Jeffrey (Editor); Smith, Robert E. (Compiler)

1994-01-01

This document provides definitions of the natural near-Earth space environment suitable for use in the initial development/design phase of any space vehicle. The natural environment includes the neutral atmosphere, plasma, charged particle radiation, electromagnetic radiation (EMR), meteoroids, orbital debris, magnetic field, physical and thermal constants, and gravitational field. Communications and other unmanned satellites operate in geosynchronous-Earth orbit (GEO); therefore, some data are given for GEO, but emphasis is on altitudes from 200 km to 1000 km (low-Earth orbit (LEO)). This document does not cover the induced environment of other effects resulting from presence of the space vehicle. Manmade factors are included as part of the ambient natural environment; i.e., orbital debris and radio frequency (RF) noise generated on Earth, because they are not caused by the presence of the space vehicle but form part of the ambient environment that the space vehicle experiences.

Orbit Determination (OD) Error Analysis Results for the Triana Sun-Earth L1 Libration Point Mission and for the Fourier Kelvin Stellar Interferometer (FKSI) Sun-Earth L2 Libration Point Mission Concept

NASA Technical Reports Server (NTRS)

Marr, Greg C.

2003-01-01

The Triana spacecraft was designed to be launched by the Space Shuttle. The nominal Triana mission orbit will be a Sun-Earth L1 libration point orbit. Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination (OD) error analysis results are presented for all phases of the Triana mission from the first correction maneuver through approximately launch plus 6 months. Results are also presented for the science data collection phase of the Fourier Kelvin Stellar Interferometer Sun-Earth L2 libration point mission concept with momentum unloading thrust perturbations during the tracking arc. The Triana analysis includes extensive analysis of an initial short arc orbit determination solution and results using both Deep Space Network (DSN) and commercial Universal Space Network (USN) statistics. These results could be utilized in support of future Sun-Earth libration point missions.

A plan for time-phased incorporation of automation and robotics on the US space station

NASA Technical Reports Server (NTRS)

Purves, R. B.; Lin, P. S.; Fisher, E. M., Jr.

1988-01-01

A plan for the incorporation of Automation and Robotics technology on the Space Station is presented. The time phased introduction of twenty two selected candidates is set forth in accordance with a technology development forecast. Twenty candidates were chosed primarily for their potential to relieve the crew of mundane or dangerous operations and maintenance burdens, thus freeing crew time for mission duties and enhancing safety. Two candidates were chosen based on a potential for increasing the productivity of laboratory experiments and thus directly enhancing the scientific value of the Space Station. A technology assessment for each candidate investigates present state of the art, development timelines including space qualification considerations, and potential for technology transfer to earth applications. Each candidate is evaluated using a crew workload model driven by crew size, number of pressurized U.S. modules and external payloads, which makes it possible to assess the impact of automation during a growth scenario. Costs for each increment of implementation are estimated and accumulated.

On the importance of an accurate representation of the initial state of the system in classical dynamics simulations

NASA Astrophysics Data System (ADS)

García-Vela, A.

2000-05-01

A definition of a quantum-type phase-space distribution is proposed in order to represent the initial state of the system in a classical dynamics simulation. The central idea is to define an initial quantum phase-space state of the system as the direct product of the coordinate and momentum representations of the quantum initial state. The phase-space distribution is then obtained as the square modulus of this phase-space state. The resulting phase-space distribution closely resembles the quantum nature of the system initial state. The initial conditions are sampled with the distribution, using a grid technique in phase space. With this type of sampling the distribution of initial conditions reproduces more faithfully the shape of the original phase-space distribution. The method is applied to generate initial conditions describing the three-dimensional state of the Ar-HCl cluster prepared by ultraviolet excitation. The photodissociation dynamics is simulated by classical trajectories, and the results are compared with those of a wave packet calculation. The classical and quantum descriptions are found in good agreement for those dynamical events less subject to quantum effects. The classical result fails to reproduce the quantum mechanical one for the more strongly quantum features of the dynamics. The properties and applicability of the phase-space distribution and the sampling technique proposed are discussed.

On-Orbit Prospective Echocardiography on International Space Station Crew

NASA Technical Reports Server (NTRS)

Hamilton, Douglas R.; Sargsyan, Ashot E.; Martin, David S.; Garcia, Kathleen M.; Melton, Shannon L.; Feiveson, Alan; Dulchavsky, Scott A.

2010-01-01

Introduction A prospective trial of echocardiography was conducted on of six crewmembers onboard the International Space Station. The main objective was to determine the efficacy of remotely guided tele-echocardiography, including just-in-time e-training methods and determine what "space normal" echocardiographic data is. Methods Each crewmember operator (n=6) had 2-hour preflight training. Baseline echocardiographic data were collected 55 to 167days preflight. Similar equipment was used in each 60-minute in-flight session (mean microgravity exposure - 114 days (34 -- 190)). On Orbit ultrasound operators used an e-learning system within 24h of these sessions. Expert assistance was provided using ultrasound video downlink and two-way voice. Testing was repeated 5 to 16 days after landing. Separate ANOVA was used on each echocardiographic variable (n=33). Within each ANOVA, three tests were made: a) effect of mission phase (preflight, in-flight, post flight); b) effect of echo technician (two technicians independently analyzed the data); c) interaction between mission phase and technician. Results Nine rejections of the null hypothesis (mission phase or technician or both had no effect) were discovered and considered for follow up. Of these, six rejections were for significant technician effects, not as a result of space flight. Three rejections of the null hypothesis (Aortic Valve time velocity integral, Mitral E wave Velocity and heart rate) were attributable to space flight, however determined not to be clinically significant. No rejections were due to the interaction between technician and space flight. Conclusion No consistent clinically significant effects of long-duration space flight were seen in echocardiographic variables of the given group of subjects.

History and Benefits of Engine Level Testing Throughout the Space Shuttle Main Engine Program

NASA Technical Reports Server (NTRS)

VanHooser, Katherine; Kan, Kenneth; Maddux, Lewis; Runkle, Everett

2010-01-01

Rocket engine testing is important throughout a program s life and is essential to the overall success of the program. Space Shuttle Main Engine (SSME) testing can be divided into three phases: development, certification, and operational. Development tests are conducted on the basic design and are used to develop safe start and shutdown transients and to demonstrate mainstage operation. This phase helps form the foundation of the program, demands navigation of a very steep learning curve, and yields results that shape the final engine design. Certification testing involves multiple engine samples and more aggressive test profiles that explore the boundaries of the engine to vehicle interface requirements. The hardware being tested may have evolved slightly from that in the development phase. Operational testing is conducted with mature hardware and includes acceptance testing of flight assets, resolving anomalies that occur in flight, continuing to expand the performance envelope, and implementing design upgrades. This paper will examine these phases of testing and their importance to the SSME program. Examples of tests conducted in each phase will also be presented.

Three-Phase 3D Reconstruction of a LiCoO 2 Cathode via FIB-SEM Tomography

DOE PAGES

Liu, Zhao; Chen-Wiegart, Yu-chen K.; Wang, Jun; ...

2016-01-14

Three-phase three-dimensional (3D) microstructural reconstructions of lithium-ion battery electrodes are critical input for 3D simulations of electrode lithiation/delithiation, which provide a detailed understanding of battery operation. In this report, 3D images of a LiCoO 2electrode are achieved using focused ion beam-scanning electron microscopy (FIB-SEM), with clear contrast among the three phases: LiCoO 2particles, carbonaceous phases (carbon and binder) and the electrolyte space. The good contrast was achieved by utilizing an improved FIB-SEM sample preparation method that combined infiltration of the electrolyte space with a low-viscosity silicone resin and triple ion-beam polishing. Morphological parameters quantified include phase volume fraction, surface area,more » feature size distribution, connectivity, and tortuosity. Electrolyte tortuosity was determined using two different geometric calculations that were in good agreement. In conclusion, the electrolyte tortuosity distribution versus position within the electrode was found to be highly inhomogeneous; this will lead to inhomogeneous electrode lithiation/delithiation at high C-rates that could potentially cause battery degradation.« less

Aerospace applications of SINDA/FLUINT at the Johnson Space Center

NASA Technical Reports Server (NTRS)

Ewert, Michael K.; Bellmore, Phillip E.; Andish, Kambiz K.; Keller, John R.

1992-01-01

SINDA/FLUINT has been found to be a versatile code for modeling aerospace systems involving single or two-phase fluid flow and all modes of heat transfer. Several applications of SINDA/FLUINT are described in this paper. SINDA/FLUINT is being used extensively to model the single phase water loops and the two-phase ammonia loops of the Space Station Freedom active thermal control system (ATCS). These models range from large integrated system models with multiple submodels to very detailed subsystem models. An integrated Space Station ATCS model has been created with ten submodels representing five water loops, three ammonia loops, a Freon loop and a thermal submodel representing the air loop. The model, which has approximately 800 FLUINT lumps and 300 thermal nodes, is used to determine the interaction between the multiple fluid loops which comprise the Space Station ATCS. Several detailed models of the flow-through radiator subsystem of the Space Station ATCS have been developed. One model, which has approximately 70 FLUINT lumps and 340 thermal nodes, provides a representation of the ATCS low temperature radiator array with two fluid loops connected only by conduction through the radiator face sheet. The detailed models are used to determine parameters such as radiator fluid return temperature, fin efficiency, flow distribution and total heat rejection for the baseline design as well as proposed alternate designs. SINDA/FLUINT has also been used as a design tool for several systems using pressurized gasses. One model examined the pressurization and depressurization of the Space Station airlock under a variety of operating conditions including convection with the side walls and internal cooling. Another model predicted the performance of a new generation of manned maneuvering units. This model included high pressure gas depressurization, internal heat transfer and supersonic thruster equations. The results of both models were used to size components, such as the heaters and gas bottles and also to point to areas where hardware testing was needed.

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

Liu, Zhao; Chen-Wiegart, Yu-chen K.; Wang, Jun

Three-phase three-dimensional (3D) microstructural reconstructions of lithium-ion battery electrodes are critical input for 3D simulations of electrode lithiation/delithiation, which provide a detailed understanding of battery operation. In this report, 3D images of a LiCoO 2electrode are achieved using focused ion beam-scanning electron microscopy (FIB-SEM), with clear contrast among the three phases: LiCoO 2particles, carbonaceous phases (carbon and binder) and the electrolyte space. The good contrast was achieved by utilizing an improved FIB-SEM sample preparation method that combined infiltration of the electrolyte space with a low-viscosity silicone resin and triple ion-beam polishing. Morphological parameters quantified include phase volume fraction, surface area,more » feature size distribution, connectivity, and tortuosity. Electrolyte tortuosity was determined using two different geometric calculations that were in good agreement. In conclusion, the electrolyte tortuosity distribution versus position within the electrode was found to be highly inhomogeneous; this will lead to inhomogeneous electrode lithiation/delithiation at high C-rates that could potentially cause battery degradation.« less

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

Liu, Zhao; Chen-Wiegart, Yu-chen K.; Wang, Jun

Abstract Three-phase three-dimensional (3D) microstructural reconstructions of lithium-ion battery electrodes are critical input for 3D simulations of electrode lithiation/delithiation, which provide a detailed understanding of battery operation. In this report, 3D images of a LiCoO 2electrode are achieved using focused ion beam-scanning electron microscopy (FIB-SEM), with clear contrast among the three phases: LiCoO 2particles, carbonaceous phases (carbon and binder) and the electrolyte space. The good contrast was achieved by utilizing an improved FIB-SEM sample preparation method that combined infiltration of the electrolyte space with a low-viscosity silicone resin and triple ion-beam polishing. Morphological parameters quantified include phase volume fraction, surfacemore » area, feature size distribution, connectivity, and tortuosity. Electrolyte tortuosity was determined using two different geometric calculations that were in good agreement. The electrolyte tortuosity distribution versus position within the electrode was found to be highly inhomogeneous; this will lead to inhomogeneous electrode lithiation/delithiation at high C-rates that could potentially cause battery degradation.« less

Space shuttle orbital maneuvering engine platelet injector program

NASA Technical Reports Server (NTRS)

1975-01-01

A platelet face injector for the Orbit Maneuvering Engine (OME) on the space shuttle was evaluated as a means of obtaining additional design margin and lower cost. The program was conducted in three phases. The first phase evaluated single injection elements, or unielements; it involved visual flow studies, mixing experiments using propellant simulants, and hot firings to assess combustion efficiency, chamber wall compatibility, and injector face temperatures. In the second phase, subscale units producing 600 lbf thrust were used to further evaluate the orifice patterns chosen on the basis of unielement testing. In addition to combustion efficiency, chamber and injector heat transfer, the subscale testing provided a preliminary indication of injector stability. Full scale testing of the selected patterns at 6,000 lbf thrust was performed in the third phase. Performance, heat transfer, and combustion stability were evaluated over the anticipated range of OMS operating conditions. The effects on combustion stability of acoustic cavity configuration, including cavity depth, open area, inlet contour, and other parameters, were investigated.

Multi-megawatt inverter/converter technology for space power applications

NASA Technical Reports Server (NTRS)

Myers, Ira T.; Baumann, Eric D.; Kraus, Robert; Hammoud, Ahmad N.

1992-01-01

Large power conditioning mass reductions will be required to enable megawatt power systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. Phase 1 of a proposed two phase interagency program has been completed to develop an 0.1 kg/kW DC/DC converter technology base for these future space applications. Three contractors, Hughes, General Electric (GE), and Maxwell were Phase 1 contractors in a competitive program to develop a megawatt lightweight DC/DC converter. Researchers at NASA Lewis Research Center and the University of Wisconsin also investigated technology in topology and control. All three contractors, as well as the University of Wisconsin, concluded at the end of the Phase 1 study, which included some critical laboratory work, that 0.1-kg/kW megawatt DC/DC converters can be built. This is an order of magnitude lower specific weight than is presently available. A brief description of each of the concepts used to meet the ambitious goals of this program are presented.

The emotional symbolism of two English e-sounds: /i/ as in "cheap" is pleasant and /I/ as in "chip" active.

PubMed

Whissell, Cynthia

2003-02-01

This article aligns the symbolism of the long (/i/) and short (/I/) e sounds in English with the two dimensions of emotional space-Pleasantness and Activation. On the basis of this alignment, the four quadrants of emotional space are labelled Cheerful (high /i/, high /I/), Cheerless (low /i/, low /I/), Tough (low /i/, high /I/), and Tender (high /i/, low /I/). In four phases, data from over 50 samples (mainly, poetry, song lyrics, and names) were plotted and compared in terms of their use of the two e sounds. Significant and meaningful differences among samples were discovered in all phases. The placement of samples in quadrants was additionally informative. Data samples including many long e sounds (/i/) tended to be more Pleasant and those including many short e sounds (/I/) tended to be more Active.

Integrated Digital Flight Control System for the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

1973-01-01

The objectives of the integrated digital flight control system (DFCS) is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the computer complex and is equally insensitive to characteristics of the processor configuration. The integrated structure is described of the control system and the DFCS executive routine which embodies that structure. The input and output, including jet selection are included. Specific estimation and control algorithm are shown for the various mission phases: cruise (including horizontal powered flight), entry, on-orbit, and boost. Attitude maneuver routines that interface with the DFCS are included.

Experimental Evidence for a Structural-Dynamical Transition in Trajectory Space.

PubMed

Pinchaipat, Rattachai; Campo, Matteo; Turci, Francesco; Hallett, James E; Speck, Thomas; Royall, C Patrick

2017-07-14

Among the key insights into the glass transition has been the identification of a nonequilibrium phase transition in trajectory space which reveals phase coexistence between the normal supercooled liquid (active phase) and a glassy state (inactive phase). Here, we present evidence that such a transition occurs in experiments. In colloidal hard spheres, we find a non-Gaussian distribution of trajectories leaning towards those rich in locally favored structures (LFSs), associated with the emergence of slow dynamics. This we interpret as evidence for a nonequilibrium transition to an inactive LFS-rich phase. Reweighting trajectories reveals a first-order phase transition in trajectory space between a normal liquid and a LFS-rich phase. We also find evidence for a purely dynamical transition in trajectory space.

A Computer Model for Analyzing Volatile Removal Assembly

NASA Technical Reports Server (NTRS)

Guo, Boyun

2010-01-01

A computer model simulates reactional gas/liquid two-phase flow processes in porous media. A typical process is the oxygen/wastewater flow in the Volatile Removal Assembly (VRA) in the Closed Environment Life Support System (CELSS) installed in the International Space Station (ISS). The volatile organics in the wastewater are combusted by oxygen gas to form clean water and carbon dioxide, which is solved in the water phase. The model predicts the oxygen gas concentration profile in the reactor, which is an indicator of reactor performance. In this innovation, a mathematical model is included in the computer model for calculating the mass transfer from the gas phase to the liquid phase. The amount of mass transfer depends on several factors, including gas-phase concentration, distribution, and reaction rate. For a given reactor dimension, these factors depend on pressure and temperature in the reactor and composition and flow rate of the influent.

Research Objectives for Human Missions in the Proving Ground of Cis-Lunar Space

NASA Astrophysics Data System (ADS)

Spann, James; Niles, Paul; Eppler, Dean; Kennedy, Kriss; Lewis, Ruthan; Sullivan, Thomas

2016-07-01

Introduction: This talk will introduce the preliminary findings in support of NASA's Future Capabilities Team. In support of the ongoing studies conducted by NASA's Future Capabilities Team, we are tasked with collecting re-search objectives for the Proving Ground activities. The objectives could include but are certainly not limited to: demonstrating crew well being and performance over long duration missions, characterizing lunar volatiles, Earth monitoring, near Earth object search and identification, support of a far-side radio telescope, and measuring impact of deep space environment on biological systems. Beginning in as early as 2023, crewed missions beyond low Earth orbit will be enabled by the new capabilities of the SLS and Orion vehicles. This will initiate the "Proving Ground" phase of human exploration with Mars as an ultimate destination. The primary goal of the Proving Ground is to demonstrate the capability of suitably long dura-tion spaceflight without need of continuous support from Earth, i.e. become Earth Independent. A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fun-damental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In Situ Resource Utilization. Mapping and prioritizing the most important objectives from these disciplines will provide a strong foundation for establishing the architecture to be utilized in the Proving Ground. Possible Architectures: Activities and objectives will be accomplished during the Proving Ground phase using a deep space habitat. This habitat will potentially be accompanied by a power/propulsion bus capable of moving the habitat to accomplish different objectives within cis-lunar space. This architecture can also potentially support stag-ing of robotic and tele-robotic assets as well as sample-return. As mission durations increase from 20 days to 300 days, increasingly ambitious objectives may be undertaken in-cluding rendezvous with an asteroid or other near-Earth object. Research activities can occur inside the habitat, outside the habitat, via externally mounted instruments, or using free flying satellites/landers. Research Objectives: Primary mission objectives are listed below. In order to help define details of the mission architecture, including the means by which the architecture can be supported, more specific research objectives are needed. Title/Objective • Crew Transportation/Provide ability to transport at least four crew to cislunar space • Heavy Launch Capability/Provide beyond-LEO launch capabilities to include crew, co-manisfested pay-loads, and large cargo • In-Space Propulsion/Provide in-space propulsion capabilities to send crew and cargo on Mars-class mission durations and distances • Deep Space Navigation and Communication/Provide and validate cislunar and Mars system navigation and communication • Science/Enable science community objectives • Deep Space Operations/Provide deep-space operation capabilities: EVA, Staging, Logistics, Human-robotic integration, Autonomous operations • In-Situ Resource Utilization/Understand the nature and distribution of volatiles and extraction techniques, and decide on their potential use in the human exploration architecture • Deep Space Habitation/Provide beyond-LEO habitation systems sufficient to support at least four crew on Mars-class mission durations and dormancy • Crew Health/Validate crew health, performance, and mitigation protocols for Mars-class missions Reference: NASA, NASA's Journey to Mars: Pioneering Next Steps in Space Exploration. 34 ( October 8, 2015).

Pore-scale Simulation and Imaging of Multi-phase Flow and Transport in Porous Media (Invited)

NASA Astrophysics Data System (ADS)

Crawshaw, J.; Welch, N.; Daher, I.; Yang, J.; Shah, S.; Grey, F.; Boek, E.

2013-12-01

We combine multi-scale imaging and computer simulation of multi-phase flow and reactive transport in rock samples to enhance our fundamental understanding of long term CO2 storage in rock formations. The imaging techniques include Confocal Laser Scanning Microscopy (CLSM), micro-CT and medical CT scanning, with spatial resolutions ranging from sub-micron to mm respectively. First, we report a new sample preparation technique to study micro-porosity in carbonates using CLSM in 3 dimensions. Second, we use micro-CT scanning to generate high resolution 3D pore space images of carbonate and cap rock samples. In addition, we employ micro-CT to image the processes of evaporation in fractures and cap rock degradation due to exposure to CO2 flow. Third, we use medical CT scanning to image spontaneous imbibition in carbonate rock samples. Our imaging studies are complemented by computer simulations of multi-phase flow and transport, using the 3D pore space images obtained from the scanning experiments. We have developed a massively parallel lattice-Boltzmann (LB) code to calculate the single phase flow field in these pore space images. The resulting flow fields are then used to calculate hydrodynamic dispersion using a novel scheme to predict probability distributions for molecular displacements using the LB method and a streamline algorithm, modified for optimal solid boundary conditions. We calculate solute transport on pore-space images of rock cores with increasing degree of heterogeneity: a bead pack, Bentheimer sandstone and Portland carbonate. We observe that for homogeneous rock samples, such as bead packs, the displacement distribution remains Gaussian with time increasing. In the more heterogeneous rocks, on the other hand, the displacement distribution develops a stagnant part. We observe that the fraction of trapped solute increases from the beadpack (0 %) to Bentheimer sandstone (1.5 %) to Portland carbonate (8.1 %), in excellent agreement with PFG-NMR experiments. We then use our preferred multi-phase model to directly calculate flow in pore space images of two different sandstones and observe excellent agreement with experimental relative permeabilities. Also we calculate cluster size distributions in good agreement with experimental studies. Our analysis shows that the simulations are able to predict both multi-phase flow and transport properties directly on large 3D pore space images of real rocks. Pore space images, left and velocity distributions, right (Yang and Boek, 2013)

Thermodynamic curvature for attractive and repulsive intermolecular forces

NASA Astrophysics Data System (ADS)

May, Helge-Otmar; Mausbach, Peter; Ruppeiner, George

2013-09-01

The thermodynamic curvature scalar R for the Lennard-Jones system is evaluated in phase space, including vapor, liquid, and solid state. We paid special attention to the investigation of R along vapor-liquid, liquid-solid, and vapor-solid equilibria. Because R is a measure of interaction strength, we traced out the line R=0 dividing the phase space into regions with effectively attractive (R<0) or repulsive (R>0) interactions. Furthermore, we analyzed the dependence of R on the strength of attraction applying a perturbation ansatz proposed by Weeks-Chandler-Anderson. Our results show clearly a transition from R>0 (for poorly repulsive interaction) to R<0 when loading attraction in the intermolecular potential.

Linear canonical transformations of coherent and squeezed states in the Wigner phase space. III - Two-mode states

NASA Technical Reports Server (NTRS)

Han, D.; Kim, Y. S.; Noz, Marilyn E.

1990-01-01

It is shown that the basic symmetry of two-mode squeezed states is governed by the group SP(4) in the Wigner phase space which is locally isomorphic to the (3 + 2)-dimensional Lorentz group. This symmetry, in the Schroedinger picture, appears as Dirac's two-oscillator representation of O(3,2). It is shown that the SU(2) and SU(1,1) interferometers exhibit the symmetry of this higher-dimensional Lorentz group. The mathematics of two-mode squeezed states is shown to be applicable to other branches of physics including thermally excited states in statistical mechanics and relativistic extended hadrons in the quark model.

Experiences in the development of rotary joints for robotic manipulators in space applications

NASA Technical Reports Server (NTRS)

Priesett, Klaus

1992-01-01

European developments in robotics for space applications have resulted in human arm-like manipulators with six or more rotational degrees of freedom. The rotary joints including their own electromechanical actuator and feedback sensors must be very compact units. The specific joint concept is presented as evolved so far. The problems encountered during the first hardware development phases are covered on both component and joint level.

Apollo experience report: Flight planning for manned space operations

NASA Technical Reports Server (NTRS)

Oneill, J. W.; Cotter, J. B.; Holloway, T. W.

1972-01-01

The history of flight planning for manned space missions is outlined, and descriptions and examples of the various evolutionary phases of flight data documents from Project Mercury to the Apollo Program are included. Emphasis is given to the Apollo flight plan. Time line format and content are discussed in relationship to the manner in which they are affected by the types of flight plans and various constraints.

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

Podesta, M.; Gorelenkova, M.; Fredrickson, E. D.

Here, integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities,ad-hocmodels can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. Themore » kick model implemented in the tokamaktransport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.« less

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

Podestà, M., E-mail: mpodesta@pppl.gov; Gorelenkova, M.; Fredrickson, E. D.

Integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities, ad-hoc models can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions.more » The kick model implemented in the tokamak transport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.« less

Building the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2012-01-01

The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. JWST will make progress In almost every area of astronomy, from the first galaxies to form in the early universe to exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory Is confirmed for launch in 2018; the design is complete and it is in its construction phase. Innovations that make JWST possible include large-area low-noise infrared detectors, cryogenic ASICs, a MEMS micro-shutter array providing multi-object spectroscopy, a non-redundant mask for interferometric coronagraphy and diffraction-limited segmented beryllium mirrors with active wavefront sensing and control. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.

Inviscid and Viscous CFD Analysis of Booster Separation for the Space Launch System Vehicle

NASA Technical Reports Server (NTRS)

Dalle, Derek J.; Rogers, Stuart E.; Chan, William M.; Lee, Henry C.

2016-01-01

This paper presents details of Computational Fluid Dynamic (CFD) simulations of the Space Launch System during solid-rocket booster separation using the Cart3D inviscid and Overflow viscous CFD codes. The discussion addresses the use of multiple data sources of computational aerodynamics, experimental aerodynamics, and trajectory simulations for this critical phase of flight. Comparisons are shown between Cart3D simulations and a wind tunnel test performed at NASA Langley Research Center's Unitary Plan Wind Tunnel, and further comparisons are shown between Cart3D and viscous Overflow solutions for the flight vehicle. The Space Launch System (SLS) is a new exploration-class launch vehicle currently in development that includes two Solid Rocket Boosters (SRBs) modified from Space Shuttle hardware. These SRBs must separate from the SLS core during a phase of flight where aerodynamic loads are nontrivial. The main challenges for creating a separation aerodynamic database are the large number of independent variables (including orientation of the core, relative position and orientation of the boosters, and rocket thrust levels) and the complex flow caused by exhaust plumes of the booster separation motors (BSMs), which are small rockets designed to push the boosters away from the core by firing partially in the direction opposite to the motion of the vehicle.

Dynamic Testing of the NASA Hypersonic Project Combined Cycle Engine Testbed for Mode Transition Experiments

NASA Technical Reports Server (NTRS)

2011-01-01

NASA is interested in developing technology that leads to more routine, safe, and affordable access to space. Access to space using airbreathing propulsion systems has potential to meet these objectives based on Airbreathing Access to Space (AAS) system studies. To this end, the NASA Fundamental Aeronautics Program (FAP) Hypersonic Project is conducting fundamental research on a Turbine Based Combined Cycle (TBCC) propulsion system. The TBCC being studied considers a dual flow-path inlet system. One flow-path includes variable geometry to regulate airflow to a turbine engine cycle. The turbine cycle provides propulsion from take-off to supersonic flight. The second flow-path supports a dual-mode scramjet (DMSJ) cycle which would be initiated at supersonic speed to further accelerate the vehicle to hypersonic speed. For a TBCC propulsion system to accelerate a vehicle from supersonic to hypersonic speed, a critical enabling technology is the ability to safely and effectively transition from the turbine to the DMSJ-referred to as mode transition. To experimentally test methods of mode transition, a Combined Cycle Engine (CCE) Large-scale Inlet testbed was designed with two flow paths-a low speed flow-path sized for a turbine cycle and a high speed flow-path designed for a DMSJ. This testbed system is identified as the CCE Large-Scale Inlet for Mode Transition studies (CCE-LIMX). The test plan for the CCE-LIMX in the NASA Glenn Research Center (GRC) 10- by 10-ft Supersonic Wind Tunnel (10x10 SWT) is segmented into multiple phases. The first phase is a matrix of inlet characterization (IC) tests to evaluate the inlet performance and establish the mode transition schedule. The second phase is a matrix of dynamic system identification (SysID) experiments designed to support closed-loop control development at mode transition schedule operating points for the CCE-LIMX. The third phase includes a direct demonstration of controlled mode transition using a closed loop control system developed with the data obtained from the first two phases. Plans for a fourth phase include mode transition experiments with a turbine engine. This paper, focusing on the first two phases of experiments, presents developed operational and analysis tools for streamlined testing and data reduction procedures.

Phase-locked laser array having a non-uniform spacing between lasing regions

NASA Technical Reports Server (NTRS)

Ackley, Donald E. (Inventor)

1986-01-01

A phase-locked semiconductor array wherein the lasing regions of the array are spaced an effective distance apart such that the modes of oscillation of the different lasing regions are phase-locked to one another. The center-to-center spacing between the lasing regions is non-uniform. This variation in spacing perturbs the preferred 180.degree. phase difference between adjacent lasing regions thereby providing an increased yield of arrays exhibiting a single-lobed, far-field radiation pattern.

An effective method to accurately calculate the phase space factors for β - β - decay

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

Neacsu, Andrei; Horoi, Mihai

2016-01-01

Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates and for the analysis of the associated electron angular and energy distributions. Here, we present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet it allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.

Energy content of stormtime ring current from phase space mapping simulations

NASA Technical Reports Server (NTRS)

Chen, Margaret W.; Schulz, Michael; Lyons, Larry R.

1993-01-01

We perform a phase space mapping study to estimate the enhancement in energy content that results from stormtime particle transport in the equatorial magnetosphere. Our pre-storm phase space distribution is based on a steady-state transport model. Using results from guiding-center simulations of ion transport during model storms having main phases of 3 hr, 6 hr, and 12 hr, we map phase space distributions of ring current protons from the pre-storm distribution in accordance with Liouville's theorem. We find that transport can account for the entire ten to twenty-fold increase in magnetospheric particle energy content typical of a major storm if a realistic stormtime enhancement of the phase space density f is imposed at the nightside tail plasma sheet (represented by an enhancement of f at the neutral line in our model).

Lunar base heat pump

NASA Technical Reports Server (NTRS)

Goldman, Jeffrey H.; Tetreault, R.; Fischbach, D.; Walker, D.

1994-01-01

A heat pump is a device which elevates the temperature of a heat flow by a means of an energy input. By doing this, the heat pump can cause heat to transfer faster from a warm region to a cool region, or it can cause heat to flow from a cool region to a warmer region. The second case is the one which finds vast commercial applications such as air conditioning, heating, and refrigeration. Aerospace applications of heat pumps include both cases. The NASA Johnson Space Center is currently developing a Life Support Systems Integration Facility (LSSIF, previously SIRF) to provide system-level integration, operational test experience, and performance data that will enable NASA to develop flight-certified hardware for future planetary missions. A high lift heat pump is a significant part of the TCS hardware development associated with the LSSIF. The high lift heat pump program discussed here is being performed in three phases. In Phase 1, the objective is to develop heat pump concepts for a lunar base, a lunar lander, and for a ground development unit for the SIRF. In Phase 2, the design of the SIRF ground test unit is being performed, including identification and evaluation of safety and reliability issues. In Phase 3, the SIRF unit will be manufactured, tested, and delivered to the NASA Johnson Space Center.

Multi-MW Closed Cycle MHD Nuclear Space Power Via Nonequilibrium He/Xe Working Plasma

NASA Technical Reports Server (NTRS)

Litchford, Ron J.; Harada, Nobuhiro

2011-01-01

Prospects for a low specific mass multi-megawatt nuclear space power plant were examined assuming closed cycle coupling of a high-temperature fission reactor with magnetohydrodynamic (MHD) energy conversion and utilization of a nonequilibrium helium/xenon frozen inert plasma (FIP). Critical evaluation of performance attributes and specific mass characteristics was based on a comprehensive systems analysis assuming a reactor operating temperature of 1800 K for a range of subsystem mass properties. Total plant efficiency was expected to be 55.2% including plasma pre-ionization power, and the effects of compressor stage number, regenerator efficiency and radiation cooler temperature on plant efficiency were assessed. Optimal specific mass characteristics were found to be dependent on overall power plant scale with 3 kg/kWe being potentially achievable at a net electrical power output of 1-MWe. This figure drops to less than 2 kg/kWe when power output exceeds 3 MWe. Key technical issues include identification of effective methods for non-equilibrium pre-ionization and achievement of frozen inert plasma conditions within the MHD generator channel. A three-phase research and development strategy is proposed encompassing Phase-I Proof of Principle Experiments, a Phase-II Subscale Power Generation Experiment, and a Phase-III Closed-Loop Prototypical Laboratory Demonstration Test.

Quantization of Simple Parametrized Systems

NASA Astrophysics Data System (ADS)

Ruffini, Giulio

1995-01-01

I study the canonical formulation and quantization of some simple parametrized systems using Dirac's formalism and the Becchi-Rouet-Stora-Tyutin (BRST) extended phase space method. These systems include the parametrized particle and minisuperspace. Using Dirac's formalism I first analyze for each case the construction of the classical reduced phase space. There are two separate features of these systems that may make this construction difficult: (a) Because of the boundary conditions used, the actions are not gauge invariant at the boundaries. (b) The constraints may have a disconnected solution space. The relativistic particle and minisuperspace have such complicated constraints, while the non-relativistic particle displays only the first feature. I first show that a change of gauge fixing is equivalent to a canonical transformation in the reduced phase space, thus resolving the problems associated with the first feature above. Then I consider the quantization of these systems using several approaches: Dirac's method, Dirac-Fock quantization, and the BRST formalism. In the cases of the relativistic particle and minisuperspace I consider first the quantization of one branch of the constraint at the time and then discuss the backgrounds in which it is possible to quantize simultaneously both branches. I motivate and define the inner product, and obtain, for example, the Klein-Gordon inner product for the relativistic case. Then I show how to construct phase space path integral representations for amplitudes in these approaches--the Batalin-Fradkin-Vilkovisky (BFV) and the Faddeev path integrals --from which one can then derive the path integrals in coordinate space--the Faddeev-Popov path integral and the geometric path integral. In particular I establish the connection between the Hilbert space representation and the range of the lapse in the path integrals. I also examine the class of paths that contribute in the path integrals and how they affect space-time covariance, concluding that it is consistent to take paths that move forward in time only when there is no electric field. The key elements in this analysis are the space-like paths and the behavior of the action under the non-trivial ( Z_2) element of the reparametrization group.

KSC-2012-6451

NASA Image and Video Library

2012-12-10

CAPE CANAVERAL, Fla. - A new sign on Space Commerce Way marks the entrance to Exploration Park near NASA’s Kennedy space Center in Florida. Land in the background has been cleared for the first phase of construction. Exploration Park encompasses 60 acres just outside Kennedy’s security gates. The park is designed to be a strategically located complex, adjacent to the Space Life Sciences Laboratory, for servicing diverse tenants and uses that will engage in activities to support the space-related activities of NASA, other government agencies and the U.S. commercial space industry. Its nine sustainable, state-of-the art buildings will include educational, office, research and laboratory, and high bay facilities and provide 350,000-square-feet of work space. Photo credit: NASA/Jim Grossmann

Materials for Space: It's Challenging!

NASA Technical Reports Server (NTRS)

Johnson, Sylvia M.

2016-01-01

Space environments place tremendous demands on materials that must perform with exceptional reliability to realize the goals of human or robotic space exploration missions. Materials are subjected to extremes of temperature, pressure, radiation and mechanical loads during all phases of use, including takeoff and ascent, exposure to space or entry into an atmosphere, and operation in a planetary atmosphere. Space materials must be robust and enable the formation of lightweight structures or components that perform the required functions; materials that perform multiple functions are of particular interest. This talk will review the unique challenges for materials in space and some of the specific material capabilities that will be needed for future exploration missions. A description of needs and trends in thermal protection materials and systems will complete the talk.

KSC-2012-4419

NASA Image and Video Library

2012-08-15

CAPE CANAVERAL, Fla. -- A new sign on Space Commerce Way marks the entrance to Exploration Park near NASA’s Kennedy Space Center in Florida. Land in the background has been cleared for the first phase of construction. Exploration Park encompasses 60 acres just outside Kennedy’s security gates. The park is designed to be a strategically located complex, adjacent to the Space Life Sciences Laboratory, for servicing diverse tenants and uses that will engage in activities to support the space-related activities of NASA, other government agencies and the U.S. commercial space industry. Its nine sustainable, state-of-the art buildings will include educational, office, research and laboratory, and high bay facilities and provide 350,000-square-feet of work space. Photo credit: NASA/Dimitri Gerondidakis

The Potential of Phased Arrays for Planetary Exploration

NASA Astrophysics Data System (ADS)

Pogorzelski, Ronald J.

2000-01-01

Phased array antennas provide a set of operational capabilities which are very attractive for certain mission applications and not very attractive for others. Such antennas are by no means a panacea for telecommunications. In this paper the features of phased arrays are reviewed and their implications for space missions are considered in terms of benefits and costs. The primary capability provided by a phased array is electronic beam agility. The beam direction may be controlled at electronic speeds (vs. mechanical actuation) permitting time division multiplexing of multiple "users." Moreover, the beam direction can be varied over a full hemisphere (for a planar array). On the other hand, such antennas are typically much more complicated than the more commonly used reflectors and horns and this implies higher cost. In some applications, this increased cost must be accepted if the mission is to be carried out at all. The SIR-C radar is an example of such a case albeit not for deep space. Assuming for the sake of argument that the complexity and cost of a phased array can be significantly reduced, where can such antennas be of value in the future of planetary exploration? Potential applications to be discussed are planetary rovers, landers, and orbiters including both the areosynchronous and low orbit varieties. In addition, consideration is given to links from deep space to earth. As may be fairly obvious, the deep space link to earth would not benefit from the wide angle steering capability provided by a phase array whereas a rover could gain advantage from the capability to steer a beam anywhere in the sky. In the rover case, however, physical size of the aperture becomes a significant factor which, of course, has implications regarding the choice of frequency band. Recent research work concerning phased arrays has suggested that future phased arrays might be made less complex and, therefore, less costly. Successful realization of such phased arrays would enable many of the planetary missions discussed in this paper and significantly broaden the telecommunications capabilities available to the mission designers of the future.

Multi-objective optimization and design for free piston Stirling engines based on the dimensionless power

NASA Astrophysics Data System (ADS)

Mou, Jian; Hong, Guotong

2017-02-01

In this paper, the dimensionless power is used to optimize the free piston Stirling engines (FPSE). The dimensionless power is defined as a ratio of the heat power loss and the output work. The heat power losses include the losses of expansion space, heater, regenerator, cooler and the compression space and every kind of the heat loss calculated by empirical formula. The output work is calculated by the adiabatic model. The results show that 82.66% of the losses come from the expansion space and 54.59% heat losses of expansion space come from the shuttle loss. At different pressure the optimum bore-stroke ratio, heat source temperature, phase angle and the frequency have different values, the optimum phase angles increase with the increase of pressure, but optimum frequencies drop with the increase of pressure. However, no matter what the heat source temperature, initial pressure and frequency are, the optimum ratios of piston stroke and displacer stroke all about 0.8. The three-dimensional diagram is used to analyse Stirling engine. From the three-dimensional diagram the optimum phase angle, frequency and heat source temperature can be acquired at the same time. This study offers some guides for the design and optimization of FPSEs.

James Webb Space Telescope Optical Simulation Testbed: Segmented Mirror Phase Retrieval Testing

NASA Astrophysics Data System (ADS)

Laginja, Iva; Egron, Sylvain; Brady, Greg; Soummer, Remi; Lajoie, Charles-Philippe; Bonnefois, Aurélie; Long, Joseph; Michau, Vincent; Choquet, Elodie; Ferrari, Marc; Leboulleux, Lucie; Mazoyer, Johan; N’Diaye, Mamadou; Perrin, Marshall; Petrone, Peter; Pueyo, Laurent; Sivaramakrishnan, Anand

2018-01-01

The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a hardware simulator designed to produce JWST-like images. A model of the JWST three mirror anastigmat is realized with three lenses in form of a Cooke Triplet, which provides JWST-like optical quality over a field equivalent to a NIRCam module, and an Iris AO segmented mirror with hexagonal elements is standing in for the JWST segmented primary. This setup successfully produces images extremely similar to NIRCam images from cryotesting in terms of the PSF morphology and sampling relative to the diffraction limit.The testbed is used for staff training of the wavefront sensing and control (WFS&C) team and for independent analysis of WFS&C scenarios of the JWST. Algorithms like geometric phase retrieval (GPR) that may be used in flight and potential upgrades to JWST WFS&C will be explored. We report on the current status of the testbed after alignment, implementation of the segmented mirror, and testing of phase retrieval techniques.This optical bench complements other work at the Makidon laboratory at the Space Telescope Science Institute, including the investigation of coronagraphy for segmented aperture telescopes. Beyond JWST we intend to use JOST for WFS&C studies for future large segmented space telescopes such as LUVOIR.

Phase equilibria in polymer blend thin films: A Hamiltonian approach

NASA Astrophysics Data System (ADS)

Souche, M.; Clarke, N.

2009-12-01

We propose a Hamiltonian formulation of the Flory-Huggins-de Gennes theory describing a polymer blend thin film. We then focus on the case of 50:50 polymer blends confined between antisymmetric walls. The different phases of the system and the transitions between them, including finite-size effects, are systematically studied through their relation with the geometry of the Hamiltonian flow in phase space. This method provides an easy and efficient way, with strong graphical insight, to infer the qualitative physical behavior of polymer blend thin films.

Solar power satellite system definition study, volume 5. Phase 2: Final briefing

NASA Technical Reports Server (NTRS)

1979-01-01

A briefing outline of the definition study is presented. Topics discussed include: Solar Power Satellite (SPS) research and development, definition study, operations control, transportation, solid state SPS, pilot link analysis, and offshore space center.

Electric dipole moments in natural supersymmetry

NASA Astrophysics Data System (ADS)

Nakai, Yuichiro; Reece, Matthew

2017-08-01

We discuss electric dipole moments (EDMs) in the framework of CP-violating natural supersymmetry (SUSY). Recent experimental results have significantly tightened constraints on the EDMs of electrons and of mercury, and substantial further progress is expected in the near future. We assess how these results constrain the parameter space of natural SUSY. In addition to our discussion of SUSY, we provide a set of general formulas for two-loop fermion EDMs, which can be applied to a wide range of models of new physics. In the SUSY context, the two-loop effects of stops and charginos respectively constrain the phases of A t μ and M 2 μ to be small in the natural part of parameter space. If the Higgs mass is lifted to 125 GeV by a new tree-level superpotential interaction and soft term with CP-violating phases, significant EDMs can arise from the two-loop effects of W bosons and tops. We compare the bounds arising from EDMs to those from other probes of new physics including colliders, b → sγ, and dark matter searches. Importantly, improvements in reach not only constrain higher masses, but require the phases to be significantly smaller in the natural parameter space at low mass. The required smallness of phases sharpens the CP problem of natural SUSY model building.

Optimal use of human and machine resources for Space Station assembly operations

NASA Technical Reports Server (NTRS)

Parrish, Joseph C.

1988-01-01

This paper investigates the issues involved in determining the best mix of human and machine resources for assembly of the Space Station. It presents the current Station assembly sequence, along with descriptions of the available assembly resources. A number of methodologies for optimizing the human/machine tradeoff problem have been developed, but the Space Station assembly offers some unique issues that have not yet been addressed. These include a strong constraint on available EVA time for early flights and a phased deployment of assembly resources over time. A methodology for incorporating the previously developed decision methods to the special case of the Space Station is presented. This methodology emphasizes an application of multiple qualitative and quantitative techniques, including simulation and decision analysis, for producing an objective, robust solution to the tradeoff problem.

Modifications to the Objective Lightning Probability Forecast Tool at Kennedy Space Center/Cape Canaveral Air Force Station, Florida

NASA Technical Reports Server (NTRS)

Crawford, Winifred; Roeder, William

2010-01-01

The 45th Weather Squadron (45 WS) at Cape Canaveral Air Force Station (CCAFS) includes the probability of lightning occurrence in their 24-Hour and Weekly Planning Forecasts, briefed at 0700 EDT for daily operations planning on Kennedy Space Center (KSC) and CCAFS. This forecast is based on subjective analyses of model and observational data and output from an objective tool developed by the Applied Meteorology Unit (AMU). This tool was developed over two phases (Lambert and Wheeler 2005, Lambert 2007). It consists of five equations, one for each warm season month (May-Sep), that calculate the probability of lightning occurrence for the day and a graphical user interface (GUI) to display the output. The Phase I and II equations outperformed previous operational tools by a total of 56%. Based on this success, the 45 WS tasked the AMU with Phase III to improve the tool further.

Approach to developing reliable space reactor power systems

NASA Technical Reports Server (NTRS)

Mondt, Jack F.; Shinbrot, Charles H.

1991-01-01

During Phase II, the Engineering Development Phase, the SP-100 Project has defined and is pursuing a new approach to developing reliable power systems. The approach to developing such a system during the early technology phase is described along with some preliminary examples to help explain the approach. Developing reliable components to meet space reactor power system requirements is based on a top-down systems approach which includes a point design based on a detailed technical specification of a 100-kW power system. The SP-100 system requirements implicitly recognize the challenge of achieving a high system reliability for a ten-year lifetime, while at the same time using technologies that require very significant development efforts. A low-cost method for assessing reliability, based on an understanding of fundamental failure mechanisms and design margins for specific failure mechanisms, is being developed as part of the SP-100 Program.

Low-Cost Approaches to III–V Semiconductor Growth for Photovoltaic Applications

DOE PAGES

Greenaway, Ann L.; Boucher, Jason W.; Oener, Sebastian Z.; ...

2017-08-31

III–V semiconductors form the most efficient single- and multijunction photovoltaics. Metal–organic vapor-phase epitaxy, which uses toxic and pyrophoric gas-phase precursors, is the primary commercial growth method for these materials. In order for the use of highly efficient III–V-based devices to be expanded as the demand for renewable electricity grows, a lower-cost approach to the growth of these materials is needed. This Review focuses on three deposition techniques compatible with current device architectures: hydride vapor-phase epitaxy, close-spaced vapor transport, and thin-film vapor–liquid–solid growth. Here, we consider recent advances in each technique, including the available materials space, before providing an in-depth comparisonmore » of growth technology advantages and limitations and considering the impact of modifications to the method of production on the cost of the final photovoltaics.« less

Free-space laser communication technologies IV; Proceedings of the 4th Conference, Los Angeles, CA, Jan. 23, 24, 1992

NASA Technical Reports Server (NTRS)

Begley, David L. (Editor); Seery, Bernard D. (Editor)

1992-01-01

Papers included in this volume are grouped under topics of receivers; laser transmitters; components; system analysis, performance, and applications; and beam control (pointing, acquisition, and tracking). Papers are presented on an experimental determination of power penalty contributions in an optical Costas-type phase-locked loop receiver, a resonant laser receiver for free-space laser communications, a simple low-loss technique for frequency-locking lasers, direct phase modulation of laser diodes, and a silex beacon. Particular attention is given to experimental results on an optical array antenna for nonmechanical beam steering, a potassium Faraday anomalous dispersion optical filter, a 100-Mbps resonant cavity phase modulator for coherent optical communications, a numerical simulation of a 325-Mbit/s QPPM optical communication system, design options for an optical multiple-access data relay terminal, CCD-based optical tracking loop design trades, and an analysis of a spatial-tracking subsystem for optical communications.

Nutritional Status Assessment During the Phase IIA and Phase III Lunar/Mars Life Support Test Project

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Block, Gladys; Davis-Street, Janis E.; DeKerlegand, Diane E.; Fanselow, Stephanie A.; Fesperman, J. Vernell; Gillman, Patricia L.; Nillen, Jeannie I.; Rice, Barbara L.; Smith, Myra D.

2000-01-01

Nutrition is a critical concern for extended-duration space missions (Smith and Lane, 1999). Loss of body weight is a primary consequence of altered nutrition, and is frequently observed during space flight (Smith and Lane; 1999). Other existing dietary concerns for space flight include excessive intakes of sodium and iron, and insufficient intakes of water and vitamin D (Smith and Lane, 1999). Furthermore, dependence on closed or semi-closed food systems increases the likelihood of inadequate intakes of key nutrients. This is a significant concern for extended-duration space missions. Space nutrition research often necessitates detailed recording of all food consumption. While this yields extremely accurate data, it requires considerable time and effort, and thus is not suitable for routine medical monitoring during space flight. To alleviate this problem, a food frequency questionnaire (FFQ) was designed to provide a quick and easy, yet reasonably accurate, method for crewmembers to provide dietary intake information to the ground. We report here a study which was designed to assess nutritional status before, during, and after the 60-d and 91-d chamber stays. An additional goal of the study was to validate a food frequency questionnaire designed specifically for use with space flight food systems.

Space Environments and Spacecraft Effects Organization Concept

NASA Technical Reports Server (NTRS)

Edwards, David L.; Burns, Howard D.; Miller, Sharon K.; Porter, Ron; Schneider, Todd A.; Spann, James F.; Xapsos, Michael

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge of the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments disciplines that will help serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environments and spacecraft effects (SENSE) organization. This SENSE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Engineering effects focuses on the material, component, sub-system and system-level selection and the testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA, other federal government agencies, and the commercial sector to ensure that communications are well established and the needs of the programs are being met. The programmatic support function also includes working in coordination with the program in anomaly resolution and generation of lessons learned documentation. The goal of this space environment and spacecraft effects organization is to develop decision-making tools and engineering products to support all mission phases from mission concept through operations by focusing on transitioning research to application. Products generated by this space environments and effects application are suitable for use in anomaly investigations. This paper will describe the scope of the TWGs and their relationship to the functional areas, and discuss an organizational structure for this space environments and spacecraft effects organization.

A Study of Phased Array Antennas for NASA's Deep Space Network

NASA Technical Reports Server (NTRS)

Jamnejad, Vahraz; Huang, John; Cesarone, Robert J.

2001-01-01

In this paper we briefly discuss various options but focus on the feasibility of the phased arrays as a viable option for this application. Of particular concern and consideration will be the cost, reliability, and performance compared to the present 70-meter antenna system, particularly the gain/noise temperature levels in the receive mode. Many alternative phased arrays including planar horizontal arrays, hybrid mechanically/electronically steered arrays, phased array of mechanically steered reflectors, multi-faceted planar arrays, phased array-fed lens antennas, and planar reflect-arrays are compared and their viability is assessed. Although they have many advantages including higher reliability, near-instantaneous beam switching or steering capability, the cost of such arrays is presently prohibitive and it is concluded that the only viable array options at the present are the arrays of a few or many small reflectors. The active planar phased arrays, however, may become feasible options in the next decade and can be considered for deployment in smaller configurations as supplementary options.

Research Objectives for Human Missions in the Proving Ground of Cis-Lunar Space

NASA Astrophysics Data System (ADS)

Spann, James; Niles, Paul B.; Eppler, Dean B.; Kennedy, Kriss J.; Lewis, Ruthan.; Sullivan, Thomas A.

2016-04-01

Introduction: This talk will introduce the preliminary findings in support of NASA's Future Capabilities Team. In support of the ongoing studies conducted by NASA's Future Capabilities Team, we are tasked with collecting research objectives for the Proving Ground activities. The objectives could include but are certainly not limited to: demonstrating crew well being and performance over long duration missions, characterizing lunar volatiles, Earth monitoring, near Earth object search and identification, support of a far-side radio telescope, and measuring impact of deep space environment on biological systems. Beginning in as early as 2023, crewed missions beyond low Earth orbit will begin enabled by the new capabilities of the SLS and Orion vehicles. This will initiate the "Proving Ground" phase of human exploration with Mars as an ultimate destination. The primary goal of the Proving Ground is to demonstrate the capability of suitably long duration spaceflight without need of continuous support from Earth, i.e. become Earth Independent. A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fundamental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In Situ Resource Utilization. Mapping and prioritizing the most important objectives from these disciplines will provide a strong foundation for establishing the architecture to be utilized in the Proving Ground. Possible Architectures: Activities and objectives will be accomplished during the Proving Ground phase using a deep space habitat. This habitat will potentially be accompanied by a power/propulsion bus capable of moving the habitat to accomplish different objectives within cis-lunar space. This architecture can also potentially support staging of robotic and tele-robotic assets as well as sample-return. As mission durations increase from 20 days to 300 days, increasingly ambitious objectives may be undertaken including rendezvous with an asteroid or other near-Earth object. Research activities can occur inside the habitat, outside the habitat, via externally mounted instruments, or using free flying satellites/landers. Research Objectives: Primary mission objectives are listed below. In order to help define details of the mission architecture, including the means by which the architecture can be supported, more specific research objectives are needed. Title/Objective Crew Transportation/Provide ability to transport at least four crew to cislunar space Heavy Launch Capability/Provide beyond LEO launch capabilities to include crew, co-manisfested payloads, and large cargo In-Space Propulsion/Provide in-sapce propulsion capabilities to send crew and cargo on Mars-class mission durations and distances Deep Space Navigation and Communication/Provide and validate cislunar and Mars system navigation and communication Science/Enable science community objectives Deep Space Operations/Provide deep-space operation capabilities: EVA, Staging, Logistics, Human-robotic integration, Autonomous operations In-Situ Resource Utilization/Understand the nature and distribution of volatiles and extraction techniques, and decide on their potential use in the human exploration architecture Deep Space Habitation/Provide beyond LEO habitation systems sufficient to support at least four crew on Mars-class mission durations and dormancy Crew Health/Validate crew health, performance, and mitigation protocols for Mars-class missions Reference: .NASA, NASA's Journey to Mars: Pioneering Next Steps in Space Exploration. 34 ( October 8, 2015).

Progress in low-resolution ab initio phasing with CrowdPhase

DOE PAGES

Jorda, Julien; Sawaya, Michael R.; Yeates, Todd O.

2016-03-01

Ab initio phasing by direct computational methods in low-resolution X-ray crystallography is a long-standing challenge. A common approach is to consider it as two subproblems: sampling of phase space and identification of the correct solution. While the former is amenable to a myriad of search algorithms, devising a reliable target function for the latter problem remains an open question. Here, recent developments in CrowdPhase, a collaborative online game powered by a genetic algorithm that evolves an initial population of individuals with random genetic make-up ( i.e. random phases) each expressing a phenotype in the form of an electron-density map, aremore » presented. Success relies on the ability of human players to visually evaluate the quality of these maps and, following a Darwinian survival-of-the-fittest concept, direct the search towards optimal solutions. While an initial study demonstrated the feasibility of the approach, some important crystallographic issues were overlooked for the sake of simplicity. To address these, the new CrowdPhase includes consideration of space-group symmetry, a method for handling missing amplitudes, the use of a map correlation coefficient as a quality metric and a solvent-flattening step. Lastly, performances of this installment are discussed for two low-resolution test cases based on bona fide diffraction data.« less

Progress in low-resolution ab initio phasing with CrowdPhase

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

Jorda, Julien; Sawaya, Michael R.; Yeates, Todd O.

Ab initio phasing by direct computational methods in low-resolution X-ray crystallography is a long-standing challenge. A common approach is to consider it as two subproblems: sampling of phase space and identification of the correct solution. While the former is amenable to a myriad of search algorithms, devising a reliable target function for the latter problem remains an open question. Here, recent developments in CrowdPhase, a collaborative online game powered by a genetic algorithm that evolves an initial population of individuals with random genetic make-up ( i.e. random phases) each expressing a phenotype in the form of an electron-density map, aremore » presented. Success relies on the ability of human players to visually evaluate the quality of these maps and, following a Darwinian survival-of-the-fittest concept, direct the search towards optimal solutions. While an initial study demonstrated the feasibility of the approach, some important crystallographic issues were overlooked for the sake of simplicity. To address these, the new CrowdPhase includes consideration of space-group symmetry, a method for handling missing amplitudes, the use of a map correlation coefficient as a quality metric and a solvent-flattening step. Lastly, performances of this installment are discussed for two low-resolution test cases based on bona fide diffraction data.« less

The Role of Independent Assessment in the International Space Station Program

NASA Technical Reports Server (NTRS)

Strachan, Russell L.; Cook, David B.; Baker, Hugh A.

1999-01-01

This paper presents the role of Independent Assessment in the International Space Station (ISS) Program. Independent Assessment is responsible for identifying and specifying technical and programmatic risks that may impact development, launch, and on-orbit assembly and operations of the ISS. The various phases of the assessment process are identified and explained. This paper also outlines current and future participation by Independent Assessment in Human Exploration and Development of Space projects including the X-38 Space Plane, Mars mission scenarios, and applications of Nanotechnology. This paper describes how Independent Assessment helps the shuttle, ISS, and other programs to safely achieve mission goals now and into the next century.

Phase space quantum mechanics - Direct

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

Nasiri, S.; Sobouti, Y.; Taati, F.

2006-09-15

Conventional approach to quantum mechanics in phase space (q,p), is to take the operator based quantum mechanics of Schroedinger, or an equivalent, and assign a c-number function in phase space to it. We propose to begin with a higher level of abstraction, in which the independence and the symmetric role of q and p is maintained throughout, and at once arrive at phase space state functions. Upon reduction to the q- or p-space the proposed formalism gives the conventional quantum mechanics, however, with a definite rule for ordering of factors of noncommuting observables. Further conceptual and practical merits of themore » formalism are demonstrated throughout the text.« less

Classical-Quantum Correspondence by Means of Probability Densities

NASA Technical Reports Server (NTRS)

Vegas, Gabino Torres; Morales-Guzman, J. D.

1996-01-01

Within the frame of the recently introduced phase space representation of non relativistic quantum mechanics, we propose a Lagrangian from which the phase space Schrodinger equation can be derived. From that Lagrangian, the associated conservation equations, according to Noether's theorem, are obtained. This shows that one can analyze quantum systems completely in phase space as it is done in coordinate space, without additional complications.

Space Phase III - The commercial era dawns

NASA Technical Reports Server (NTRS)

Allnutt, R. F.

1983-01-01

After the 'Phase I' of space activities, the period bounded by Sputnik and Apollo, 'Phase II', has been entered, a phase in which concerns over the use and the protection of space assets which support national security predominate. However, it is only when the commercial motive becomes prominent that human activity in new regions truly prospers and enters periods of exponential growth. It is believed that there are increasing signs that such a period, called 'Space Phase III', may be coming soon. A description is presented of developments and results upon which this conclusion is based. Since 1980, there have been three developments of great importance for the future of space activities. Six highly successful flights have demonstrated that the Space Shuttle concept works. A series of Soviet missions are related to the emergence of a capability to construct and service modular space stations. Successful tests of the European Ariane 1 indicate an end to U.S. monopoly with respect to the provision of launch services to the Western World.

Phase-space reaction network on a multisaddle energy landscape: HCN isomerization.

PubMed

Li, Chun-Biu; Matsunaga, Yasuhiro; Toda, Mikito; Komatsuzaki, Tamiki

2005-11-08

By using the HCN/CNH isomerization reaction as an illustrative vehicle of chemical reactions on multisaddle energy landscapes, we give explicit visualizations of molecular motions associated with a straight-through reaction tube in the phase space inside which all reactive trajectories pass from one basin to another, with eliminating recrossing trajectories in the configuration space. This visualization provides us with a chemical intuition of how chemical species "walk along" the reaction-rate slope in the multidimensional phase space compared with the intrinsic reaction path in the configuration space. The distinct nonergodic features in the two different HCN and CNH wells can be easily demonstrated by a section of Poincare surface of section in those potential minima, which predicts in a priori the pattern of trajectories residing in the potential well. We elucidate the global phase-space structure which gives rise to the non-Markovian dynamics or the dynamical correlation of sequential multisaddle chemical reactions. The phase-space structure relevant to the controllability of the product state in chemical reactions is also discussed.

Expanding the term "Design Space" in high performance liquid chromatography (I).

PubMed

Monks, K E; Rieger, H-J; Molnár, I

2011-12-15

The current article presents a novel approach to applying Quality by Design (QbD) principles to the development of high pressure reversed phase liquid chromatography (HPLC) methods. Four common critical parameters in HPLC--gradient time, temperature, pH of the aqueous eluent, and stationary phase--are evaluated within the Quality by Design framework by the means of computer modeling software and a column database, to a satisfactory degree. This work proposes the establishment of two mutually complimentary Design Spaces to fully depict a chromatographic method; one Column Design Space (CDS) and one Eluent Design Space (EDS) to describe the influence of the stationary phase and of the mobile phase on the separation selectivity, respectively. The merge of both Design Spaces into one is founded on the continuous nature of the mobile phase influence on retention and the great variety of the stationary phases available. Copyright © 2011 Elsevier B.V. All rights reserved.

An approach for automated fault diagnosis based on a fuzzy decision tree and boundary analysis of a reconstructed phase space.

PubMed

Aydin, Ilhan; Karakose, Mehmet; Akin, Erhan

2014-03-01

Although reconstructed phase space is one of the most powerful methods for analyzing a time series, it can fail in fault diagnosis of an induction motor when the appropriate pre-processing is not performed. Therefore, boundary analysis based a new feature extraction method in phase space is proposed for diagnosis of induction motor faults. The proposed approach requires the measurement of one phase current signal to construct the phase space representation. Each phase space is converted into an image, and the boundary of each image is extracted by a boundary detection algorithm. A fuzzy decision tree has been designed to detect broken rotor bars and broken connector faults. The results indicate that the proposed approach has a higher recognition rate than other methods on the same dataset. © 2013 ISA Published by ISA All rights reserved.

Transverse emittance and phase space program developed for use at the Fermilab A0 Photoinjector

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

Thurman-Keup, R.; Johnson, A.S.; Lumpkin, A.H.

2011-03-01

The Fermilab A0 Photoinjector is a 16 MeV high intensity, high brightness electron linac developed for advanced accelerator R&D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties. An integral part of accelerator research is a measurement of the beam phase space. Measurements of the transverse phase space can be accomplished by a variety of methods includingmore » multiple screens separated by drift spaces, or by sampling phase space via pepper pots or slits. In any case, the measurement of the phase space parameters, in particular the emittance, can be drastically simplified and sped up by automating the measurement in an intuitive fashion utilizing a graphical interface. At the A0 Photoinjector (A0PI), the control system is DOOCS, which originated at DESY. In addition, there is a library for interfacing to MATLAB, a graphically capable numerical analysis package sold by The Mathworks. It is this graphical package which was chosen as the basis for a graphical phase space measurement system due to its combination of analysis and display capabilities.« less

NASA Research Announcement Phase 1 Report and Phase 2 Proposal for the Development of a Power Assisted Space Suit Glove Assembly

NASA Technical Reports Server (NTRS)

Cadogan, Dave; Lingo, Bob

1996-01-01

In July of 1996, ILC Dover was awarded Phase 1 of a contract for NASA to develop a prototype Power Assisted Space Suit glove to enhance the performance of astronauts during Extra-Vehicular Activity (EVA). This report summarizes the work performed to date on Phase 1, and details the work to be conducted on Phase 2 of the program. Phase 1 of the program consisted of research and review of related technical sources, concept brainstorming, baseline design development, modeling and analysis, component mock-up testing, and test data analysis. ILC worked in conjunction with the University of Maryland's Space Systems Laboratory (SSL) to develop the power assisted glove. Phase 2 activities will focus on the design maturation and the manufacture of a working prototype system. The prototype will be tested and evaluated in conjunction with existing space suit glove technology to determine the performance enhancement anticipated with the implementation of the power assisted joint technology in space suit gloves.

Efficient characterization of phase space mapping in axially symmetric optical systems

NASA Astrophysics Data System (ADS)

Barbero, Sergio; Portilla, Javier

2018-01-01

Phase space mapping, typically between an object and image plane, characterizes an optical system within a geometrical optics framework. We propose a novel conceptual frame to characterize the phase mapping in axially symmetric optical systems for arbitrary object locations, not restricted to a specific object plane. The idea is based on decomposing the phase mapping into a set of bivariate equations corresponding to different values of the radial coordinate on a specific object surface (most likely the entrance pupil). These equations are then approximated through bivariate Chebyshev interpolation at Chebyshev nodes, which guarantees uniform convergence. Additionally, we propose the use of a new concept (effective object phase space), defined as the set of points of the phase space at the first optical element (typically the entrance pupil) that are effectively mapped onto the image surface. The effective object phase space provides, by means of an inclusion test, a way to avoid tracing rays that do not reach the image surface.

Families of vector-like deformations of relativistic quantum phase spaces, twists and symmetries

NASA Astrophysics Data System (ADS)

Meljanac, Daniel; Meljanac, Stjepan; Pikutić, Danijel

2017-12-01

Families of vector-like deformed relativistic quantum phase spaces and corresponding realizations are analyzed. A method for a general construction of the star product is presented. The corresponding twist, expressed in terms of phase space coordinates, in the Hopf algebroid sense is presented. General linear realizations are considered and corresponding twists, in terms of momenta and Poincaré-Weyl generators or gl(n) generators are constructed and R-matrix is discussed. A classification of linear realizations leading to vector-like deformed phase spaces is given. There are three types of spaces: (i) commutative spaces, (ii) κ -Minkowski spaces and (iii) κ -Snyder spaces. The corresponding star products are (i) associative and commutative (but non-local), (ii) associative and non-commutative and (iii) non-associative and non-commutative, respectively. Twisted symmetry algebras are considered. Transposed twists and left-right dual algebras are presented. Finally, some physical applications are discussed.

Active debris removal GNC challenges over design and required ground validation

NASA Astrophysics Data System (ADS)

Colmenarejo, Pablo; Avilés, Marcos; di Sotto, Emanuele

2015-06-01

Because of the exponential growth of space debris, the access to space in the medium-term future is considered as being seriously compromised, particularly within LEO polar Sun-synchronous orbits and within geostationary orbits. The active debris removal (ADR) application poses new and challenging requirements on: first, the new required Guidance, Navigation and Control (GNC) technologies and, second, how to validate these new technologies before being applied in real missions. There is no doubt about the strong safety and collision risk aspects affecting the real operational ADR missions. But it shall be considered that even ADR demonstration missions will be affected by significant risk of collision during the demonstration, and that the ADR GNC systems/technologies to be used shall be well mature before using/demonstrating them in space. Specific and dedicated on-ground validation approaches, techniques and facilities are mandatory. The different ADR techniques can be roughly catalogued in three main groups (rigid capture, non-rigid capture and contactless). All of them have a strong impact on the GNC system of the active vehicle during the capture/proximity phase and, particularly, during the active vehicle/debris combo control phase after capture and during the de-orbiting phase. The main operational phases on an ADR scenario are: (1) ground controlled phase (ADR vehicle and debris are far), (2) fine orbit synchronization phase (ADR vehicle to reach debris ±V-bar), (3) short range phase (along track distance reduction till 10-100 s of metres), (4) terminal approach/capture phase and (5) de-orbiting. While phases 1-3 are somehow conventional and already addressed in detail during past/on-going studies related to rendezvous and/or formation flying, phases 4-5 are very specific and not mature in terms of GNC needed technologies and HW equipment. GMV is currently performing different internal activities and ESA studies/developments related to ADR mission, GNC and capture technologies. This paper focuses on some specific aspects and technologies related to ADR terminal phases involved technologies and ground validation approaches: (1) Terminal ADR approach phase using visual-based navigation (VBN). Potential Image Processing techniques and preliminary performances will be described, together with the challenge of generating on-ground realistic images as input for the HW/SW VBN system. Some results of image generation (including comparison with real flight image missions) and processing using GMV's Optical Laboratory (image generation by rendering spacecraft 3D models and projecting on a screen in front of the HW camera) and using GMV's platform-art ® laboratory to reproduce space-realistic physical scenarios (to be captured by a HW camera) using 1:1 physical spacecraft mock-ups in an absolutely dark environment with a Sun-like single illumination source. (2) Ground validation of GNC systems based on HW-in-the-Loop (HIL) test facilities, including realistic space-representative avionics (at processor, interfaces and real-time operating system), realistic and air-to-air stimulated breadboard perception sensors (IMU, optical cameras, laser 3D sensors) through the use of dynamic robotic devices hosting the active vehicle and debris mock-ups and reproducing accurately the spatial relative dynamic corresponding to an ADR scenario. This type of ground validation can effectively achieve validation in relevant environment, till TRL (Technology Readiness Level) 5/6 on ground and minimizing the uncertainty/risk of such technologies/systems with respect to its operational use. Description and video demonstration of some ADR applicable test case/s using GMV's platform-art ® dynamic test facility will be included. Particular attention will be paid on the needed type of structural/functional active ADR vehicle and debris mock-ups, force/torque measurement and feedback capability over debris contact or momentum exchange actions, ground gravity compensation.

Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986

NASA Technical Reports Server (NTRS)

Holland, Albert W. (Editor)

1987-01-01

Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.

Self-dual phase space for (3 +1 )-dimensional lattice Yang-Mills theory

NASA Astrophysics Data System (ADS)

Riello, Aldo

2018-01-01

I propose a self-dual deformation of the classical phase space of lattice Yang-Mills theory, in which both the electric and magnetic fluxes take value in the compact gauge Lie group. A local construction of the deformed phase space requires the machinery of "quasi-Hamiltonian spaces" by Alekseev et al., which is reviewed here. The results is a full-fledged finite-dimensional and gauge-invariant phase space, the self-duality properties of which are largely enhanced in (3 +1 ) spacetime dimensions. This enhancement is due to a correspondence with the moduli space of an auxiliary noncommutative flat connection living on a Riemann surface defined from the lattice itself, which in turn equips the duality between electric and magnetic fluxes with a neat geometrical interpretation in terms of a Heegaard splitting of the space manifold. Finally, I discuss the consequences of the proposed deformation on the quantization of the phase space, its quantum gravitational interpretation, as well as its relevance for the construction of (3 +1 )-dimensional topological field theories with defects.

Longitudinal phase space tomography using a booster cavity at PITZ

NASA Astrophysics Data System (ADS)

Malyutin, D.; Gross, M.; Isaev, I.; Khojoyan, M.; Kourkafas, G.; Krasilnikov, M.; Marchetti, B.; Otevrel, M.; Stephan, F.; Vashchenko, G.

2017-11-01

The knowledge of the longitudinal phase space (LPS) of electron beams is of great importance for optimizing the performance of high brightness photo injectors. To get the longitudinal phase space of an electron bunch in a linear accelerator a tomographic technique can be used. The method is based on measurements of the bunch momentum spectra while varying the bunch energy chirp. The energy chirp can be varied by one of the RF accelerating structures in the accelerator and the resulting momentum distribution can be measured with a dipole spectrometer further downstream. As a result, the longitudinal phase space can be reconstructed. Application of the tomographic technique for reconstruction of the longitudinal phase space is introduced in detail in this paper. Measurement results from the PITZ facility are shown and analyzed.

A Phase-Space Approach to Collisionless Stellar Systems Using a Particle Method

NASA Astrophysics Data System (ADS)

Hozumi, Shunsuke

1997-10-01

A particle method for reproducing the phase space of collisionless stellar systems is described. The key idea originates in Liouville's theorem, which states that the distribution function (DF) at time t can be derived from tracing necessary orbits back to t = 0. To make this procedure feasible, a self-consistent field (SCF) method for solving Poisson's equation is adopted to compute the orbits of arbitrary stars. As an example, for the violent relaxation of a uniform density sphere, the phase-space evolution generated by the current method is compared to that obtained with a phase-space method for integrating the collisionless Boltzmann equation, on the assumption of spherical symmetry. Excellent agreement is found between the two methods if an optimal basis set for the SCF technique is chosen. Since this reproduction method requires only the functional form of initial DFs and does not require any assumptions to be made about the symmetry of the system, success in reproducing the phase-space evolution implies that there would be no need of directly solving the collisionless Boltzmann equation in order to access phase space even for systems without any special symmetries. The effects of basis sets used in SCF simulations on the reproduced phase space are also discussed.

Early Program Development

NASA Image and Video Library

1970-01-01

In 1970, NASA initiated Phase A contracts to study alternate Space Shuttle designs in addition to the two-stage fully-reusable Space Shuttle system already under development. A number of alternate systems were developed to ensure the development of the optimum earth-to-orbit system, including the Stage-and-a-half Chemical Interorbital Shuttle, shown here. The concept would utilize a reusable marned spacecraft with an onboard propulsion system attached to an expendable fuel tank to provide supplementary propellants.

Space station electric power system requirements and design

NASA Technical Reports Server (NTRS)

Teren, Fred

1987-01-01

An overview of the conceptual definition and design of the space station Electric Power System (EPS) is given. Responsibilities for the design and development of the EPS are defined. The EPS requirements are listed and discussed, including average and peak power requirements, contingency requirements, and fault tolerance. The most significant Phase B trade study results are summarized, and the design selections and rationale are given. Finally, the power management and distribution system architecture is presented.

Evolution of Government and Industrial Partnerships to Open the Space Frontier

NASA Technical Reports Server (NTRS)

Martin, Gary L.

2008-01-01

If the logical extension of the current exploration program is to develop self-sustaining settlements on the Moon and Mars over the next few centuries, then there is a path that takes civilization from its current one planet existence to a multi-world future. By considering the far term goal of space settlements as a desired endpoint and using the current state as a starting point, the policy drivers and potential pathways to the goal of sustainable space settlements can be explored. This paper describes a three-phased evolution of government and industrial partnerships from current day relationships to a time when there are sustainable settlements in space. Phase I details the current state government-led exploration while Phase III describes a desired endpoint of self-sufficient settlements in space. Phase II is an important transition phase, which acts as a bridge between now and the future. This paper discusses the critical evolution that must take place in two key areas to ensure a thriving future in space; space transportation and the right to use space property and resources. This paper focuses on the enabling role of government necessary to achieve United States (U.S.) goals for space exploration and open the frontier.

Tandem resonator reflectance modulator

DOEpatents

Fritz, I.J.; Wendt, J.R.

1994-09-06

A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

Simulation of multiple scattering in a medium with an anisotropic scattering pattern

NASA Astrophysics Data System (ADS)

Kuzmin, V. L.; Val'kov, A. Yu.

2017-03-01

Multiple backscattering from layers with various thicknesses, including the case of half-space, is numerically simulated and a comparative analysis is performed for systems with the anisotropy of scattering described by the Henyey-Greenstein and Rayleigh-Gans phase functions. It is shown that the intensity of backscattering depends on the form of the phase function; the difference between the intensities obtained within the two models increases with anisotropy.

Common Aperture Techniques for Imaging Electro-Optical Sensors (CATIES).

DTIC Science & Technology

1980-02-01

milliradians ) at the 5.33:1 zoom point. The zoom optics contain five elements with two moveable air -spaced doublets for accomplishing the zoom function...included in the electrical and optical design but due to funding limitations, system safety requirements during the testing phase and lack of long-term...determined during the system testing phase to be conducted by the Air Force. Limited electronic signal processing (split screen and video mix) was

GPS and GLONASS 1 Hz phase rate observations to study high latitudes ionospheric irregularities

NASA Astrophysics Data System (ADS)

Ghoddousi-Fard, R.; Prikryl, P.; Jacobsen, K. S.; Lahaye, F.

2016-12-01

It has been shown that dual frequency 1 Hz GPS phase rate observations can serve as a promising proxy for phase scintillation over high latitudes (see e.g. Ghoddousi-Fard et al., 2013, 2015). However signals from other GNSS constellations including GLONASS have been available and widely used for positioning applications. Usage of additional GNSS constellations should allow improved sampling of the ionosphere, a critical advantage to study small scale ionospheric irregularities over high latitudes. Migration of global GPS networks to multi-GNSS are now underway such as International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) and other national, public and private sector networks. In this presentation, GPS and GLONASS observations from high latitude MGEX stations as well as a dense regional network over Norway are used to map high latitude ionospheric irregularities by means of standard deviation of phase rate variations. Occurrence of GPS phase irregularities as a function of magnetic latitude and local time are compared with those from both GPS and GLONASS. By including 1 Hz GLONASS measurements at about 185 stations over Norway during geomagnetic storm of March 17-18, 2015, this study complements a recently submitted paper that examined the GPS phase scintillation occurrence in the context of solar wind coupling to the magnetosphere-ionosphere system and auroral electrojet currents (Prikryl et al., 2016). Ghoddousi-Fard et al. (2013). GPS phase difference variation statistics: A comparison between phase scintillation index and proxy indices. Adv. Space Res., 52, 1397-1405, doi: 10.1016/j.asr.2013.06.035. Ghoddousi-Fard et al. (2015). Analysis of GPS phase rate variations in response to geomagnetic field perturbations over the Canadian auroral region. Adv. Space Res., 55, 1372-1381, doi: 10.1016/j.asr.2014.12.021. Prikryl et al. (2016). GPS phase scintillation at high latitudes during the geomagnetic storm of March 17-18, 2015, submitted to J. Geophys. Res. ESS contribution number: 20160112

Virtual Auditory Space Training-Induced Changes of Auditory Spatial Processing in Listeners with Normal Hearing.

PubMed

Nisha, Kavassery Venkateswaran; Kumar, Ajith Uppunda

2017-04-01

Localization involves processing of subtle yet highly enriched monaural and binaural spatial cues. Remediation programs aimed at resolving spatial deficits are surprisingly scanty in literature. The present study is designed to explore the changes that occur in the spatial performance of normal-hearing listeners before and after subjecting them to virtual acoustic space (VAS) training paradigm using behavioral and electrophysiological measures. Ten normal-hearing listeners participated in the study, which was conducted in three phases, including a pre-training, training, and post-training phase. At the pre- and post-training phases both behavioral measures of spatial acuity and electrophysiological P300 were administered. The spatial acuity of the participants in the free field and closed field were measured apart from quantifying their binaural processing abilities. The training phase consisted of 5-8 sessions (20 min each) carried out using a hierarchy of graded VAS stimuli. The results obtained from descriptive statistics were indicative of an improvement in all the spatial acuity measures in the post-training phase. Statistically, significant changes were noted in interaural time difference (ITD) and virtual acoustic space identification scores measured in the post-training phase. Effect sizes (r) for all of these measures were substantially large, indicating the clinical relevance of these measures in documenting the impact of training. However, the same was not reflected in P300. The training protocol used in the present study on a preliminary basis proves to be effective in normal-hearing listeners, and its implications can be extended to other clinical population as well.

SPACE MEDICINE and Medical Operations Overview

NASA Technical Reports Server (NTRS)

Dervay, Joe

2009-01-01

This presentation is an overview of the function of the work of the Space Medicine & Health Care Systems Office. The objective of the medical operations is to ensure the health, safety and well being of the astronaut corps and ground support team during all phases of space flight. There are many issues that impact the health of the astronauts. Some of them are physiological, and others relate to behavior, psychological issues and issues of the environment of space itself. Reviews of the medical events that have affected both Russian, and Americans while in space are included. Some views of shuttle liftoff, and ascent, the medical training aboard NASA's KC-135 and training in weightlessness, the Shuttle Orbiter Medical system (SOMS), and some of the medical equipment are included. Also included are a graphs showing Fluid loading countermeasures, and vertical pursuit tracking with head and eye. The final views are representations of the future crew exploration vehicle (CEV) approaching the International Space Station, and the moon, and a series of perspective representations of the earth in comparison to the other planets and the Sun, the Sun in relation to other stars, and a view of where in the galaxy the Sun is.

Analyzing signal attenuation in PFG anomalous diffusion via a non-Gaussian phase distribution approximation approach by fractional derivatives.

PubMed

Lin, Guoxing

2016-11-21

Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) techniques have been increasingly used to study anomalous diffusion in nuclear magnetic resonance and magnetic resonance imaging. However, the interpretation of PFG anomalous diffusion is complicated. Moreover, the exact signal attenuation expression including the finite gradient pulse width effect has not been obtained based on fractional derivatives for PFG anomalous diffusion. In this paper, a new method, a Mainardi-Luchko-Pagnini (MLP) phase distribution approximation, is proposed to describe PFG fractional diffusion. MLP phase distribution is a non-Gaussian phase distribution. From the fractional derivative model, both the probability density function (PDF) of a spin in real space and the PDF of the spin's accumulating phase shift in virtual phase space are MLP distributions. The MLP phase distribution leads to a Mittag-Leffler function based PFG signal attenuation, which differs significantly from the exponential attenuation for normal diffusion and from the stretched exponential attenuation for fractional diffusion based on the fractal derivative model. A complete signal attenuation expression E α (-D f b α,β * ) including the finite gradient pulse width effect was obtained and it can handle all three types of PFG fractional diffusions. The result was also extended in a straightforward way to give a signal attenuation expression of fractional diffusion in PFG intramolecular multiple quantum coherence experiments, which has an n β dependence upon the order of coherence which is different from the familiar n 2 dependence in normal diffusion. The results obtained in this study are in agreement with the results from the literature. The results in this paper provide a set of new, convenient approximation formalisms to interpret complex PFG fractional diffusion experiments.

International Space Station Environmental Control and Life Support System Status: 2002-2003

NASA Technical Reports Server (NTRS)

Wiliams, David E.; Lewis, John F.; Gentry, Gregory

2003-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between April 2002 and March 2003. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence. Work continued on the Phase 3 pressurized elements with Node 3 just completing its final design review so that it can proceed towards manufacturing and the continued manufacturing of the regenerative ECLS equipment that will be integrated into Node 3.

Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

NASA Technical Reports Server (NTRS)

1975-01-01

Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

Haloes gone MAD: The Halo-Finder Comparison Project

NASA Astrophysics Data System (ADS)

Knebe, Alexander; Knollmann, Steffen R.; Muldrew, Stuart I.; Pearce, Frazer R.; Aragon-Calvo, Miguel Angel; Ascasibar, Yago; Behroozi, Peter S.; Ceverino, Daniel; Colombi, Stephane; Diemand, Juerg; Dolag, Klaus; Falck, Bridget L.; Fasel, Patricia; Gardner, Jeff; Gottlöber, Stefan; Hsu, Chung-Hsing; Iannuzzi, Francesca; Klypin, Anatoly; Lukić, Zarija; Maciejewski, Michal; McBride, Cameron; Neyrinck, Mark C.; Planelles, Susana; Potter, Doug; Quilis, Vicent; Rasera, Yann; Read, Justin I.; Ricker, Paul M.; Roy, Fabrice; Springel, Volker; Stadel, Joachim; Stinson, Greg; Sutter, P. M.; Turchaninov, Victor; Tweed, Dylan; Yepes, Gustavo; Zemp, Marcel

2011-08-01

We present a detailed comparison of fundamental dark matter halo properties retrieved by a substantial number of different halo finders. These codes span a wide range of techniques including friends-of-friends, spherical-overdensity and phase-space-based algorithms. We further introduce a robust (and publicly available) suite of test scenarios that allow halo finder developers to compare the performance of their codes against those presented here. This set includes mock haloes containing various levels and distributions of substructure at a range of resolutions as well as a cosmological simulation of the large-scale structure of the universe. All the halo-finding codes tested could successfully recover the spatial location of our mock haloes. They further returned lists of particles (potentially) belonging to the object that led to coinciding values for the maximum of the circular velocity profile and the radius where it is reached. All the finders based in configuration space struggled to recover substructure that was located close to the centre of the host halo, and the radial dependence of the mass recovered varies from finder to finder. Those finders based in phase space could resolve central substructure although they found difficulties in accurately recovering its properties. Through a resolution study we found that most of the finders could not reliably recover substructure containing fewer than 30-40 particles. However, also here the phase-space finders excelled by resolving substructure down to 10-20 particles. By comparing the halo finders using a high-resolution cosmological volume, we found that they agree remarkably well on fundamental properties of astrophysical significance (e.g. mass, position, velocity and peak of the rotation curve). We further suggest to utilize the peak of the rotation curve, vmax, as a proxy for mass, given the arbitrariness in defining a proper halo edge. Airport code for Madrid, Spain

Effective increase in beam emittance by phase-space expansion using asymmetric Bragg diffraction.

PubMed

Chu, Chia-Hung; Tang, Mau-Tsu; Chang, Shih-Lin

2015-08-24

We propose an innovative method to extend the utilization of the phase space downstream of a synchrotron light source for X-ray transmission microscopy. Based on the dynamical theory of X-ray diffraction, asymmetrically cut perfect crystals are applied to reshape the position-angle-wavelength space of the light source, by which the usable phase space of the source can be magnified by over one hundred times, thereby "phase-space-matching" the source with the objective lens of the microscope. The method's validity is confirmed using SHADOW code simulations, and aberration through an optical lens such as a Fresnel zone plate is examined via matrix optics for nano-resolution X-ray images.

Estimating long-term behavior of periodically driven flows without trajectory integration

NASA Astrophysics Data System (ADS)

Froyland, Gary; Koltai, Péter

2017-05-01

Periodically driven flows are fundamental models of chaotic behavior and the study of their transport properties is an active area of research. A well-known analytic construction is the augmentation of phase space with an additional time dimension; in this augmented space, the flow becomes autonomous or time-independent. We prove several results concerning the connections between the original time-periodic representation and the time-extended representation, focusing on transport properties. In the deterministic setting, these include single-period outflows and time-asymptotic escape rates from time-parameterized families of sets. We also consider stochastic differential equations with time-periodic advection term. In this stochastic setting one has a time-periodic generator (the differential operator given by the right-hand-side of the corresponding time-periodic Fokker-Planck equation). We define in a natural way an autonomous generator corresponding to the flow on time-extended phase space. We prove relationships between these two generator representations and use these to quantify decay rates of observables and to determine time-periodic families of sets with slow escape rate. Finally, we use the generator on the time-extended phase space to create efficient numerical schemes to implement the various theoretical constructions. These ideas build on the work of Froyland et al (2013 SIAM J. Numer. Anal. 51 223-47), and no expensive time integration is required. We introduce an efficient new hybrid approach, which treats the space and time dimensions separately.

Solar dynamic power for Space Station Freedom

NASA Technical Reports Server (NTRS)

Labus, Thomas L.; Secunde, Richard R.; Lovely, Ronald G.

1989-01-01

The Space Station Freedom Program is presently planned to consist of two phases. At the completion of Phase 1, Freedom's manned base will consist of a transverse boom with attached manned modules and 75 kW of available electric power supplied by photovoltaic (PV) power sources. In Phase 2, electric power available to the manned base will be increased to 125 kW by the addition of two solar dynamic (SD) power modules, one at each end of the transverse boom. Power for manned base growth beyond Phase 2 will be supplied by additional SD modules. Studies show that SD power for the growth eras will result in life cycle cost savings of $3 to $4 billion when compared to PV-supplied power. In the SD power modules for Space Station Freedom, an offset parabolic concentrator collects and focuses solar energy into a heat receiver. To allow full power operation over the entire orbit, the receiver includes integral thermal energy storage by means of the heat of fusion of a salt mixture. Thermal energy is removed from the receiver and converted to electrical energy by a power conversion unit (PCU) which includes a closed brayton cycle (CBC) heat engine and an alternator. The receiver/PCU/radiator combination will be completely assembled and charged with gas and cooling fluid on earth before launch to orbit. The concentrator subassemblies will be pre-aligned and stowed in the orbiter bay before launch. On orbit, the receiver/PCU/radiator assembly will be installed as a unit. The pre-aligned concentrator panels will then be latched together and the total concentrator attached to the receiver/PCU/radiator by the astronauts. After final electric connections are made and checkout is complete, the SD power module will be ready for operation.

Solar dynamic power for space station freedom

NASA Technical Reports Server (NTRS)

Labus, Thomas L.; Secunde, Richard R.; Lovely, Ronald G.

1989-01-01

The Space Station Freedom Program is presently planned to consist of two phases. At the completion of Phase 1, Freedom's manned base will consist of a transverse boom with attached manned modules and 75 kW of available electric power supplied by photovoltaic (PV) power sources. In Phase 2, electric power available to the manned base will be increased to 125 kW by the addition of two solar dynamic (SD) power modules, one at each end of the transverse boom. Power for manned base growth beyond Phase 2 will be supplied by additional SD modules. Studies show that SD power for the growth eras will result in life cycle cost savings of $3 to $4 billion when compared to PV-supplied power. In the SD power modules for Space Station Freedom, an offset parabolic concentrator collects and focuses solar energy into a heat receiver. To allow full power operation over the entire orbit, the receiver includes integral thermal energy storage by means of the heat of fusion of a salt mixture. Thermal energy is removed from the receiver and converted to electrical energy by a power conversion unit (PCU) which includes a closed brayton cycle (CBC) heat engine and an alternator. The receiver/PCU/radiator combination will be completely assembled and charged with gas and cooling fluid on Earth before launch to orbit. The concentrator subassemblies will be pre-aligned and stowed in the orbiter bay before launch. On orbit, the receiver/PCU/radiator assembly will be installed as a unit. The pre-aligned concentrator panels will then be latched together and the total concentrator attached to the receiver/PCU/radiator by the astronauts. After final electric connections are made and checkout is complete, the SD power module will be ready for operation.

Servicing capability for the evolutionary Space Station

NASA Technical Reports Server (NTRS)

Thomas, Edward F.; Grems, Edward G., III; Corbo, James E.

1990-01-01

Since the beginning of the Space Station Freedom (SSF) program the concept of on-orbit servicing of user hardware has been an integral part of the program implementation. The user servicing system architecture has been divided into a baseline and a growth phase. The baseline system consists of the following hardware elements that will support user servicing - flight telerobotic servicer, crew and equipment translation aid, crew intravehicular and extravehicular servicing support, logistics supply system, mobile servicing center, and the special purpose dextrous manipulator. The growth phase incorporates a customer servicing facility (CSF), a station-based orbital maneuvering vehicle and an orbital spacecraft consumables resupply system. The requirements for user servicing were derived from the necessity to service attached payloads, free flyers and coorbiting platforms. These requirements include: orbital replacement units (ORU) and instrument changeout, National Space Transportation System cargo bay loading and unloading, contamination control and monitoring, thermal protection, payload berthing, storage, access to SSF distributed systems, functional checkout, and fluid replenishment. The baseline user servicing capabilities accommodate ORU and instrument changeout. However, this service is limited to attached payloads, either in situ or at a locally adjacent site. The growth phase satisfies all identified user servicing requirements by expanding servicing capabilities to include complex servicing tasks for attached payloads, free-flyers and coorbiting platforms at a dedicated, protected Servicing site. To provide a smooth evolution of user servicing the SSF interfaces that are necessary to accommodate the growth phase have been identified. The interface requirements on SSF have been greatly simplified by accommodating the growth servicing support elements within the CSF. This results in a single SSF interface: SSF to the CSF.

Life Support Systems Microbial Challenges

NASA Technical Reports Server (NTRS)

Roman, Monsi C.

2010-01-01

Many microbiological studies were performed during the development of the Space Station Water Recovery and Management System from1990-2009. Studies include assessments of: (1) bulk phase (planktonic) microbial population (2) biofilms, (3) microbially influenced corrosion (4) biofouling treatments. This slide presentation summarizes the studies performed to assess the bulk phase microbial community during the Space Station Water Recovery Tests (WRT) from 1990 to 1998. This report provides an overview of some of the microbiological analyses performed during the Space Station WRT program. These tests not only integrated several technologies with the goal of producing water that met NASA s potable water specifications, but also integrated humans, and therefore human flora into the protocols. At the time these tests were performed, not much was known (or published) about the microbial composition of these types of wastewater. It is important to note that design changes to the WRS have been implemented over the years and results discussed in this report might be directly related to test configurations that were not chosen for the final flight configuration. Results microbiological analyses performed Conclusion from the during the WRT showed that it was possible to recycle water from different sources, including urine, and produce water that can exceed the quality of municipally produced water.

The issue is leadership. [Space Station program

NASA Technical Reports Server (NTRS)

Beggs, J. M.

1985-01-01

Four NASA Phase B centers (NASA-Johnson, NASA-Marshall, NASA-Goddard, and NASA-Lewis) are responsible for construction, assembly, servicing, habitat, and other particular tasks and functions of the Space Station. The project has been joined by the aerospace programs of Canada, Japan, and the European Space Agency, ensuring technological and financial support, and cooperative use by the participants. Some of the future uses of the Space Station include biomedical research and applications; experiments in solar-terrestrial physics and astronomy; building, maintenance, and launching of space instruments and planetary missions; manufacturing and processing of materials that call for the conditions of microgravity and weightlessness; supporting communication operations; and improving earth and atmospheric observations. The political significance of the Space Station as a symbol of leadership and of friendly cooperation is noted.

NASA physics and chemistry experiments in-space program

NASA Technical Reports Server (NTRS)

Gabris, E. A.

1981-01-01

The Physics and Chemistry Experiments Program (PACE) is part of the Office of Aeronautics and Space Technology (OAST) research and technology effort in understanding the fundamental characteristics of physics and chemical phenomena. This program seeks to increase the basic knowledge in these areas by well-planned research efforts which include in-space experiments when the limitations of ground-based activities precludes or restricts the achievement of research goals. Overview study areas are concerned with molecular beam experiments for Space Shuttle, experiments on drops and bubbles in a manned earth-orbiting laboratory, the study of combustion experiments in space, combustion experiments in orbiting spacecraft, gravitation experiments in space, and fluid physics, thermodynamics, and heat-transfer experiments. Procedures for the study program have four phases. An overview study was conducted in the area of materials science.

Image reconstruction: an overview for clinicians.

PubMed

Hansen, Michael S; Kellman, Peter

2015-03-01

Image reconstruction plays a critical role in the clinical use of magnetic resonance imaging (MRI). The MRI raw data is not acquired in image space and the role of the image reconstruction process is to transform the acquired raw data into images that can be interpreted clinically. This process involves multiple signal processing steps that each have an impact on the image quality. This review explains the basic terminology used for describing and quantifying image quality in terms of signal-to-noise ratio and point spread function. In this context, several commonly used image reconstruction components are discussed. The image reconstruction components covered include noise prewhitening for phased array data acquisition, interpolation needed to reconstruct square pixels, raw data filtering for reducing Gibbs ringing artifacts, Fourier transforms connecting the raw data with image space, and phased array coil combination. The treatment of phased array coils includes a general explanation of parallel imaging as a coil combination technique. The review is aimed at readers with no signal processing experience and should enable them to understand what role basic image reconstruction steps play in the formation of clinical images and how the resulting image quality is described. © 2014 Wiley Periodicals, Inc.

Delta space plot analysis of cardiovascular coupling in vasovagal syncope during orthostatic challenge.

PubMed

Reulecke, S; Charleston-Villalobos, S; Voss, A; Gonzalez-Camarena, R; Gaitan-Gonzalez, M; Gonzalez-Hermosillo, J; Hernandez-Pacheco, G; Aljama-Corrales, T

2016-08-01

In this work, a graphical method to study cardiovascular coupling, called delta space plot analysis (DSPA), was introduced. The graphical representation is susceptible to be parameterized in shape and orientation. The usefulness of this technique was studied on cardiovascular data from patients with vasovagal syncope (VVS) and from controls. The study included 15 female patients diagnosed with VVS and 11 age-matched healthy female subjects. All subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5 minutes of supine position (baseline) and 18 minutes of 70° orthostatic phase. The DSPA parameters were obtained at different times during the HUT test, i.e., at baseline, early (first 5 min) and late (10-15 min) orthostatic phases. In baseline there were no considerable differences between female controls and female patients. During the late orthostatic phase, parameters from DSPA showed highly significantly (p=0.000003) reduced cardiovascular coupling in patients. Findings indicated a loss of control on cardiovascular coupling in female patients susceptible to vasovagal syncope during orthostatic challenge. In addition, this study provided promising results for a new graphical method to investigate cardiovascular coupling.

Initial-value semiclassical propagators for the Wigner phase space representation: Formulation based on the interpretation of the Moyal equation as a Schrödinger equation.

PubMed

Koda, Shin-ichi

2015-12-28

We formulate various semiclassical propagators for the Wigner phase space representation from a unified point of view. As is shown in several studies, the Moyal equation, which is an equation of motion for the Wigner distribution function, can be regarded as the Schrödinger equation of an extended Hamiltonian system where its "position" and "momentum" correspond to the middle point of two points of the original phase space and the difference between them, respectively. Then we show that various phase-space semiclassical propagators can be formulated just by applying existing semiclassical propagators to the extended system. As a result, a phase space version of the Van Vleck propagator, the initial-value Van Vleck propagator, the Herman-Kluk propagator, and the thawed Gaussian approximation are obtained. In addition, we numerically compare the initial-value phase-space Van Vleck propagator, the phase-space Herman-Kluk propagator, and the classical mechanical propagation as approximation methods for the time propagation of the Wigner distribution function in terms of both accuracy and convergence speed. As a result, we find that the convergence speed of the Van Vleck propagator is far slower than others as is the case of the Hilbert space, and the Herman-Kluk propagator keeps its accuracy for a long period compared with the classical mechanical propagation while the convergence speed of the latter is faster than the former.

Soyuz-TM-based interim Assured Crew Return Vehicle (ACRV) for the Space Station Freedom

NASA Technical Reports Server (NTRS)

Semenov, Yu. P.; Babkov, Oleg I.; Timchenko, Vladimir A.; Craig, Jerry W.

1993-01-01

The concept of using the available Soyuz-TM Assured Crew Return Vehicle (ACRV) spacecraft for the assurance of the safety of the Space Station Freedom (SSF) crew after the departure of the Space Shuttle from SSF was proposed by the NPO Energia and was accepted by NASA in 1992. The ACRV will provide the crew with the capability to evacuate a seriously injured/ill crewmember from the SSF to a ground-based care facility under medically tolerable conditions and with the capability for a safe evacuation from SSF in the events SSF becomes uninhabitable or the Space Shuttle flights are interrupted for a time that exceeds SSF ability for crew support and/or safe operations. This paper presents the main results of studies on Phase A (including studies on the service life of ACRV; spacecraft design and operations; prelaunch processing; mission support; safety, reliability, maintenance and quality and assurance; landing, and search/rescue operations; interfaces with the SSF and with Space Shuttle; crew accommodation; motion of orbital an service modules; and ACRV injection by the Expendable Launch Vehicles), along with the objectives of further work on the Phase B.

Life Cycle of a Mission

NASA Technical Reports Server (NTRS)

Bothwell, Mary

2004-01-01

A viewgraph presentation describing the the six phases of a space mission is shown. The contents include: 1) What Does Planning Involve?; 2) Designing the Flight System; 3) Building the Flight System; 4) Testing the Flight System; 5) Flying the Mission; and 6) Analyzing the Data.

User manual of the CATSS system (version 1.0) communication analysis tool for space station

NASA Technical Reports Server (NTRS)

Tsang, C. S.; Su, Y. T.; Lindsey, W. C.

1983-01-01

The Communication Analysis Tool for the Space Station (CATSS) is a FORTRAN language software package capable of predicting the communications links performance for the Space Station (SS) communication and tracking (C & T) system. An interactive software package was currently developed to run on the DEC/VAX computers. The CATSS models and evaluates the various C & T links of the SS, which includes the modulation schemes such as Binary-Phase-Shift-Keying (BPSK), BPSK with Direct Sequence Spread Spectrum (PN/BPSK), and M-ary Frequency-Shift-Keying with Frequency Hopping (FH/MFSK). Optical Space Communication link is also included. CATSS is a C & T system engineering tool used to predict and analyze the system performance for different link environment. Identification of system weaknesses is achieved through evaluation of performance with varying system parameters. System tradeoff for different values of system parameters are made based on the performance prediction.

Phase shifts in I = 2 ππ-scattering from two lattice approaches

NASA Astrophysics Data System (ADS)

Kurth, T.; Ishii, N.; Doi, T.; Aoki, S.; Hatsuda, T.

2013-12-01

We present a lattice QCD study of the phase shift of I = 2 ππ scattering on the basis of two different approaches: the standard finite volume approach by Lüscher and the recently introduced HAL QCD potential method. Quenched QCD simulations are performed on lattices with extents N s = 16 , 24 , 32 , 48 and N t = 128 as well as lattice spacing a ~ 0 .115 fm and a pion mass of m π ~ 940 MeV. The phase shift and the scattering length are calculated in these two methods. In the potential method, the error is dominated by the systematic uncertainty associated with the violation of rotational symmetry due to finite lattice spacing. In Lüscher's approach, such systematic uncertainty is difficult to be evaluated and thus is not included in this work. A systematic uncertainty attributed to the quenched approximation, however, is not evaluated in both methods. In case of the potential method, the phase shift can be calculated for arbitrary energies below the inelastic threshold. The energy dependence of the phase shift is also obtained from Lüscher's method using different volumes and/or nonrest-frame extension of it. The results are found to agree well with the potential method.

Heat storage system utilizing phase change materials government rights

DOEpatents

Salyer, Ival O.

2000-09-12

A thermal energy transport and storage system is provided which includes an evaporator containing a mixture of a first phase change material and a silica powder, and a condenser containing a second phase change material. The silica powder/PCM mixture absorbs heat energy from a source such as a solar collector such that the phase change material forms a vapor which is transported from the evaporator to the condenser, where the second phase change material melts and stores the heat energy, then releases the energy to an environmental space via a heat exchanger. The vapor is condensed to a liquid which is transported back to the evaporator. The system allows the repeated transfer of thermal energy using the heat of vaporization and condensation of the phase change material.

An assessment of space shuttle flight software development processes

NASA Technical Reports Server (NTRS)

1993-01-01

In early 1991, the National Aeronautics and Space Administration's (NASA's) Office of Space Flight commissioned the Aeronautics and Space Engineering Board (ASEB) of the National Research Council (NRC) to investigate the adequacy of the current process by which NASA develops and verifies changes and updates to the Space Shuttle flight software. The Committee for Review of Oversight Mechanisms for Space Shuttle Flight Software Processes was convened in Jan. 1992 to accomplish the following tasks: (1) review the entire flight software development process from the initial requirements definition phase to final implementation, including object code build and final machine loading; (2) review and critique NASA's independent verification and validation process and mechanisms, including NASA's established software development and testing standards; (3) determine the acceptability and adequacy of the complete flight software development process, including the embedded validation and verification processes through comparison with (1) generally accepted industry practices, and (2) generally accepted Department of Defense and/or other government practices (comparing NASA's program with organizations and projects having similar volumes of software development, software maturity, complexity, criticality, lines of code, and national standards); (4) consider whether independent verification and validation should continue. An overview of the study, independent verification and validation of critical software, and the Space Shuttle flight software development process are addressed. Findings and recommendations are presented.

Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

NASA Astrophysics Data System (ADS)

Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

On the theory of 3-phase squirrel-cage induction motors including space harmonics and mutual slotting

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

Papp, G.C.

1991-03-01

In this paper general equations for the asynchronous squirrel-cage motor which contain the influence of space harmonics and the mutual slotting are derived by using among others the power-invariant symmetrical component transformation and a time-dependent transformation with which, under certain circumstances, the rotor-position angle can be removed from the coefficient matrix. The developed models implemented in a machine-independent computer program form powerful tools, with which the influence of space harmonics in relation to the geometric data of specific motors can be analyzed for steady-state and transient performances.

A space-based concept for a collision warning sensor

NASA Technical Reports Server (NTRS)

Talent, David L.; Vilas, Faith

1990-01-01

This paper describes a concept for a space-based collision warning sensor experiment, the Debris Collision Warning Sensor (DCWS) experiment, in which the sensor will rely on passive sensing of debris in optical and IR passband. The DCWS experiment will be carried out under various conditions of solar phase angle and pass geometry; debris from 1.5 m to 1 mm diam will be observable. The mission characteristics include inclination in the 55-60 deg range and an altitude of about 500 km. The results of the DCWS experiment will be used to generate collision warning scenarios for the Space Station Freedom.

Manned space flight nuclear system safety. Volume 6: Space base nuclear system safety plan

NASA Technical Reports Server (NTRS)

1972-01-01

A qualitative identification of the steps required to assure the incorporation of radiological system safety principles and objectives into all phases of a manned space base program are presented. Specific areas of emphasis include: (1) radiological program management, (2) nuclear system safety plan implementation, (3) impact on program, and (4) summary of the key operation and design guidelines and requirements. The plan clearly indicates the necessity of considering and implementing radiological system safety recommendations as early as possible in the development cycle to assure maximum safety and minimize the impact on design and mission plans.

Overview and Recent Accomplishments of Advanced Mirror Technology Development Phase 2 (AMTD-2)

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2015-01-01

AMTD uses a science-driven systems engineering approach to define & execute a long-term strategy to mature technologies necessary to enable future large aperture space telescopes. Because we cannot predict the future, we are pursuing multiple technology paths including monolithic & segmented mirrors. Assembled outstanding team from academia, industry & government; experts in science & space telescope engineering. Derived engineering specifications from science measurement needs & implementation constraints. Maturing 6 critical technologies required to enable 4 to 8 meter UVOIR space telescope mirror assemblies for both general astrophysics & ultra-high contrast exoplanet imaging. AMTD achieving all its goals & accomplishing all its milestones.

Space Station personal hygiene study

NASA Technical Reports Server (NTRS)

Prejean, Stephen E.; Booher, Cletis R.

1986-01-01

A personal hygiene system is currently under development for Space Station application that will provide capabilities equivalent to those found on earth. This paper addresses the study approach for specifying both primary and contingency personal hygiene systems and provisions for specified growth. Topics covered are system definition and subsystem descriptions. Subsystem interfaces are explored to determine which concurrent NASA study efforts must be monitored during future design phases to stay up-to-date on critical Space Station parameters. A design concept for a three (3) compartment personal hygiene facility is included as a baseline for planned test and verification activities.

KSC-08pd1348

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron and a volunteer (in the stretcher) from the NASA Vehicle Integration Test Team office get ready to demonstrate rescue equipment on the HH-60G helicopter that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base, Fla. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

KSC-08pd1347

NASA Image and Video Library

2008-05-12

CAPE CANAVERAL, Fla. -- A representative of the 301st Rescue Squadron and a volunteer from the NASA Vehicle Integration Test Team office get ready to demonstrate rescue equipment that is used by participants in the Mode VIII exercise being conducted at Patrick Air Force Base. In the background is an HH-60G helicopter. In support of, and with logistical support from, NASA, USSTRATCOM is hosting a major exercise involving Department of Defense, Department of Homeland Security, search and rescue (SAR) forces, including the 45th Space Wing at Patrick Air Force Base, which support space shuttle astronaut bailout contingency operations, known as Mode VIII. This exercise tests SAR capabilities to locate, recover and provide medical treatment for astronauts following a space shuttle launch phase open-ocean bailout. Participants include members of the U.S. Navy, U.S. Coast Guard, U.S. Air Force, and NASA's Kennedy Space Center and Johnson Space Center. This will be the 15th Mode VIII exercise conducted in the past 20 years. Photo credit: NASA/Kim Shiflett

Two Virasoro symmetries in stringy warped AdS 3

DOE PAGES

Compere, Geoffrey; Guica, Monica; Rodriguez, Maria J.

2014-12-02

We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS 3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS 3. Consequently, for each consistent choice of boundary conditions in AdS 3, we can define a consistent phase space in warped AdS 3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS 3; two different types of Virasoro × Kač-Moody symmetriesmore » are also consistent alternatives. Next, we study the phase space of these theories when propagating modes are included. We show that, as long as one can define a conserved symplectic form without introducing instabilities, the Virasoro × Virasoro asymptotic symmetries can be extended to the entire (linearised) phase space. In conclusion, this implies that, at least at semi-classical level, consistent theories of gravity in warped AdS 3 are described by a two-dimensional conformal field theory, as long as stability is not an issue.« less

The Dark Matter Crisis: Falsification of the Current Standard Model of Cosmology

NASA Astrophysics Data System (ADS)

Kroupa, P.

2012-06-01

The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. Type A dwarfs surround the host approximately spherically, while type B dwarfs are typically correlated in phase-space. Type B dwarfs must exist in any cosmological theory in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. The Milky Way satellite system forms a vast phase-space-correlated structure that includes globular clusters and stellar and gaseous streams. Other galaxies also have phase-space correlated satellite systems. Therefore, The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations. Other theoretical solutions to cosmological observations exist. In particular, alone the empirical mass-discrepancy-acceleration correlation constitutes convincing evidence that galactic-scale dynamics must be Milgromian. Major problems with inflationary big bang cosmologies remain unresolved.

Two Virasoro symmetries in stringy warped AdS 3

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

Compere, Geoffrey; Guica, Monica; Rodriguez, Maria J.

We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS 3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS 3. Consequently, for each consistent choice of boundary conditions in AdS 3, we can define a consistent phase space in warped AdS 3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS 3; two different types of Virasoro × Kač-Moody symmetriesmore » are also consistent alternatives. Next, we study the phase space of these theories when propagating modes are included. We show that, as long as one can define a conserved symplectic form without introducing instabilities, the Virasoro × Virasoro asymptotic symmetries can be extended to the entire (linearised) phase space. In conclusion, this implies that, at least at semi-classical level, consistent theories of gravity in warped AdS 3 are described by a two-dimensional conformal field theory, as long as stability is not an issue.« less

Explicit methods in extended phase space for inseparable Hamiltonian problems

NASA Astrophysics Data System (ADS)

Pihajoki, Pauli

2015-03-01

We present a method for explicit leapfrog integration of inseparable Hamiltonian systems by means of an extended phase space. A suitably defined new Hamiltonian on the extended phase space leads to equations of motion that can be numerically integrated by standard symplectic leapfrog (splitting) methods. When the leapfrog is combined with coordinate mixing transformations, the resulting algorithm shows good long term stability and error behaviour. We extend the method to non-Hamiltonian problems as well, and investigate optimal methods of projecting the extended phase space back to original dimension. Finally, we apply the methods to a Hamiltonian problem of geodesics in a curved space, and a non-Hamiltonian problem of a forced non-linear oscillator. We compare the performance of the methods to a general purpose differential equation solver LSODE, and the implicit midpoint method, a symplectic one-step method. We find the extended phase space methods to compare favorably to both for the Hamiltonian problem, and to the implicit midpoint method in the case of the non-linear oscillator.

Integrability and nonintegrability of quantum systems. II. Dynamics in quantum phase space

NASA Astrophysics Data System (ADS)

Zhang, Wei-Min; Feng, Da Hsuan; Yuan, Jian-Min

1990-12-01

Based on the concepts of integrability and nonintegrability of a quantum system presented in a previous paper [Zhang, Feng, Yuan, and Wang, Phys. Rev. A 40, 438 (1989)], a realization of the dynamics in the quantum phase space is now presented. For a quantum system with dynamical group scrG and in one of its unitary irreducible-representation carrier spaces gerhΛ, the quantum phase space is a 2MΛ-dimensional topological space, where MΛ is the quantum-dynamical degrees of freedom. This quantum phase space is isomorphic to a coset space scrG/scrH via the unitary exponential mapping of the elementary excitation operator subspace of scrg (algebra of scrG), where scrH (⊂scrG) is the maximal stability subgroup of a fixed state in gerhΛ. The phase-space representation of the system is realized on scrG/scrH, and its classical analogy can be obtained naturally. It is also shown that there is consistency between quantum and classical integrability. Finally, a general algorithm for seeking the manifestation of ``quantum chaos'' via the classical analogy is provided. Illustrations of this formulation in several important quantum systems are presented.

Singlet-catalyzed electroweak phase transitions and precision Higgs boson studies

NASA Astrophysics Data System (ADS)

Profumo, Stefano; Ramsey-Musolf, Michael J.; Wainwright, Carroll L.; Winslow, Peter

2015-02-01

We update the phenomenology of gauge-singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. Considering the introduction of one real scalar singlet to the scalar potential, we analyze present constraints on the potential parameters from Higgs coupling measurements at the Large Hadron Collider (LHC) and electroweak precision observables for the kinematic regime in which no new scalar decay modes arise. We then show how future precision measurements of Higgs boson signal strengths and the Higgs self-coupling could probe the scalar potential parameter space associated with a strong first-order electroweak phase transition. We illustrate using benchmark precision for several future collider options, including the high-luminosity LHC, the International Linear Collider, Triple-Large Electron-Positron collider, the China Electron-Positron Collider, and a 100 TeV proton-proton collider, such as the Very High Energy LHC or the Super Proton-Proton Collider. For the regions of parameter space leading to a strong first-order electroweak phase transition, we find that there exists considerable potential for observable deviations from purely Standard Model Higgs properties at these prospective future colliders.

Developing and Applying Synthesis Models of Emerging Space Systems

DTIC Science & Technology

2016-03-01

enables the exploration of small satellite physical trade -offs early in the conceptual design phase of the DOD space acquisition process. Early...provide trade space insights that can assist DOD space acquisition professionals in making better decisions in the conceptual design phase. More informed

Airborne electronically steerable phased array. [steerable antennas - systems analysis

NASA Technical Reports Server (NTRS)

Coats, R.

1975-01-01

Results of a study directed to the design of a lightweight high-gain, spaceborne communications array are presented. The array includes simultaneous transmission and receiving, automatic acquisition and tracking of a signal within a 60-degree cone from the array normal, and provides for independent forming of the transmit and receive beams. Application for this array is the space shuttle, space station, or any of the advanced manned (or unmanned) orbital vehicles. Performance specifications are also given.

Diffusion paths formation for Cu + ions in superionic Cu 6PS 5I single crystals studied in terms of structural phase transition

NASA Astrophysics Data System (ADS)

Gągor, A.; Pietraszko, A.; Kaynts, D.

2005-11-01

In order to understand the structural transformations leading to high ionic conductivity of Cu + ions in Cu 6PS 5I argyrodite compound, the detailed structure analysis based on single-crystal X-ray diffraction has been performed. Below the phase transition at T=(144-169) K Cu 6PS 5I belongs to monoclinic, ferroelastic phase (space group Cc) with ordered copper sublattice. Above Tc delocalization of copper ions begins and crystal changes the symmetry to cubic superstructure with space group F-43 c ( a'=19.528 Å, z=32). Finally, above T1=274 K increasing disordering of the Cu + ions heightens the symmetry to F-43 m ( a=9.794 Å, z=4). In this work, the final structural model of two cubic phases is presented including the detailed temperature evolution of positions and site occupation factors of copper ions ( R1=0.0397 for F-43 c phase, and 0.0245 for F-43 m phase). Possible diffusion paths for the copper ions are represented by means of the atomic displacement factors and split model. The structural results coincide well with the previously reported non-Arrhenius behavior of conductivity and indicate significant change in conduction mechanism.

Modeling of Nonlinear Dynamics and Synchronized Oscillations of Microbial Populations, Carbon and Oxygen Concentrations, Induced by Root Exudation in the Rhizosphere

NASA Astrophysics Data System (ADS)

Molz, F. J.; Faybishenko, B.; Jenkins, E. W.

2012-12-01

Mass and energy fluxes within the soil-plant-atmosphere continuum are highly coupled and inherently nonlinear. The main focus of this presentation is to demonstrate the results of numerical modeling of a system of 4 coupled, nonlinear ordinary differential equations (ODEs), which are used to describe the long-term, rhizosphere processes of soil microbial dynamics, including the competition between nitrogen-fixing bacteria and those unable to fix nitrogen, along with substrate concentration (nutrient supply) and oxygen concentration. Modeling results demonstrate the synchronized patterns of temporal oscillations of competing microbial populations, which are affected by carbon and oxygen concentrations. The temporal dynamics and amplitude of the root exudation process serve as a driving force for microbial and geochemical phenomena, and lead to the development of the Gompetzian dynamics, synchronized oscillations, and phase-space attractors of microbial populations and carbon and oxygen concentrations. The nonlinear dynamic analysis of time series concentrations from the solution of the ODEs was used to identify several types of phase-space attractors, which appear to be dependent on the parameters of the exudation function and Monod kinetic parameters. This phase space analysis was conducted by means of assessing the global and local embedding dimensions, correlation time, capacity and correlation dimensions, and Lyapunov exponents of the calculated model variables defining the phase space. Such results can be used for planning experimental and theoretical studies of biogeochemical processes in the fields of plant nutrition, phyto- and bio-remediation, and other ecological areas.

Fluid mechanics phenomena in microgravity; ASME Winter Annual Meeting, Anaheim, CA, Nov. 8-13, 1992

NASA Technical Reports Server (NTRS)

Siginer, Dennis A. (Editor); Weislogel, Mark M. (Editor)

1992-01-01

This paper is the first in a series of symposia presenting research activity in microgravity fluid mechanics. General topics addressed include two-phase flow and transport phenomena, thermo-capillary flow, and interfacial stability. Papers present mathmatical models of fluid dynamics in the microgravity environment. Applications suggested include space manufacturing and storage of liquids in low gravity.

Other Challenges in the Development of the Orbiter Environmental Control Hardware

NASA Technical Reports Server (NTRS)

Gibb, J. W.; Mcintosh, M. E.; Heinrich, S. R.; Thomas, E.; Steele, M.; Schubert, F.; Koszenski, E. P.; Wynveen, R. A.; Murray, R. W.; Schelkopf, J. D.

1985-01-01

Development of the Space Shuttle orbiter environmental control and life support system (ECLSS) included the identification and resolution of several interesting problems in several systems. Some of these problems occurred late in the program, including the flight phase. Problems and solutions related to the ammonia boiler system (ABS), smoke detector, water/hydrogen separator, and waste collector system (WCS) are addressed.

Space station needs, attributes, and architectural options study. Volume 1: Missions and requirements

NASA Technical Reports Server (NTRS)

1983-01-01

Science and applications, NOAA environmental observation, commercial resource observations, commercial space processing, commercial communications, national security, technology development, and GEO servicing are addressed. Approach to time phasing of mission requirements, system sizing summary, time-phased user mission payload support, space station facility requirements, and integrated time-phased system requirements are also addressed.

Asymptotically stable phase synchronization revealed by autoregressive circle maps

NASA Astrophysics Data System (ADS)

Drepper, F. R.

2000-11-01

A specially designed of nonlinear time series analysis is introduced based on phases, which are defined as polar angles in spaces spanned by a finite number of delayed coordinates. A canonical choice of the polar axis and a related implicit estimation scheme for the potentially underlying autoregressive circle map (next phase map) guarantee the invertibility of reconstructed phase space trajectories to the original coordinates. The resulting Fourier approximated, invertibility enforcing phase space map allows us to detect conditional asymptotic stability of coupled phases. This comparatively general synchronization criterion unites two existing generalizations of the old concept and can successfully be applied, e.g., to phases obtained from electrocardiogram and airflow recordings characterizing cardiorespiratory interaction.

Permanent-magnet linear alternators. I - Fundamental equations. II - Design guidelines

NASA Astrophysics Data System (ADS)

Boldea, I.; Nasar, S. A.

1987-01-01

The general equations of permanent-magnet heteropolar three-phase and single-phase linear alternators, powered by free-piston Stirling engines, are presented, with application to space power stations and domestic applications including solar power plants. The equations are applied to no-load and short-circuit conditions, illustrating the end-effect caused by the speed-reversal process. In the second part, basic design guidelines for a three-phase tubular linear alternator are given, and the procedure is demonstrated with the numerical example of the design of a 25-kVA, 14.4-m/s, 120/220-V, 60-Hz alternator.

Review of two-phase flow liquid metal MHD and turbine energy conversion concepts for space applications

NASA Technical Reports Server (NTRS)

Fabris, Gracio

1992-01-01

Two-phase energy conversion systems could be liquid metal magnetohydrodynamic (LMMHD) with no moving parts or two-phase turbines. Both of them are inherently simple and reliable devices which can operate in a wide range of temperatures. Their thermal efficiency is significantly higher than for conventional cycles due to reheat of vapor by liquid phase during the energy converting expansion. Often they can be more easily coupled to heat sources. These features make two-phase systems particularly promising for space application. Insufficient research has been done in the past. So far achieved LMMHD generator and two-phase turbine efficiencies are in the 40 to 45 percent range. However if certain fluid dynamic and design problems are resolved these efficiencies could be brought into the range of 70 percent. This would make two-phase systems extremely competitive as compared to present or other proposed conversion system for space. Accordingly, well directed research effort on potential space applications of two-phase conversion systems would be a wise investment.

Spacecraft-to-Earth Communications for Juno and Mars Science Laboratory Critical Events

NASA Technical Reports Server (NTRS)

Soriano, Melissa; Finley, Susan; Jongeling, Andre; Fort, David; Goodhart, Charles; Rogstad, David; Navarro, Robert

2012-01-01

Deep Space communications typically utilize closed loop receivers and Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). Critical spacecraft events include orbit insertion and entry, descent, and landing.---Low gain antennas--> low signal -to-noise-ratio.---High dynamics such as parachute deployment or spin --> Doppler shift. During critical events, open loop receivers and Multiple Frequency Shift Keying (MFSK) used. Entry, Descent, Landing (EDL) Data Analysis (EDA) system detects tones in real-time.

Quantum walks with an anisotropic coin II: scattering theory

NASA Astrophysics Data System (ADS)

Richard, S.; Suzuki, A.; de Aldecoa, R. Tiedra

2018-05-01

We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase quantum walks, and topological phase quantum walks as special cases. Our analysis is based on an abstract framework for the scattering theory of unitary operators in a two-Hilbert spaces setting, which is of independent interest.

Human Factors in Training - Space Medicine Proficiency Training

NASA Technical Reports Server (NTRS)

Connell, Erin; Arsintescu, Lucia

2009-01-01

The early Constellation space missions are expected to have medical capabilities very similar to those currently on the Space Shuttle and International Space Station (ISS). For Crew Exploration Vehicle (CEV) missions to ISS, medical equipment will be located on ISS, and carried into CEV in the event of an emergency. Flight Surgeons (FS) on the ground in Mission Control will be expected to direct the Crew Medical Officer (CMO) during medical situations. If there is a loss of signal and the crew is unable to communicate with the ground, a CMO would be expected to carry out medical procedures without the aid of a FS. In these situations, performance support tools can be used to reduce errors and time to perform emergency medical tasks. Work on medical training has been conducted in collaboration with the Medical Training Group at the Space Life Sciences Directorate and with Wyle Lab which provides medical training to crew members, Biomedical Engineers (BMEs), and to flight surgeons under the JSC Space Life Sciences Directorate s Bioastronautics contract. The space medical training work is part of the Human Factors in Training Directed Research Project (DRP) of the Space Human Factors Engineering (SHFE) Project under the Space Human Factors and Habitability (SHFH) Element of the Human Research Program (HRP). Human factors researchers at Johnson Space Center have recently investigated medical performance support tools for CMOs on-orbit, and FSs on the ground, and researchers at the Ames Research Center performed a literature review on medical errors. The work proposed for FY10 continues to build on this strong collaboration with the Space Medical Training Group and previous research. This abstract focuses on two areas of work involving Performance Support Tools for Space Medical Operations. One area of research building on activities from FY08, involved the feasibility of just-in-time (JIT) training techniques and concepts for real-time medical procedures. In Phase 1, preliminary feasibility data was gathered for two types of prototype display technologies: a hand-held PDA, and a Head Mounted Display (HMD). The PDA and HMD were compared while performing a simulated medical procedure using ISS flight-like medical equipment. Based on the outcome of Phase 1, including data on user preferences, further testing was completed using the PDA only. Phase 2 explored a wrist-mounted PDA, and compared it to a paper cue card. For each phase, time to complete procedures, errors, and user satisfaction ratings were captured.

Space Station Freedom Toxic and Reactive Materials Handling

NASA Technical Reports Server (NTRS)

Baugher, Charles R. (Editor)

1990-01-01

Viable research in materials processing in space requires the utilization of a wide variety of chemicals and materials, many of which are considered toxic and/or highly reactive with other substances. A realistic view of the experiments which are most likely to be accomplished in the early Space Station phases are examined and design issues addressed which are related to their safe implementation. Included are discussions of materials research on Skylab, Spacelab, and the Shuttle mid-deck; overviews of early concepts for specialized Space Station systems designed to help contain potential problems; descriptions of industrial experience with ground-based research; and an overview of the state-of-the-art in contamination detection systems.

An Overview of the James Webb Space Telescope (JWST) Project

NASA Technical Reports Server (NTRS)

Sabelhaus, Phillip A.

2004-01-01

The JWST project at the GSFC is responsible for the development, launch, operations and science data processing for the James Webb Space Telescope. The JWST project is currently in phase B with its launch scheduled for August 2011. The project is a partnership between NASA, ESA and CSA. The U.S. JWST team is now fully in place with the recent selection of Northrop Grumman Space Technology (NGST) as the prime contractor for the telescope and the Space Telescope Science Institute (STScI) as the mission operations and science data processing lead. This paper will provide an overview of the current JWST architecture and mission status including technology developments and risks.

An Overview of the James Webb Space Telescope (JWST) Project

NASA Technical Reports Server (NTRS)

Sabelhaus, Phillip A.; Campbell, Doug; Clampin, Mark; Decker, John; Greenhouse, Matt; Johns, Alan; Menzel, Mike; Smith, Robert; Sullivan, Pam

2005-01-01

The JWST project at the GSFC is responsible for the development, launch, operations and science data processing for the James Webb Space Telescope. The JWST project is currently in phase B with its launch scheduled for August 2011. The project is a partnership between NASA, ESA and CSA. The U.S. JWST team is now fully in place with the selection of Northrop Grumman Space Technology (NGST) as the prime contractor for the telescope and the Space Telescope Science Institute (STScI) as the mission operations and science data processing lead. This paper will provide an overview of the current JWST architecture and mission status including technology developments and risks.

National Aeronautics and Space Administration Biological Specimen Repository

NASA Technical Reports Server (NTRS)

McMonigal, Kathleen A.; Pietrzyk, Robert a.; Johnson, Mary Anne

2008-01-01

The National Aeronautics and Space Administration Biological Specimen Repository (Repository) is a storage bank that is used to maintain biological specimens over extended periods of time and under well-controlled conditions. Samples from the International Space Station (ISS), including blood and urine, will be collected, processed and archived during the preflight, inflight and postflight phases of ISS missions. This investigation has been developed to archive biosamples for use as a resource for future space flight related research. The International Space Station (ISS) provides a platform to investigate the effects of microgravity on human physiology prior to lunar and exploration class missions. The storage of crewmember samples from many different ISS flights in a single repository will be a valuable resource with which researchers can study space flight related changes and investigate physiological markers. The development of the National Aeronautics and Space Administration Biological Specimen Repository will allow for the collection, processing, storage, maintenance, and ethical distribution of biosamples to meet goals of scientific and programmatic relevance to the space program. Archiving of the biosamples will provide future research opportunities including investigating patterns of physiological changes, analysis of components unknown at this time or analyses performed by new methodologies.

Real-space Berry phases: Skyrmion soccer (invited)

NASA Astrophysics Data System (ADS)

Everschor-Sitte, Karin; Sitte, Matthias

2014-05-01

Berry phases occur when a system adiabatically evolves along a closed curve in parameter space. This tutorial-like article focuses on Berry phases accumulated in real space. In particular, we consider the situation where an electron traverses a smooth magnetic structure, while its magnetic moment adjusts to the local magnetization direction. Mapping the adiabatic physics to an effective problem in terms of emergent fields reveals that certain magnetic textures, skyrmions, are tailormade to study these Berry phase effects.

Real-space Berry phases: Skyrmion soccer (invited)

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

Everschor-Sitte, Karin, E-mail: karin@physics.utexas.edu; Sitte, Matthias

Berry phases occur when a system adiabatically evolves along a closed curve in parameter space. This tutorial-like article focuses on Berry phases accumulated in real space. In particular, we consider the situation where an electron traverses a smooth magnetic structure, while its magnetic moment adjusts to the local magnetization direction. Mapping the adiabatic physics to an effective problem in terms of emergent fields reveals that certain magnetic textures, skyrmions, are tailormade to study these Berry phase effects.

Hamiltonian flow over saddles for exploring molecular phase space structures

NASA Astrophysics Data System (ADS)

Farantos, Stavros C.

2018-03-01

Despite using potential energy surfaces, multivariable functions on molecular configuration space, to comprehend chemical dynamics for decades, the real happenings in molecules occur in phase space, in which the states of a classical dynamical system are completely determined by the coordinates and their conjugate momenta. Theoretical and numerical results are presented, employing alanine dipeptide as a model system, to support the view that geometrical structures in phase space dictate the dynamics of molecules, the fingerprints of which are traced by following the Hamiltonian flow above saddles. By properly selecting initial conditions in alanine dipeptide, we have found internally free rotor trajectories the existence of which can only be justified in a phase space perspective. This article is part of the theme issue `Modern theoretical chemistry'.

An extensive phase space for the potential martian biosphere.

PubMed

Jones, Eriita G; Lineweaver, Charles H; Clarke, Jonathan D

2011-12-01

We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of ∼310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the ∼5 km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to ∼3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life.

Mutually unbiased coarse-grained measurements of two or more phase-space variables

NASA Astrophysics Data System (ADS)

Paul, E. C.; Walborn, S. P.; Tasca, D. S.; Rudnicki, Łukasz

2018-05-01

Mutual unbiasedness of the eigenstates of phase-space operators—such as position and momentum, or their standard coarse-grained versions—exists only in the limiting case of infinite squeezing. In Phys. Rev. Lett. 120, 040403 (2018), 10.1103/PhysRevLett.120.040403, it was shown that mutual unbiasedness can be recovered for periodic coarse graining of these two operators. Here we investigate mutual unbiasedness of coarse-grained measurements for more than two phase-space variables. We show that mutual unbiasedness can be recovered between periodic coarse graining of any two nonparallel phase-space operators. We illustrate these results through optics experiments, using the fractional Fourier transform to prepare and measure mutually unbiased phase-space variables. The differences between two and three mutually unbiased measurements is discussed. Our results contribute to bridging the gap between continuous and discrete quantum mechanics, and they could be useful in quantum-information protocols.

Practical Control Algorithms for Nonlinear Dynamical Systems Using Phase-Space Knowledge and Mixed Numeric and Geometric Computation.

DTIC Science & Technology

1997-10-01

Research results include: (1) Developed empirical performance criteria for characterizing stabilities and robustness of the maglev control... Maglev Experience’ at HS󈨥: Fifth International Hybrid Systems Workshop, Notre Dame, IN, Sept. 11-13,1997

New SmAPF Mesogens Designed for Analog Electrooptics Applications

PubMed Central

Guzman, Edward; Glaser, Matthew A.; Shao, Renfan; Garcia, Edgardo; Shen, Yongqiang; Clark, Noel A.

2017-01-01

We have previously reported the first realization of an orthogonal ferroelectric bent-core SmAPF phase by directed design in mesogens with a single tricarbosilane-terminated alkoxy tail. Given the potentially useful electrooptic properties of this phase, including analog phase-only electrooptic index modulation with optical latching, we have been exploring its “structure space”, searching for novel SmAPF mesogens. Here, we report two classes of these—the first designed to optimize the dynamic range of the index modulation in parallel-aligned cells by lowering the bend angle of the rigid core, and the second expanding the structure space of the phase by replacing the tricarbosilane-terminated alkyl tail with a polyfluorinated polyethylene glycol oligomer. PMID:29120371

Performance of synchronous optical receivers using atmospheric compensation techniques.

PubMed

Belmonte, Aniceto; Khan, Joseph

2008-09-01

We model the impact of atmospheric turbulence-induced phase and amplitude fluctuations on free-space optical links using synchronous detection. We derive exact expressions for the probability density function of the signal-to-noise ratio in the presence of turbulence. We consider the effects of log-normal amplitude fluctuations and Gaussian phase fluctuations, in addition to local oscillator shot noise, for both passive receivers and those employing active modal compensation of wave-front phase distortion. We compute error probabilities for M-ary phase-shift keying, and evaluate the impact of various parameters, including the ratio of receiver aperture diameter to the wave-front coherence diameter, and the number of modes compensated.

Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

NASA Astrophysics Data System (ADS)

Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

2009-04-01

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ-1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

An overview of space medicine.

PubMed

Hodkinson, P D; Anderton, R A; Posselt, B N; Fong, K J

2017-12-01

Space medicine is fundamental to the human exploration of space. It supports survival, function and performance in this challenging and potentially lethal environment. It is international, intercultural and interdisciplinary, operating at the boundaries of exploration, science, technology and medicine. Space medicine is also the latest UK specialty to be recognized by the Royal College of Physicians in the UK and the General Medical Council. This review introduces the field of space medicine and describes the different types of spaceflight, environmental challenges, associated medical and physiological effects, and operational medical considerations. It will describe the varied roles of the space medicine doctor, including the conduct of surgery and anaesthesia, and concludes with a vision of the future for space medicine in the UK.Space medicine doctors have a responsibility to space workers and spaceflight participants. These 'flight surgeons' are key in developing mitigation strategies to ensure the safety, health and performance of space travellers in what is an extreme and hazardous environment. This includes all phases from selection, training and spaceflight itself to post-flight rehabilitation and long-term health. The recent recognition of the speciality provides a pathway to train in this fascinating field of medicine and is a key enabler for the UK Government's commercial spaceflight ambition. © Crown copyright 2017.

Ab initio phasing by molecular averaging in real space with new criteria: application to structure determination of a betanodavirus.

PubMed

Yoshimura, Masato; Chen, Nai Chi; Guan, Hong Hsiang; Chuankhayan, Phimonphan; Lin, Chien Chih; Nakagawa, Atsushi; Chen, Chun Jung

2016-07-01

Molecular averaging, including noncrystallographic symmetry (NCS) averaging, is a powerful method for ab initio phase determination and phase improvement. Applications of the cross-crystal averaging (CCA) method have been shown to be effective for phase improvement after initial phasing by molecular replacement, isomorphous replacement, anomalous dispersion or combinations of these methods. Here, a two-step process for phase determination in the X-ray structural analysis of a new coat protein from a betanodavirus, Grouper nervous necrosis virus, is described in detail. The first step is ab initio structure determination of the T = 3 icosahedral virus-like particle using NCS averaging (NCSA). The second step involves structure determination of the protrusion domain of the viral molecule using cross-crystal averaging. In this method, molecular averaging and solvent flattening constrain the electron density in real space. To quantify these constraints, a new, simple and general indicator, free fraction (ff), is introduced, where ff is defined as the ratio of the volume of the electron density that is freely changed to the total volume of the crystal unit cell. This indicator is useful and effective to evaluate the strengths of both NCSA and CCA. Under the condition that a mask (envelope) covers the target molecule well, an ff value of less than 0.1, as a new rule of thumb, gives sufficient phasing power for the successful construction of new structures.

Research on calibration error of carrier phase against antenna arraying

NASA Astrophysics Data System (ADS)

Sun, Ke; Hou, Xiaomin

2016-11-01

It is the technical difficulty of uplink antenna arraying that signals from various quarters can not be automatically aligned at the target in deep space. The size of the far-field power combining gain is directly determined by the accuracy of carrier phase calibration. It is necessary to analyze the entire arraying system in order to improve the accuracy of the phase calibration. This paper analyzes the factors affecting the calibration error of carrier phase of uplink antenna arraying system including the error of phase measurement and equipment, the error of the uplink channel phase shift, the position error of ground antenna, calibration receiver and target spacecraft, the error of the atmospheric turbulence disturbance. Discuss the spatial and temporal autocorrelation model of atmospheric disturbances. Each antenna of the uplink antenna arraying is no common reference signal for continuous calibration. So it must be a system of the periodic calibration. Calibration is refered to communication of one or more spacecrafts in a certain period. Because the deep space targets are not automatically aligned to multiplexing received signal. Therefore the aligned signal should be done in advance on the ground. Data is shown that the error can be controlled within the range of demand by the use of existing technology to meet the accuracy of carrier phase calibration. The total error can be controlled within a reasonable range.

Using computer graphics to enhance astronaut and systems safety

NASA Technical Reports Server (NTRS)

Brown, J. W.

1985-01-01

Computer graphics is being employed at the NASA Johnson Space Center as a tool to perform rapid, efficient and economical analyses for man-machine integration, flight operations development and systems engineering. The Operator Station Design System (OSDS), a computer-based facility featuring a highly flexible and versatile interactive software package, PLAID, is described. This unique evaluation tool, with its expanding data base of Space Shuttle elements, various payloads, experiments, crew equipment and man models, supports a multitude of technical evaluations, including spacecraft and workstation layout, definition of astronaut visual access, flight techniques development, cargo integration and crew training. As OSDS is being applied to the Space Shuttle, Orbiter payloads (including the European Space Agency's Spacelab) and future space vehicles and stations, astronaut and systems safety are being enhanced. Typical OSDS examples are presented. By performing physical and operational evaluations during early conceptual phases. supporting systems verification for flight readiness, and applying its capabilities to real-time mission support, the OSDS provides the wherewithal to satisfy a growing need of the current and future space programs for efficient, economical analyses.

Integrated Photonic Comb Generation: Applications in Coherent Communication and Sensing

NASA Astrophysics Data System (ADS)

Parker, John S.

Integrated photonics combines many optical components including lasers, modulators, waveguides, and detectors in close proximity via homogeneous (monolithic) or heterogeneous (using multiple materials) integration. This improves stability for interferometers and lasers, reduces the occurrence of unwanted reflections, and it avoids coupling losses between different components as they are on the same chip. Thus, less power is needed to compensate for these added losses, and less heat needs to be removed due to these power savings. In addition, integration allows the many components that comprise a system to be fabricated together, thereby reducing the cost per system and allowing rapid scaling in production throughput. Integrated optical combs have many applications including: metrology, THz frequency generation, arbitrary waveform generation, optical clocks, photonic analog-to-digital converters, sensing (imaging), spectroscopy, and data communication. A comb is a set of optical sources evenly spaced in frequency. Several methods of comb generation including mode-locking and optical parametric oscillation produce phase-matched optical outputs with a fixed phase relationship between the frequency lines. When the absolute frequency of a single comb line is stabilized along with the frequency spacing between comb lines, absolute phase and frequency precision can be achieved over the entire comb bandwidth. This functionality provides tremendous benefits to many applications such as coherent communication and optical sensing. The goals for this work were achieving a broad comb bandwidth and noise reduction, i.e., frequency and phase stability. Integrated mode-locked lasers on the InGaAsP/InP material platform were chosen, as they could be monolithically integrated with the wide range of highly functional and versatile photonic integrated circuits (PICs) previously demonstrated on this platform at UCSB. Gain flattening filters were implemented to increase the comb bandwidths to 2.5 THz. Active mode-locking with an RF source was used to precisely set the frequency spacing between comb lines with better than 10 Hz accuracy. An integrated optical phase-locked loop (OPLL) for the comb was designed, built, and tested. The OPLL fixed a single comb line to a stable single linewidth laser, demonstrating a ˜430 Hz FWHM optical linewidth on the locked comb line and 20º RMS phase deviation between the comb and optical reference. The free-running linewidth is 50--100 MHz, demonstrating over 50 dB improvement in optical linewidth via locking. An integrated tunable laser (SG-DBR) with an OPLL was phase-locked to a comb source with a fixed offset frequency, thus showing the potential for using a comb with SG-DBRs as a compact frequency synthesizer.

Enabling and Enhancing Space Mission Success and Reduction of Risk through the Application of an Integrated Data Architecture

NASA Technical Reports Server (NTRS)

Brummett, Robert C.

2008-01-01

The engineering phases of design, development, test, and evaluation (DDT and E) and subsequent planning, preparation, and operation (Ops) of space vehicles in a complex and distributed environment requires massive and continuous flows of information across the enterprise and across temporal stages of the vehicle lifecycle. The resulting capabilities at each subsequent stage depend in part on the capture, preparation, storage, and subsequent provision of information from prior stages. The United States National Aeronautics and Space Administration (NASA) is currently designing a fleet of new vehicles that will replace the Space Shuttle and expand space operations and exploration capabilities. This includes the 2 stage human rated lift vehicle Ares 1 and its associated crew vehicle the Orion, and a service module; the heavy lift cargo vehicle, Ares 5, and an associated cargo stage known as the Earth Departure Stage; and a Lunar Lander vehicle that contains a descent stage, and ascent stage, and a habitation module. A variety of concurrent assorted ground operations infrastructure including software and facilities are also being developed, assorted technology and assembly designs and development for equipment such as EVA suits, life support systems, command and control technologies are also in the pipeline. The development is occurring in a distributed manner, with project deliverables being contributed by a large and diverse assortment of vendors and most space faring nations. Critical information about all of the components, software, and procedures must be shared during the DDT and E phases and then made readily available to the mission operations staff for access during the planning, preparation, and operations phases, and also need to be readily available for system to system interactions. The Constellation Data Systems Project (CxDS) is identifying the needs, and designing and deploying systems and processes to support these needs. This paper details the steps and processes that NASA is applying within the Constellation Program to manage this data and information, and to insure that the correct information is available, correctly annotated, and can be provisioned digitally to enhance response times, and support engineering analysis and anomaly resolution.

BFV-BRST analysis of the classical and quantum q-deformations of the sl(2) algebra

NASA Astrophysics Data System (ADS)

Dayi, O. F.

1994-01-01

BFV--BRST charge for q-deformed algebras is not unique. Different constructions of it in the classical as well as in the quantum phase space for the $q$-deformed algebra sl_q(2) are discussed. Moreover, deformation of the phase space without deforming the generators of sl(2) is considered. $\\hbar$-q-deformation of the phase space is shown to yield the Witten's second deformation. To study the BFV--BRST cohomology problem when both the quantum phase space and the group are deformed, a two parameter deformation of sl(2) is proposed, and its BFV-BRST charge is given.

Sensitivity of Space Shuttle Weight and Cost to Structure Subsystem Weights

NASA Technical Reports Server (NTRS)

Wedge, T. E.; Williamson, R. P.

1973-01-01

Quantitative relationships between changes in space shuttle weights and costs with changes in weight of various portions of space shuttle structural subsystems are investigated. These sensitivity relationships, as they apply at each of three points in the development program (preliminary design phase, detail design phase, and test/operational phase) have been established for five typical space shuttle designs, each of which was responsive to the missions in the NASA Shuttle RFP, and one design was that selected by NASA.

The analysis of 3-phase squirrel-cage induction motors including space harmonics and mutual slotting in transient and steady state

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

Paap, G.C.

1991-03-01

From general equations which describe the transient electromechanical behavior of the asynchronous squirrel-cage motor, and which include the influence of space harmonics and mutual slotting, simplified models are derived and compared. The models derived are demonstrated in examples where special attention is paid to the influence of the place of the harmonics in the mutual inductance matrix and the influence of mutual slotting. Further, the steady-state equations are derived and the back-transformation for the stator and rotor currents is given. One example is compared with the result of measurements.

Advanced Life Support Research and Technology Development

NASA Technical Reports Server (NTRS)

Kliss, Mark

2001-01-01

A videograph outlining life support research. The Human Exploration and Development of Space (HEDS) Enterprise's goals are to provide life support self-sufficiency for human beings to carry out research and exploration productively in space, to open the door for planetary exploration, and for benefits on Earth. Topics presented include the role of NASA Ames, funding, and technical monitoring. The focused research areas discussed include air regeneration, carbon dioxide removal, Mars Life Support, water recovery, Vapor Phase Catalytic Ammonia Removal (VPCAR), solid waste treatment, and Supercritical Water Oxidation (SCWC). Focus is placed on the utilization of Systems Integration, Modeling and Analysis (SIMA) and Dynamic Systems Modeling in this research.

Room temperature stretch forming of scale space shuttle external tank dome gores. Volume 1: Technical

NASA Technical Reports Server (NTRS)

Blunck, R. D.; Krantz, D. E.

1974-01-01

An account of activities and data gathered in the Room Temperature Stretch Forming of One-third Scale External Tank Bulkhead Gores for space shuttle study, and a tooling design and production cost study are reported. The following study phases are described: (1) the stretch forming of three approximately one-third scale external tank dome gores from single sheets of 2219-T37 aluminum alloy; (2) the designing of a full scale production die, including a determination of tooling requirements; and (3) the determination of cost per gore at the required production rates, including manufacturing, packaging, and shipping.

Space Station - An integrated approach to operational logistics support

NASA Technical Reports Server (NTRS)

Hosmer, G. J.

1986-01-01

Development of an efficient and cost effective operational logistics system for the Space Station will require logistics planning early in the program's design and development phase. This paper will focus on Integrated Logistics Support (ILS) Program techniques and their application to the Space Station program design, production and deployment phases to assure the development of an effective and cost efficient operational logistics system. The paper will provide the methodology and time-phased programmatic steps required to establish a Space Station ILS Program that will provide an operational logistics system based on planned Space Station program logistics support.

Wavelets and the squeezed states of quantum optics

NASA Technical Reports Server (NTRS)

Defacio, B.

1992-01-01

Wavelets are new mathematical objects which act as 'designer trigonometric functions.' To obtain a wavelet, the original function space of finite energy signals is generalized to a phase-space, and the translation operator in the original space has a scale change in the new variable adjoined to the translation. Localization properties in the phase-space can be improved and unconditional bases are obtained for a broad class of function and distribution spaces. Operators in phase space are 'almost diagonal' instead of the traditional condition of being diagonal in the original function space. These wavelets are applied to the squeezed states of quantum optics. The scale change required for a quantum wavelet is shown to be a Yuen squeeze operator acting on an arbitrary density operator.

Surface Wave Propagation on a Laterally Heterogeneous Earth

NASA Astrophysics Data System (ADS)

Tromp, Jeroen

1992-01-01

Love and Rayleigh waves propagating on the surface of the Earth exhibit path, phase and amplitude anomalies as a result of the lateral heterogeneity of the mantle. In the JWKB approximation, these anomalies can be determined by tracing surface wave trajectories, and calculating phase and amplitude anomalies along them. A time- or frequency -domain JWKB analysis yields local eigenfunctions, local dispersion relations, and conservation laws for the surface wave energy. The local dispersion relations determine the surface wave trajectories, and the energy equations determine the surface wave amplitudes. On an anisotrophic Earth model the local dispersion relation and the local vertical eigenfunctions depend explicitly on the direction of the local wavevector. Apart from the usual dynamical phase, which is the integral of the local wavevector along a raypath, there is an additional variation is phase. This additional phase, which is an analogue of the Berry phase in adiabatic quantum mechanics, vanishes in a waveguide with a local vertical two-fold symmetry axis or a local horizontal mirror plane. JWKB theory breaks down in the vicinity of caustics, where neighboring rays merge and the surface wave amplitude diverges. Based upon a potential representation of the surface wave field, a uniformly valid Maslov theory can be obtained. Surface wave trajectories are determined by a system of four ordinary differential equations which define a three-dimensional manifold in four-dimensional phase space (theta,phi,k_theta,k _phi), where theta is colatitude, phi is longitude, and k_theta and k _phi are the covariant components of the wavevector. There are no caustics in phase space; it is only when the rays in phase space are projected onto configuration space (theta,phi), the mixed spaces (k_theta,phi ) and (theta,k_phi), or onto momentum space (k_theta,k _phi), that caustics occur. The essential strategy is to employ a mixed or momentum space representation of the wavefield in the vicinity of a configuration space caustic.

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John

2004-01-01

Boeing-Canoga Park (BCP) and NASA-Marshall Space Flight Center (NASA-MSFC) are developing an Advanced Health Management System (AHMS) for use on the Space Shuttle Main Engine (SSME) that will improve Shuttle safety by reducing the probability of catastrophic engine failures during the powered ascent phase of a Shuttle mission. This is a phased approach that consists of an upgrade to the current Space Shuttle Main Engine Controller (SSMEC) to add turbomachinery synchronous vibration protection and addition of a separate Health Management Computer (HMC) that will utilize advanced algorithms to detect and mitigate predefined engine anomalies. The purpose of the Shuttle AHMS is twofold; one is to increase the probability of successfully placing the Orbiter into the intended orbit, and the other is to increase the probability of being able to safely execute an abort of a Space Transportation System (STS) launch. Both objectives are achieved by increasing the useful work envelope of a Space Shuttle Main Engine after it has developed anomalous performance during launch and the ascent phase of the mission. This increase in work envelope will be the result of two new anomaly mitigation options, in addition to existing engine shutdown, that were previously unavailable. The added anomaly mitigation options include engine throttle-down and performance correction (adjustment of engine oxidizer to fuel ratio), as well as enhanced sensor disqualification capability. The HMC is intended to provide the computing power necessary to diagnose selected anomalous engine behaviors and for making recommendations to the engine controller for anomaly mitigation. Independent auditors have assessed the reduction in Shuttle ascent risk to be on the order of 40% with the combined system and a three times improvement in mission success.

Galvanic Liquid Applied Coating Development for Protection of Steel in Concrete

NASA Technical Reports Server (NTRS)

Curran, Joseph John; Curran, Jerry; MacDowell, Louis

2004-01-01

Corrosion of reinforcing steel in concrete is a major problem affecting NASA facilities at Kennedy Space Center (KSC), other government agencies, and the general public. Problems include damage to KSC launch support structures, transportation and marine infrastructures, as well as building structures. A galvanic liquid applied coating was developed at KSC in order to address this problem. The coating is a non-epoxy metal rich ethyl silicate liquid coating. The coating is applied as a liquid from initial stage to final stage. Preliminary data shows that this coating system exceeds the NACE 100 millivolt shift criterion. The remainder of the paper details the development of the coating system through the following phases: Phase I: Development of multiple formulations of the coating to achieve easy application characteristics, predictable galvanic activity, long-term protection, and minimum environmental impact. Phase II: Improvement of the formulations tested in Phase I including optimization of metallic loading as well as incorporation of humectants for continuous activation. Phase III: Application and testing of improved formulations on the test blocks. Phase IV: Incorporation of the final formulation upgrades onto large instrumented structures (slabs).

Analysis of nulling phase functions suitable to image plane coronagraphy

NASA Astrophysics Data System (ADS)

Hénault, François; Carlotti, Alexis; Vérinaud, Christophe

2016-07-01

Coronagraphy is a very efficient technique for identifying and characterizing extra-solar planets orbiting in the habitable zone of their parent star, especially in a space environment. An important family of coronagraphs is actually based on phase plates located at an intermediate image plane of the optical system, and spreading the starlight outside the "Lyot" exit pupil plane of the instrument. In this commutation we present a set of candidate phase functions generating a central null at the Lyot plane, and study how it propagates to the image plane of the coronagraph. These functions include linear azimuthal phase ramps (the well-known optical vortex), azimuthally cosine-modulated phase profiles, and circular phase gratings. Nnumerical simulations of the expected null depth, inner working angle, sensitivity to pointing errors, effect of central obscuration located at the pupil or image planes, and effective throughput including image mask and Lyot stop transmissions are presented and discussed. The preliminary conclusion is that azimuthal cosine functions appear as an interesting alternative to the classical optical vortex of integer topological charge.

In-step inflatable antenna experiment

NASA Astrophysics Data System (ADS)

Freeland, R. E.; Bilyeu, G.

Large deployable space antennas are needed to accommodate a number of applications that include mobile communications, earth observation radiometry, active microwave sensing, space-orbiting very long baseline interferometry, and Department of Defense (DoD) space-based radar. The criteria for evaluating candidate structural concepts for essentially all the applications is the same; high deployment reliability, low cost, low weight, low launch volume, and high aperture precision. A new class of space structures, called inflatable deployable structures, have tremendous potential for completely satisfying the first four criteria and good potential for accommodating the longer wavelength applications. An inflatable deployable antenna under development by L'Garde Inc. of Tustin, California, represents such a concept. Its level of technology is mature enough to support a meaningful orbital technology experiment. The NASA Office of Aeronautics and Space Technology initiated the In-Space Technology Experiments Program (IN-STEP) specifically to sponsor the verification and/or validation of unique and innovative space technologies in the space environment. The potential of the L'Garde concept has been recognized and resulted in its selection for an IN-STEP experiment. The objective of the experiment is to (a) validate the deployment of a 14-meter, inflatable parabolic reflector structure, (b) measure the reflector surface accuracy, and (c) investigate structural damping characteristics under operational conditions. The experiment approach will be to use the NASA Spartan Spacecraft to carry the experiment on orbit. Reflector deployment will be monitored by two high-resolution video cameras. Reflector surface quality will be measured with a digital imaging radiometer. Structural damping will be based on measuring the decay of reflector structure amplitude. The experiment is being managed by the Jet Propulsion Laboratory. The experiment definition phase (Phase B) will be completed by the end of fiscal year (FY) 1992; hardware development (Phase C/D) is expected to start by early FY 1993; and launch is scheduled for 1995. The paper describes the accomplishments to date and the approach for the remainder of the experiment.

Space exploration and colonization - Towards a space faring society

NASA Technical Reports Server (NTRS)

Hammond, Walter E.

1990-01-01

Development trends of space exploration and colonization since 1957 are reviewed, and a five-phase evolutionary program planned for the long-term future is described. The International Geosphere-Biosphere program which is intended to provide the database on enviromental changes of the earth as a global system is considered. Evolution encompasses the anticipated advantages of such NASA observation projects as the Hubble Space Telescope, the Gamma Ray Observatory, the Advanced X-Ray Astrophysics Facility, and the Cosmic Background Explorer. Attention is given to requirements for space colonization, including development of artificial gravity and countermeasures to mitigate zero gravity problems; robotics and systems aimed to minimize human exposure to the space environment; the use of nuclear propulsion; and international collaboration on lunar-Mars projects. It is recommended that nuclear energy sources be developed for both propulsion and as extraterrestrial power plants.

Quantum robots and environments

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

Benioff, P.

1998-08-01

Quantum robots and their interactions with environments of quantum systems are described, and their study justified. A quantum robot is a mobile quantum system that includes an on-board quantum computer and needed ancillary systems. Quantum robots carry out tasks whose goals include specified changes in the state of the environment, or carrying out measurements on the environment. Each task is a sequence of alternating computation and action phases. Computation phase activites include determination of the action to be carried out in the next phase, and recording of information on neighborhood environmental system states. Action phase activities include motion of themore » quantum robot and changes in the neighborhood environment system states. Models of quantum robots and their interactions with environments are described using discrete space and time. A unitary step operator T that gives the single time step dynamics is associated with each task. T=T{sub a}+T{sub c} is a sum of action phase and computation phase step operators. Conditions that T{sub a} and T{sub c} should satisfy are given along with a description of the evolution as a sum over paths of completed phase input and output states. A simple example of a task{emdash}carrying out a measurement on a very simple environment{emdash}is analyzed in detail. A decision tree for the task is presented and discussed in terms of the sums over phase paths. It is seen that no definite times or durations are associated with the phase steps in the tree, and that the tree describes the successive phase steps in each path in the sum over phase paths. {copyright} {ital 1998} {ital The American Physical Society}« less

A study of quantification of aortic compliance in mice using radial acquisition phase contrast MRI

NASA Astrophysics Data System (ADS)

Zhao, Xuandong

Spatiotemporal changes in blood flow velocity measured using Phase contrast Magnetic Resonance Imaging (MRI) can be used to quantify Pulse Wave Velocity (PWV) and Wall Shear Stress (WSS), well known indices of vessel compliance. A study was conducted to measure the PWV in the aortic arch in young healthy children using conventional phase contrast MRI and a post processing algorithm that automatically track the peak velocity in phase contrast images. It is shown that the PWV calculated using peak velocity-time data has less variability compared to that using mean velocity and flow. Conventional MR data acquisition techniques lack both the spatial and temporal resolution needed to accurately calculate PWV and WSS in in vivo studies using transgenic animal models of arterial diseases. Radial k-space acquisition can improve both spatial and temporal resolution. A major part of this thesis was devoted to developing technology for Radial Phase Contrast Magnetic Resonance (RPCMR) cine imaging on a 7 Tesla Animal scanner. A pulse sequence with asymmetric radial k-space acquisition was designed and implemented. Software developed to reconstruct the RPCMR images include gridding, density compensation and centering of k-Space that corrects the image ghosting introduced by hardware response time. Image processing software was developed to automatically segment the vessel lumen and correct for phase offset due to eddy currents. Finally, in vivo and ex vivo aortic compliance measurements were conducted in a well-established mouse model for atherosclerosis: Apolipoprotein E-knockout (ApoE-KO). Using RPCMR technique, a significantly higher PWV value as well as a higher average WSS was detected among 9 months old ApoE-KO mice compare to in wild type mice. A follow up ex-vivo test of tissue elasticity confirmed the impaired distensibility of aortic arteries among ApoE-KO mice.

Method and device for electroextraction of heavy metals from technological solutions and wastewater

DOEpatents

Khalemsky, Aron Mikhailov; Payusov, Sergei Abramovic; Kelner, Leonid; Jo, Jae

2005-05-03

The basic principles of the method for heavy metals electroextraction from technological solutions and wastewater includes pretreating to remove Chromium-6 and high concentrations of heavy metals and periodically treating in a six-electrode bipolar cylindrical electroreactor made of non-conducting material to achieve lower accepted levels of impurities. Six cylindrical steel electrodes form two triode stacks and are fed with three-phase alternating current of commercial frequency (50-60 Hz), which can be pulsed. Each phase of the three-phase current is connected to three electrodes of one triode stack or in parallel to two triode stacks. The parallel connection of three-phase current to two triode stacks is performed so that the same phase of the three phase current is connected in parallel with each two opposite electrodes of six electrodes located along the periphery, or with two adjacent electrodes. A bipolar stationary aluminum electrode is situated in the inter-electrode space. In one of the embodiments, the bipolar electrode is made of a perforated heat-resistant plastic container filled with secondary aluminum and duralumin scrap. In another embodiment, the bipolar electrode of aluminum or duralumin scrap may be made without a perforated container and is placed in the inter-electrode space as a bulk scrap. In this case, to prevent shorts, each of six steel electrodes is placed in isolated perforated plastic shell with holes of 5 mm in diameter. Non-ferrous metals are extracted in a form of ferrite-chromites, and aluminates as well as hydroxyl salts deposited in the inter-electrode space without electrolysis deposits on electrodes. Deposits are separated from solution by known methods of filtration.

Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1-x)Bi(Mg1/2Ti1/2)O3-xPbTiO3 piezoceramics

NASA Astrophysics Data System (ADS)

Upadhyay, Ashutosh; Singh, Akhilesh Kumar

2015-04-01

Results of the room temperature structural studies on (1-x)Bi(Mg1/2Ti1/2)O3-xPbTiO3 ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28 ≤ x ≤ 0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4 mm) phases in the composition range 0.33 ≤ x ≤ 0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28 ≤ x ≤ 0.32. The structure for the compositions with x ≥ 0.45 is found to be predominantly tetragonal with space group P4 mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x = .35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.

Analysis and Assessment of Peak Lightning Current Probabilities at the NASA Kennedy Space Center

NASA Technical Reports Server (NTRS)

Johnson, D. L.; Vaughan, W. W.

1999-01-01

This technical memorandum presents a summary by the Electromagnetics and Aerospace Environments Branch at the Marshall Space Flight Center of lightning characteristics and lightning criteria for the protection of aerospace vehicles. Probability estimates are included for certain lightning strikes (peak currents of 200, 100, and 50 kA) applicable to the National Aeronautics and Space Administration Space Shuttle at the Kennedy Space Center, Florida, during rollout, on-pad, and boost/launch phases. Results of an extensive literature search to compile information on this subject are presented in order to answer key questions posed by the Space Shuttle Program Office at the Johnson Space Center concerning peak lightning current probabilities if a vehicle is hit by a lightning cloud-to-ground stroke. Vehicle-triggered lightning probability estimates for the aforementioned peak currents are still being worked. Section 4.5, however, does provide some insight on estimating these same peaks.