Command and data handling of science signals on Spacelab

NASA Technical Reports Server (NTRS)

Mccain, H. G.

1975-01-01

The Orbiter Avionics and the Spacelab Command and Data Management System (CDMS) combine to provide a relatively complete command, control, and data handling service to the instrument complement during a Shuttle Sortie Mission. The Spacelab CDMS services the instruments and the Orbiter in turn services the Spacelab. The CDMS computer system includes three computers, two I/O units, a mass memory, and a variable number of remote acquisition units. Attention is given to the CDMS high rate multiplexer, CDMS tape recorders, closed circuit television for the visual monitoring of payload bay and cabin area activities, methods of science data acquisition, questions of transmission and recording, CDMS experiment computer usage, and experiment electronics.

The Outer Solar System Origin Survey full data release orbit catalog and characterization.

NASA Astrophysics Data System (ADS)

Kavelaars, J. J.; Bannister, Michele T.; Gladman, Brett; Petit, Jean-Marc; Gwyn, Stephen; Alexandersen, Mike; Chen, Ying-Tung; Volk, Kathryn; OSSOS Collaboration.

2017-10-01

The Outer Solar System Origin Survey (OSSOS) completed main data acquisition in February 2017. Here we report the release of our full orbit sample, which include 836 TNOs with high precision orbit determination and classification. We combine the OSSOS orbit sample with previously release Canada-France Ecliptic Plane Survey (CFEPS) and a precursor survey to OSSOS by Alexandersen et al. to provide a sample of over 1100 TNO orbits with high precision classified orbits and precisely determined discovery and tracking circumstances (characterization). We are releasing the full sample and characterization to the world community, along with software for conducting ‘Survey Simulations’, so that this sample of orbits can be used to test models of the formation of our outer solar system against the observed sample. Here I will present the characteristics of the data set and present a parametric model for the structure of the classical Kuiper belt.

Cryogenic on-orbit liquid depot storage acquisition and transfer (COLD-SAT) experiment subsystem instrumentation and wire harness design report

NASA Technical Reports Server (NTRS)

Edwards, Lawrence G.

1994-01-01

Subcritical cryogens such as liquid hydrogen (LH2) and liquid oxygen (LO2) are required for space based transportation propellant, reactant, and life support systems. Future long-duration space missions will require on-orbit systems capable of long-term cryogen storage and efficient fluid transfer capabilities. COLD-SAT, which stands for cryogenic orbiting liquid depot-storage acquisition and transfer, is a free-flying liquid hydrogen management flight experiment. Experiments to determine optimum methods of fluid storage and transfer will be performed on the COLD-SAT mission. The success of the mission is directly related to the type and accuracy of measurements made. The instrumentation and measurement techniques used are therefore critical to the success of the mission. This paper presents the results of the COLD-SAT experiment subsystem instrumentation and wire harness design effort. Candidate transducers capable of fulfilling the COLD-SAT experiment measurement requirements are identified. Signal conditioning techniques, data acquisition requirements, and measurement uncertainty analysis are presented. Electrical harnessing materials and wiring techniques for the instrumentation designed to minimize heat conduction to the cryogenic tanks and provide optimum measurement accuracy are listed.

Feasibility study for a Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT) satellite

NASA Technical Reports Server (NTRS)

Rybak, S. C.; Willen, G. S.; Follett, W. H.; Hanna, G. J.; Cady, E. C.; Distefano, E.; Meserole, J. S.

1990-01-01

This feasibility study presents the conceptual design of a spacecraft for performing a series of cryogenic fluid management flight experiments. This spacecraft, the Cryogenic On-Orbit Liquid Depot-Storage, Acquisition, and Transfer (COLD-SAT) satellite, will use liquid hydrogen as the test fluid, be launched on a Delta expendable launch vehicle, and conduct a series of experiments over a two to three month period. These experiments will investigate the physics of subcritical cryogens in the low gravity space environment to characterize their behavior and to correlate the data with analytical and numerical models of in-space cryogenic fluid management systems. Primary technologies addressed by COLD-SAT are: (1) pressure control; (2) chilldown; (3) no-vent fill; (4) liquid acquisition device fill; (5) pressurization; (6) low-g fill and drain; (7) liquid acquisition device expulsion; (8) line chilldown; (9) thermodynamic state control; and (10) fluid dumping.

Method and apparatus for autonomous, in-receiver prediction of GNSS ephemerides

NASA Technical Reports Server (NTRS)

Bar-Sever, Yoaz E. (Inventor); Bertiger, William I. (Inventor)

2012-01-01

Methods and apparatus for autonomous in-receiver prediction of orbit and clock states of Global Navigation Satellite Systems (GNSS) are described. Only the GNSS broadcast message is used, without need for periodic externally-communicated information. Earth orientation information is extracted from the GNSS broadcast ephemeris. With the accurate estimation of the Earth orientation parameters it is possible to propagate the best-fit GNSS orbits forward in time in an inertial reference frame. Using the estimated Earth orientation parameters, the predicted orbits are then transformed into Earth-Centered-Earth-Fixed (ECEF) coordinates to be used to assist the GNSS receiver in the acquisition of the signals. GNSS satellite clock states are also extracted from the broadcast ephemeris and a parameterized model of clock behavior is fit to that data. The estimated modeled clocks are then propagated forward in time to enable, together with the predicted orbits, quicker GNSS signal acquisition.

Acquisition/expulsion system for earth orbital propulsion system study. Volume 4: Flight test article

NASA Technical Reports Server (NTRS)

1973-01-01

Two orbital test plans were prepared to verify one of the passive cryogenic storage tank/feedline candidate designs. One plan considered the orbital test article to be launched as a dedicated payload using an Atlas F burner launching configuration. The second plan proposed to launch the orbital test article as a secondary payload on the Titan E/Centaur proof flight. The secondary payload concept was pursued until January 1973, when work to build the hardware for this phase of the contract was terminated for lack of a sponsor for the flight. The dedicated payload launched on an Atlas F is described.

Spacecraft system study: A study to define the impact of laser communication systems on their host spacecraft

NASA Technical Reports Server (NTRS)

1984-01-01

The mutual influence of a laser communication system and its host spacecraft and the degree to which the mutual influence limited acquisition, tracking and pointing processes were investigated. A laser klink between a low earth orbiting (LEO) satellite and a geosynchronous earth orbiting (GEO) satellite was used as a baseline. The laser link between satellites was a generic channel transferring 500 Mbps data from the LEO to GEO using the GaAlAs laser as the laser light source. Major aspects of pointing and tracking with a satelliteborne optical system were evaluated including: (1) orbital aspects such as spacecraft relative motions, point ahead, and Sun snd Moon optical noise; (2) burst errors introduced by the electronic and optical noise levels; (3) servo system design and configurations, and the noise sources such as, sensor noise, base motion disturbances, gimbal friction torque noise; (4) an evaluation of the tracking and beacon link and the type of sensors used; (5) the function of the acquisition procedure and an evaluation of the sensors employed; and (6) an estimate of the size, weight and power needed for the satellite system.

Acquisition system testing with superfluid helium. [cryopumping for space

NASA Technical Reports Server (NTRS)

Anderson, John E.; Fester, Dale A.; Dipirro, Michael J.

1988-01-01

Minus one-g outflow tests were conducted with superfluid helium in conjunction with a thermomechanical pump setup in order to study the use of capillary acquisition systems for NASA's Superfluid Helium On-Orbit Transfer (SHOOT) flight experiment. Results show that both fine mesh screen and porous sponge systems are capable of supplying superfluid helium to the thermomechanical pump inlet against a one-g head up to 4 cm, fulfilling the SHOOT requirements. Sponge results were found to be reproducible, while the screen results were not.

Flat panel detector-based cone beam computed tomography with a circle-plus-two-arcs data acquisition orbit: preliminary phantom study.

PubMed

Ning, Ruola; Tang, Xiangyang; Conover, David; Yu, Rongfeng

2003-07-01

Cone beam computed tomography (CBCT) has been investigated in the past two decades due to its potential advantages over a fan beam CT. These advantages include (a) great improvement in data acquisition efficiency, spatial resolution, and spatial resolution uniformity, (b) substantially better utilization of x-ray photons generated by the x-ray tube compared to a fan beam CT, and (c) significant advancement in clinical three-dimensional (3D) CT applications. However, most studies of CBCT in the past are focused on cone beam data acquisition theories and reconstruction algorithms. The recent development of x-ray flat panel detectors (FPD) has made CBCT imaging feasible and practical. This paper reports a newly built flat panel detector-based CBCT prototype scanner and presents the results of the preliminary evaluation of the prototype through a phantom study. The prototype consisted of an x-ray tube, a flat panel detector, a GE 8800 CT gantry, a patient table and a computer system. The prototype was constructed by modifying a GE 8800 CT gantry such that both a single-circle cone beam acquisition orbit and a circle-plus-two-arcs orbit can be achieved. With a circle-plus-two-arcs orbit, a complete set of cone beam projection data can be obtained, consisting of a set of circle projections and a set of arc projections. Using the prototype scanner, the set of circle projections were acquired by rotating the x-ray tube and the FPD together on the gantry, and the set of arc projections were obtained by tilting the gantry while the x-ray tube and detector were at the 12 and 6 o'clock positions, respectively. A filtered backprojection exact cone beam reconstruction algorithm based on a circle-plus-two-arcs orbit was used for cone beam reconstruction from both the circle and arc projections. The system was first characterized in terms of the linearity and dynamic range of the detector. Then the uniformity, spatial resolution and low contrast resolution were assessed using different phantoms mainly in the central plane of the cone beam reconstruction. Finally, the reconstruction accuracy of using the circle-plus-two-arcs orbit and its related filtered backprojection cone beam volume CT reconstruction algorithm was evaluated with a specially designed disk phantom. The results obtained using the new cone beam acquisition orbit and the related reconstruction algorithm were compared to those obtained using a single-circle cone beam geometry and Feldkamp's algorithm in terms of reconstruction accuracy. The results of the study demonstrate that the circle-plus-two-arcs cone beam orbit is achievable in practice. Also, the reconstruction accuracy of cone beam reconstruction is significantly improved with the circle-plus-two-arcs orbit and its related exact CB-FPB algorithm, as compared to using a single circle cone beam orbit and Feldkamp's algorithm.

Advanced long term cryogenic storage systems

NASA Technical Reports Server (NTRS)

Brown, Norman S.

1987-01-01

Long term, cryogenic fluid storage facilities will be required to support future space programs such as the space-based Orbital Transfer Vehicle (OTV), Telescopes, and Laser Systems. An orbital liquid oxygen/liquid hydrogen storage system with an initial capacity of approximately 200,000 lb will be required. The storage facility tank design must have the capability of fluid acquisition in microgravity and limit cryogen boiloff due to environmental heating. Cryogenic boiloff management features, minimizing Earth-to-orbit transportation costs, will include advanced thick multilayer insulation/integrated vapor cooled shield concepts, low conductance support structures, and refrigeration/reliquefaction systems. Contracted study efforts are under way to develop storage system designs, technology plans, test article hardware designs, and develop plans for ground/flight testing.

Autonomous Navigation Using Celestial Objects

NASA Technical Reports Server (NTRS)

Folta, David; Gramling, Cheryl; Leung, Dominic; Belur, Sheela; Long, Anne

1999-01-01

In the twenty-first century, National Aeronautics and Space Administration (NASA) Enterprises envision frequent low-cost missions to explore the solar system, observe the universe, and study our planet. Satellite autonomy is a key technology required to reduce satellite operating costs. The Guidance, Navigation, and Control Center (GNCC) at the Goddard Space Flight Center (GSFC) currently sponsors several initiatives associated with the development of advanced spacecraft systems to provide autonomous navigation and control. Autonomous navigation has the potential both to increase spacecraft navigation system performance and to reduce total mission cost. By eliminating the need for routine ground-based orbit determination and special tracking services, autonomous navigation can streamline spacecraft ground systems. Autonomous navigation products can be included in the science telemetry and forwarded directly to the scientific investigators. In addition, autonomous navigation products are available onboard to enable other autonomous capabilities, such as attitude control, maneuver planning and orbit control, and communications signal acquisition. Autonomous navigation is required to support advanced mission concepts such as satellite formation flying. GNCC has successfully developed high-accuracy autonomous navigation systems for near-Earth spacecraft using NASA's space and ground communications systems and the Global Positioning System (GPS). Recently, GNCC has expanded its autonomous navigation initiative to include satellite orbits that are beyond the regime in which use of GPS is possible. Currently, GNCC is assessing the feasibility of using standard spacecraft attitude sensors and communication components to provide autonomous navigation for missions including: libration point, gravity assist, high-Earth, and interplanetary orbits. The concept being evaluated uses a combination of star, Sun, and Earth sensor measurements along with forward-link Doppler measurements from the command link carrier to autonomously estimate the spacecraft's orbit and reference oscillator's frequency. To support autonomous attitude determination and control and maneuver planning and control, the orbit determination accuracy should be on the order of kilometers in position and centimeters per second in velocity. A less accurate solution (one hundred kilometers in position) could be used for acquisition purposes for command and science downloads. This paper provides performance results for both libration point orbiting and high Earth orbiting satellites as a function of sensor measurement accuracy, measurement types, measurement frequency, initial state errors, and dynamic modeling errors.

REPORT ON AN ORBITAL MAPPING SYSTEM.

USGS Publications Warehouse

Colvocoresses, Alden P.; ,

1984-01-01

During June 1984, the International Society for Photogrammetry and Remote Sensing accepted a committee report that defines an Orbital Mapping System (OMS) to follow Landsat and other Earth-sensing systems. The OMS involves the same orbital parameters of Landsats 1, 2, and 3, three wave bands (two in the visible and one in the near infrared) and continuous stereoscopic capability. The sensors involve solid-state linear arrays and data acquisition (including stereo) designed for one-dimensional data processing. It has a resolution capability of 10-m pixels and is capable of producing 1:50,000-scale image maps with 20-m contours. In addition to mapping, the system is designed to monitor the works of man as well as nature and in a cost-effective manner.

Project Copernicus: An Earth observing system

NASA Technical Reports Server (NTRS)

1991-01-01

Hunsaker Aerospace Corporation is presenting this proposal for Project Copernicus to fulfill the need for space-based remote sensing of Earth. Concentration is on data acquisition. Copernicus is designed to be a flexible system of spacecraft in a low near-polar orbit. The goal is to acquire data so that the scientists may begin to understand many Earth processes and interactions. The mission objective of Copernicus is to provide a space-based, remote-sensing measurement data acquisition and transfer system for 15 years. A description of the design project is presented.

Space environmental effects on materials

NASA Technical Reports Server (NTRS)

Schwinghmaer, R. J.

1980-01-01

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

Orbital debris measurements

NASA Astrophysics Data System (ADS)

Kessler, D. J.

What is currently known about the orbital debris flux is from a combination of ground based and in-space measurements. These measurements have revealed an increasing population with decreasing size. A summary of measurements is presented for the following sources: the North American Aerospace Defense Command Catalog, the Perimeter Acquisition and Attack Characterization System Radar, ground based optical telescopes, the Explorer 46 Meteoroid Bumper Experiment, spacecraft windows, and Solar Max surfaces.

Orbital debris measurements

NASA Technical Reports Server (NTRS)

Kessler, D. J.

1986-01-01

What is currently known about the orbital debris flux is from a combination of ground based and in-space measurements. These measurements have revealed an increasing population with decreasing size. A summary of measurements is presented for the following sources: the North American Aerospace Defense Command Catalog, the Perimeter Acquisition and Attack Characterization System Radar, ground based optical telescopes, the Explorer 46 Meteoroid Bumper Experiment, spacecraft windows, and Solar Max surfaces.

A Laser Optical System to Remove Low Earth Orbit Space Debris

NASA Astrophysics Data System (ADS)

Phipps, Claude R.; Baker, Kevin L.; Libby, Stephen B.; Liedahl, Duane A.; Olivier, Scot S.; Pleasance, Lyn D.; Rubenchik, Alexander; Nikolaev, Sergey; Trebes, James E.; George, Victor E.; Marrcovici, Bogdan; Valley, Michael T.

2013-08-01

Collisions between existing Low Earth Orbit (LEO) debris are now a main source of new debris, threatening future use of LEO space. As solutions, flying up and interacting with each object is inefficient due to the energy cost of orbit plane changes, while debris removal systems using blocks of aerogel or gas-filled balloons are prohibitively expensive. Furthermore, these solutions to the debris problem address only large debris, but it is also imperative to remove 10-cm-class debris. In Laser-Orbital-Debris-Removal (LODR), a ground-based pulsed laser makes plasma jets on LEO debris objects, slowing them slightly, and causing them to re-enter the atmosphere and burn up. LODR takes advantage of recent advances in pulsed lasers, large mirrors, nonlinear optics and acquisition systems. LODR is the only solution that can address both large and small debris. International cooperation is essential for building and operating such a system. We also briefly discuss the orbiting laser debris removal alternative.

Tracker implementation for the orbiter Ku-band communications antenna

NASA Technical Reports Server (NTRS)

Rudnicki, J. F.; Lindsey, J. F.

1976-01-01

Possible implementations and recommendations for the Space Shuttle Ku-Band integrated communications/radar antenna tracking system were evaluated. Communication aspects involving the Tracking Data Relay Satellite (TDRS)/Orbiter Ku-Band link are emphasized. Detailed analysis of antenna sizes, gains and signal-to-noise ratios shows the desirability of using maximum size 36-inch diameter dish and a triple channel monopulse. The use of the original baselined 20 inch dish is found to result in excessive acquisition time since the despread signal would be used in the tracking loop. An evaluation of scan procedures which includes vehicle dynamics, designation error, time for acquisition and probability of acquisition shows that the conical scan is preferred since the time for lock-on for relatively slow look angle rates will be significantly shorter than the raster scan. Significant improvement in spherical coverage may be obtained by reorienting the antenna gimbal to obtain maximum blockage overlap.

Acquisition/expulsion system for earth orbital propulsion system study. Volume 2: Cryogenic design

NASA Technical Reports Server (NTRS)

1973-01-01

Detailed designs were made for three earth orbital propulsion systems; (1) the space shuttle (integrated) OMS/RCS, (2) the space shuttle (dedicated) OMS (LO2), and (3) the space tug. The preferred designs from the integrated OMS/RCS were used as the basis for the flight test article design. A plan was prepared that outlines the steps, cost, and schedule required to complete the development of the prototype DSL tank and feedline (LH2 and LO2) systems. Ground testing of a subscale model using LH2 verified the expulsion characteristics of the preferred DSL designs.

Improvements in Space Surveillance Processing for Wide Field of View Optical Sensors

NASA Astrophysics Data System (ADS)

Sydney, P.; Wetterer, C.

2014-09-01

For more than a decade, an autonomous satellite tracking system at the Air Force Maui Optical and Supercomputing (AMOS) observatory has been generating routine astrometric measurements of Earth-orbiting Resident Space Objects (RSOs) using small commercial telescopes and sensors. Recent work has focused on developing an improved processing system, enhancing measurement performance and response while supporting other sensor systems and missions. This paper will outline improved techniques in scheduling, detection, astrometric and photometric measurements, and catalog maintenance. The processing system now integrates with Special Perturbation (SP) based astrodynamics algorithms, allowing covariance-based scheduling and more precise orbital estimates and object identification. A merit-based scheduling algorithm provides a global optimization framework to support diverse collection tasks and missions. The detection algorithms support a range of target tracking and camera acquisition rates. New comprehensive star catalogs allow for more precise astrometric and photometric calibrations including differential photometry for monitoring environmental changes. This paper will also examine measurement performance with varying tracking rates and acquisition parameters.

Acquisition/expulsion system for earth orbital propulsion system study. Volume 3: Cryogenic test

NASA Technical Reports Server (NTRS)

1973-01-01

A ground test program was conducted to verify several of the design methods and techniques that were used in designing cryogenic acquisition/expulsion systems. The testing of a 63.5-cm diameter DSL subscale model was particularly significant. Under these tests, the operational characteristics of the DSL concept were verified using LH2 and LN2. Demonstration of the gas free liquid expulsion characteristics was accomplished by expelling LH2 under -1 g using both GH2 and GHe pressurization. Loading of the acquisition/expulsion device was successfully accomplished using LH2 and LN2. The liquid free vapor venting performance of the model was limited because of the thermal stratification under the -1 g test conditions.

Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer Satellite (COLD-SAT)

NASA Technical Reports Server (NTRS)

Schuster, John R.; Russ, Edwin J.; Wachter, Joseph P.

1990-01-01

The Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer Satellite (COLD-SAT) will perform subcritical liquid hydrogen handling experiments under low gravity conditions to provide engineering data for future space transportation missions. Comprising the four Class 1 enabling experiments are tank press control, tank chilldown, tank no-vent fill, and liquid acquisition device fill/refill. The nine Class 2 enhancing experiments are tanker thermal performance, pressurization, low-gravity setting and outflow, liquid acquisition device performance, transfer line chilldown, outflow subcooling, low-gravity vented fill, fluid dumping, and advanced instrumentation. Consisting of an experiment module mated to a spacecraft bus, COLD-SAT will be placed in an initial 1300 km circular orbit by an Atlas commercial launch vehicle, and will perform experiments in a semi-autonomous mode for a period of up to six months. The three-axis controlled spacecraft bus provides electric power, control and data management, communications, and attitude control along with propulsive acceleration levels ranging from 10(exp -6) to 10(exp -4) g. It is desired to understand the effects that low acceleration levels might have on the heat and mass transfer processes involved in some of the experiments. The experiment module contains the three liquid hydrogen tanks, valves, pressurization and pumping equipment, and instrumentation. Within the highly insulated tanks are specialized fluid management equipment that might be used in future space transportation systems. At launch all the liquid hydrogen for the experiments is contained in the largest tank, which has helium-purged insulation to prevent cryo-pumping of air on the launch pad. The tank is loaded by the hydrogen tanking system used for the Centaur upper stage of the Atlas. After reaching orbit the two smaller tanks become receivers for fluid transfers, and when tanked, become the vessels for performing many of the experiments.

A Feasibility Study of A Persistent Monitoring System For The Flight Deck of U.S. Navy Aircraft Carriers

DTIC Science & Technology

2009-03-01

utilize L2 measurements via proprietary methods. The coarse/ acquisition (C/A) code transmitted on L1 is used for the vast majority of GPS position... code , which can be acquired and tracked by a GPS receiver. The satellites are in a near-circular orbit with a radius of 26,560 km. There are six orbital...planes, each with at least four satellites. The orbital planes have an inclination of 55◦ from the equator. [33, p . 33] The GPS satellite

Defense Acquisitions: Assessments of Selected Weapon Programs

DTIC Science & Technology

2014-03-01

Frequency (UHF) Follow-On ( UFO ) satellite system currently in operation and provide interoperability with legacy terminals. MUOS consists of a...failures of two UFO satellites and predicted end-of-life of on-orbit UFO satellites, one of which was taken off-line in November 2012. A...needed because most on-orbit UFO satellites are past their design lives. Two of these unexpectedly failed—one in June 2005 and another in

Integrated source and channel encoded digital communication system design study

NASA Technical Reports Server (NTRS)

Udalov, S.; Huth, G. K.

1977-01-01

The analysis of the forward link signal structure for the shuttle orbiter Ku-band communication system was carried out, based on the assumptions of a 3.03 Mcps PN code. It is shown that acquisition requirements for the forward link can be met at the acquisition threshold C/N0 sub 0 value of about 60 dB-Hz, which corresponds to a bit error rate (BER) of about 0.001. It is also shown that the tracking threshold for the forward link is at about 57 dB-Hz. The analysis of the bent pipe concept for the orbiter was carried out, along with the comparative analysis of the empirical data. The complexity of the analytical approach warrants further investigation to reconcile the empirical and theoretical results. Techniques for incorporating a text and graphics capability into the forward link data stream are considered and a baseline configuration is described.

Post-Newtonian equations of motion for LEO debris objects and space-based acquisition, pointing and tracking laser systems

NASA Astrophysics Data System (ADS)

Gambi, J. M.; García del Pino, M. L.; Gschwindl, J.; Weinmüller, E. B.

2017-12-01

This paper deals with the problem of throwing middle-sized low Earth orbit debris objects into the atmosphere via laser ablation. The post-Newtonian equations here provided allow (hypothetical) space-based acquisition, pointing and tracking systems endowed with very narrow laser beams to reach the pointing accuracy presently prescribed. In fact, whatever the orbital elements of these objects may be, these equations will allow the operators to account for the corrections needed to balance the deviations of the line of sight directions due to the curvature of the paths the laser beams are to travel along. To minimize the respective corrections, the systems will have to perform initial positioning manoeuvres, and the shooting point-ahead angles will have to be adapted in real time. The enclosed numerical experiments suggest that neglecting these measures will cause fatal errors, due to differences in the actual locations of the objects comparable to their size.

The IBEX Flight Segment

NASA Astrophysics Data System (ADS)

Scherrer, J.; Carrico, J.; Crock, J.; Cross, W.; Delossantos, A.; Dunn, A.; Dunn, G.; Epperly, M.; Fields, B.; Fowler, E.; Gaio, T.; Gerhardus, J.; Grossman, W.; Hanley, J.; Hautamaki, B.; Hawes, D.; Holemans, W.; Kinaman, S.; Kirn, S.; Loeffler, C.; McComas, D. J.; Osovets, A.; Perry, T.; Peterson, M.; Phillips, M.; Pope, S.; Rahal, G.; Tapley, M.; Tyler, R.; Ungar, B.; Walter, E.; Wesley, S.; Wiegand, T.

2009-08-01

IBEX provides the observations needed for detailed modeling and in-depth understanding of the interstellar interaction (McComas et al. in Physics of the Outer Heliosphere, Third Annual IGPP Conference, pp. 162-181, 2004; Space Sci. Rev., 2009a, this issue). From mission design to launch and acquisition, this goal drove all flight system development. This paper describes the management, design, testing and integration of IBEX’s flight system, which successfully launched from Kwajalein Atoll on October 19, 2008. The payload is supported by a simple, Sun-pointing, spin-stabilized spacecraft with no deployables. The spacecraft bus consists of the following subsystems: attitude control, command and data handling, electrical power, hydrazine propulsion, RF, thermal, and structures. A novel 3-step orbit approach was employed to put IBEX in its highly elliptical, 8-day final orbit using a Solid Rocket Motor, which provided large delta-V after IBEX separated from the Pegasus launch vehicle; an adapter cone, which interfaced between the SRM and Pegasus; Motorized Lightbands, which performed separation from the Pegasus, ejection of the adapter cone, and separation of the spent SRM from the spacecraft; a ShockRing isolation system to lower expected launch loads; and the onboard Hydrazine Propulsion System. After orbit raising, IBEX transitioned from commissioning to nominal operations and science acquisition. At every phase of development, the Systems Engineering and Mission Assurance teams supervised the design, testing and integration of all IBEX flight elements.

Liquid Acquisition Strategies for Exploration Missions: Current Status 2010

NASA Technical Reports Server (NTRS)

Chato, David J.

2010-01-01

NASA is currently developing the propulsion system concepts for human exploration missions to the lunar surface. The propulsion concepts being investigated are considering the use of cryogenic propellants for the low gravity portion of the mission, that is, the lunar transit, lunar orbit insertion, lunar descent and the rendezvous in lunar orbit with a service module after ascent from the lunar surface. These propulsion concepts will require the vapor free delivery of the cryogenic propellants stored in the propulsion tanks to the exploration vehicles main propulsion system (MPS) engines and reaction control system (RCS) engines. Propellant management devices (PMD s) such as screen channel capillary liquid acquisition devices (LAD s), vanes and sponges currently are used for earth storable propellants in the Space Shuttle Orbiter OMS and RCS applications and spacecraft propulsion applications but only very limited propellant management capability exists for cryogenic propellants. NASA has begun a technology program to develop LAD cryogenic fluid management (CFM) technology through a government in-house ground test program of accurately measuring the bubble point delta-pressure for typical screen samples using LO2, LN2, LH2 and LCH4 as test fluids at various fluid temperatures and pressures. This presentation will document the CFM project s progress to date in concept designs, as well ground testing results.

Space Shuttle Orbiter Digital Outer Mold Line Scanning

NASA Technical Reports Server (NTRS)

Campbell, Charles H.; Wilson, Brad; Pavek, Mike; Berger, Karen

2012-01-01

The Space Shuttle Orbiters Discovery and Endeavor have been digitally scanned to produce post-flight configuration outer mold line surfaces. Very detailed scans of the windward side of these vehicles provide resolution of the detailed tile step and gap geometry, as well as the reinforced carbon carbon nose cap and leading edges. Lower resolution scans of the upper surface provide definition of the crew cabin windows, wing upper surfaces, payload bay doors, orbital maneuvering system pods and the vertical tail. The process for acquisition of these digital scans as well as post-processing of the very large data set will be described.

Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer satellite (COLD-SAT) feasibility study

NASA Technical Reports Server (NTRS)

Bailey, William J.; Weiner, Stephen P.; Beekman, Douglas H.; Dennis, Mark F.; Martin, Timothy A.

1990-01-01

The Cryogenic On-Orbit Liquid Depot Storage, Acquisition, and Transfer Satellite (COLD-SAT) is an experimental spacecraft launched from an expendable launch vehicle which is designed to investigate the systems and technologies required for efficient, effective, and reliable management of cryogenic fluid in the reduced gravity space environment. The COLD-SAT program will provide the necessary data base and provide low-g proving of fluid and thermal models of cryogenic storage, transfer, and resupply concepts and processes. A conceptual approach was developed and an overview of the results of the 24 month COLD-SAT Phase A feasibility is described which includes: (1) a definition of the technology needs and the accompanying experimental 3 month baseline mission; (2) a description of the experiment subsystem, major features and rationale for satisfaction of primary and secondary experiment requirements using liquid hydrogen as the test fluid; and (3) a presentation of the conceptual design of the COLD-SAT spacecraft subsystems which support the on-orbit experiment with emphasis on areas of greatest challenge.

Low-G fluid transfer technology study

NASA Technical Reports Server (NTRS)

Stark, J. A.

1976-01-01

Technology gaps and system characteristics critical to cryogenic and noncryogenic in-orbit fluid transfer were identified. Four different supply systems were conceptually designed as space shuttle payloads. These were; (1) space tug supply - LH2, LO2, N2H4, He - linear acceleration for liquid acquisition with supply module and tug separated from shuttle, (2) tug supply using orbiter drag, (3) orbiter supply - N2O4,MMH,He, H2,O2 - surface tension screens, (4) multiple receivers supply 0 solar electric propulsion stage, Hg, diaphragm - HEAO B, HEe, paddle fluid rotation-satellite control section, N2H4, screens. It was found that screens had the best overall potential for low weight and simplicity, however, thermal problems with cryogenics still need final resolution.

A preliminary experiment definition for video landmark acquisition and tracking

NASA Technical Reports Server (NTRS)

Schappell, R. T.; Tietz, J. C.; Hulstrom, R. L.; Cunningham, R. A.; Reel, G. M.

1976-01-01

Six scientific objectives/experiments were derived which consisted of agriculture/forestry/range resources, land use, geology/mineral resources, water resources, marine resources and environmental surveys. Computer calculations were then made of the spectral radiance signature of each of 25 candidate targets as seen by a satellite sensor system. An imaging system capable of recognizing, acquiring and tracking specific generic type surface features was defined. A preliminary experiment definition and design of a video Landmark Acquisition and Tracking system is given. This device will search a 10-mile swath while orbiting the earth, looking for land/water interfaces such as coastlines and rivers.

Hubble space telescope six-battery test bed

NASA Technical Reports Server (NTRS)

Pajak, J. A.; Bush, J. R., Jr.; Lanier, J. R., Jr.

1990-01-01

A test bed for a large space power system breadboard for the Hubble Space Telescope (HST) was designed and built to test the system under simulated orbital conditions. A discussion of the data acquisition and control subsystems designed to provide for continuous 24 hr per day operation and a general overview of the test bed is presented. The data acquisition and control subsystems provided the necessary monitoring and protection to assure safe shutdown with protection of test articles in case of loss of power or equipment failure over the life of the test (up to 5 years).

Space Fence PDR Concept Development Phase

NASA Astrophysics Data System (ADS)

Haines, L.; Phu, P.

2011-09-01

The Space Fence, a major Air Force acquisition program, will become the dominant low-earth orbit uncued sensor in the space surveillance network (SSN). Its primary objective is to provide a 24/7 un-cued capability to find, fix, and track small objects in low earth orbit to include emerging and evolving threats, as well as the rapidly growing population of orbital debris. Composed of up to two geographically dispersed large-scale S-band phased array radars, this new system-of-systems concept will provide comprehensive Space Situational Awareness through net-centric operations and integrated decision support. Additionally, this program will facilitate cost saving force structure changes in the SSN, specifically including the decommissioning of very-high frequency VHF Air Force Space Surveillance System (AFSSS). The Space Fence Program Office entered a Preliminary Design Review (PDR) concept development phase in January 2011 to achieve the delivery of the Initial Operational Capability (IOC) expected in FY17. Two contractors were awarded to perform preliminary system design, conduct radar performance analyses and evaluations, and develop a functional PDR radar system prototype. The key objectives for the Phase A PDR effort are to reduce Space Fence total program technical, cost, schedule, and performance risk. The overall program objective is to achieve a preliminary design that demonstrates sufficient technical and manufacturing maturity and that represents a low risk, affordable approach to meet the Space Fence Technical Requirements Document (TRD) requirements for the final development and production phase to begin in 3QFY12. This paper provides an overview of the revised Space Fence program acquisition strategy for the Phase-A PDR phase to IOC, the overall program milestones and major technical efforts. In addition, the key system trade studies and modeling/simulation efforts undertaken during the System Design Requirement (SDR) phase to address and mitigate technical challenges of the Space Fence System will also be discussed. Examples include radar system optimization studies, modeling and simulation for system performance assessment, investigation of innovative Astrodynamics algorithms for initial orbit determination and observation correlation.

KSC-01pp1560

NASA Image and Video Library

2001-09-11

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, Fla., the Atlas Centaur booster segment of an Atlas II rocket is offloaded. It will be mated to the first segment on Launch Pad 36-A, CCAFS, in preparation for launch of the TDRS-I spacecraft Oct. 30. The 40-minute launch window begins at 11:19 p.m. EST. The TDRS System (TDRSS) is a communication signal relay system that provides tracking and data acquisition services between low-Earth orbiting spacecraft and NASA/customer control and/or data processing facilities. The system is capable of transmitting to and receiving data from customer spacecrafts over 100 percent of their orbit (some limitations may apply depending on actual orbit). The TDRS-I provides a Ka-band service that will allow customers with extremely high data rates to be supported by TDRSS if they desire

A stellar tracking reference system

NASA Technical Reports Server (NTRS)

Klestadt, B.

1971-01-01

A stellar attitude reference system concept for satellites was studied which promises to permit continuous precision pointing of payloads with accuracies of 0.001 degree without the use of gyroscopes. It is accomplished with the use of a single, clustered star tracker assembly mounted on a non-orthogonal, two gimbal mechanism, driven so as to unwind satellite orbital and orbit precession rates. A set of eight stars was found which assures the presence of an adequate inertial reference on a continuous basis in an arbitrary orbit. Acquisition and operational considerations were investigated and inherent reference redundancy/reliability was established. Preliminary designs for the gimbal mechanism, its servo drive, and the star tracker cluster with its associated signal processing were developed for a baseline sun-synchronous, noon-midnight orbit. The functions required of the onboard computer were determined and the equations to be solved were found. In addition detailed error analyses were carried out, based on structural, thermal and other operational considerations.

14 CFR 1215.100 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false General. 1215.100 Section 1215.100 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... data acquisition services to spacecraft in low earth orbit or to mobile terrestrial users such as...

14 CFR 1215.100 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false General. 1215.100 Section 1215.100 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... data acquisition services to spacecraft in low earth orbit or to mobile terrestrial users such as...

14 CFR 1215.100 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true General. 1215.100 Section 1215.100 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... data acquisition services to spacecraft in low earth orbit or to mobile terrestrial users such as...

Study to investigate and evaluate means of optimizing the Ku-band communication function for the space shuttle

NASA Technical Reports Server (NTRS)

Simon, M. K.; Udalov, S.; Huth, G. K.

1976-01-01

The forward link of the overall Ku-band communication system consists of the ground- TDRS-orbiter communication path. Because the last segment of the link is directed towards a relatively low orbiting shuttle, a PN code is used to reduce the spectral density. A method is presented for incorporating code acquisition and tracking functions into the orbiter's Ku-band receiver. Optimization of a three channel multiplexing technique is described. The importance of Costas loop parameters to provide false lock immunity for the receiver, and the advantage of using a sinusoidal subcarrier waveform, rather than square wave, are discussed.

An intelligent interface for satellite operations: Your Orbit Determination Assistant (YODA)

NASA Technical Reports Server (NTRS)

Schur, Anne

1988-01-01

An intelligent interface is often characterized by the ability to adapt evaluation criteria as the environment and user goals change. Some factors that impact these adaptations are redefinition of task goals and, hence, user requirements; time criticality; and system status. To implement adaptations affected by these factors, a new set of capabilities must be incorporated into the human-computer interface design. These capabilities include: (1) dynamic update and removal of control states based on user inputs, (2) generation and removal of logical dependencies as change occurs, (3) uniform and smooth interfacing to numerous processes, databases, and expert systems, and (4) unobtrusive on-line assistance to users of concepts were applied and incorporated into a human-computer interface using artificial intelligence techniques to create a prototype expert system, Your Orbit Determination Assistant (YODA). YODA is a smart interface that supports, in real teime, orbit analysts who must determine the location of a satellite during the station acquisition phase of a mission. Also described is the integration of four knowledge sources required to support the orbit determination assistant: orbital mechanics, spacecraft specifications, characteristics of the mission support software, and orbit analyst experience. This initial effort is continuing with expansion of YODA's capabilities, including evaluation of results of the orbit determination task.

14 CFR 1215.100 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false General. 1215.100 Section 1215.100 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... acquisition services to spacecraft in low-Earth orbit or to mobile terrestrial users such as aircraft or...

Navigator GPS Receiver for Fast Acquisition and Weak Signal Space Applications

NASA Technical Reports Server (NTRS)

Winternitz, Luke; Moreau, Michael; Boegner, Gregory J.; Sirotzky, Steve

2004-01-01

NASA Goddard Space Flight Center (GSFC) is developing a new space-borne GPS receiver that can operate effectively in the full range of Earth orbiting missions from Low Earth Orbit (LEO) to geostationary and beyond. Navigator is designed to be a fully space flight qualified GPS receiver optimized for fast signal acquisition and weak signal tracking. The fast acquisition capabilities provide exceptional time to first fix performance (TIFF) with no a priori receiver state or GPS almanac information, even in the presence of high Doppler shifts present in LEO (or near perigee in highly eccentric orbits). The fast acquisition capability also makes it feasible to implement extended correlation intervals and therefore significantly reduce Navigator s acquisition threshold. This greatly improves GPS observability when the receiver is above the GPS constellation (and satellites must be tracked from the opposite side of the Earth) by providing at least 10 dB of increased acquisition sensitivity. Fast acquisition and weak signal tracking algorithms have been implemented and validated on a hardware development board. A fully functional version of the receiver, employing most of the flight parts, with integrated navigation software is expected by mid 2005. An ultimate goal of this project is to license the Navigator design to an industry partner who will then market the receiver as a commercial product.

Acquisition of Modular Low Earth Orbit Satellites for Improved Intelligence Collection

DTIC Science & Technology

2012-09-01

26 4. Space Enabled Effects for Military Engagements ( SeeMe ) Architecture...27 Figure 7. A Depiction of the SeeMe Notional Concept of Operations (From Barnhart, 2012...Evaluation SATCOM Satellite Communications SBIRS Space Based Infrared Systems SeeMe Space Enabled Effects for Military Engagements SMAD Space

14 CFR § 1215.100 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false General. § 1215.100 Section § 1215.100 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... acquisition services to spacecraft in low-Earth orbit or to mobile terrestrial users such as aircraft or...

Model-independent and fast determination of optical functions in storage rings via multiturn and closed-orbit data

NASA Astrophysics Data System (ADS)

Riemann, Bernard; Grete, Patrick; Weis, Thomas

2011-06-01

Multiturn (or turn-by-turn) data acquisition has proven to be a new source of direct measurements for Twiss parameters in storage rings. On the other hand, closed-orbit measurements are a long-known tool for analyzing closed-orbit perturbations with conventional beam position monitor (BPM) systems and are necessarily available at every storage ring. This paper aims at combining the advantages of multiturn measurements and closed-orbit data. We show that only two multiturn BPMs and four correctors in one localized drift space in the storage ring (diagnostic drift) are sufficient for model-independent and absolute measuring of β and φ functions at all BPMs, including the conventional ones, instead of requiring all BPMs being equipped with multiturn electronics.

WE-EF-207-01: FEATURED PRESENTATION and BEST IN PHYSICS (IMAGING): Task-Driven Imaging for Cone-Beam CT in Interventional Guidance

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

Gang, G; Stayman, J; Ouadah, S

2015-06-15

Purpose: This work introduces a task-driven imaging framework that utilizes a patient-specific anatomical model, mathematical definition of the imaging task, and a model of the imaging system to prospectively design acquisition and reconstruction techniques that maximize task-based imaging performance. Utility of the framework is demonstrated in the joint optimization of tube current modulation and view-dependent reconstruction kernel in filtered-backprojection reconstruction and non-circular orbit design in model-based reconstruction. Methods: The system model is based on a cascaded systems analysis of cone-beam CT capable of predicting the spatially varying noise and resolution characteristics as a function of the anatomical model and amore » wide range of imaging parameters. Detectability index for a non-prewhitening observer model is used as the objective function in a task-driven optimization. The combination of tube current and reconstruction kernel modulation profiles were identified through an alternating optimization algorithm where tube current was updated analytically followed by a gradient-based optimization of reconstruction kernel. The non-circular orbit is first parameterized as a linear combination of bases functions and the coefficients were then optimized using an evolutionary algorithm. The task-driven strategy was compared with conventional acquisitions without modulation, using automatic exposure control, and in a circular orbit. Results: The task-driven strategy outperformed conventional techniques in all tasks investigated, improving the detectability of a spherical lesion detection task by an average of 50% in the interior of a pelvis phantom. The non-circular orbit design successfully mitigated photon starvation effects arising from a dense embolization coil in a head phantom, improving the conspicuity of an intracranial hemorrhage proximal to the coil. Conclusion: The task-driven imaging framework leverages a knowledge of the imaging task within a patient-specific anatomical model to optimize image acquisition and reconstruction techniques, thereby improving imaging performance beyond that achievable with conventional approaches. 2R01-CA-112163; R01-EB-017226; U01-EB-018758; Siemens Healthcare (Forcheim, Germany)« less

Ku-band signal design study. [for space shuttle orbiter communication links

NASA Technical Reports Server (NTRS)

Lindsey, W. L.; Woo, K. T.

1977-01-01

The acquisition/tracking performance of a practical squaring loop in which the times two multiplier is mechanized as a limiter/multiplier combination is evaluated. This squaring approach serves to produce the absolute value of the arriving signal as opposed to the perfect square law action which is required in order to render acquisition and tracking performance equivalent to that of a Costas loop. The Ku-Band orbiter signal design for the forward link is assessed. Acquisition time results and acquisition and tracking thresholds are summarized. A tradeoff study which pertains to bit synchronization techniques for the high rate Ku-Band channel is included and an optimum selection is made based upon the appropriate design constraints.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1995-01-01

This quarterly publiction provides archival reports on developments in programs managed by JPL Telecommunications and Mission Operations Directorate (TMOD), which now includes the former communications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The Orbital Debris Radar Program, funded by the Office of Space Systems Development, makes use of the planetary radar capability when the antennas are configured at science instruments making direct observations of planets, their satellites, and asteroids of our solar system.

Space shuttle launch era spacecraft injection errors and DSN initial acquisition

NASA Technical Reports Server (NTRS)

Khatib, A. R.; Berman, A. L.; Wackley, J. A.

1981-01-01

The initial acquisition of a spacecraft by the Deep Space Network (DSN) is a critical mission event. This results from the importance of rapidly evaluating the health and trajectory of a spacecraft in the event that immediate corrective action might be required. Further, the DSN initial acquisition is always complicated by the most extreme tracking rates of the mission. The DSN initial acquisition characteristics will change considerably in the upcoming space shuttle launch era. How given injection errors at spacecraft separation from the upper stage launch vehicle (carried into orbit by the space shuttle) impact the DSN initial acquisition, and how this information can be factored into injection accuracy requirements to be levied on the Space Transportation System (STS) is addressed. The approach developed begins with the DSN initial acquisition parameters, generates a covariance matrix, and maps this covariance matrix backward to the spacecraft injection, thereby greatly simplifying the task of levying accuracy requirements on the STS, by providing such requirements in a format both familiar and convenient to STS.

Earth Orbiter 1: Wideband Advanced Recorder and Processor (WARP)

NASA Technical Reports Server (NTRS)

Smith, Terry; Kessler, John

1999-01-01

An advanced on-board spacecraft data system component is presented. The component is computer-based and provides science data acquisition, processing, storage, and base-band transmission functions. Specifically, the component is a very high rate solid state recorder, serving as a pathfinder for achieving the data handling requirements of next-generation hyperspectral imaging missions.

Mission specification for three generic mission classes

NASA Technical Reports Server (NTRS)

1979-01-01

Mission specifications for three generic mission classes are generated to provide a baseline for definition and analysis of data acquisition platform system concepts. The mission specifications define compatible groupings of sensors that satisfy specific earth resources and environmental mission objectives. The driving force behind the definition of sensor groupings is mission need; platform and space transportation system constraints are of secondary importance. The three generic mission classes are: (1) low earth orbit sun-synchronous; (2) geosynchronous; and (3) non-sun-synchronous, nongeosynchronous. These missions are chosen to provide a variety of sensor complements and implementation concepts. Each mission specification relates mission categories, mission objectives, measured parameters, and candidate sensors to orbits and coverage, operations compatibility, and platform fleet size.

Safe Laser Beam Propagation for Interplanetary Links

NASA Technical Reports Server (NTRS)

Wilson, Keith E.

2011-01-01

Ground-to-space laser uplinks to Earth–orbiting satellites and deep space probes serve both as a beacon and an uplink command channel for deep space probes and Earth-orbiting satellites. An acquisition and tracking point design to support a high bandwidth downlink from a 20-cm optical terminal on an orbiting Mars spacecraft typically calls for 2.5 kW of 1030-nm uplink optical power in 40 micro-radians divergent beams.2 The NOHD (nominal ocular hazard distance) of the 1030nm uplink is in excess of 2E5 km, approximately half the distance to the moon. Recognizing the possible threat of high power laser uplinks to the flying public and to sensitive Earth-orbiting satellites, JPL developed a three-tiered system at its Optical Communications Telescope Laboratory (OCTL) to ensure safe laser beam propagation through navigational and near-Earth space.

The Spacelab Instrument Pointing System (IPS) and its first flight

NASA Astrophysics Data System (ADS)

Heusmann, H.; Wolf, P.

1985-11-01

The development of the Instrument Pointing System (IPS) as part of Spacelab's experimental apparatus for open Pallet direct space exposure, and its test flight aboard the Shuttle Orbiter are discussed. The IPS is a three-axis-controlled platform with stellar, sun and earth pointing modes, and a better than 1 arcsec pointing ability. The development of an 'inside-out gimbal' configuration with the platform acting like a joint between the unstable Shuttle and the inertially stabilized payload facilitated close to hemispherical pointing and the adaptability for payloads of almost any size. Gimbal axes torquers counteract Orbiter acceleration due to crew movement and thruster firings, and facilitate target acquisition and precision pointing, by command from a crew-engaged computer preprogrammed for all possible control steps. Carrying an experimental solar-physics payload, the IPS correctly performed all intended functions and withstood launch and orbital loads. Several anomalies were detected and successfully corrected in-flight.

Tethered orbital propellant depot

NASA Technical Reports Server (NTRS)

Fester, D. A.; Rudolph, L. K.; Kiefel, E. R.

1985-01-01

A planned function of the Space Station is to refurbish and refuel an advanced space-based LO2/LH2 orbit transfer vehicle. An alternative to propellant storage at the station is to use a remote facility tied to the station with a log tether. Preliminary design of such a facility is described with emphasis on fluid transfer and storage requirements. Using tether lengths of at least 300 ft, gravity gradient forces will dominate surface tension in such a system. Although gravity given transfer is difficult because of line pressure drops, fluid settling over the tank outlet greatly alleviates acquisition concerns and will facilitate vented tank fills. The major concern with a tethered orbital refueling facility is its considerable operational complexity including transport of the OTV to and from the facility.

Tracking and data system support for the Mariner Mars 1971 mission. Volume 3: Orbit insertion through end of primary mission

NASA Technical Reports Server (NTRS)

Barnum, P. W.; Renzetti, N. A.; Textor, G. P.; Kelly, L. B.

1973-01-01

The Tracking and Data System (TDS) Support for the Mariner Mars 1971 Mission final report contains the deep space tracking and data acquisition activities in support of orbital operations. During this period a major NASA objective was accomplished: completion of the 180th revolution and 90th day of data gathering with the spacecraft about the planet Mars. Included are presentations of the TDS flight support pass chronology data for each of the Deep Space Stations used, and performance evaluation for the Deep Space Network Telemetry, Tracking, Command, and Monitor Systems. With the loss of Mariner 8 at launch, Mariner 9 assumed the mission plan of Mariner 8, which included the TV mapping cycles and a 12-hr orbital period. The mission plan was modified as a result of a severe dust storm on the surface of Mars, which delayed the start of the TV mapping cycles. Thus, the end of primary mission date was extended to complete the TV mapping cycles.

New beam-position monitor system for upgraded Photon Factory storage ring.

PubMed

Haga, K; Honda, T; Tadano, M; Obina, T; Kasuga, T

1998-05-01

Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 micro m in both directions, which is 1/2-1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

Orbital operations with the Shuttle Infrared Telescope Facility /SIRTF/

NASA Technical Reports Server (NTRS)

Werner, M. W.; Lorell, K. R.

1981-01-01

The Shuttle Infrared Telescope Facility (SIRTF) is a cryogenically-cooled, 1-m-class telescope that will be operated from the Space Shuttle as an observatory for infrared astronomy. This paper discusses the scientific constraints on and the requirements for pointing and controlling SIRTF as well as several aspects of SIRTF orbital operations. The basic pointing requirement is for an rms stability of 0.25 arcsec, which is necessary to realize the full angular resolution of the 5-micron diffraction-limited SIRTF. Achieving this stability requires the use of hardware and software integral to SIRTF working interactively with the gyrostabilized Shuttle pointing-mount. The higher sensitivity of SIRTF, together with orbital and time constraints, puts a premium on rapid target acquisition and on efficient operational and observational procedures. Several possible acquisition modes are discussed, and the importance of source acquisition by maximizing the output of an infrared detector is emphasized.

System design of the Pioneer Venus spacecraft. Volume 9: Attitude control/mechanisms subsystems studies

NASA Technical Reports Server (NTRS)

Neil, A. L.

1973-01-01

The Pioneer Venus mission study was conducted for a probe spacecraft and an orbiter spacecraft to be launched by either a Thor/Delta or an Atlas/Centaur launch vehicle. Both spacecraft are spin stabilized. The spin speed is controlled by ground commands to as low as 5 rpm for science instrument scanning on the orbiter and as high as 71 rpm for small probes released from the probe bus. A major objective in the design of the attitude control and mechanism subsystem (ACMS) was to provide, in the interest of costs, maximum commonality of the elements between the probe bus and orbiter spacecraft configurations. This design study was made considering the use of either launch vehicle. The basic functional requirements of the ACMS are derived from spin axis pointing and spin speed control requirements implicit in the acquisition, cruise, encounter and orbital phases of the Pioneer Venus missions.

Space America's commercial space program

NASA Technical Reports Server (NTRS)

Macleod, N. H.

1984-01-01

Space America prepared a private sector land observing space system which includes a sensor system with eight spectral channels configured for stereoscopic data acquisition of four stereo pairs, a spacecraft bus with active three-axis stabilization, a ground station for data acquisition, preprocessing and retransmission. The land observing system is a component of Space America's end-to-end system for Earth resources management, monitoring and exploration. In the context of the Federal Government's program of commercialization of the US land remote sensing program, Space America's space system is characteristic of US industry's use of advanced technology and of commercial, entrepreneurial management. Well before the issuance of the Request for Proposals for Transfer of the United States Land Remote Sensing Program to the Private Sector by the US Department of Commerce, Space Services, Inc., the managing venturer of Space America, used private funds to develop and manage its sub-orbital launch of its Conestoga launch vehicle.

Earth Observatory Satellite (EOS) Definition Phase Report, Volume 1

NASA Technical Reports Server (NTRS)

1971-01-01

System definition studies were conducted of the Earth Observatory Satellite (EOS). The studies show that the concept of an Earth Observatory Satellite in a near-earth, sun-synchronous orbit would make a unique contribution to the goals of a coordinated program for acquisition of data for environmental research with applications to earth resource inventory and management. The technical details for the proposed development of sensors, spacecraft, and a ground data processing system are presented.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1993-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) in the following areas: space communications, radio navigation, radio science, and ground-based radio and radar astronomy. This document also reports on the activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). The TDA Office also performs work funded by another NASA program office through and with the cooperation of OSC. This is the Orbital Debris Radar Program with the Office of Space Systems Development.

Overview of the Miniature Sensor Technology Integration (MSTI) spacecraft attitude control system

NASA Technical Reports Server (NTRS)

Mcewen, Rob

1994-01-01

Msti2 is a small, 164 kg (362 lb), 3-axis stabilized, low-Earth-orbiting satellite whose mission is missile booster tracking. The spacecraft is actuated by 3 reaction wheels and 12 hot gas thrusters. It carries enough fuel for a projected life of 6 months. The sensor complement consists of a Horizon Sensor, a Sun Sensor, low-rate gyros, and a high rate gyro for despin. The total pointing control error allocation is 6 mRad (.34 Deg), and this is while tracking a target on the Earth's surface. This paper describes the Attitude Control System (ACS) algorithms which include the following: attitude acquisition (despin, Sun and Earth acquisition), attitude determination, attitude control, and linear stability analysis.

Orbital refill of propulsion vehicle tankage

NASA Technical Reports Server (NTRS)

Merino, F.; Risberg, J. A.; Hill, M.

1980-01-01

Techniques for orbital refueling of space based vehicles were developed and experimental programs to verify these techniques were identified. Orbital refueling operations were developed for two cryogenic orbital transfer vehicles (OTV's) and an Earth storable low thrust liquid propellant vehicle. Refueling operations were performed assuming an orbiter tanker for near term missions and an orbital depot. Analyses were conducted using liquid hydrogen and N2O4. The influence of a pressurization system and acquisition device on operations was also considered. Analyses showed that vehicle refill operations will be more difficult with a cryogen than with an earth storable. The major elements of a successful refill with cryogens include tank prechill and fill. Propellant quantities expended for tank prechill appear to to insignificant. Techniques were identified to avoid loss of liquid or excessive tank pressures during refill. It was determined that refill operations will be similar whether or not an orbiter tanker or orbital depot is available. Modeling analyses were performed for prechill and fill tests to be conducted assuming the Spacelab as a test bed, and a 1/10 scale model OTV (with LN2 as a test fluid) as an experimental package.

The METOP-A Orbit Acquisition Strategy and its LEOP Operational Experience

NASA Technical Reports Server (NTRS)

Merz, K.; Serrano, M. A. Martin; Kuijper, D.; Matatoros, M. A. Garcia

2007-01-01

Europe's first polar-orbiting weather satellite, METOPA, was launched by a Soyuz launcher from Baikonur Cosmodrome on the 19th of October of 2006. The routine operations of METOP-A are conducted by EUMETSAT (European Organization for Exploitation of Meteorological Satellites) in the frame of the European Polar System mission (EPS). The METOP-A Launch and Early Orbit Phase (LEOP) operations have been performed by ESA/ESOC. The Flight Dynamics Orbit Determination and Control team (OD&C) at ESOC was in charge of correcting the S/C orbit as delivered by the launcher in such a way that EUMETSAT would be able to acquire the reference orbit with a drift-stop manoeuvre approximately two weeks after a LEOP of 3 days and Hand-Over to the EUMETSAT Control Centre (EUMETSAT-CC) in Darmstadt, Germany. The various strict constraints and the short amount of time available for ESOC operations made this task challenging. Several strategies were prepared before launch and analysed during LEOP based on the achieved injection orbit. This paper presents the different manoeuvre strategies investigated and finally applied to acquire the operational orbit, reporting as well the details of its execution and final achieved state.

A Space Station tethered orbital refueling facility

NASA Technical Reports Server (NTRS)

Fester, D. A.; Rudolph, L. K.; Kiefel, E. R.

1985-01-01

A planned function of the Space Station is to refurbish and refuel an advanced space-based LO2/LH2 orbit transfer vehicle. An alternative to propellant storage at the station is to use a remote facility tied to the station with a long tether. Preliminary design of such a facility is described with emphasis on fluid transfer and storage requirements. Using tether lengths of at least 300 ft, gravity gradient forces will dominate surface tension in such a system. Although gravity driven transfer is difficult because of line pressure drops, fluid settling over the tank outlet greatly alleviates acquisition concerns and will facilitate vented tank fills. The major concern with a tethered orbital refueling facility is its considerable operational complexity including transport of the OTV to and from the facility.

STS-53 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1993-01-01

The STS-53 Space Shuttle Program Mission Report provides a summary of the Orbiter, External Tank (ET), Solid Rocket Booster/Redesigned Solid Rocket Motor (SRB/RSRM), and the Space Shuttle Main Engine (SSME) subsystems performance during the fifty-second flight of the Space Shuttle Program, and the fifteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET, which was designated as ET-49/LWT-42; three SSME's, which were serial numbers 2024, 2012, and 2017 in positions 1, 2, and 3, respectively; and two SRB's, which were designated BI-055. The lightweight RSRM's that were installed in each SRB were designated 360L028A for the left SRB, and 360L028B for the right SRB. The primary objective of this flight was to successfully deploy the Department of Defense 1 (DOD-1) payload. The secondary objectives of this flight were to perform the operations required by the Glow Experiment/Cryogenic Heat Pipe Experiment Payload (GCP); the Hand-Held, Earth-Oriented, Real-Time, Cooperative, User-Friendly, Location-Targeting and Environmental System (HERCULES); the Space Tissue Loss (STL); the Battlefield Laser Acquisition Sensor Test (BLAST); the Radiation Monitoring Equipment-III (RME-III); the Microcapsules in Space-1 (MIS-1); the Visual Function Tester-2 (VFT-2); the Cosmic Radiation Effects and Activation Monitor (CREAM); the Clouds Logic to Optimize Use of Defense Systems-1A (CLOUDS-1A); the Fluids Acquisition and Resupply Experiment (FARE); and the Orbital Debris Radar Calibration Spheres (ODERACS). In addition to presenting a summary of subsystem performance, this report also discusses each Orbiter, ET, SSME, SRB, and RSRM in-flight anomaly in the applicable section of the report. Listed in the discussion of each anomaly is the officially assigned tracking number as published by each Project Office in their respective Problem Tracking List. All times given in this report are in Greenwich mean time (G.m.t.) as well as mission elapsed time (MET).

STS-53 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W., Jr.

1993-02-01

The STS-53 Space Shuttle Program Mission Report provides a summary of the Orbiter, External Tank (ET), Solid Rocket Booster/Redesigned Solid Rocket Motor (SRB/RSRM), and the Space Shuttle Main Engine (SSME) subsystems performance during the fifty-second flight of the Space Shuttle Program, and the fifteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET, which was designated as ET-49/LWT-42; three SSME's, which were serial numbers 2024, 2012, and 2017 in positions 1, 2, and 3, respectively; and two SRB's, which were designated BI-055. The lightweight RSRM's that were installed in each SRB were designated 360L028A for the left SRB, and 360L028B for the right SRB. The primary objective of this flight was to successfully deploy the Department of Defense 1 (DOD-1) payload. The secondary objectives of this flight were to perform the operations required by the Glow Experiment/Cryogenic Heat Pipe Experiment Payload (GCP); the Hand-Held, Earth-Oriented, Real-Time, Cooperative, User-Friendly, Location-Targeting and Environmental System (HERCULES); the Space Tissue Loss (STL); the Battlefield Laser Acquisition Sensor Test (BLAST); the Radiation Monitoring Equipment-III (RME-III); the Microcapsules in Space-1 (MIS-1); the Visual Function Tester-2 (VFT-2); the Cosmic Radiation Effects and Activation Monitor (CREAM); the Clouds Logic to Optimize Use of Defense Systems-1A (CLOUDS-1A); the Fluids Acquisition and Resupply Experiment (FARE); and the Orbital Debris Radar Calibration Spheres (ODERACS). In addition to presenting a summary of subsystem performance, this report also discusses each Orbiter, ET, SSME, SRB, and RSRM in-flight anomaly in the applicable section of the report. Listed in the discussion of each anomaly is the officially assigned tracking number as published by each Project Office in their respective Problem Tracking List. All times given in this report are in Greenwich mean time (G.m.t.) as well as mission elapsed time (MET).

Experiment S-213 selenocentric geodetic reference system

NASA Technical Reports Server (NTRS)

Doyle, F. J.; Elassal, A. A.; Lucas, J. R.

1976-01-01

Development and implementation of a photogrammetric system was undertaken to provide accurate selenodetic positions and topographic mapping of all areas overflown by orbital spacecraft. The system was installed in the scientific instrument module (SIM) bay of the Apollo command service module (CSM). In theory, this system provided everything a photogrammetrist could want: the position of each exposure station would be obtained from Earth-based tracking; the orientation of each photograph could be computed from the synchronized stellar exposure and the lock-angles determined by preflight calibration; and the scale of each stereomodel would be obtained directly from the altimeter data. Operationally, the data acquisition was adequate, but less than optimum. Systematic errors are believed to be the result of the primitive orbit determination procedures in use at the time of the Apollo 15 mission, inadequate models of the lunar gravity field, and spacecraft oscillations induced by uncoupled thrusting and various activities of the astronauts.

Global navigation satellite system receiver for weak signals under all dynamic conditions

NASA Astrophysics Data System (ADS)

Ziedan, Nesreen Ibrahim

The ability of the Global Navigation Satellite System (GNSS) receiver to work under weak signal and various dynamic conditions is required in some applications. For example, to provide a positioning capability in wireless devices, or orbit determination of Geostationary and high Earth orbit satellites. This dissertation develops Global Positioning System (GPS) receiver algorithms for such applications. Fifteen algorithms are developed for the GPS C/A signal. They cover all the receiver main functions, which include acquisition, fine acquisition, bit synchronization, code and carrier tracking, and navigation message decoding. They are integrated together, and they can be used in any software GPS receiver. They also can be modified to fit any other GPS or GNSS signals. The algorithms have new capabilities. The processing and memory requirements are considered in the design to allow the algorithms to fit the limited resources of some applications; they do not require any assisting information. Weak signals can be acquired in the presence of strong interfering signals and under high dynamic conditions. The fine acquisition, bit synchronization, and tracking algorithms are based on the Viterbi algorithm and Extended Kalman filter approaches. The tracking algorithms capabilities increase the time to lose lock. They have the ability to adaptively change the integration length and the code delay separation. More than one code delay separation can be used in the same time. Large tracking errors can be detected and then corrected by a re-initialization and an acquisition-like algorithms. Detecting the navigation message is needed to increase the coherent integration; decoding it is needed to calculate the navigation solution. The decoding algorithm utilizes the message structure to enable its decoding for signals with high Bit Error Rate. The algorithms are demonstrated using simulated GPS C/A code signals, and TCXO clocks. The results have shown the algorithms ability to reliably work with 15 dB-Hz signals and acceleration over 6 g.

Evaluation of Relative Navigation Algorithms for Formation-Flying Satellites

NASA Technical Reports Server (NTRS)

Kelbel, David; Lee, Taesul; Long, Anne; Carpenter, J. Russell; Gramling, Cheryl

2001-01-01

Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autonomous navigation and control of formation flyers. This paper discusses autonomous relative navigation performance for formations in eccentric, medium, and high-altitude Earth orbits using Global Positioning System (GPS) Standard Positioning Service (SPS) and intersatellite range measurements. The performance of several candidate relative navigation approaches is evaluated. These analyses indicate that the relative navigation accuracy is primarily a function of the frequency of acquisition and tracking of the GPS signals. A relative navigation position accuracy of 0.5 meters root-mean-square (RMS) can be achieved for formations in medium-attitude eccentric orbits that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 75 meters RMS can be achieved for formations in high-altitude eccentric orbits that have sparse tracking of the GPS signals. The addition of round-trip intersatellite range measurements can significantly improve relative navigation accuracy for formations with sparse tracking of the GPS signals.

The Colour and Stereo Surface Imaging System (CaSSIS) for the ExoMars Trace Gas Orbiter

USGS Publications Warehouse

Thomas, N.; Cremonese, G.; Ziethe, R.; Gerber, M.; Brändli, M.; Bruno, G.; Erismann, M.; Gambicorti, L.; Gerber, T.; Ghose, K.; Gruber, M.; Gubler, P.; Mischler, H.; Jost, J.; Piazza, D.; Pommerol, A.; Rieder, M.; Roloff, V.; Servonet, A.; Trottmann, W.; Uthaicharoenpong, T.; Zimmermann, C.; Vernani, D.; Johnson, M.; Pelò, E.; Weigel, T.; Viertl, J.; De Roux, N.; Lochmatter, P.; Sutter, G.; Casciello, A.; Hausner, T.; Ficai Veltroni, I.; Da Deppo, V.; Orleanski, P.; Nowosielski, W.; Zawistowski, T.; Szalai, S.; Sodor, B.; Tulyakov, S.; Troznai, G.; Banaskiewicz, M.; Bridges, J.C.; Byrne, S.; Debei, S.; El-Maarry, M. R.; Hauber, E.; Hansen, C.J.; Ivanov, A.; Keszthelyil, L.; Kirk, Randolph L.; Kuzmin, R.; Mangold, N.; Marinangeli, L.; Markiewicz, W. J.; Massironi, M.; McEwen, A.S.; Okubo, Chris H.; Tornabene, L.L.; Wajer, P.; Wray, J.J.

2017-01-01

The Colour and Stereo Surface Imaging System (CaSSIS) is the main imaging system onboard the European Space Agency’s ExoMars Trace Gas Orbiter (TGO) which was launched on 14 March 2016. CaSSIS is intended to acquire moderately high resolution (4.6 m/pixel) targeted images of Mars at a rate of 10–20 images per day from a roughly circular orbit 400 km above the surface. Each image can be acquired in up to four colours and stereo capability is foreseen by the use of a novel rotation mechanism. A typical product from one image acquisition will be a 9.5 km×∼45 km">9.5 km×∼45 km9.5 km×∼45 km swath in full colour and stereo in one over-flight of the target thereby reducing atmospheric influences inherent in stereo and colour products from previous high resolution imagers. This paper describes the instrument including several novel technical solutions required to achieve the scientific requirements.

Task-Driven Orbit Design and Implementation on a Robotic C-Arm System for Cone-Beam CT.

PubMed

Ouadah, S; Jacobson, M; Stayman, J W; Ehtiati, T; Weiss, C; Siewerdsen, J H

2017-03-01

This work applies task-driven optimization to the design of non-circular orbits that maximize imaging performance for a particular imaging task. First implementation of task-driven imaging on a clinical robotic C-arm system is demonstrated, and a framework for orbit calculation is described and evaluated. We implemented a task-driven imaging framework to optimize orbit parameters that maximize detectability index d '. This framework utilizes a specified Fourier domain task function and an analytical model for system spatial resolution and noise. Two experiments were conducted to test the framework. First, a simple task was considered consisting of frequencies lying entirely on the f z -axis (e.g., discrimination of structures oriented parallel to the central axial plane), and a "circle + arc" orbit was incorporated into the framework as a means to improve sampling of these frequencies, and thereby increase task-based detectability. The orbit was implemented on a robotic C-arm (Artis Zeego, Siemens Healthcare). A second task considered visualization of a cochlear implant simulated within a head phantom, with spatial frequency response emphasizing high-frequency content in the ( f y , f z ) plane of the cochlea. An optimal orbit was computed using the task-driven framework, and the resulting image was compared to that for a circular orbit. For the f z -axis task, the circle + arc orbit was shown to increase d ' by a factor of 1.20, with an improvement of 0.71 mm in a 3D edge-spread measurement for edges located far from the central plane and a decrease in streak artifacts compared to a circular orbit. For the cochlear implant task, the resulting orbit favored complementary views of high tilt angles in a 360° orbit, and d ' was increased by a factor of 1.83. This work shows that a prospective definition of imaging task can be used to optimize source-detector orbit and improve imaging performance. The method was implemented for execution of non-circular, task-driven orbits on a clinical robotic C-arm system. The framework is sufficiently general to include both acquisition parameters (e.g., orbit, kV, and mA selection) and reconstruction parameters (e.g., a spatially varying regularizer).

Task-driven orbit design and implementation on a robotic C-arm system for cone-beam CT

NASA Astrophysics Data System (ADS)

Ouadah, S.; Jacobson, M.; Stayman, J. W.; Ehtiati, T.; Weiss, C.; Siewerdsen, J. H.

2017-03-01

Purpose: This work applies task-driven optimization to the design of non-circular orbits that maximize imaging performance for a particular imaging task. First implementation of task-driven imaging on a clinical robotic C-arm system is demonstrated, and a framework for orbit calculation is described and evaluated. Methods: We implemented a task-driven imaging framework to optimize orbit parameters that maximize detectability index d'. This framework utilizes a specified Fourier domain task function and an analytical model for system spatial resolution and noise. Two experiments were conducted to test the framework. First, a simple task was considered consisting of frequencies lying entirely on the fz-axis (e.g., discrimination of structures oriented parallel to the central axial plane), and a "circle + arc" orbit was incorporated into the framework as a means to improve sampling of these frequencies, and thereby increase task-based detectability. The orbit was implemented on a robotic C-arm (Artis Zeego, Siemens Healthcare). A second task considered visualization of a cochlear implant simulated within a head phantom, with spatial frequency response emphasizing high-frequency content in the (fy, fz) plane of the cochlea. An optimal orbit was computed using the task-driven framework, and the resulting image was compared to that for a circular orbit. Results: For the fz-axis task, the circle + arc orbit was shown to increase d' by a factor of 1.20, with an improvement of 0.71 mm in a 3D edge-spread measurement for edges located far from the central plane and a decrease in streak artifacts compared to a circular orbit. For the cochlear implant task, the resulting orbit favored complementary views of high tilt angles in a 360° orbit, and d' was increased by a factor of 1.83. Conclusions: This work shows that a prospective definition of imaging task can be used to optimize source-detector orbit and improve imaging performance. The method was implemented for execution of non-circular, task-driven orbits on a clinical robotic C-arm system. The framework is sufficiently general to include both acquisition parameters (e.g., orbit, kV, and mA selection) and reconstruction parameters (e.g., a spatially varying regularizer).

Defense Acquisitions: Assessments of Selected Weapon Programs

DTIC Science & Technology

2011-03-01

Frequency (UHF) Follow-On ( UFO ) satellite system currently in operation and provide interoperability with legacy terminals. MUOS consists of a...delivery of MUOS capabilities is time-critical due to the operational failures of two UFO satellites. The MUOS program has taken several steps to...launch increased due to the unexpected failures of two UFO satellites. Based on the current health of on-orbit satellites, UHF communication

Defense Acquisitions: Assessments of Selected Weapon Programs

DTIC Science & Technology

2013-03-01

UHF) Follow-On ( UFO ) satellite system currently in operation and provide interoperability with legacy terminals. MUOS consists of a network of...MUOS satellites remain important due to the past operational failures of two UFO satellites and predicted end-of-life of on-orbit UFO satellites...Despite the delay and earlier, unexpected failures of two UFO satellites, the required availability level of UHF communication capabilities has been

Sentinel-1 Precise Orbit Calibration and Validation

NASA Astrophysics Data System (ADS)

Monti Guarnieri, Andrea; Mancon, Simone; Tebaldini, Stefano

2015-05-01

In this paper, we propose a model-based procedure to calibrate and validate Sentinel-1 orbit products by the Multi-Squint (MS) phase. The technique allows to calibrate an interferometric pair geometry by refining the slave orbit with reference to the orbit of a master image. Accordingly, we state the geometric model of the InSAR phase as function of positioning errors of targets and slave track; and the MS phase model as derivative of the InSAR phase geometric model with respect to the squint angle. In this paper we focus on the TOPSAR acquisition modes of Sentinel-1 (IW and EW) assuming at the most a linear error in the known slave trajectory. In particular, we describe a dedicated methodology to prevent InSAR phase artifacts on data acquired by the TOPSAR acquisition mode. Experimental results obtained by interferometric pairs acquired by Sentinel-1 sensor will be displayed.

LANDSAT-2 launch and flight activation. Launch through orbit 50 and orbit adjust operation. [telemetry data processing

NASA Technical Reports Server (NTRS)

1975-01-01

The results of the analysis conducted on the telemetry data from the prelaunch, launch, and flight activation phases of LANDSAT-2 spacecraft are presented according to subsystems and interrelationships that exist between subsystems. Subsystem characteristics are included along with the flight evaluation results. Flight data are compared to baseline data established at the 20 C plateau during thermal vacuum testing of the spacecraft. Evaluation guidelines are derived from the specifications developed from the LANDSAT program objectives: (1) acquisition of multispectral images of the surface of the earth; and (2) use of the LANDSAT-2 receiving, frequency translating, and transmitting equipment as a relay system to gather data from fixed earth-based sensor platforms which are operated by individual investigators. Data are presented on the first 50 orbits of the spacecraft.

Dual-energy computed tomography of the head: a phantom study assessing axial dose distribution, eye lens dose, and image noise level

NASA Astrophysics Data System (ADS)

Matsubara, Kosuke; Kawashima, Hiroki; Hamaguchi, Takashi; Takata, Tadanori; Kobayashi, Masanao; Ichikawa, Katsuhiro; Koshida, Kichiro

2016-03-01

The aim of this study was to propose a calibration method for small dosimeters to measure absorbed doses during dual- source dual-energy computed tomography (DECT) and to compare the axial dose distribution, eye lens dose, and image noise level between DE and standard, single-energy (SE) head CT angiography. Three DE (100/Sn140 kVp 80/Sn140 kVp, and 140/80 kVp) and one SE (120 kVp) acquisitions were performed using a second-generation dual-source CT device and a female head phantom, with an equivalent volumetric CT dose index. The axial absorbed dose distribution at the orbital level and the absorbed doses for the eye lens were measured using radiophotoluminescent glass dosimeters. CT attenuation numbers were obtained in the DE composite images and the SE images of the phantom at the orbital level. The doses absorbed at the orbital level and in the eye lens were lower and standard deviations for the CT attenuation numbers were slightly higher in the DE acquisitions than those in the SE acquisition. The anterior surface dose was especially higher in the SE acquisition than that in the DE acquisitions. Thus, DE head CT angiography can be performed with a radiation dose lower than that required for a standard SE head CT angiography, with a slight increase in the image noise level. The 100/Sn140 kVp acquisition revealed the most balanced axial dose distribution. In addition, our proposed method was effective for calibrating small dosimeters to measure absorbed doses in DECT.

Infrared Imagery of Shuttle (IRIS). Task 1

NASA Technical Reports Server (NTRS)

Chocol, C. J.

1977-01-01

Assessment of available IR sensor technology showed that the four aerothermodynamic conditions of interest during the entry trajectory of space shuttle can be accommodated by an aircraft flying parallel to the orbiter reentry ground track. Thermal information from the sides of the vehicle can be obtained with degraded performance (temperatures below 800 K) by flying the C-141 aircraft on the opposite side of the shuttle ground track and in the direction opposite that which is optimum for lower surface viewing. An acquisition system using a 6.25-cm aperture telescope and a single indium antimonide detector were designed to meet the acquisition requirements and interface with the 91.5-cm telescope with minimum modification. An image plane system using 600 indium antimonide detectors in two arrays which requires no modification to the existing telescope was also designed. Currently available components were used in a data handling system with interfaces with the experimentors station and the HP2100 computer.

Video guidance, landing, and imaging systems

NASA Technical Reports Server (NTRS)

Schappell, R. T.; Knickerbocker, R. L.; Tietz, J. C.; Grant, C.; Rice, R. B.; Moog, R. D.

1975-01-01

The adaptive potential of video guidance technology for earth orbital and interplanetary missions was explored. The application of video acquisition, pointing, tracking, and navigation technology was considered to three primary missions: planetary landing, earth resources satellite, and spacecraft rendezvous and docking. It was found that an imaging system can be mechanized to provide a spacecraft or satellite with a considerable amount of adaptability with respect to its environment. It also provides a level of autonomy essential to many future missions and enhances their data gathering ability. The feasibility of an autonomous video guidance system capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was successfully demonstrated in the laboratory. The techniques developed for acquisition, pointing, and tracking show promise for recognizing and tracking coastlines, rivers, and other constituents of interest. Routines were written and checked for rendezvous, docking, and station-keeping functions.

Limitations on Ku-band communications due to multipath

NASA Technical Reports Server (NTRS)

Lindsey, J. F.; Rudnicki, J. F.

1977-01-01

The earth and orbiter body reflections involving the Tracking Data Relay Satellite (TDRS)/orbiter communications link are evaluated. Recommendations address operational conditions in order to avoid critical multipath impacts, modulation preferences during acquisition, and preferred scan limit implementation.

The NASA Meter Class Autonomous Telescope: Ascension Island

NASA Astrophysics Data System (ADS)

Lederer, S.; Stansbery, E. G.; Cowardin, H. M.; Kervin, P.; Hickson, P.

2013-09-01

The Meter Class Autonomous Telescope (MCAT) is the newest optical sensor dedicated to NASA's mission to characterize the space debris environment. It is the successor to a series of optical telescopes developed and operated by the JSC Orbital Debris Program Office (ODPO) to monitor and assess the debris environment in (1) Low Earth Orbit (LEO), (2) Medium Earth Orbit (MEO), and (3) Geosynchronous Orbit (GEO), with emphasis on LEO and GEO altitudes. A joint NASA-Air Force Research Labs project, MCAT is a 1.3m optical telescope dedicated to debris research. Its optical path and sensor yield a large survey fence at the cutting edge of current detector performance. It has four primary operational observing modes, two of which were not computationally feasible a decade ago. Operations are supported by a sophisticated software suite that monitors clouds and weather conditions, and controls everything from data collection to dome rotation to processing tens of GB of imagery data nightly. With fainter detection limits, precision detection, acquisition and tracking of targets, multi-color photometry, precision astrometry, automated re-acquisition capability, and the ability to process all data at the acquisition rate, MCAT is capable of producing and processing a volume and quality of data far in excess of any current (or prior) ODPO operations. This means higher fidelity population inputs and eliminating the multi-year backlog from acquisition-to-product typical of optical campaigns. All of this is possible given a suitable observing location. Originally planned for the island of Legan, part of the Kwajalein Atoll Islands, recent developments have led to a change in venue. Specifically, the Ground-based Electro-Optical Deep Space Surveillance, or GEODSS, System of telescopes is the United States' major tracking system for deep space. This network consists of telescopes in Maui, Hawaii; Diego Garcia (Indian Ocean), and Socorro, New Mexico. A fourth optical telescope, though smaller in size, has been operating in conjunction with this effort until recently in M?ron, Spain. With the M?ron site closing, a significant gap in longitude exists between the New Mexico and Diego Garcia sites. This longitudinal gap is well covered by placing a telescope on Ascension Island (7deg 58' 20" S, 14deg 24' 4"W), in the Atlantic Ocean. Ascension Island offers the benefits of both location and weather. The near equatorial location affords the opportunity to access under-sampled low-inclination orbits and new GEO longitudes, while simultaneously filling in the GEODSS longitudinal gap. Ascension Island is a volcanic, desert island, receiving only 7" of rain per year on average. With consistent trade winds blowing from the SSE direction off Africa, the combination of an island location with consistent winds will create the smooth laminar flow sought after by all astronomical sites, which creates stable atmospheric (‘seeing') conditions. Finally, this low population island has minimal lighting, resulting in very dark skies, ideal for an observatory.

Galileo Jupiter approach orbit determination

NASA Technical Reports Server (NTRS)

Miller, J. K.; Nicholson, F. T.

1984-01-01

Orbit determination characteristics of the Jupiter approach phase of the Galileo mission are described. Predicted orbit determination performance is given for the various mission events that occur during Jupiter approach. These mission events include delivery of an atmospheric entry probe, acquisition of probe science data by the Galileo orbiter for relay to earth, delivery of an orbiter to a close encounter of the Galilean satellite Io, and insertion of the orbiter into orbit about Jupiter. The orbit determination strategy and resulting accuracies are discussed for the data types which include Doppler, range, optical imaging of Io, and a new Very Long Baseline Interferometry (VLBI) data type called Differential One-Way Range (DOR).

Independent Orbiter Assessment (IOA): Analysis of the DPS subsystem

NASA Technical Reports Server (NTRS)

Lowery, H. J.; Haufler, W. A.; Pietz, K. C.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) is presented. The IOA approach features a top-down analysis of the hardware to independently determine failure modes, criticality, and potential critical items. The independent analysis results corresponding to the Orbiter Data Processing System (DPS) hardware are documented. The DPS hardware is required for performing critical functions of data acquisition, data manipulation, data display, and data transfer throughout the Orbiter. Specifically, the DPS hardware consists of the following components: Multiplexer/Demultiplexer (MDM); General Purpose Computer (GPC); Multifunction CRT Display System (MCDS); Data Buses and Data Bus Couplers (DBC); Data Bus Isolation Amplifiers (DBIA); Mass Memory Unit (MMU); and Engine Interface Unit (EIU). The IOA analysis process utilized available DPS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the extensive redundancy built into the DPS the number of critical items are few. Those identified resulted from premature operation and erroneous output of the GPCs.

Autonomous docking system for space structures and satellites

NASA Astrophysics Data System (ADS)

Prasad, Guru; Tajudeen, Eddie; Spenser, James

2005-05-01

Aximetric proposes Distributed Command and Control (C2) architecture for autonomous on-orbit assembly in space with our unique vision and sensor driven docking mechanism. Aximetric is currently working on ip based distributed control strategies, docking/mating plate, alignment and latching mechanism, umbilical structure/cord designs, and hardware/software in a closed loop architecture for smart autonomous demonstration utilizing proven developments in sensor and docking technology. These technologies can be effectively applied to many transferring/conveying and on-orbit servicing applications to include the capturing and coupling of space bound vehicles and components. The autonomous system will be a "smart" system that will incorporate a vision system used for identifying, tracking, locating and mating the transferring device to the receiving device. A robustly designed coupler for the transfer of the fuel will be integrated. Advanced sealing technology will be utilized for isolation and purging of resulting cavities from the mating process and/or from the incorporation of other electrical and data acquisition devices used as part of the overall smart system.

An expert system that performs a satellite station keepimg maneuver

NASA Technical Reports Server (NTRS)

Linesbrowning, M. Kate; Stone, John L., Jr.

1987-01-01

The development and characteristics of a prototype expert system, Expert System for Satellite Orbit Control (ESSOC), capable of providing real-time spacecraft system analysis and command generation for a geostationary satellite are described. The ESSOC recommends appropriate commands that reflect both the changing spacecraft condition and previous procedural action. An internal knowledge base stores satellite status information and is updated with processed spacecraft telemetry. Procedural structure data are encoded in production rules. Structural methods of knowledge acquisition and the design and performance-enhancing techniques that enable ESSOC to operate in real time are also considered.

Defense Acquisitions: Assessments of Selected Weapon Programs

DTIC Science & Technology

2010-03-01

improved availability for small terminals. It is to replace the Ultra High Frequency (UHF) Follow-On ( UFO ) satellite system currently in operation...of MUOS capabilities is time-critical due to the operational failures of two UFO satellites. The MUOS program has taken several steps to address...failures of two UFO satellites. Based on the current health of on-orbit satellites, UHF communication capabilities are predicted to fall below the

The Deep Space Network

NASA Technical Reports Server (NTRS)

1974-01-01

The objectives, functions, and organization, of the Deep Space Network are summarized. Deep Space stations, ground communications, and network operations control capabilities are described. The network is designed for two-way communications with unmanned spacecraft traveling approximately 1600 km from earth to the farthest planets in the solar system. It has provided tracking and data acquisition support for the following projects: Ranger, Surveyor, Mariner, Pioneer, Apollo, Helios, Viking, and the Lunar Orbiter.

Apparent rotation properties of space debris extracted from photometric measurements

NASA Astrophysics Data System (ADS)

Šilha, Jiří; Pittet, Jean-Noël; Hamara, Michal; Schildknecht, Thomas

2018-02-01

Knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. Different orbital regions and object's physical properties lead to different attitude states and their change over time. Since 2007 the Astronomical Institute of the University of Bern (AIUB) performs photometric measurements of space debris objects. To June 2016 almost 2000 light curves of more than 400 individual objects have been acquired and processed. These objects are situated in all orbital regions, from low Earth orbit (LEO), via global navigation systems orbits and high eccentricity orbit (HEO), to geosynchronous Earth orbit (GEO). All types of objects were observed including the non-functional spacecraft, rocket bodies, fragmentation debris and uncorrelated objects discovered during dedicated surveys. For data acquisition, we used the 1-meter Zimmerwald Laser and Astrometry Telescope (ZIMLAT) at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland. We applied our own method of phase-diagram reconstruction to extract the apparent rotation period from the light curve. Presented is the AIUB's light curve database and the obtained rotation properties of space debris as a function of object type and orbit.

SHOOT performance testing. [Superfluid Helium On-Orbit Transfer Flight Demonstration

NASA Technical Reports Server (NTRS)

Dipirro, M. J.; Shirron, P. J.; Volz, S. M.; Schein, M. E.

1991-01-01

The Superfluid Helium On-Orbit Transfer (SHOOT) Flight Demonstration is a shuttle attached payload designed to demonstrate the technology necessary to resupply liquid helium dewars in space. Many SHOOT components will also have use in other aerospace cryogenic systems. The first of two SHOOT dewar systems has been fabricated. The ground performance testing of this dewar is described. The performance tests include measurements of heat leak, impedances of the two vent lines, heat pulse mass gauging accuracy, and superfluid transfer parameters such as flow rate and efficiency. A laboratory dewar was substituted for the second flight dewar for the transfer tests. These tests enable a precise analytical model of the transfer process to be verified. SHOOT performance is thus quantified, except for components such as the liquid acquisition devices and a phase separator which cannot be verified in one gravity.

Space Science

NASA Image and Video Library

1995-06-08

Scientists at Marshall's Adaptive Optics Lab demonstrate the Wave Front Sensor alignment using the Phased Array Mirror Extendible Large Aperture (PAMELA) optics adjustment. The primary objective of the PAMELA project is to develop methods for aligning and controlling adaptive optics segmented mirror systems. These systems can be used to acquire or project light energy. The Next Generation Space Telescope is an example of an energy acquisition system that will employ segmented mirrors. Light projection systems can also be used for power beaming and orbital debris removal. All segmented optical systems must be adjusted to provide maximum performance. PAMELA is an on going project that NASA is utilizing to investigate various methods for maximizing system performance.

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.

Designing Delta-DOR acquisition strategies to determine highly elliptical earth orbits

NASA Technical Reports Server (NTRS)

Frauenholz, R. B.

1986-01-01

Delta-DOR acquisition strategies are designed for use in determining highly elliptical earth orbits. The requirements for a possible flight demonstration are evaluated for the Charged Composition Explorer spacecraft of the Active Magnetospheric Particle Tracer Explorers. The best-performing strategy uses data spanning the view periods of two orthogonal baselines near the same orbit periapse. The rapidly changing viewing geometry yields both angular position and velocity information, but each observation may require a different reference quasar. The Delta-DOR data noise is highly dependent on acquisition geometry, varying several orders of magnitude across the baseline view periods. Strategies are selected to minimize the measurement noise predicted by a theoretical model. Although the CCE transponder is limited by S-band and a small bandwidth, the addition of Delta-DOR to coherent Doppler and range improves the one-sigma apogee position accuracy by more than an order of magnitude. Additional Delta-DOR accuracy improvements possible using dual-frequency (S/X) calibration, increased spanned bandwidth, and water-vapor radiometry are presented for comparison. With these benefits, the residual Delta-DOR data noise is primarily due to quasar position uncertainties.

Spaceflight payload design flight experience G-408

NASA Technical Reports Server (NTRS)

Durgin, William W.; Looft, Fred J.; Sacco, Albert, Jr.; Thompson, Robert; Dixon, Anthony G.; Roberti, Dino; Labonte, Robert; Moschini, Larry

1992-01-01

Worcester Polytechnic Institute's first payload of spaceflight experiments flew aboard Columbia, STS-40, during June of 1991 and culminated eight years of work by students and faculty. The Get Away Special (GAS) payload was installed on the GAS bridge assembly at the aft end of the cargo bay behind the Spacelab Life Sciences (SLS-1) laboratory. The Experiments were turned on by astronaut signal after reaching orbit and then functioned for 72 hours. Environmental and experimental measurements were recorded on three cassette tapes which, together with zeolite crystals grown on orbit, formed the basis of subsequent analyses. The experiments were developed over a number of years by undergraduate students meeting their project requirements for graduation. The experiments included zeolite crystal growth, fluid behavior, and microgravity acceleration measurement in addition to environmental data acquisition. Preparation also included structural design, thermal design, payload integration, and experiment control. All of the experiments functioned on orbit and the payload system performed within design estimates.

Free-space laser communication technologies II; Proceedings of the Meeting, Los Angeles, CA, Jan. 15-17, 1990

NASA Technical Reports Server (NTRS)

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

1990-01-01

Various papers on free-space laser communication technologies are presented. Individual topics addressed include: optical intersatellite link experiment between the earth station and ETS-VI, the Goddard optical communications program, technologies and techniques for lasercom terminal size, weight, and cost reduction, laser beam acquisition and tracking system for ETS-VI laser communication equipment, analog dividers for acquisition and tracking signal normalization, fine pointing mechanism using multilayered piezoelectric actuator for optical ISL system, analysis of SILEX tracking sensor performance, new telescope concept for space communication, telescope considered as a very high gain antenna, design of compact transceiver optical systems for optical intersatellite links, ultralightweight optics for laser communications, highly sensitive measurement method for stray light and retroreflected light, depolarization effects on free space laser transceiver communication systems, in-orbit measurements of microaccelerations of ESA's communication satellite Olympus, high-performance laser diode transmitter for optical free space communication, diode-pumped Nd:host laser transmitter for intersatellite optical communications, single-frequency diode-pumped laser for free-space communication.

Astronaut Alan Bean looks over data acquisition camera on Skylab trainer

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut Alan L. Bean, commander for Skylab 3, the second manned Skylab mission, looks over the data acquisition camera mounted on the water tank in the upper level of the Orbital Workshop (OWS) one-G trainer at the Manned Spacecraft Center (MSC).

Long term orbital storage of cryogenic propellants for advanced space transportation missions

NASA Technical Reports Server (NTRS)

Schuster, John R.; Brown, Norman S.

1987-01-01

A comprehensive study has developed the major features of a large capacity orbital propellant depot for the space-based, cryogenic OTV. The study has treated both the Dual-Keel Space Station and co-orbiting platforms as the accommodations base for the propellant storage facilities, and trades have examined both tethered and hard-docked options. Five tank set concepts were developed for storing the propellants, and along with layout options for the station and platform, were evaluated from the standpoints of servicing, propellant delivery, boiloff, micrometeoroid/debris shielding, development requirements, and cost. These trades led to the recommendation that an all-passive storage concept be considered for the platform and an actively refrigerated concept providing for reliquefaction of all boiloff be considered for the Space Station. The tank sets are modular, each storing up to 45,400 kg of LO2/LH2, and employ many advanced features to provide for microgravity fluid management and to limit boiloff. The features include such technologies as zero-gravity mass gauging, total communication capillary liquid acquisition devices, autogenous pressurization, thermodynamic vent systems, thick multilayer insulation, vapor-cooled shields, solar-selective coatings, advanced micrometeoroid/debris protection systems, and long-lived cryogenic refrigeration systems.

A Sub-Orbital Platform for Flight Tests of Small Space Capsules

NASA Astrophysics Data System (ADS)

Pereira, P. Moraes A. L., Jr.; Silva, C. R.; Villas Bôas, D. J.; Corrêa, F., Jr.; Miyoshi, J. H.; Loures da Costa, L. E.

2002-01-01

In the development of a small recoverable space capsule, flight tests using sub-orbital rockets are considered. For this test series, a platform for aerodynamic and thermal measurements as also for qualification tests of onboard sub-systems and equipment was specified and is actually under development. This platform, known as SARA Suborbital, is specified to withstand a sub-orbital flight with the high performance sounding rocket VS40 and to be recovered at the sea. To perform the testing program, a flight trajectory with adequate aeroballistic parameters, as for instance high velocities in dense atmosphere and average re-entry velocity, is considered. The testing program includes measurements of aerodynamic pressures and thermal characteristics, three- axis acceleration, acoustic pressure level inside the platform and vibration environment. Beside this, tests to characterise the performance of the data acquisition and transmission system, the micro-gravity environment and to qualify the recovery system will be carried out. During the return flight, the dynamics of parachutes deployment and platform water impact, as also rescue procedures will also be observed. The present article shows the concept of the platform, describes in detail the experiments, and concludes with a discussion on the flight trajectory and recovery procedure.

NASA's Orbital Space Plane Risk Reduction Strategy

NASA Technical Reports Server (NTRS)

Dumbacher, Dan

2003-01-01

This paper documents the transformation of NASA s Space Launch Initiative (SLI) Second Generation Reusable Launch Vehicle Program under the revised Integrated Space Transportation Plan, announced November 2002. Outlining the technology development approach followed by the original SLI, this paper gives insight into the current risk-reduction strategy that will enable confident development of the Nation s first orbital space plane (OSP). The OSP will perform an astronaut and contingency cargo transportation function, with an early crew rescue capability, thus enabling increased crew size and enhanced science operations aboard the International Space Station. The OSP design chosen for full-scale development will take advantage of the latest innovations American industry has to offer. The OSP Program identifies critical technologies that must be advanced to field a safe, reliable, affordable space transportation system for U.S. access to the Station and low-Earth orbit. OSP flight demonstrators will test crew safety features, validate autonomous operations, and mature thermal protection systems. Additional enabling technologies may be identified during the OSP design process as part of an overall risk-management strategy. The OSP Program uses a comprehensive and evolutionary systems acquisition approach, while applying appropriate lessons learned.

OAST Space Theme Workshop. Volume 2: Theme summary. 4: Solar system exploration (no. 10). A: Statement of theme: B. 26 April 1976 Presentation. C. Summary. D. Initiative actions (form 5)

NASA Technical Reports Server (NTRS)

1976-01-01

Major strategies for exploring the solar system focus on the return of information and the return of matter. Both the planetary exploration facility, and an orbiting automated space station, and the sample return and exploration facility have similar requirements. The single most essential need to enable intensive study of the outer solar system is nuclear propulsion and power capability. New initiatives in 1978 related to the reactor, data and sample acquisition and return, navigation, and environmental protection are examined.

Shuttle GPS R/PA configuration and specification study

NASA Technical Reports Server (NTRS)

Booth, R. W. D.

1979-01-01

Changes in the technical specifications for a global positioning system (GPS) receiving system dedicated to space shuttle use are presented. Various hardware functions including acquisition, tracking, and measurement are emphasized. The anti-jam performance of the baseline GPS systems are evaluated. Other topics addressed include: the impact on R/PA design of the use of ground based transmitters; problems involved with the use of single channel tests sets; utility of various R/PA antenna interconnections topologies; the choice of the averaging interval for delta range measurements; and the use of interferometry techniques for the computation of orbiter attitude were undertaken.

Production and quality assurance automation in the Goddard Space Flight Center Flight Dynamics Facility

NASA Technical Reports Server (NTRS)

Chapman, K. B.; Cox, C. M.; Thomas, C. W.; Cuevas, O. O.; Beckman, R. M.

1994-01-01

The Flight Dynamics Facility (FDF) at the NASA Goddard Space Flight Center (GSFC) generates numerous products for NASA-supported spacecraft, including the Tracking and Data Relay Satellites (TDRS's), the Hubble Space Telescope (HST), the Extreme Ultraviolet Explorer (EUVE), and the space shuttle. These products include orbit determination data, acquisition data, event scheduling data, and attitude data. In most cases, product generation involves repetitive execution of many programs. The increasing number of missions supported by the FDF has necessitated the use of automated systems to schedule, execute, and quality assure these products. This automation allows the delivery of accurate products in a timely and cost-efficient manner. To be effective, these systems must automate as many repetitive operations as possible and must be flexible enough to meet changing support requirements. The FDF Orbit Determination Task (ODT) has implemented several systems that automate product generation and quality assurance (QA). These systems include the Orbit Production Automation System (OPAS), the New Enhanced Operations Log (NEOLOG), and the Quality Assurance Automation Software (QA Tool). Implementation of these systems has resulted in a significant reduction in required manpower, elimination of shift work and most weekend support, and improved support quality, while incurring minimal development cost. This paper will present an overview of the concepts used and experiences gained from the implementation of these automation systems.

Evaluation of supercritical cryogen storage and transfer systems for future NASA missions

NASA Technical Reports Server (NTRS)

Arif, Hugh; Aydelott, John C.; Chato, David J.

1990-01-01

Conceptual designs of Space Transportation Vehicles (STV), and their orbital servicing facilities, that utilize supercritical, single phase, cryogenic propellant were established and compared with conventional subcritical, two phases, STV concepts. The analytical study was motivated by the desire to avoid fluid management problems associated with the storage, acquisition and transfer of subcritical liquid oxygen and hydrogen propellants in the low gravity environment of space. Although feasible, the supercritical concepts suffer from STV weight penalties and propellant resupply system power requirements which make the concepts impractical.

Evaluation of supercritical cryogen storage and transfer systems for future NASA missions

NASA Technical Reports Server (NTRS)

Arif, Hugh; Aydelott, John C.; Chato, David J.

1989-01-01

Conceptual designs of Space Transportation Vehicles (STV), and their orbital servicing facilities, that utilize supercritical, single phase, cryogenic propellants were established and compared with conventional subcritical, two phase, STV concepts. The analytical study was motivated by the desire to avoid fluid management problems associated with the storage, acquisition and transfer of subcritical liquid oxygen and hydrogen propellants in the low gravity environment of space. Although feasible, the supercritical concepts suffer from STV weight penalties and propellant resupply system power requirements which make the concepts impractical.

Functional design for operational earth resources ground data processing

NASA Technical Reports Server (NTRS)

Baldwin, C. J. (Principal Investigator); Bradford, L. H.; Hutson, D. E.; Jugle, D. R.

1972-01-01

The author has identified the following significant results. Study emphasis was on developing a unified concept for the required ground system, capable of handling data from all viable acquisition platforms and sensor groupings envisaged as supporting operational earth survey programs. The platforms considered include both manned and unmanned spacecraft in near earth orbit, and continued use of low and high altitude aircraft. The sensor systems include both imaging and nonimaging devices, operated both passively and actively, from the ultraviolet to the microwave regions of the electromagnetic spectrum.

Research and technology, fiscal year 1983

NASA Technical Reports Server (NTRS)

1983-01-01

The responibilities and programs of the Goddard Space Flight Center are ranged from basic research in the space and Earth sciences through the management of numerous flight projects to operational responsibility for the tracking of and data acquisition from NASA's Earth orbiting satellites, Progress in the areas of spacecraft technology, sensor development and data system development, as well as in the basic and applied to research in the space and Earth sciences that they support is highlighted.

Mars Sample Return - Launch and Detection Strategies for Orbital Rendezvous

NASA Technical Reports Server (NTRS)

Woolley, Ryan C.; Mattingly, Richard L.; Riedel, Joseph E.; Sturm, Erick J.

2011-01-01

This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/cache rover in 2018, an orbiter with an Earth return vehicle in 2022, and a fetch rover and ascent vehicle in 2024. Strategies are presented to launch the sample into a coplanar orbit with the Orbiter which facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits exist at 457 and 572 km which provide multiple launch opportunities with similar geometries for detection and rendezvous.

Mars Sample Return: Launch and Detection Strategies for Orbital Rendezvous

NASA Technical Reports Server (NTRS)

Woolley, Ryan C.; Mattingly, Richard L.; Riedel, Joseph E.; Sturm, Erick J.

2011-01-01

This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/ caching rover in 2018, an Earth return orbiter in 2022, and a fetch rover with ascent vehicle in 2024. Strategies are presented to launch the sample into a nearly coplanar orbit with the Orbiter which would facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits existat 457 and 572 km which would provide multiple launch opportunities with similar geometries for detection and rendezvous.

Advanced propulsion for LEO-Moon transport. 1: A method for evaluating advanced propulsion performance

NASA Technical Reports Server (NTRS)

Stern, Martin O.

1992-01-01

This report describes a study to evaluate the benefits of advanced propulsion technologies for transporting materials between low Earth orbit and the Moon. A relatively conventional reference transportation system, and several other systems, each of which includes one advanced technology component, are compared in terms of how well they perform a chosen mission objective. The evaluation method is based on a pairwise life-cycle cost comparison of each of the advanced systems with the reference system. Somewhat novel and economically important features of the procedure are the inclusion not only of mass payback ratios based on Earth launch costs, but also of repair and capital acquisition costs, and of adjustments in the latter to reflect the technological maturity of the advanced technologies. The required input information is developed by panels of experts. The overall scope and approach of the study are presented in the introduction. The bulk of the paper describes the evaluation method; the reference system and an advanced transportation system, including a spinning tether in an eccentric Earth orbit, are used to illustrate it.

Space-to-Space Communications System

NASA Technical Reports Server (NTRS)

Tu, Kwei; Gaylor, Kent; Vitalpur, Sharada; Sham, Cathy

1999-01-01

The Space-to-Space Communications System (SSCS) is an Ultra High Frequency (UHF) Time-Division-Multiple Access (TDMA) system that is designed, developed, and deployed by the NASA Johnson Space Center (JSC) to provide voice, commands, telemetry and data services in close proximity among three space elements: International Space Station (ISS), Space Shuttle Orbiter, and Extravehicular Mobility Units (EMU). The SSCS consists of a family of three radios which are, Space-to-Space Station Radio (SSSR), Space-to-Space Orbiter Radio (SSOR), and Space-to-Space Extravehicular Mobility Radio (SSER). The SSCS can support up to five such radios at a time. Each user has its own time slot within which to transmit voice and data. Continuous Phase Frequency Shift Keying (CPFSK) carrier modulation with a burst data rate of 695 kbps and a frequency deviation of 486.5 kHz is employed by the system. Reed-Solomon (R-S) coding is also adopted to ensure data quality. In this paper, the SSCS system requirements, operational scenario, detailed system architecture and parameters, link acquisition strategy, and link performance analysis will be presented and discussed

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1992-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, in supporting research and technology, in implementation, and in operations. Also included is standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Operations (OSO). The TDA Office also performs work funded by two other NASA program offices through and with the cooperation of the OSO. These are the Orbital Debris Radar Program and 21st Century Communication Studies.

On-Orbit ACDS Performance of the Landsat 7 Spacecraft

NASA Technical Reports Server (NTRS)

Sabelhaus, Phillip; Bolek, Joseph; Scott, Steve; Holmes, Eric; O'Donnell, James R., Jr.; Storey, James

2001-01-01

Landsat 7 is part of NASA's Earth Science Enterprise (ESE). The ESE is committed to developing an understanding of the total Earth system, the effects of natural and human-induced changes on the global environment, and how natural processes affect humans and how humans affect them. The Landsat 7 satellite consists of the spacecraft bus which was provided under a NASA contract with Lockheed Martin Missiles and Space in Philadelphia, PA, and the Enhanced Thematic Mapper-Plus (ETM+) instrument, procured under a NASA contract with Raytheon Santa Barbara Remote Sensing, in Santa Barbara, CA. The Landsat 7 Attitude Control and Determination System (ACDS) provides many essential functions for the operation of the spacecraft bus and for ETM+. The ACDS maintains the required attitude and orbit at the degree of accuracy necessary for power generation, command and telemetry, thermal balance, image acquisition, Gimbaled X-Band Antenna (GXA) pointing and data for image post-processing. Descriptions of the Landsat 7 mission and the ACDS modes and requirements are presented. A brief summary of significant events of the on-orbit initialization and validation period are provided. Finally, the Landsat 7 product generation system is described and the impact that the ACDS performance has on the ground based image processing system is explored.

Design and development of Shuttle Get-Away-Special experiment G-0074. [off-load capability for a full-tank propellant acquisition system

NASA Technical Reports Server (NTRS)

Orton, G. F.

1984-01-01

An experiment to investigate more versatile, lower cost surface tension propellant acquisition approaches for future satellite and spacecraft propellant tanks is designed to demonstrate a propellant off-load capability for a full-tank gallery surface tension device, such as that employed in the shuttle reaction control subsystem, and demonstrate a low-cost refillable trap concept that could be used in future orbit maneuver propulsion systems for multiple engine restarts. A Plexiglas test tank, movie camera and lights, auxiliary liquid accumulator, control electronics, battery pack, and associated valving and plumbing are used. The test liquid is Freon 113, dyed blue for color movie coverage. The fully loaded experiments weighs 106 pounds and is to be installed in a NASA five-cubic-foot flight canister. Vibration tests, acoustic tests, and high and low temperature tests were performed to quality the experiment for flight.

Development of data processing, interpretation and analysis system for the remote sensing of trace atmospheric gas species

NASA Technical Reports Server (NTRS)

Casas, Joseph C.; Saylor, Mary S.; Kindle, Earl C.

1987-01-01

The major emphasis is on the advancement of remote sensing technology. In particular, the gas filter correlation radiometer (GFCR) technique was applied to the measurement of trace gas species, such as carbon monoxide (CO), from airborne and Earth orbiting platforms. Through a series of low altitude aircraft flights, high altitude aircraft flights, and orbiting space platform flights, data were collected and analyzed, culminating in the first global map of carbon monoxide concentration in the middle troposphere and stratosphere. The four major areas of this remote sensing program, known as the Measurement of Air Pollution from Satellites (MAPS) experiment, are: (1) data acquisition, (2) data processing, analysis, and interpretation algorithms, (3) data display techniques, and (4) information processing.

Results from Navigator GPS Flight Testing for the Magnetospheric MultiScale Mission

NASA Technical Reports Server (NTRS)

Lulich, Tyler D.; Bamford, William A.; Wintermitz, Luke M. B.; Price, Samuel R.

2012-01-01

The recent delivery of the first Goddard Space Flight Center (GSFC) Navigator Global Positioning System (GPS) receivers to the Magnetospheric MultiScale (MMS) mission spacecraft is a high water mark crowning a decade of research and development in high-altitude space-based GPS. Preceding MMS delivery, the engineering team had developed receivers to support multiple missions and mission studies, such as Low Earth Orbit (LEO) navigation for the Global Precipitation Mission (GPM), above the constellation navigation for the Geostationary Operational Environmental Satellite (GOES) proof-of-concept studies, cis-Lunar navigation with rapid re-acquisition during re-entry for the Orion Project and an orbital demonstration on the Space Shuttle during the Hubble Servicing Mission (HSM-4).

Liquid acquisition devices for superfluid helium transfer

NASA Technical Reports Server (NTRS)

Dipirro, M. J.

1990-01-01

To transfer superfluid helium (He II) in the milli-g or micro-g environment in orbit, it is necessary to provide a reasonably steady supply of liquid to the inlet of the pump in the supply dewar. To accomplish this without providing an artificial gravity through acceleration requires a liquid acquisition device. Fluid swirl and electrostatic devices have been proposed to orientate the fluid. However, the simplest mechanisms appear to be the use of surface tension or the thermomechanical effect. This paper examines four concepts for providing He II to the inlet of a thermomechanical pump. The devices are a distributed thermomechanical pump, a distributed pump with a main thermomechanical pump, a screened channel system and a vane/sponge combination. Calculations on the efficiency of these types of liquid acquisition devices are made using laboratory data from tests involving small scale devices where applicable. These calculations show that the latter two types of liquid acquisition devices are the most efficient. Questions as to the probability of cavitation and the effect of the residual shuttle acceleration on their operation remain to be answered, however.

Guidance, Navigation, and Control Techniques and Technologies for Active Satellite Removal

NASA Astrophysics Data System (ADS)

Ortega Hernando, Guillermo; Erb, Sven; Cropp, Alexander; Voirin, Thomas; Dubois-Matra, Olivier; Rinalducci, Antonio; Visentin, Gianfranco; Innocenti, Luisa; Raposo, Ana

2013-09-01

This paper shows an internal feasibility analysis to de- orbit a non-functional satellite of big dimensions by the Technical Directorate of the European Space Agency ESA. The paper focuses specifically on the design of the techniques and technologies for the Guidance, Navigation, and Control (GNC) system of the spacecraft mission that will capture the satellite and ultimately will de-orbit it on a controlled re-entry.The paper explains the guidance strategies to launch, rendezvous, close-approach, and capture the target satellite. The guidance strategy uses chaser manoeuvres, hold points, and collision avoidance trajectories to ensure a safe capture. It also details the guidance profile to de-orbit it in a controlled re-entry.The paper continues with an analysis of the required sensing suite and the navigation algorithms to allow the homing, fly-around, and capture of the target satellite. The emphasis is placed around the design of a system to allow the rendezvous with an un-cooperative target, including the autonomous acquisition of both the orbital elements and the attitude of the target satellite.Analysing the capture phase, the paper provides a trade- off between two selected capture systems: the net and the tentacles. Both are studied from the point of view of the GNC system.The paper analyses as well the advanced algorithms proposed to control the final compound after the capture that will allow the controlled de-orbiting of the assembly in a safe place in the Earth.The paper ends proposing the continuation of this work with the extension to the analysis of the destruction process of the compound in consecutive segments starting from the entry gate to the rupture and break up.

Phased Array Mirror Extendible Large Aperture (PAMELA) Optics Adjustment

NASA Technical Reports Server (NTRS)

1995-01-01

Scientists at Marshall's Adaptive Optics Lab demonstrate the Wave Front Sensor alignment using the Phased Array Mirror Extendible Large Aperture (PAMELA) optics adjustment. The primary objective of the PAMELA project is to develop methods for aligning and controlling adaptive optics segmented mirror systems. These systems can be used to acquire or project light energy. The Next Generation Space Telescope is an example of an energy acquisition system that will employ segmented mirrors. Light projection systems can also be used for power beaming and orbital debris removal. All segmented optical systems must be adjusted to provide maximum performance. PAMELA is an on going project that NASA is utilizing to investigate various methods for maximizing system performance.

Tracking and data relay satellite system: NASA's new spacecraft data acquisition system

NASA Astrophysics Data System (ADS)

Schneider, W. C.; Garman, A. A.

The growth in NASA's ground network complexity and cost triggered a search for an alternative. Through a lease service contract, Western Union will provide to NASA 10 years of space communications services with a Tracking and Data Relay Satellite System (TDRSS). A constellation of four operating satellites in geostationary orbit and a single ground terminal will provide complete tracking, telemetry and command service for all of NASA's Earth orbital satellites below an altitude of 12,000 km. The system is shared: two satellites will be dedicated to NASA service; a third will provide backup as a shared spare; the fourth satellite will be dedicated to Western Union's Advanced Westar commercial service. Western Union will operate the ground terminal and provide operational satellite control. NASA's Network Control Center will provide the focal point for scheduling user services and controlling the interface between TDRSS and the rest of the NASA communications network, project control centers and data processing facilities. TDRSS single access user spacecraft data systems should be designed for efficient time shared data relay support. Reimbursement policy and rate structure for non-NASA users are currently being developed.

Attitude control system design using a flywheel suspended by two gimbals

NASA Astrophysics Data System (ADS)

Peres, R. W.; Ricci, M. C.

2015-10-01

This work presents the attitude control system design procedures for a three axis stabilized satellite in geostationary orbit, which contains a flywheel suspended by two gimbals. The use of a flywheel with two DOFs is an interesting option because with only one device it's possible to control the torques about vehicle's three axes; through the wheel speed control and gyrotorquing phenomenon with two DOFs. If the wheel size and speed are determined properly it's possible to cancel cyclic torques using gas jets only periodically to cancel secular disturbance torques. The system, based on a flywheel, takes only one pitch/roll (earth) sensor to maintain precise attitude, unlike mass expulsion based control systems, which uses propellants continuously, beyond roll, pitch and yaw sensors. It is considered the satellite is in nominal orbit and, therefore, that the attitude's acquisition phase has already elapsed. Control laws and system parameters are determined in order to cancel the solar pressure radiation disturbance torque and the torque due to misalignment of the thrusters. Stability is analyzed and step and cyclic responses are obtained.

Ku-band system design study and TDRSS interface analysis

NASA Technical Reports Server (NTRS)

Lindsey, W. C.; Mckenzie, T. M.; Choi, H. J.; Tsang, C. S.; An, S. H.

1983-01-01

The capabilities of the Shuttle/TDRSS link simulation program (LinCsim) were expanded to account for radio frequency interference (RFI) effects on the Shuttle S-band links, the channel models were updated to reflect the RFI related hardware changes, the ESTL hardware modeling of the TDRS communication payload was reviewed and evaluated, in LinCsim the Shuttle/TDRSS signal acquisition was modeled, LinCsim was upgraded, and possible Shuttle on-orbit navigation techniques was evaluated.

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.

Anatomical background and generalized detectability in tomosynthesis and cone-beam CT.

PubMed

Gang, G J; Tward, D J; Lee, J; Siewerdsen, J H

2010-05-01

Anatomical background presents a major impediment to detectability in 2D radiography as well as 3D tomosynthesis and cone-beam CT (CBCT). This article incorporates theoretical and experimental analysis of anatomical background "noise" in cascaded systems analysis of 2D and 3D imaging performance to yield "generalized" metrics of noise-equivalent quanta (NEQ) and detectability index as a function of the orbital extent of the (circular arc) source-detector orbit. A physical phantom was designed based on principles of fractal self-similarity to exhibit power-law spectral density (kappa/Fbeta) comparable to various anatomical sites (e.g., breast and lung). Background power spectra [S(B)(F)] were computed as a function of source-detector orbital extent, including tomosynthesis (approximately 10 degrees -180 degrees) and CBCT (180 degrees + fan to 360 degrees) under two acquisition schemes: (1) Constant angular separation between projections (variable dose) and (2) constant total number of projections (constant dose). The resulting S(B) was incorporated in the generalized NEQ, and detectability index was computed from 3D cascaded systems analysis for a variety of imaging tasks. The phantom yielded power-law spectra within the expected spatial frequency range, quantifying the dependence of clutter magnitude (kappa) and correlation (beta) with increasing tomosynthesis angle. Incorporation of S(B) in the 3D NEQ provided a useful framework for analyzing the tradeoffs among anatomical, quantum, and electronic noise with dose and orbital extent. Distinct implications are posed for breast and chest tomosynthesis imaging system design-applications varying significantly in kappa and beta, and imaging task and, therefore, in optimal selection of orbital extent, number of projections, and dose. For example, low-frequency tasks (e.g., soft-tissue masses or nodules) tend to benefit from larger orbital extent and more fully 3D tomographic imaging, whereas high-frequency tasks (e.g., microcalcifications) require careful, application-specific selection of orbital extent and number of projections to minimize negative effects of quantum and electronic noise. The complex tradeoffs among anatomical background, quantum noise, and electronic noise in projection imaging, tomosynthesis, and CBCT can be described by generalized cascaded systems analysis, providing a useful framework for system design and optimization.

Synchronisation, acquisition and tracking for telemetry and data reception

NASA Astrophysics Data System (ADS)

Vandoninck, A.

1992-06-01

The important parameters of synchronization, acquisition, and tracking are addressed, and each function is highlighted separately. The following sequence is such as the functions occur in the system in time and for the type of data to be received, with distinction between telemetry and data reception, between direct carrier modulation or the use of a subcarrier, and between deep space and normal reception. For the telemetry reception the acquisition is described taking into account the difference in performances as geostationary or polar orbits, and the dependencies on the different Doppler offsets and rates are distinguished. The related functions and parameters are covered and the specifications of an average receiver are summarized. The synchronization of the valid data is described with a distinction for data directly modulated or via a subcarrier, the type of modulation and bitrate. The relevant functions and parameters of the average receiver/demodulator are summarized. The tracking of the signal in the course of the operational phase is described and relevant parameters of an actual system are presented. The reception of real data is handled and a sequence of acquisition, synchronization, and tracking is applied. Here higher bitrates and direct modulation schemes play an important role. The market equipment with the relevant parameters are discussed. The three functions in cases where deep reception is needed are covered. The high performance receiver/demodulator functions and how the acquisition, synchronization, and tracking is handled in such application, are explained.

Astronaut Alan Bean looks over data acquisition camera on Skylab trainer

NASA Image and Video Library

1972-09-01

S72-39256 (1972) --- Astronaut Alan L. Bean, commander for Skylab 3, the second manned Skylab mission, looks over the data acquisition camera mounted on the water tank in the upper level of the Orbital Workshop (OWS) one-G trainer at the Manned Spacecraft Center (MSC). Photo credit: NASA

Titan probe technology assessment and technology development plan study

NASA Technical Reports Server (NTRS)

Castro, A. J.

1980-01-01

The need for technology advances to accomplish the Titan probe mission was determined by defining mission conditions and requirements and evaluating the technology impact on the baseline probe configuration. Mission characteristics found to be technology drivers include (1) ten years dormant life in space vacuum; (2) unknown surface conditions, various sample materials, and a surface temperature; and (3) mission constraints of the Saturn Orbiter Dual Probe mission regarding weight allocation. The following areas were identified for further development: surface sample acquisition system; battery powered system; nonmetallic materials; magnetic bubble memory devices, and the landing system. Preentry science, reliability, and weight reduction and redundancy must also be considered.

Performance of a capillary propellant management device with hydrazine

NASA Technical Reports Server (NTRS)

Tegart, J. R.

1979-01-01

The propellant management device that was successfully used in the Viking Orbiter spacecraft was selected for the main propulsion system of the Teleoperator Retrieval System (TRS). Due to differences in the missions and different propellants, the operation of this sheet metal vane device required reverification for the TRS application. An analytical investigation was performed considering the adverse acceleration environment and the high contract angle of the hydrazine propellant. Drop tower tests demonstrated that the device would provide propellant acquisition while the TRS was docked with Skylab, but its operation would have to be supplemented through propellant settling when free-flying.

Large Diameter Shuttle Launched-AEM (LDSL-AEM) study

NASA Technical Reports Server (NTRS)

1976-01-01

A technical description of a Large Diameter Shuttle Launched-AEM (LDSL-AEM), an AEM base module adapted to carry 5 ft diameter payloads in the shuttle with propulsion for carrying payloads to higher altitude orbits from a 150 NM shuttle orbit, is described. The AEM is designed for launch on the scout launch vehicle. Onboard equipment provides capability to despin, acquire the earth, and control the vehicle in an earth pointing mode using reaction wheels for torque with magnets for all attitude acquisition, wheel desaturation, and nutation damping. Earth sensors in the wheels provide pitch and roll attitude. This system provides autonomous control capability to 1 degree in pitch and roll and 2 degrees in yaw. The attitude can be determined to .5 degrees in pitch and roll and 2 degrees in yaw.

Laser Calibration Experiment for Small Objects in Space

NASA Technical Reports Server (NTRS)

Campbell, Jonathan; Ayers, K.; Carreras, R.; Carruth, R.; Freestone, T.; Sharp, J.; Rawleigh, A.; Brewer, J.; Schrock, K.; Bell, L.;

Study of an evolutionary interim earth orbit program

NASA Technical Reports Server (NTRS)

Anderson, J. L.; Alton, L. R.; Arno, R. D.; Deerwester, J. M.; Edsinger, L. E.; Sinclair, K. F.; Tindle, E. L.; Wood, R. D.

1971-01-01

An evolutionary, gradual, and step-wise spacecraft systems technology development from those used on the Apollos and Skylab 1 to that required for the space station was considered. The four mission spacecraft were dry workshop versions of the Saturn 4-B stage, and each individually configured, outfitted and launched by INT-21 vehicles. These spacecraft were evaluated for crews of three, six and nine men and for mission lifetimes of one year. Two versions of the Apollo CSM, a three man and a four man crew, were considered as the logistic vehicle. The solar cell electrical power system of the first mission evolves into a light weight panel system supplemented by an operating isotope-Brayton system on the later missions. The open life support system of the first mission evolves to a system which recovers both water and oxygen on the last mission. The data handling, communications, radiation shielding, micrometeoroid protection, and orbit keeping systems were determined. The program costs were estimated and, excluding operational costs, the cost for each mission would average about $2 billion of which one-sixth would be for development, one-fourth for experiments, and the balance for vehicle acquisition.

Goldstone solar system radar

NASA Technical Reports Server (NTRS)

Jurgens, R. F.; Clark, P. E.; Goldstein, R. M.; Ostro, S. J.; Slade, M. A.; Thompson, T. W.; Saunders, R. S.

1986-01-01

Information is provided about physical nature planetary surfaces and their topography as well as dynamical properties such as orbits and spin states using ground based radar as a remote sensing tool. Accessible targets are the terrestrial planets: the Earth's Moon, Mercury, Venus and Mars, the outer planets rings and major moons, and many transient objects such as asteroids and comets. Data acquisition utilizes the unique facilities of the Goldstone Deep Space Network, occasionally the Arecibo radar, and proposed use of the VLA (very large array).

Remote sensing: Physical principles, sensors and products, and the LANDSAT

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Steffen, C. A.; Lorenzzetti, J. A.; Stech, J. L.; Desouza, R. C. M.

1981-01-01

Techniques of data acquisition by remote sensing are introduced in this teaching aid. The properties of the elements involved (radiant energy, topograph, atmospheric attenuation, surfaces, and sensors) are covered. Radiometers, photography, scanners, and radar are described as well as their products. Aspects of the LANDSAT system examined include the characteristics of the satellite and its orbit, the multispectral band scanner, and the return beam vidicon. Pixels (picture elements), pattern registration, and the characteristics, reception, and processing of LANDSAT imagery are also considered.

Propellant Feed Subsystem for the X-34 Main Propulsion System

NASA Technical Reports Server (NTRS)

McDonald, J. P.; Minor, R. B.; Knight, K. C.; Champion, R. H., Jr.; Russell, F. J., Jr.

1998-01-01

The Orbital Sciences Corporation X-34 vehicle demonstrates technologies and operations key to future reusable launch vehicles. The general flight performance goal of this unmanned rocket plane is Mach 8 flight at an altitude of 250,000 feet. The Main Propulsion System supplies liquid propellants to the main engine, which provides the primary thrust for attaining mission goals. Major NMS design and operational goals are aircraft-like ground operations, quick turnaround between missions, and low initial/operational costs. This paper reviews major design and analysis aspects of the X-34 propellant feed subsystem of the X-34 Main Propulsion System. Topics include system requirements, system design, the integration of flight and feed system performance, propellant acquisition at engine start, and propellant tank terminal drain.

NASA's Marshall Space Flight Center Recent Studies and Technology Developments in the Area of SSA/Orbital Debris

NASA Technical Reports Server (NTRS)

Wiegmann, Bruce M.; Hovater, Mary; Kos, Larry

2012-01-01

NASA/MSFC has been investigating the various aspects of the growing orbital debris problem since early 2009. Data shows that debris ranging in size from 5 mm to 10 cm presents the greatest threat to operational spacecraft today. Therefore, MSFC has focused its efforts on small orbital debris. Using off-the-shelf analysis packages, like the ESA MASTER software, analysts at MSFC have begun to characterize the small debris environment in LEO to support several spacecraft concept studies and hardware test programs addressing the characterization, mitigation, and ultimate removal, if necessary, of small debris. The Small Orbital Debris Active Removal (SODAR) architectural study investigated the overall effectiveness of removing small orbital debris from LEO using a low power, space-based laser. The Small Orbital Debris Detection, Acquisition, and Tracking (SODDAT) conceptual technology demonstration spacecraft was developed to address the challenges of in-situ small orbital debris environment classification including debris observability and instrument requirements for small debris observation. Work is underway at MSFC in the areas of hardware and testing. By combining off the shelf digital video technology, telescope lenses, and advanced video image FPGA processing, MSFC is building a breadboard of a space based, passive orbital tracking camera that can detect and track faint objects (including small debris, satellites, rocket bodies, and NEOs) at ranges of tens to hundreds of kilometers and speeds in excess of 15 km/sec,. MSFC is also sponsoring the development of a one-of-a-kind Dynamic Star Field Simulator with a high resolution large monochrome display and a custom collimator capable of projecting realistic star images with simple orbital debris spots (down to star magnitude 11-12) into a passive orbital detection and tracking system with simulated real-time angular motions of the vehicle mounted sensor. The dynamic star field simulator can be expanded for multiple sensors (including advanced star trackers), real-time vehicle pointing inputs, and more complex orbital debris images. This system is also adaptable to other sensor optics, missions, and installed sensor testing.

SKYLAB (SL)-4 - CREW TRAINING (ORBITAL WORKSTATION [OWS]) - JSC

NASA Image and Video Library

1973-08-22

S73-32848 (10 Sept. 1973) --- Scientist-astronaut Edward G. Gibson, science pilot for the third manned Skylab mission (Skylab 4), reads the markings on a magazine of 400 feet of film for the 16mm Data Acquisition Camera (DAC), during a training exercise in the Orbital Workshop (OWS) trainer at Johnson Space Center. Photo credit: NASA

Radar cross section measurements of a scale model of the space shuttle orbiter vehicle

NASA Technical Reports Server (NTRS)

Yates, W. T.

1978-01-01

A series of microwave measurements was conducted to determine the radar cross section of the Space Shuttle Orbiter vehicle at a frequency and at aspect angles applicable to re-entry radar acquisition and tracking. The measurements were performed in a microwave anechoic chamber using a 1/15th scale model and a frequency applicable to C-band tracking radars. The data were digitally recorded and processed to yield statistical descriptions useful for prediction of orbiter re-entry detection and tracking ranges.

The quick acquisition technique for laser communication between LEO and GEO

NASA Astrophysics Data System (ADS)

Zhang, Li-zhong; Zhang, Rui-qin; Li, Yong-hao; Meng, Li-xin; Li, Xiao-ming

2013-08-01

The sight-axis alignment can be accomplished by the quick acquisition operation between two laser communication terminals, which is the premise of establishing a free-space optical communication link. Especially for the laser communication links of LEO (Low Earth Orbit)-Ground and LEO-GEO (Geostationary Earth Orbit), since the earth would break the transmission of laser and break the communication as well, so the effective time for each communication is very shot (several minutes~ dozens of minutes), as a result the communication terminals have to capture each other to rebuild the laser communication link. In the paper, on the basis of the analysis of the traditional methods, it presents a new idea that using the long beacon light instead of the circular beacon light; thereby the original of two-dimensional raster spiral scanning is replaced by one-dimensional scanning. This method will reduce the setup time and decrease the failure probability of acquisition for the LEO-GEO laser communication link. Firstly, the analysis of the external constraint conditions in the acquisition phase has been presented in this paper. Furthermore, the acquisition algorithm models have been established. The optimization analysis for the parameters of the acquisition unit has been carried out, and the ground validation experiments of the acquisition strategy have also been performed. The experiments and analysis show that compared with traditional capturing methods, the method presented in this article can make the capturing time be shortened by about 40%, and the failure probability of capturing be reduced by about 30%. So, the method is significant for the LEO-GEO laser communication link.

The 60 GHz antenna system analyses for intersatellite links, phase A

NASA Technical Reports Server (NTRS)

1984-01-01

A tradeoff study for 60 GHz antenna systems applicable to an advanced Tracking and Data Acquisition System is also discussed. A conceptual design of a preferred antenna system is also discussed. The tradeoff results for four types of antenna systems are presented: (1) Reflector/fixed feed, (2) Mechanical scan, (3) Electronic scan; and (4) Hybrid mechanical/electronic scan. The 12 candidate antennas were assessed on the basis of a preliminary design and a performance analysis then were scored against 15 weighted parameters. This process resulted in the ranking of the 12 candidates for the two applications, namely, for the geostationary TDAS only with a narrow field of view and for low orbit user satellites with a wide field of view.

The NASA Meter Class Autonomous Telescope: Ascension Island

NASA Technical Reports Server (NTRS)

Lederer, S. M.; Stansbery, E. G.; Cowardin, H. M.; Kervin, P.; Hickson, P.

2013-01-01

The Meter Class Autonomous Telescope (MCAT) is the newest optical sensor dedicated to NASA s mission to characterize the space debris environment. It is the successor to a series of optical telescopes developed and operated by the JSC Orbital Debris Program Office (ODPO) to monitor and assess the debris environment in (1) Low Earth Orbit (LEO), (2) Medium Earth Orbit (MEO), and (3) Geosynchronous Orbit (GEO), with emphasis on LEO and GEO altitudes. A joint NASA-Air Force Research Labs project, MCAT is a 1.3m optical telescope dedicated to debris research. Its optical path and sensor yield a large survey fence at the cutting edge of current detector performance. It has four primary operational observing modes, two of which were not computationally feasible a decade ago. Operations are supported by a sophisticated software suite that monitors clouds and weather conditions, and controls everything from data collection to dome rotation to processing tens of GB of imagery data nightly. With fainter detection limits, precision detection, acquisition and tracking of targets, multi-color photometry, precision astrometry, automated reacquisition capability, and the ability to process all data at the acquisition rate, MCAT is capable of producing and processing a volume and quality of data far in excess of any current (or prior) ODPO operations. This means higher fidelity population inputs and eliminating the multi-year backlog from acquisition-to-product typical of optical campaigns. All of this is possible given a suitable observing location. Originally planned for the island of Legan, part of the Kwajalein Atoll Islands, recent developments have led to a change in venue. Specifically, the Ground-based Electro-Optical Deep Space Surveillance, or GEODSS, System of telescopes is the United States major tracking system for deep space. This network consists of telescopes in Maui, Hawaii; Diego Garcia (Indian Ocean), and Socorro, New Mexico. A fourth optical telescope, though smaller in size, has been operating in conjunction with this effort until recently in M.ron, Spain. With the M.ron site closing, a significant gap in longitude exists between the New Mexico and Diego Garcia sites. This longitudinal gap is well covered by placing a telescope on Ascension Island (7degrees 58'20" S, 14degrees 24'4"W), in the Atlantic Ocean. Ascension Island offers the benefits of both location and weather. The near equatorial location affords the opportunity to access under-sampled low-inclination orbits and new GEO longitudes, while simultaneously filling in the GEODSS longitudinal gap. Ascension Island is a volcanic, desert island, receiving only 7" of rain per year on average. With consistent trade winds blowing from the SSE direction off Africa, the combination of an island location with consistent winds will create the smooth laminar flow sought after by all astronomical sites, which creates stable atmospheric ('seeing') conditions. Finally, this low population island has minimal lighting, resulting in very dark skies, ideal for an observatory.

Aladdin: Exploration and Sample Return from the Moons of Mars

NASA Technical Reports Server (NTRS)

Pieters, C.; Cheng, A.; Clark, B.; Murchie, S.; Mustard, J.; Zolensky, M.; Papike, J.

2000-01-01

Aladdin is a remote sensing and sample return mission focused on the two small moons of Mars, Phobos and Deimos. Understanding the moons of Mars will help us to understand the early history of Mars itself. Aladdin's primary objective is to acquire well documented, representative samples from both moons and return them to Earth for detailed analyses. Samples arrive at Earth within three years of launch. Aladdin addresses several of NASA's highest priority science objectives: the origin and evolution of the Martian system (one of two silicate planets with satellites) and the composition and nature of small bodies (the building blocks of the solar system). The Aladdin mission has been selected as a finalist in both the 1997 and 1999 Discovery competitions based on the high quality of science it would accomplish. The equivalent of Aladdin's Phase A development has been successfully completed, yielding a high degree of technical maturity. Aladdin uses an innovative flyby sample acquisition method, which has been validated experimentally and does not require soft landing or anchoring. An initial phasing orbit at Mars reduces mission propulsion requirements, enabling Aladdin to use proven, low-risk chemical propulsion with good mass margin. This phasing orbit is followed by a five month elliptical mission during which there are redundant opportunities for acquisition of samples and characterization of their geologic context using remote sensing. The Aladdin mission is a partnership between Brown University, the Johns Hopkins University Applied Physics Laboratory, Lockheed Martin Astronautics, and NASA Johnson Space Center.

Active 3D camera design for target capture on Mars orbit

NASA Astrophysics Data System (ADS)

Cottin, Pierre; Babin, François; Cantin, Daniel; Deslauriers, Adam; Sylvestre, Bruno

2010-04-01

During the ESA Mars Sample Return (MSR) mission, a sample canister launched from Mars will be autonomously captured by an orbiting satellite. We present the concept and the design of an active 3D camera supporting the orbiter navigation system during the rendezvous and capture phase. This camera aims at providing the range and bearing of a 20 cm diameter canister from 2 m to 5 km within a 20° field-of-view without moving parts (scannerless). The concept exploits the sensitivity and the gating capability of a gated intensified camera. It is supported by a pulsed source based on an array of laser diodes with adjustable amplitude and pulse duration (from nanoseconds to microseconds). The ranging capability is obtained by adequately controlling the timing between the acquisition of 2D images and the emission of the light pulses. Three modes of acquisition are identified to accommodate the different levels of ranging and bearing accuracy and the 3D data refresh rate. To come up with a single 3D image, each mode requires a different number of images to be processed. These modes can be applied to the different approach phases. The entire concept of operation of this camera is detailed with an emphasis on the extreme lighting conditions. Its uses for other space missions and terrestrial applications are also highlighted. This design is implemented in a prototype with shorter ranging capabilities for concept validation. Preliminary results obtained with this prototype are also presented. This work is financed by the Canadian Space Agency.

The Kaguya Mission Overview

NASA Astrophysics Data System (ADS)

Kato, Manabu; Sasaki, Susumu; Takizawa, Yoshisada

2010-07-01

The Japanese lunar orbiter Kaguya (SELENE) was successfully launched by an H2A rocket on September 14, 2007. On October 4, 2007, after passing through a phasing orbit 2.5 times around the Earth, Kaguya was inserted into a large elliptical orbit circling the Moon. After the apolune altitude was lowered, Kaguya reached its nominal 100 km circular polar observation orbit on October 19. During the process of realizing the nominal orbit, two subsatellites Okina (Rstar) and Ouna (Vstar) were released into elliptical orbits with 2400 km and 800 km apolune, respectively; both elliptical orbits had 100 km perilunes. After the functionality of bus system was verified, four radar antennas and a magnetometer boom were extended, and a plasma imager was deployed. Acquisition of scientific data was carried out for 10 months of nominal mission that began in mid-December 2007. During the 8-month extended mission, magnetic fields and gamma-rays from lower orbits were measured; in addition to this, low-altitude observations were carried out using a Terrain Camera, a Multiband Imager, and an HDTV camera. New data pertaining to an intense magnetic anomaly and GRS data with higher spatial resolution were acquired to study magnetism and the elemental distribution of the Moon. After some orbital maneuvers were performed by using the saved fuel, the Kaguya spacecraft finally impacted on the southeast part of the Moon. The Kaguya team has archived the initial science data, and since November 2, 2009, the data has been made available to public, and can be accessed at the Kaguya homepage of JAXA. The team continues to also study and publish initial results in international journals. Science purposes of the mission and onboard instruments including initial science results are described in this overview.

Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT) Experiment Conceptual Design and Feasibility Study

NASA Technical Reports Server (NTRS)

Kramer, Edward (Editor)

1998-01-01

The cryogenic fluid management technologies required for the exploration of the solar system can only be fully developed via space-based experiments. A dedicated spacecraft is the most efficient way to perform these experiments. This report documents the extended conceptual design of the COLD-SAT spacecraft, capable of meeting these experimental requirements. All elements, including the spacecraft, ground segment, launch site modifications and launch vehicle operations, and flight operations are included. Greatly expanded coverage is provided for those areas unique to this cryogenic spacecraft, such as the experiment system, attitude control system, and spacecraft operations. Supporting analyses are included as are testing requirements, facilities surveys, and proposed project timelines.

Tracking Data Acquisition System (TDAS) for the 1990's. Volume 6: TDAS navigation system architecture

NASA Technical Reports Server (NTRS)

Elrod, B. D.; Jacobsen, A.; Cook, R. A.; Singh, R. N. P.

1983-01-01

One-way range and Doppler methods for providing user orbit and time determination are examined. Forward link beacon tracking, with on-board processing of independent navigation signals broadcast continuously by TDAS spacecraft; forward link scheduled tracking; with on-board processing of navigation data received during scheduled TDAS forward link service intervals; and return link scheduled tracking; with ground-based processing of user generated navigation data during scheduled TDAS return link service intervals are discussed. A system level definition and requirements assessment for each alternative, an evaluation of potential navigation performance and comparison with TDAS mission model requirements is included. TDAS satellite tracking is also addressed for two alternatives: BRTS and VLBI tracking.

Dual S and Ku-band tracking feed for a TDRS reflector antenna

NASA Technical Reports Server (NTRS)

Pullara, J. C.; Bales, C. W.; Kefalas, G. P.; Uyehara, M.

1974-01-01

The results are presented of a trade study designed to identify a synchronous satellite antenna system suitable for receiving and transmitting data from lower orbiting satellites at both S- and K sub u-bands simultaneously as part of the Tracking and Data Relay Satellite System. All related problems associated with maintaining a data link between two satellites with a K sub u-band half-power beamwidth of 0.4 db are considered including data link maintenance techniques, beam pointing accuracies, gimbal and servo errors, solar heating, angle tracking schemes, acquisition problems and aids, tracking accuracies versus SNR, antenna feed designs, equipment designs, weight and power budgets, and detailed candidate antenna system designs.

Data archiving and serving system implementation in CLEP's GRAS Core System

NASA Astrophysics Data System (ADS)

Zuo, Wei; Zeng, Xingguo; Zhang, Zhoubin; Geng, Liang; Li, Chunlai

2017-04-01

The Ground Research & Applications System(GRAS) is one of the five systems of China's Lunar Exploration Project(CLEP), it is responsible for data acquisition, processing, management and application, and it is also the operation control center during satellite in-orbit and payload operation management. Chang'E-1, Chang'E-2 and Chang'E-3 have collected abundant lunar exploration data. The aim of this work is to present the implementation of data archiving and Serving in CLEP's GRAS Core System software. This first approach provides a client side API and server side software allowing the creation of a simplified version of CLEPDB data archiving software, and implements all required elements to complete data archiving flow from data acquisition until its persistent storage technology. The client side includes all necessary components that run on devices that acquire or produce data, distributing and streaming to configure remote archiving servers. The server side comprises an archiving service that stores into PDS files all received data. The archiving solution aims at storing data coming for the Data Acquisition Subsystem, the Operation Management Subsystem, the Data Preprocessing Subsystem and the Scientific Application & Research Subsystem. The serving solution aims at serving data for the various business systems, scientific researchers and public users. The data-driven and component clustering methods was adopted in this system, the former is used to solve real-time data archiving and data persistence services; the latter is used to keep the continuous supporting ability of archive and service to new data from Chang'E Mission. Meanwhile, it can save software development cost as well.

Evaluation of fluid behavior in spinning toroidal tanks

NASA Technical Reports Server (NTRS)

Anderson, J. E.; Fester, D. A.; Dugan, D. W.

1976-01-01

An experimental study was conducted to evaluate propellant behavior in spinning toroidal tanks that could be used in a retro-propulsion system of an advanced outer-planet Pioneer orbiter. Information on propellant slosh and settling and on ullage orientation and stability was obtained. The effects of axial acceleration, spin rate, spin rate change, and spacecraft wobble, both singly and in combination, were evaluated using a 1/8-scale transparent tank in one-g and low-g environments. Liquid loadings ranged from 5% to 96% full. The impact of a surface tension acquisition device was assessed. Testing simulated the behavior of F2/N2H4 and N2O4/MMH propellants. Results are presented which indicate no major fluid behavior problems would be encountered with any of the four propellants in the toroidal tanks of a spin-stabilized orbiter spacecraft.

Fluid interaction with spinning toroidal tanks

NASA Technical Reports Server (NTRS)

Fester, D. A.; Anderson, J. E.

1977-01-01

An experimental study was conducted to evaluate propellant behavior in spinning torroidal tanks that could be used in a retropropulsion system of an advanced outer-planet Pioneer orbiter. Information on propellant slosh and settling and on ullage orientation and stability was obtained. The effects of axial acceleration, spin rate, spin-rate change, and spacecraft wobble, both singly and in combination, were evaluated using a one-eighth scale transparent tank in one-g and low-g environments. Liquid loadings ranged from 5% to 96% full. The impact of a surface tension acquisition device was assessed by comparison with bare-tank results. The testing simulated the behavior of the fluorine/hydrazine and nitrogen textroxide/monomethylhydrazine propellants. Results are presented that indicate that no major fluid behavior problems would be encountered with any of the four propellants in the toroidal tanks of a spin-stabilized orbiter spacecraft.

Optical deep space communication via relay satellite

NASA Technical Reports Server (NTRS)

Gagliardi, R. M.; Vilnrotter, V. A.; Dolinar, S. J., Jr.

1981-01-01

The possible use of an optical for high rate data transmission from a deep space vehicle to an Earth-orbiting relay satellite while RF links are envisioned for the relay to Earth link was studied. A preliminary link analysis is presented for initial sizing of optical components and power levels, in terms of achievable data rates and feasible range distances. Modulation formats are restricted to pulsed laser operation, involving bot coded and uncoded schemes. The advantage of an optical link over present RF deep space link capabilities is shown. The problems of acquisition, pointing and tracking with narrow optical beams are presented and discussed. Mathematical models of beam trackers are derived, aiding in the design of such systems for minimizing beam pointing errors. The expected orbital geometry between spacecraft and relay satellite, and its impact on beam pointing dynamics are discussed.

A simple second-order digital phase-locked loop.

NASA Technical Reports Server (NTRS)

Tegnelia, C. R.

1972-01-01

A simple second-order digital phase-locked loop has been designed for the Viking Orbiter 1975 command system. Excluding analog-to-digital conversion, implementation of the loop requires only an adder/subtractor, two registers, and a correctable counter with control logic. The loop considers only the polarity of phase error and corrects system clocks according to a filtered sequence of this polarity. The loop is insensitive to input gain variation, and therefore offers the advantage of stable performance over long life. Predictable performance is guaranteed by extreme reliability of acquisition, yet in the steady state the loop produces only a slight degradation with respect to analog loop performance.

COLD-SAT feasibility study safety analysis

NASA Technical Reports Server (NTRS)

Mchenry, Steven T.; Yost, James M.

1991-01-01

The Cryogenic On-orbit Liquid Depot-Storage, Acquisition, and Transfer (COLD-SAT) satellite presents some unique safety issues. The feasibility study conducted at NASA-Lewis desired a systems safety program that would be involved from the initial design in order to eliminate and/or control the inherent hazards. Because of this, a hazards analysis method was needed that: (1) identified issues that needed to be addressed for a feasibility assessment; and (2) identified all potential hazards that would need to be controlled and/or eliminated during the detailed design phases. The developed analysis method is presented as well as the results generated for the COLD-SAT system.

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.

Thermal management system technology development for space station applications

NASA Technical Reports Server (NTRS)

Rankin, J. G.; Marshall, P. F.

1983-01-01

A short discussion of the history to date of the NASA thermal management system technology development program is presented, and the current status of several ongoing studies and hardware demonstration tasks is reported. One element of technology that is required for long-life, high-power orbital platforms/stations that is being developed is heat rejection and a space-constructable radiator system. Aspects of this project include high-efficiency fin concepts, a heat pipe quick-disconnect device, high-capacity heat pipes, and an alternate interface heat exchanger design. In the area of heat acquisition and transport, developments in a pumped two-phase transport loop, a capillary pumped transport loop using the concept of thermal utility are reported. An example of a thermal management system concept is provided.

Inverted Outflow Ground Testing of Cryogenic Propellant Liquid Acquisition Devices

NASA Technical Reports Server (NTRS)

Chato, David J.; Hartwig, Jason W.; Rame, Enrique; McQuillen, John B.

2014-01-01

NASA is currently developing propulsion system concepts for human exploration. These propulsion concepts will require the vapor free acquisition and delivery of the cryogenic propellants stored in the propulsion tanks during periods of microgravity to the exploration vehicles engines. Propellant management devices (PMDs), such as screen channel capillary liquid acquisition devices (LADs), vanes and sponges have been used for earth storable propellants in the Space Shuttle Orbiter and other spacecraft propulsion systems, but only very limited propellant management capability currently exists for cryogenic propellants. NASA is developing PMD technology as a part of their cryogenic fluid management (CFM) project. System concept studies have looked at the key factors that dictate the size and shape of PMD devices and established screen channel LADs as an important component of PMD design. Modeling validated by normal gravity experiments is examining the behavior of the flow in the LAD channel assemblies (as opposed to only prior testing of screen samples) at the flow rates representative of actual engine service (similar in size to current launch vehicle upper stage engines). Recently testing of rectangular LAD channels has included inverted outflow in liquid oxygen and liquid hydrogen. This paper will report the results of liquid oxygen testing compare and contrast them with the recently published hydrogen results; and identify the sensitivity these results to flow rate and tank internal pressure.

Inverted Outflow Ground Testing of Cryogenic Propellant Liquid Acquisition Devices

NASA Technical Reports Server (NTRS)

Chato, David J.; Hartwig, Jason W.; Rame, Enrique; McQuillen, John B.

2014-01-01

NASA is currently developing propulsion system concepts for human exploration. These propulsion concepts will require the vapor free acquisition and delivery of the cryogenic propellants stored in the propulsion tanks during periods of microgravity to the exploration vehicles engines. Propellant management devices (PMD's), such as screen channel capillary liquid acquisition devices (LAD's), vanes and sponges have been used for earth storable propellants in the Space Shuttle Orbiter and other spacecraft propulsion systems, but only very limited propellant management capability currently exists for cryogenic propellants. NASA is developing PMD technology as a part of their cryogenic fluid management (CFM) project. System concept studies have looked at the key factors that dictate the size and shape of PMD devices and established screen channel LADs as an important component of PMD design. Modeling validated by normal gravity experiments is examining the behavior of the flow in the LAD channel assemblies (as opposed to only prior testing of screen samples) at the flow rates representative of actual engine service (similar in size to current launch vehicle upper stage engines). Recently testing of rectangular LAD channels has included inverted outflow in liquid oxygen and liquid hydrogen. This paper will report the results of liquid oxygen testing compare and contrast them with the recently published hydrogen results; and identify the sensitivity of these results to flow rate and tank internal pressure.

A GPS Receiver for Lunar Missions

NASA Technical Reports Server (NTRS)

Bamford, William A.; Heckler, Gregory W.; Holt, Greg N.; Moreau, Michael C.

2008-01-01

Beginning with the launch of the Lunar Reconnaissance Orbiter (LRO) in October of 2008, NASA will once again begin its quest to land humans on the Moon. This effort will require the development of new spacecraft which will safely transport people from the Earth to the Moon and back again, as well as robotic probes tagged with science, re-supply, and communication duties. In addition to the next-generation spacecraft currently under construction, including the Orion capsule, NASA is also investigating and developing cutting edge navigation sensors which will allow for autonomous state estimation in low Earth orbit (LEO) and cislunar space. Such instruments could provide an extra layer of redundancy in avionics systems and reduce the reliance on support and on the Deep Space Network (DSN). One such sensor is the weak-signal Global Positioning System (GPS) receiver "Navigator" being developed at NASA's Goddard Space Flight Center (GSFC). At the heart of the Navigator is a Field Programmable Gate Array (FPGA) based acquisition engine. This engine allows for the rapid acquisition/reacquisition of strong GPS signals, enabling the receiver to quickly recover from outages due to blocked satellites or atmospheric entry. Additionally, the acquisition algorithm provides significantly lower sensitivities than a conventional space-based GPS receiver, permitting it to acquire satellites well above the GPS constellation. This paper assesses the performance of the Navigator receiver based upon three of the major flight regimes of a manned lunar mission: Earth ascent, cislunar navigation, and entry. Representative trajectories for each of these segments were provided by NASA. The Navigator receiver was connected to a Spirent GPS signal generator, to allow for the collection of real-time, hardware-in-the-loop results for each phase of the flight. For each of the flight segments, the Navigator was tested on its ability to acquire and track GPS satellites under the dynamical environment unique to that trajectory.

Time and frequency requirement for the earth and ocean physics applications program. [characteristics and orbital mechanics of artificial satellites for data acquisition

NASA Technical Reports Server (NTRS)

Vonbun, F. O.

1972-01-01

The application of time and frequency standards to the Earth and Ocean Physics Applications Program (EOPAP) is discussed. The goals and experiments of the EOPAP are described. Methods for obtaining frequency stability and time synchronization are analyzed. The orbits, trajectories, and characteristics of the satellites used in the program are reported.

Viking site selection and certification

NASA Technical Reports Server (NTRS)

Masursky, H.; Crabill, N. L.

1981-01-01

The landing site selection and certification effort for the Viking mission to Mars is reviewed from the premission phase through the acquisition of data and decisions during mission operations and the immediate postlanding evaluation. The utility and limitations of the orbital television and infrared data and ground based radar observation of candidate and actual landing sites are evaluated. Additional instruments and types of observations which would have been useful include higher resolution cameras, radar altimeters, and terrain hazard avoidance capability in the landing system. Suggestions based on this experience that might be applied to future missions are included.

Report of the Terrestrial Bodies Science Working Group. Volume 9: Complementary research and development

NASA Technical Reports Server (NTRS)

Fanale, F. P.; Kaula, W. M.; Mccord, T. B.; Trombka, J. L.

1977-01-01

Topics discussed include the need for: the conception and development of a wide spectrum of experiments, instruments, and vehicles in order to derive the proper return from an exploration program; the effective use of alternative methods of data acquisition involving ground-based, airborne and near Earth orbital techniques to supplement spacraft mission; and continued reduction and analysis of existing data including laboratory and theoretical studies in order to benefit fully from experiments and to build on the past programs toward a logical and efficient exploration of the solar system.

Results of aerodynamic heat transfer tests of a 0.0175-scale model of the Rockwell International Space Shuttle Orbiter 139 (model number 22-0) in the NASA/Ames 3.5-foot hypersonic wind tunnel (test OH6)

NASA Technical Reports Server (NTRS)

Dye, W. H.; Lockman, W. K.

1975-01-01

The results of a hypersonic wind tunnel test program conducted using a 0.0175 scale thin-skin thermocouple model of the Space Shuttle Orbiter to obtain aerodynamic heat transfer data on the Orbiter under simulated reentry conditions were presented. The test program was conducted at a Mach number of 7.3 and a freestream Reynolds number ranging between 1.0 and 6.0 million/foot. The model was tested for angles of attack ranging between 10 deg and 30 deg and a sideslip angle of 0 deg. The model was constructed of 15-5 PH stainless steel with the instrumented areas machined to a nominal skin thickness of 0.030 in. The model instrumentation consisted of 288 iron-constantan thermocouples spot welded to the skin inner surface, but only 75 of these were used in this test program. A high-speed, analog-to-digital data acquisition system was used to record data on magnetic tape.

PLÉIADES: Responsiveness, Flexibility, Reactivity

NASA Astrophysics Data System (ADS)

Gabriel-Robez, C.; Lees, R.; Bernard, M.

2012-08-01

By the end of 2011, Astrium GEO-Information Services launched Pléiades 1, the first of two identical optical imaging satellites that will be operated on a phased orbit. This satellite system, designed by the French Space Agency, CNES, based upon French Defense specifications, will provide 50-cm products in record time. The overall aim of this paper is to describe the benefits of the innovative features of Pléiades 1 and its operations, so as to assess their combined potential in emergency situations, crisis recovery, regular monitoring or large area mapping. Specific care will be brought to describe the reactivity enabled by the system. Based on real-life examples, the paper will lead the analysis on the two main components of the system. On the one hand, the space segment will be presented through the following characteristics: revisit capacity, agility, acquisition capacity and acquisition scenarios (target, single-pass mosaics, stereo, tristereo, linear monitoring, persistent surveillance). On the other hand, the flexibility of the ground segment will be assessed. The benefits of multiple tasking plans per day, direct tasking capacity, automated processing and on-line ordering and delivering will be illustrated, tested and qualified for applications requiring a high level of responsiveness and reactivity. The presentation will end with a summary of the benefits of the space segment features and the flexibility of the ground segment, fine-tuned to answer both military and civilian / commercial needs. The analysis will be extended in the perspective of the second Pléiades' launch, highlighting the advantages of having two satellites operating on a phased orbit, affording a daily revisit anywhere on Earth, with very high resolution.

SeaTrack: Ground station orbit prediction and planning software for sea-viewing satellites

NASA Technical Reports Server (NTRS)

Lambert, Kenneth S.; Gregg, Watson W.; Hoisington, Charles M.; Patt, Frederick S.

1993-01-01

An orbit prediction software package (Sea Track) was designed to assist High Resolution Picture Transmission (HRPT) stations in the acquisition of direct broadcast data from sea-viewing spacecraft. Such spacecraft will be common in the near future, with the launch of the Sea viewing Wide Field-of-view Sensor (SeaWiFS) in 1994, along with the continued Advanced Very High Resolution Radiometer (AVHRR) series on NOAA platforms. The Brouwer-Lyddane model was chosen for orbit prediction because it meets the needs of HRPT tracking accuracies, provided orbital elements can be obtained frequently (up to within 1 week). Sea Track requires elements from the U.S. Space Command (NORAD Two-Line Elements) for the satellite's initial position. Updated Two-Line Elements are routinely available from many electronic sources (some are listed in the Appendix). Sea Track is a menu-driven program that allows users to alter input and output formats. The propagation period is entered by a start date and end date with times in either Greenwich Mean Time (GMT) or local time. Antenna pointing information is provided in tabular form and includes azimuth/elevation pointing angles, sub-satellite longitude/latitude, acquisition of signal (AOS), loss of signal (LOS), pass orbit number, and other pertinent pointing information. One version of Sea Track (non-graphical) allows operation under DOS (for IBM-compatible personal computers) and UNIX (for Sun and Silicon Graphics workstations). A second, graphical, version displays orbit tracks, and azimuth-elevation for IBM-compatible PC's, but requires a VGA card and Microsoft FORTRAN.

Flexible attosecond beamline for high harmonic spectroscopy and XUV/near-IR pump probe experiments requiring long acquisition times

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

Weber, S. J., E-mail: sebastien.weber@cea.fr; Manschwetus, B.; Billon, M.

2015-03-15

We describe the versatile features of the attosecond beamline recently installed at CEA-Saclay on the PLFA kHz laser. It combines a fine and very complete set of diagnostics enabling high harmonic spectroscopy (HHS) through the advanced characterization of the amplitude, phase, and polarization of the harmonic emission. It also allows a variety of photo-ionization experiments using magnetic bottle and COLTRIMS (COLd Target Recoil Ion Momentum Microscopy) electron spectrometers that may be used simultaneously, thanks to a two-foci configuration. Using both passive and active stabilization, special care was paid to the long term stability of the system to allow, using bothmore » experimental approaches, time resolved studies with attosecond precision, typically over several hours of acquisition times. As an illustration, applications to multi-orbital HHS and electron-ion coincidence time resolved spectroscopy are presented.« less

Space station user's handbook (Revised)

NASA Technical Reports Server (NTRS)

1972-01-01

A modular space station concept that furnishes facilities which may be used for experimentation and application during earth orbit missions is described in a user's handbook. The subjects discussed are: (1) overall profile and mission activities for five year on-orbit program, (2) electromagnetic energy transmission through earth atmosphere, (3) effects of atmosphere in limiting resolution, and (4) the hydrological cycle as these subjects apply to the space station data acquisition function.

The deep space network

NASA Technical Reports Server (NTRS)

1975-01-01

The objectives, functions, and organization of the Deep Space Network are summarized along with deep space station, ground communication, and network operations control capabilities. Mission support of ongoing planetary/interplanetary flight projects is discussed with emphasis on Viking orbiter radio frequency compatibility tests, the Pioneer Venus orbiter mission, and Helios-1 mission status and operations. Progress is also reported in tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations.

Real-time orbit estimation for ATS-6 from redundant attitude sensors

NASA Technical Reports Server (NTRS)

Englar, T. S., Jr.

1975-01-01

A program installed in the ATSOCC on-line computer operates with attitude sensor data to produce a smoothed real-time orbit estimate. This estimate is obtained from a Kalman filter which enables the estimate to be maintained in the absence of T/M data. The results are described of analytical and numerical investigations into the sensitivity of Control Center output to the position errors resulting from the real-time estimation. The results of the numerical investigation, which used several segments of ATS-6 data gathered during the Sensor Data Acquisition run on August 19, 1974, show that the implemented system can achieve absolute position determination with an error of about 100 km, implying pointing errors of less than 0.2 deg in latitude and longitude. This compares very favorably with ATS-6 specifications of approximately 0.5 deg in latitude-longitude.

A feasibility study of developing toroidal tanks for a spinning spacecraft

NASA Technical Reports Server (NTRS)

Anderson, J. E.; Fester, D. A.

1973-01-01

A study was made to determine the feasibility of developing toroidal propellant tanks for a bipropellant (N204/MMH) propulsion system to be used in a proposed advanced Pioneer spin-stabilized vehicle intended for a Jupiter-orbiter and possibly a Saturn-orbiter mission. The rationale for considering the use of two toroidal tanks rather than the proposed use of four spherical tanks includes the belief that a more symmetrical distribution of propellant mass and a smaller variation in the position of the vehicle center-of-mass during propellant consumption would result, reducing requirements for attitude-control propellants, for balance weight, and for other weights associated with the dynamics of the spinning spacecraft. Results lead to the conclusion that a toroidal tank containing an effective, passive surface tension propellant acquisition device could be fabricated with available manufacturing methods and could be used interchangeably for either fuel or oxidizer.

System definition phase and acquisition phase project plan for Small Astronomy Satellite SAS-D

NASA Technical Reports Server (NTRS)

1971-01-01

The objective of the SAS-D project is to conduct spectral distribution studies of celestial ultraviolet sources using an Explorer-class spacecraft launched by a Delta vehicle into a geosynchronous orbit in the last half of 1975. The telescope system is intended for use by guest astronomers for a major portion of the total observing time. The concept of the overall system, designed to resemble functionally the operation of a ground-based observatory, should maximize the usefulness of the instrument to the astronomical community by limiting the amount of special instruction needed to use the spaceborne telescope. The SAS-D mission will obtain information on what stars, nebulae, and galaxies are and how they develop.

Multi-sun-synchronous (MSS) orbits for earth observation

NASA Astrophysics Data System (ADS)

Ulivieri, Carlo; Anselmo, Luciano

1992-08-01

A case study is outlined for a remote-sensing mission at low and middle latitudes based on multi-sun-synchronous (MSS) orbits. The scenario involves the use of small payloads in low-earth posigrade orbits that would overfly the Mediterranean region. A 600-kg spacecraft is considered in an orbit that is 571 km in altitude and at an inclination of 42.5 deg. The orbit is analyzed in terms of mission characteristics, and two years of operation is shown to be feasible with a fuel-consumption rate of less than three kg/yr of hydrazine. The mission could be based on the use of a Scout solid-propellant rockets into an MSS orbit, and only a limited number of ground stations are required for good data collection. A remote-sensing mission at low/middle latitudes is shown to be efficient in terms of both revisit frequency, fuel consumption, and data acquisition.

Navigating highly elliptical earth orbiters with simultaneous VLBI from orthogonal baseline pairs

NASA Technical Reports Server (NTRS)

Frauenholz, Raymond B.

1986-01-01

Navigation strategies for determining highly elliptical orbits with VLBI are described. The predicted performance of wideband VLBI and Delta VLBI measurements obtained by orthogonal baseline pairs are compared for a 16-hr equatorial orbit. It is observed that the one-sigma apogee position accuracy improves two orders of magnitude to the meter level when Delta VLBI measurements are added to coherent Doppler and range, and the simpler VLBI strategy provides nearly the same orbit accuracy. The effects of differential measurement noise and acquisition geometry on orbit accuracy are investigated. The data reveal that quasar position uncertainty limits the accuracy of wideband Delta VLBI measurements, and that polar motion and baseline uncertainties and offsets between station clocks affect the wideband VLBI data. It is noted that differential one-way range (DOR) has performance nearly equal to that of the more complex Delta DOR and is recommended for use on spacecraft in high elliptical orbits.

An experiment to evaluate liquid hydrogen storage in space

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Fester, D. A.; Johns, W. A.; Marino, J. S.

1981-01-01

The design and verification of a Cryogenic Fluid Management Experiment for orbital operation on the Shuttle is described. The experiment will furnish engineering data to establish design criteria for storage and supply of cryogenic fluids, mainly hydrogen, for use in low gravity environments. The apparatus comprises an LAD (liquid acquisition device) and a TVS (thermodynamic vent system). The hydrogen will be either vented or forced out by injected helium and the flow rates will be monitored. The data will be compared with ground-based simulations to determine optimal flow rates for the pressurizing gas and the release of the cryogenic fluid. It is noted that tests on a one-g, one-third size LAD system are under way.

Development of a high resolution chemostratigraphy for the Late Triassic-Early Jurassic Newark Basin

NASA Astrophysics Data System (ADS)

Kinney, S.; Olsen, P. E.; Chang, C.

2017-12-01

The 6.7 km of continuous core recovered from the paleo-tropical Triassic-Jurassic Newark rift basin during the Newark Basin Coring Project (NBCP) has provided a wealth of data since the conclusion of drilling 25 years ago. These cores comprise the longest ( 30 Myr) continuously-cored record of orbitally-paced environmental change and have informed our understanding in several different areas including tropical climate change, history of CO­2, mass extinctions, the geological time scale, and solar system dynamics. Despite the utility of NBCP cores for these endeavors, a critical missing dataset is a comprehensive characterization of their geochemical variations relevant to paleoenvironmental and paleoclimatic interests, largely a consequence of the cost of analyses at an appropriate resolution using conventional techniques. With the advent of new technology permitting the rapid acquisition of reliable geochemical data, such limitations may no longer be an obstacle for constructing a high-resolution chemostratigraphic record for the NBCP. We present the results of a proof-of-concept study using both ICP-MS-calibrated scanning ITRAX XRF and handheld Laser Induced Breakdown Spectroscopy (LIBS) using the SciAps Z-300. We will show elemental abundances at resolutions as high as 500 mm obtained using these methods from correlative sections of the Titusville and Nursery cores (Lockatong Fm.). These sections are sufficiently long to capture orbital variations and include the range of lithologies present throughout the entire section. Our preliminary results are consistent with previous, semi-quantitative means (e.g., depth ranks) of assessing Milankovitch-scale orbital variations and are also consistent with core and hole geophysical data, demonstrating that these methods can acquire meaningful geochemical data from the entire NBCP. With continued work, we aim to provide an objective characterization of orbitally-paced lake level cyclicity using geochemical proxy variations, leading to an improved basis for disentangling the links between basin evolution, the evolution of the CO2-climate system, orbitally paced cyclicity, and solar system chaos.

Cosmic Origins Spectrograph: On-Orbit Performance of Target Acquisitions

NASA Astrophysics Data System (ADS)

Penton, Steven V.

2010-07-01

COS is a slit-less spectrograph with a very small aperture (R=1.2500). To achieve the desired wavelength accuracies, HST+COS must center the target to within 0.100 of the center of the aperture for the FUV channel, and 0.0400 for NUV. During SMOV and early Cycle 17 we fine-tuned the COS target acquisition (TA) procedures to exceed this accuracy for all three COS TA modes; NUV imaging, NUV spectroscopic, and FUV spectroscopic. In Cycle 17, we also adjusted the COSto- FGS offsets in the SIAF file. This allows us to recommend skipping the time consuming ACQ/SEARCH in cases where the target coordinates are well known. Here we will compare the on-orbit performance of all COS TA modes in terms of centering accuracy, efficiency, and required signal-to-noise (S/N).

Movements of the First Satellite-Tagged Cuvier’s and Blainville’s Beaked Whales in Hawaii

DTIC Science & Technology

2008-10-06

satellite tagging 6 Data acquisition and processing PTT transmissions are received by a series of NOAA Polar Orbiting Environmental Satellites... polar orbiting path of the satellites means that there are fewer overpasses as you get closer to the equator. In Hawai‘i in 2008 for example, the...between consecutive locations, and rate and bearings among consecutive movement vectors). The Douglas filter incorporates several user-defined variables

Infrared radiometer for the Pioneer Venus orbiter. I - Instrument description

NASA Technical Reports Server (NTRS)

Taylor, F. W.; Vescelus, F. E.; Locke, J. R.; Beer, R.; Foster, G. T.; Forney, P. B.; Houghton, J. T.; Delderfield, J.; Schofield, J. T.

1979-01-01

A ten-channel IR radiometer for the Pioneer Venus orbiter is described. The experimental techniques used and the design of the instrumentation by which they were implemented are considered. Emphasis is placed on temperature sounding, limb sounding, limb darkening, zenith scanning, cloud top temperature, spectral albedo and water vapor measurements. Instrumentation description is also given including optics, detectors, and electronics. Attention is given to data acquisition and handling, calibration, and in-flight performance.

Skylon: An Example of Commercial Launcher System Development

NASA Astrophysics Data System (ADS)

Hempsell, M.; Bond, A.

SKYLON is a reusable single stage to orbit spaceplane that can take off from a runway, reach a 300 km altitude low earth orbit with a payload of 15 tonnes and then return to earth for a runway landing. The feature that enables this is the Synergistic AirBreathing Rocket Engine (SABRE) which has both air breathing and pure rocket modes. The project has been conceived as a commercial venture with the objective that the price charged for the launch, covers all operational and acquisition cost with profit. That means access to space becomes a pure economic activity without the need for public subsidy of the development or day to day running costs of the launch activity. A key way to achieve this objective is the separation of the supplier of the SKYLON system and the operator, following the model in the air transport industry where airliner manufacturers build aircraft that are then sold to many different competing airlines. This approach allows commercial development operations without any assumptions about growth in the market for space launches.

Update on imaging techniques in oculoplastics

PubMed Central

Cetinkaya, Altug

2012-01-01

Imaging is a beneficial aid to the oculoplastic surgeon especially in orbital and lacrimal disorders when the pathology is not visible from outside. It is a powerful tool that may be benefited in not only diagnosis but also management and follow-up. The most common imaging modalities required are CT and MRI, with CT being more frequently ordered by oculoplastic surgeons. Improvements in technology enabled the acquisition times to shorten incredibly. Radiologists can now obtain images with superb resolution, and isolate the site and tissue of interest from other structures with special techniques. Better contrast agents and 3D imaging capabilities make complicated cases easier to identify. Color Doppler imaging is becoming more popular both for research and clinical purposes. Magnetic resonance angiography (MRA) added so much to the vascular system imaging recently. Although angiography is still the gold standard, new software and techniques rendered MRA as valuable as angiography in most circumstances. Stereotactic navigation, although in use for a long time, recently became the focus of interest for the oculoplastic surgeon especially in orbital decompressions. Improvements in radiology and nuclear medicine techniques of lacrimal drainage system imaging provided more detailed analysis of the system. PMID:23961020

Libration Point Navigation Concepts Supporting Exploration Vision

NASA Technical Reports Server (NTRS)

Carpenter, J. Russell; Folta, David C.; Moreau, Michael C.; Gramling, Cheryl J.

2004-01-01

Farquhar described several libration point navigation concepts that would appear to support NASA s current exploration vision. One concept is a Lunar Relay Satellite operating in the vicinity of Earth-Moon L2, providing Earth-to-lunar far-side and long- range surface-to-surface navigation and communications capability. Reference [ 1] lists several advantages of such a system in comparison to a lunar orbiting relay satellite constellation. Among these are one or two vs. many satellites for coverage, simplified acquisition and tracking due to very low relative motion, much longer contact times, and simpler antenna pointing. An obvious additional advantage of such a system is that uninterrupted links to Earth avoid performing critical maneuvers "in the blind." Another concept described is the use of Earth-Moon L1 for lunar orbit rendezvous, rather than low lunar orbit as was done for Apollo. This rendezvous technique would avoid large plane change and high fuel cost associated with high latitude landing sites and long stay times. Earth-Moon L1 also offers unconstrained launch windows from the lunar surface. Farquhar claims this technique requires only slightly higher fuel cost than low lunar orbit rendezvous for short-stay equatorial landings. Farquhar also describes an Interplanetary Transportation System that would use libration points as terminals for an interplanetary shuttle. This approach would offer increased operational flexibility in terms of launch windows, rendezvous, aborts, etc. in comparison to elliptical orbit transfers. More recently, other works including Folta[3] and Howell[4] have shown that patching together unstable trajectories departing Earth-Moon libration points with stable trajectories approaching planetary libration points may also offer lower overall fuel costs than elliptical orbit transfers. Another concept Farquhar described was a Deep Space Relay at Earth-Moon IA and/or L5 that would serve as a high data rate optical navigation and communications relay satellite. The advantages in comparison to a geosynchronous relay are minimal Earth occultation, distance from large noise sources on Earth, easier pointing due to smaller relative velocity, and a large baseline for interferometry if both L4 and L5 are used.

In-Flight performance of MESSENGER's Mercury dual imaging system

USGS Publications Warehouse

Hawkins, S.E.; Murchie, S.L.; Becker, K.J.; Selby, C.M.; Turner, F.S.; Noble, M.W.; Chabot, N.L.; Choo, T.H.; Darlington, E.H.; Denevi, B.W.; Domingue, D.L.; Ernst, C.M.; Holsclaw, G.M.; Laslo, N.R.; Mcclintock, W.E.; Prockter, L.M.; Robinson, M.S.; Solomon, S.C.; Sterner, R.E.

2009-01-01

The Mercury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 and planned for insertion into orbit around Mercury in 2011, has already completed two flybys of the innermost planet. The Mercury Dual Imaging System (MDIS) acquired nearly 2500 images from the first two flybys and viewed portions of Mercury's surface not viewed by Mariner 10 in 1974-1975. Mercury's proximity to the Sun and its slow rotation present challenges to the thermal design for a camera on an orbital mission around Mercury. In addition, strict limitations on spacecraft pointing and the highly elliptical orbit create challenges in attaining coverage at desired geometries and relatively uniform spatial resolution. The instrument designed to meet these challenges consists of dual imagers, a monochrome narrow-angle camera (NAC) with a 1.5?? field of view (FOV) and a multispectral wide-angle camera (WAC) with a 10.5?? FOV, co-aligned on a pivoting platform. The focal-plane electronics of each camera are identical and use a 1024??1024 charge-coupled device detector. The cameras are passively cooled but use diode heat pipes and phase-change-material thermal reservoirs to maintain the thermal configuration during the hot portions of the orbit. Here we present an overview of the instrument design and how the design meets its technical challenges. We also review results from the first two flybys, discuss the quality of MDIS data from the initial periods of data acquisition and how that compares with requirements, and summarize how in-flight tests are being used to improve the quality of the instrument calibration. ?? 2009 SPIE.

Alumina Based 500 C Electronic Packaging Systems and Future Development

NASA Technical Reports Server (NTRS)

Chen, Liang-Yu

2012-01-01

NASA space and aeronautical missions for probing the inner solar planets as well as for in situ monitoring and control of next-generation aeronautical engines require high-temperature environment operable sensors and electronics. A 96% aluminum oxide and Au thick-film metallization based packaging system including chip-level packages, printed circuit board, and edge-connector is in development for high temperature SiC electronics. An electronic packaging system based on this material system was successfully tested and demonstrated with SiC electronics at 500 C for over 10,000 hours in laboratory conditions previously. In addition to the tests in laboratory environments, this packaging system has more recently been tested with a SiC junction field effect transistor (JFET) on low earth orbit through the NASA Materials on the International Space Station Experiment 7 (MISSE7). A SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE7 suite to International Space Station via a Shuttle mission and tested on the orbit for eighteen months. A summary of results of tests in both laboratory and space environments will be presented. The future development of alumina based high temperature packaging using co-fired material systems for improved performance at high temperature and more feasible mass production will also be discussed.

Micro–Single-Photon Emission Computed Tomography Image Acquisition and Quantification of Sodium-Iodide Symporter–Mediated Radionuclide Accumulation in Mouse Thyroid and Salivary Glands

PubMed Central

Brandt, Michael P.; Kloos, Richard T.; Shen, Daniel H.; Zhang, Xiaoli; Liu, Yu-Yu

2012-01-01

Background Micro–single-photon emission computed tomography (SPECT) provides a noninvasive way to evaluate the effects of genetic and/or pharmacological modulation on sodium-iodide symporter (NIS)–mediated radionuclide accumulation in mouse thyroid and salivary glands. However, parameters affecting image acquisition and analysis of mouse thyroids and salivary glands have not been thoroughly investigated. In this study, we investigated the effects of region-of-interest (ROI) selection, collimation, scan time, and imaging orbit on image acquisition and quantification of thyroidal and salivary radionuclide accumulation in mice. Methods The effects of data window minima and maxima on thyroidal and salivary ROI selection using a visual boundary method were examined in SPECT images acquired from mice injected with 123I NaI. The effects of collimation, scan time, and imaging orbit on counting linearity and signal intensity were investigated using phantoms filled with various activities of 123I NaI or Tc-99m pertechnetate. Spatial resolution of target organs in whole-animal images was compared between circular orbit with parallel-hole collimation and spiral orbit with five-pinhole collimation. Lastly, the inter-experimental variability of the same mouse scanned multiple times was compared with the intra-experimental variability among different mice scanned at the same time. Results Thyroid ROI was separated from salivary glands by empirically increasing the data window maxima. Counting linearity within the range of 0.5–14.2 μCi was validated by phantom imaging using single- or multiple-pinhole collimators with circular or spiral imaging orbit. Scanning time could be shortened to 15 minutes per mouse without compromising counting linearity despite proportionally decreased signal intensity. Whole-animal imaging using a spiral orbit with five-pinhole collimators achieved a high spatial resolution and counting linearity. Finally, the extent of inter-experimental variability of NIS-mediated radionuclide accumulation in the thyroid and salivary glands by SPECT imaging in the same mouse was less than the magnitude of variability among the littermates. Conclusions The impacts of multiple variables and experimental designs on micro-SPECT imaging and quantification of radionuclide accumulation in mouse thyroid and salivary glands can be minimized. This platform will serve as an invaluable tool to screen for pharmacologic reagents that differentially modulate thyroidal and salivary radioiodine accumulation in preclinical mouse models. PMID:22540327

Performance Analysis of Ranging Techniques for the KPLO Mission

NASA Astrophysics Data System (ADS)

Park, Sungjoon; Moon, Sangman

2018-03-01

In this study, the performance of ranging techniques for the Korea Pathfinder Lunar Orbiter (KPLO) space communication system is investigated. KPLO is the first lunar mission of Korea, and pseudo-noise (PN) ranging will be used to support the mission along with sequential ranging. We compared the performance of both ranging techniques using the criteria of accuracy, acquisition probability, and measurement time. First, we investigated the end-to-end accuracy error of a ranging technique incorporating all sources of errors such as from ground stations and the spacecraft communication system. This study demonstrates that increasing the clock frequency of the ranging system is not required when the dominant factor of accuracy error is independent of the thermal noise of the ranging technique being used in the system. Based on the understanding of ranging accuracy, the measurement time of PN and sequential ranging are further investigated and compared, while both techniques satisfied the accuracy and acquisition requirements. We demonstrated that PN ranging performed better than sequential ranging in the signal-to-noise ratio (SNR) regime where KPLO will be operating, and we found that the T2B (weighted-voting balanced Tausworthe, voting v = 2) code is the best choice among the PN codes available for the KPLO mission.

RHIC BPM SYSTEM MODIFICATIONS AND PERFORMANCE.

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

SATOGATA, T.; CALAGA, R.; CAMERON, P.

2005-05-16

The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region beam-based alignment efforts. We also summarize performancemore » of recently-added DSP profile scan capability, and improved million-turn TBT acquisition channels for 10 Hz triplet vibration, nonlinear dynamics, and echo studies.« less

Navigation system and method

NASA Technical Reports Server (NTRS)

Taylor, R. E.; Sennott, J. W. (Inventor)

1984-01-01

In a global positioning system (GPS), such as the NAVSTAR/GPS system, wherein the position coordinates of user terminals are obtained by processing multiple signals transmitted by a constellation of orbiting satellites, an acquisition-aiding signal generated by an earth-based control station is relayed to user terminals via a geostationary satellite to simplify user equipment. The aiding signal is FSK modulated on a reference channel slightly offset from the standard GPS channel. The aiding signal identifies satellites in view having best geometry and includes Doppler prediction data as well as GPS satellite coordinates and identification data associated with user terminals within an area being served by the control station and relay satellite. The aiding signal significantly reduces user equipment by simplifying spread spectrum signal demodulation and reducing data processing functions previously carried out at the user terminals.

A novel methodology for estimating upper limits of major cost drivers for profitable conceptual launch system architectures

NASA Astrophysics Data System (ADS)

Rhodes, Russel E.; Byrd, Raymond J.

1998-01-01

This paper presents a ``back of the envelope'' technique for fast, timely, on-the-spot, assessment of affordability (profitability) of commercial space transportation architectural concepts. The tool presented here is not intended to replace conventional, detailed costing methodology. The process described enables ``quick look'' estimations and assumptions to effectively determine whether an initial concept (with its attendant cost estimating line items) provides focus for major leapfrog improvement. The Cost Charts Users Guide provides a generic sample tutorial, building an approximate understanding of the basic launch system cost factors and their representative magnitudes. This process will enable the user to develop a net ``cost (and price) per payload-mass unit to orbit'' incorporating a variety of significant cost drivers, supplemental to basic vehicle cost estimates. If acquisition cost and recurring cost factors (as a function of cost per payload-mass unit to orbit) do not meet the predetermined system-profitability goal, the concept in question will be clearly seen as non-competitive. Multiple analytical approaches, and applications of a variety of interrelated assumptions, can be examined in a quick, (on-the-spot) cost approximation analysis as this tool has inherent flexibility. The technique will allow determination of concept conformance to system objectives.

Characterization and Design of Digital Pointing Subsystem for Optical Communication Demonstrator

NASA Technical Reports Server (NTRS)

Racho, C.; Portillo, A.

1998-01-01

The Optical Communications Demonstrator (OCD) is a laboratory-based lasercom demonstration terminal designed to validate several key technologies, including beacon acquisition, high bandwidth tracking, precision bearn pointing, and point-ahead compensation functions. It has been under active development over the past few years. The instrument uses a CCD array detector for both spatial acquisition and high-bandwidth tracking, and a fiber coupled laser transmitter. The array detector tracking concept provides wide field-of-view acquisition and permits effective platform jitter compensation and point-ahead control using only one steering mirror. This paper describes the detailed design and characterization of the digital control loop system which includes the Fast Steering Mirror (FSM), the CCD image tracker, and the associated electronics. The objective is to improve the overall system performance using laboratory measured data. The. design of the digital control loop is based on a linear time invariant open loop model. The closed loop performance is predicted using the theoretical model. With the digital filter programmed into the OCD control software, data is collected to verify the predictions. This paper presents the results of the, system modeling and performance analysis. It has been shown that measurement data closely matches theoretical predictions. An important part of the laser communication experiment is the ability of FSM to track the laser beacon within the. required tolerances. The pointing must be maintained to an accuracy that is much smaller than the transmit signal beamwidth. For an earth orbit distance, the system must be able to track the receiving station to within a few microradians. The failure. to do so will result in a severely degraded system performance.

Space Shuttle Orbiter logistics - Managing in a dynamic environment

NASA Technical Reports Server (NTRS)

Renfroe, Michael B.; Bradshaw, Kimberly

1990-01-01

The importance and methods of monitoring logistics vital signs, logistics data sources and acquisition, and converting data into useful management information are presented. With the launch and landing site for the Shuttle Orbiter project at the Kennedy Space Center now totally responsible for its own supportability posture, it is imperative that logistics resource requirements and management be continually monitored and reassessed. Detailed graphs and data concerning various aspects of logistics activities including objectives, inventory operating levels, customer environment, and data sources are provided. Finally, some lessons learned from the Shuttle Orbiter project and logistics options which should be considered by other space programs are discussed.

A comparison of the UHF Follow-On and MILSTAR satellite communication systems

NASA Astrophysics Data System (ADS)

Perkins, Clifton E., Jr.

1991-09-01

The author compares the UHF Follow-On and MILSTAR satellite communication systems. The comparison uses an analytical hierarchy process. Although the two systems have been tasked with different missions, a comparison of cost, capability, and orbit is conducted. UFO provides many of the same capabilities as MILSTAR, but on a smaller scale. Since UFO is also a new space system acquisition, it is used to compare dollars spent to field a viable communication system. A review of frequency bands, losses, and problems is conducted to establish the relationship. Cost data is provided to establish the major difference in the systems. While MILSTAR does possess more total capability than UFO, it is 10 times more costly. Additionally, UFO is a satellite that will evolve with new technology while MILSTAR is built to full capability immediately. In the author's opinion, the incremental performance of MILSTAR does not justify its incremental cost.

Earth Observatory Satellite system definition study. Report no. 3: Design/cost tradeoff studies. Appendix E: EOS program supporting system trade data. Part 2: System trade studies no. 9 - 19

NASA Technical Reports Server (NTRS)

1974-01-01

The relative merits of several international data acquisition (IDA) alternatives for the Earth Observatory Satellite (EOS) are established and rated on a cost effectiveness basis. The primary alternatives under consideration are: (1) direct transmission to foreign ground stations, (2) a wideband video tape recorder system for collection of foreign data and processing and distribution from the United States, and (3) a tracking and data relay satellite (TDRS) system for the relay of foreign data to the United States for processing and distribution. A requirements model is established for the analysis on the basis of the heaviest concentration of agricultural areas around the world. The model, the orbit path and the constraints of EOS and data volume summaries are presented. Alternative system descriptions and costs are given in addition to cost-performance summaries.

Understanding Skill in EVA Mass Handling. Volume 1; Theoretical and Operational Foundations

NASA Technical Reports Server (NTRS)

Riccio, Gary; McDonald, Vernon; Peters, Brian; Layne, Charles; Bloomberg, Jacob

1997-01-01

This report describes the theoretical and operational foundations for our analysis of skill in extravehicular mass handling. A review of our research on postural control, human-environment interactions, and exploratory behavior in skill acquisition is used to motivate our analysis. This scientific material is presented within the context of operationally valid issues concerning extravehicular mass handling. We describe the development of meaningful empirical measures that are relevant to a special class of nested control systems: manual interactions between an individual and the substantial environment. These measures are incorporated into a unique empirical protocol implemented on NASA's principal mass handling simulator, the precision air-bearing floor, in order to evaluate skill in extravehicular mass handling. We discuss the components of such skill with reference to the relationship between postural configuration and controllability of an orbital replacement unit, the relationship between orbital replacement unit control and postural stability, the relationship between antecedent and consequent movements of an orbital replacement unit, and the relationship between antecedent and consequent postural movements. Finally, we describe our expectations regarding the operational relevance of the empirical results as it pertains to extravehicular activity tools, training, monitoring, and planning.

Fluid management systems technology summaries

NASA Technical Reports Server (NTRS)

Stark, J. A.; Blatt, M. H.; Bennett, F. O., Jr.; Campbell, B. J.

1974-01-01

A summarization and categorization of the pertinent literature associated with fluid management systems technology having potential application to in-orbit fluid transfer and/or associated storage are presented. A literature search was conducted to obtain pertinent documents for review. Reports determined to be of primary significance were summarized in the following manner: (1) report identification, (2) objective(s) of the work, (3) description of pertinent work performed, (4) major results, and (5) comments of the reviewer. Pertinent figures are presented on a single facing page separate from the text. Specific areas covered are: fluid line dynamics and thermodynamics, low-g mass gauging, other instrumentation, stratification/pressurization, low-g vent systems, fluid mixing refrigeration and reliquefaction, and low-g interface control and liquid acquisition systems. Reports which were reviewed and not summarized, along with reasons for not summarizing, are also listed.

New progress of ranging technology at Wuhan Satellite Laser Ranging Station

NASA Technical Reports Server (NTRS)

Xia, Zhiz-Hong; Ye, Wen-Wei; Cai, Qing-Fu

1993-01-01

A satellite laser ranging system with an accuracy of the level of centimeter has been successfully developed at the Institute of Seismology, State Seismological Bureau with the cooperation of the Institute of Geodesy and Geophysics, Chinese Academy of Science. With significant improvements on the base of the second generation SLR system developed in 1985, ranging accuracy of the new system has been upgraded from 15 cm to 3-4 cm. Measuring range has also been expanded, so that the ETALON satellite with an orbit height of 20,000 km launched by the former U.S.S.R. can now be tracked. Compared with the 2nd generation SLR system, the newly developed system has the following improvements. A Q modulated laser is replaced by a mode-locked YAG laser. The new device has a pulse width of 150 ps and a repetition rate of 1-4 pps. A quick response photomultiplier has been adopted as the receiver for echo; for example, the adoption of the MCP tube has obviously reduced the jitter error of the transit time and has improved the ranging accuracy. The whole system is controlled by an IBM PC/XT Computer to guide automatic tracking and measurement. It can carry out these functions for satellite orbit calculation, real-time tracking and adjusting, data acquisition and the preprocessed of observing data, etc. The automatization level and reliability of the observation have obviously improved.

Efficient mission control for the 48-satellite Globalstar Constellation

NASA Technical Reports Server (NTRS)

Smith, Dan

1994-01-01

The Globalstar system is being developed by Globalstar, Limited Partnership and will utilize 48 satellites in low earth orbit (See Figure 1) to create a world-wide mobile communications system consistent with Vice President Gore's vision of a Global Information Infrastructure. As a large long term commercial system developed by a newly formed organization, Globalstar provides an excellent opportunity to explore innovative solutions for highly efficient satellite command and control. Design and operational concepts being developed are unencumbered by existing physical and organizational infrastructures. This program really is 'starting with a clean sheet of paper'. Globalstar operations challenges can appear enormous. Clearly, assigning even a single person around the clock to monitor and control each satellite is excessive for Globalstar (it would require a staff of 200! . Even with only a single contact per orbit per satellite, data acquisitions will start or stop every 45 seconds! Although essentially identical, over time the satellites will develop their own 'personalities'and will re quire different data calibrations and levels of support. This paper discusses the Globalstar system and challenges and presents engineering concepts, system design decisions, and operations concepts which address the combined needs and concerns of satellite, ground system, and operations teams. Lessons from past missions have been applied, organizational barriers broken, partnerships formed across the mission segments, and new operations concepts developed for satellite constellation management. Control center requirements were then developed from the operations concepts.

Safety Practices Followed in ISRO Launch Complex- An Overview

NASA Astrophysics Data System (ADS)

Krishnamurty, V.; Srivastava, V. K.; Ramesh, M.

2005-12-01

The spaceport of India, Satish Dhawan Space Centre (SDSC) SHAR of Indian Space Research Organisation (ISRO), is located at Sriharikota, a spindle shaped island on the east coast of southern India.SDSC SHAR has a unique combination of facilities, such as a solid propellant production plant, a rocket motor static test facility, launch complexes for different types of rockets, telemetry, telecommand, tracking, data acquisition and processing facilities and other support services.The Solid Propellant Space Booster Plant (SPROB) located at SDSC SHAR produces composite solid propellant for rocket motors of ISRO. The main ingredients of the propellant produced here are ammonium perchlorate (oxidizer), fine aluminium powder (fuel) and hydroxyl terminated polybutadiene (binder).SDSC SHAR has facilities for testing solid rocket motors, both at ambient conditions and at simulated high altitude conditions. Other test facilities for the environmental testing of rocket motors and their subsystems include Vibration, Shock, Constant Acceleration and Thermal / Humidity.SDSC SHAR has the necessary infrastructure for launching satellites into low earth orbit, polar orbit and geo-stationary transfer orbit. The launch complexes provide complete support for vehicle assembly, fuelling with both earth storable and cryogenic propellants, checkout and launch operations. Apart from these, it has facilities for launching sounding rockets for studying the Earth's upper atmosphere and for controlled reentry and recovery of ISRO's space capsule reentry missions.Safety plays a major role at SDSC SHAR right from the mission / facility design phase to post launch operations. This paper presents briefly the infrastructure available at SDSC SHAR of ISRO for launching sounding rockets, satellite launch vehicles, controlled reentry missions and the built in safety systems. The range safety methodology followed as a part of the real time mission monitoring is presented. The built in safety systems provided onboard the launch vehicle are automatic shut off the propulsion system based on real time mission performance and a passivation system incorporated in the orbit insertion stage are highlighted.

Network Adjustment of Orbit Errors in SAR Interferometry

NASA Astrophysics Data System (ADS)

Bahr, Hermann; Hanssen, Ramon

2010-03-01

Orbit errors can induce significant long wavelength error signals in synthetic aperture radar (SAR) interferograms and thus bias estimates of wide-scale deformation phenomena. The presented approach aims for correcting orbit errors in a preprocessing step to deformation analysis by modifying state vectors. Whereas absolute errors in the orbital trajectory are negligible, the influence of relative errors (baseline errors) is parametrised by their parallel and perpendicular component as a linear function of time. As the sensitivity of the interferometric phase is only significant with respect to the perpendicular base-line and the rate of change of the parallel baseline, the algorithm focuses on estimating updates to these two parameters. This is achieved by a least squares approach, where the unwrapped residual interferometric phase is observed and atmospheric contributions are considered to be stochastic with constant mean. To enhance reliability, baseline errors are adjusted in an overdetermined network of interferograms, yielding individual orbit corrections per acquisition.

Solar Thermal Upper Stage Cryogen System Engineering Checkout Test

NASA Technical Reports Server (NTRS)

Olsen, A. D; Cady, E. C.; Jenkins, D. S.

1999-01-01

The Solar Thermal Upper Stage technology (STUSTD) program is a solar thermal propulsion technology program cooperatively sponsored by a Boeing led team and by NASA MSFC. A key element of its technology program is development of a liquid hydrogen (LH2) storage and supply system which employs multi-layer insulation, liquid acquisition devices, active and passive thermodynamic vent systems, and variable 40W tank heaters to reliably provide near constant pressure H2 to a solar thermal engine in the low-gravity of space operation. The LH2 storage and supply system is designed to operate as a passive, pressure fed supply system at a constant pressure of about 45 psia. During operation of the solar thermal engine over a small portion of the orbit the LH2 storage and supply system propulsively vents through the enjoy at a controlled flowrate. During the long coast portion of the orbit, the LH2 tank is locked up (unvented). Thus, all of the vented H2 flow is used in the engine for thrust and none is wastefully vented overboard. The key to managing the tank pressure and therefore the H2 flow to the engine is to manage and balance the energy flow into the LH2 tank with the MLI and tank heaters with the energy flow out of the LH2 tank through the vented H2 flow. A moderate scale (71 cu ft) LH2 storage and supply system was installed and insulated at the NASA MSFC Test Area 300. The operation of the system is described in this paper. The test program for the LH2 system consisted of two parts: 1) a series of engineering tests to characterize the performance of the various components in the system: and 2) a 30-day simulation of a complete LEO and GEO transfer mission. This paper describes the results of the engineering tests, and correlates these results with analytical models used to design future advanced Solar Orbit Transfer Vehicles.

MERCATOR: Methods and Realization for Control of the Attitude and the Orbit of spacecraft

NASA Technical Reports Server (NTRS)

Tavernier, Gilles; Campan, Genevieve

1993-01-01

Since 1974, CNES has been involved in geostationary positioning. Among different entities participating in operations and their preparation, the Flight Dynamics Center (FDC) is in charge of performing the following tasks: orbit determination; attitude determination; computation, monitoring, and calibration of orbit maneuvers; computation, monitoring, and calibration of attitude maneuvers; and operational predictions. In order to fulfill this mission, the FDC receives telemetry from the satellite and localization measurements from ground stations (e.g., CNES, NASA, INTELSAT). These data are processed by space dynamics programs integrated in the MERCATOR system which is run on SUN workstations (UNIX O.S.). The main features of MERCATOR are redundancy, modularity, and flexibility: efficient, flexible, and user friendly man-machine interface; and four identical SUN stations redundantly linked in an Ethernet network. Each workstation can perform all the tasks from data acquisition to computation results dissemination through a video network. A team of four engineers can handle the space mechanics aspects of a complete geostationary positioning from the injection into a transfer orbit to the final maneuvers in the station-keeping window. MERCATOR has been or is to be used for operations related to more than ten geostationary positionings. Initially developed for geostationary satellites, MERCATOR's methodology was also used for satellite control centers and can be applied to a wide range of satellites and to future manned missions.

Mercury in Retrograde: Shaking Up the Study of Orbital Motion with Kinesthetic Learning

NASA Astrophysics Data System (ADS)

DeStefano, Paul; Allen, Thomas; Widenhorn, Ralf

2018-06-01

We are investigating the use of kinesthetic activities to teach the orbital motion of planets at the introductory astronomy level. In addition to breaking the monotony of traditional classroom settings, kinesthetic activities can allow novel connections to form between the student and the material, as established in a recent study. In our example active learning activity, two students walk along predetermined paths in the classroom, simulating the dynamics of any two real or fictional bodies in orbital motion about a common object. Each student carries a short-range, local positioning device that records its 2D position, continuously. The position data from both devices are collected on a single computer. After acquisition, the data can be used to highlight interesting features of orbital dynamics. For example, we demonstrate a particular transformation of the data that shows apparent retrograde motion arising directly from the relative motion of two bodies orbiting a common object. This activity provides students with the opportunity to observe interesting orbital dynamics on a human scale.

The magnetosphere, ionosphere, and atmosphere as a system - Dynamics Explorer 5 years later

NASA Technical Reports Server (NTRS)

Hoffman, R. A.

1988-01-01

The Dynamics Explorer (DE) program summarizes its accomplishments during the first 5 years since the launch of the two DE satellites. This introduction to six review articles provides background information and a brief history of the program, especially citing the contributions of many people to its development. The principal investigators who had primary responsibility to implement the program are listed, together with the instruments they provided. Orbital information and approaches and constraints to data acquisition are explained. The brief description of the ground data processing and analysis system provides information on access to data catalogs and data sets. Each review article is then placed in the context of the categories of scientific objectives of the program.

First CaSSIS Colour Images of Mars

NASA Astrophysics Data System (ADS)

Alfred, M.; Pommerol, A.; Thomas, N.; Cremonese, G.

2017-12-01

The Colour and Stereo Surface Imaging System (CaSSIS) on board ESA's Exomars Trace Gas Orbiter has acquired its first images of the surface of Mars on the 22nd and 26th of November, 2016. This commissioning campaign on the initial capture orbit was highly successful, allowing us to test the instrument, establish its performance and collect detailed images from the surface. Many of them have been publicly released within days following acquisition. These images and other commissioning data have demonstrated that the capabilities of the instrument are fully in-line with expectation. Although a colour image of Phobos produced from observations acquired on the 26th of November was rapidly released, the calibration and production of colour images from the surface of Mars proved to be more challenging. Having fixed technical issues, acquired and processed necessary in-flight calibration data, we have recently recalibrated the whole dataset, improving significantly the quality of the data and allowing us, for the first time, to produce high-quality colour images from the surface of Mars with CaSSIS data. The absolute calibration of the instrument is currently verified using stellar observations but the values of reflectivity obtained in each of the four colour channels for the surfaces of Mars and Phobos already show good consistency with other orbital data. The timing of CaSSIS acquisitions is very accurate and results in good colour matching, as already verified on-ground during the calibration campaign. The first few images acquired on the 22nd of November, shortly after TGO crossed the morning terminator, show unique views of the dusty terrains of the Tharsis region with solar incidence angle ranging between 60° and 80°. Comparison with images of the same areas acquired at later local times by other orbiters shows intriguing differences, related in particular to the brightness and colour of the floor of dust-filled craters that look bluer in the morning than in the afternoon. These observations and possible explanations of these changes in terms of diurnal volatile cycles will be presented and discussed, providing a glimpse into the future scientific activities permitted by CaSSIS once the nominal science phase begins in 2018.

Downlink Acquisition and Tracking Procedures for the ASCAMP Satellite Communications Terminal

DTIC Science & Technology

1993-09-14

ACQUISITION AND TRACKING PROCEDURES FOR THE ASCAMP SATELLITE COMMUNICATIONS TERMINAL R.J. FIGUCIA Group 66 DM QUAIrTY INPECTED S Accesion For NTIS CRAMI...accuracy of 50 ns for clock drifts up to 100 ns/s. 1 ne spatial tracking procedure sustains a 0.250 accuraci for a typical geosynchronous orbit and is...Fishman, Private communication (15 June 1990). 2. G. Gorski-Popiel, " Architecture of ASCAMP digital hardware," 1991 IEEE MiW. Commun. Conf. Rec., 1110-1116

Geodetic imaging of tectonic deformation with InSAR

NASA Astrophysics Data System (ADS)

Fattahi, Heresh

Precise measurements of ground deformation across the plate boundaries are crucial observations to evaluate the location of strain localization and to understand the pattern of strain accumulation at depth. Such information can be used to evaluate the possible location and magnitude of future earthquakes. Interferometric Synthetic Aperture Radar (InSAR) potentially can deliver small-scale (few mm/yr) ground displacement over long distances (hundreds of kilometers) across the plate boundaries and over continents. However, Given the ground displacement as our signal of interest, the InSAR observations of ground deformation are usually affected by several sources of systematic and random noises. In this dissertation I identify several sources of systematic and random noise, develop new methods to model and mitigate the systematic noise and to evaluate the uncertainty of the ground displacement measured with InSAR. I use the developed approach to characterize the tectonic deformation and evaluate the rate of strain accumulation along the Chaman fault system, the western boundary of the India with Eurasia tectonic plates. I evaluate the bias due to the topographic residuals in the InSAR range-change time-series and develope a new method to estimate the topographic residuals and mitigate the effect from the InSAR range-change time-series (Chapter 2). I develop a new method to evaluate the uncertainty of the InSAR velocity field due to the uncertainty of the satellite orbits (Chapter 3) and a new algorithm to automatically detect and correct the phase unwrapping errors in a dense network of interferograms (Chapter 4). I develop a new approach to evaluate the impact of systematic and stochastic components of the tropospheric delay on the InSAR displacement time-series and its uncertainty (Chapter 5). Using the new InSAR time-series approach developed in the previous chapters, I study the tectonic deformation across the western boundary of the India plate with Eurasia and evaluated the rate of strain accumulation along the Chaman fault system (Chapter 5). I also evaluate the co-seismic and post-seismic displacement of a moderate M5.5 earthquake on the Ghazaband fault (Chapter 6). The developed methods to mitigate the systematic noise from InSAR time-series, significantly improve the accuracy of the InSAR displacement time-series and velocity. The approaches to evaluate the effect of the stochastic components of noise in InSAR displacement time-series enable us to obtain the variance-covariance matrix of the InSAR displacement time-series and to express their uncertainties. The effect of the topographic residuals in the InSAR range-change time-series is proportional to the perpendicular baseline history of the set of SAR acquisitions. The proposed method for topographic residual correction, efficiently corrects the displacement time-series. Evaluation of the uncertainty of velocity due to the orbital errors shows that for modern SAR satellites with precise orbits such as TerraSAR-X and Sentinel-1, the uncertainty of 0.2 mm/yr per 100 km and for older satellites with less accurate orbits such as ERS and Envisat, the uncertainty of 1.5 and 0.5mm/yr per 100 km, respectively are achievable. However, the uncertainty due to the orbital errors depends on the orbital uncertainties, the number and time span of SAR acquisitions. Contribution of the tropospheric delay to the InSAR range-change time-series can be subdivided to systematic (seasonal delay) and stochastic components. The systematic component biases the displacement times-series and velocity field as a function of the acquisition time and the non-seasonal component significantly contributes to the InSAR uncertainty. Both components are spatially correlated and therefore the covariance of noise between pixels should be considered for evaluating the uncertainty due to the random tropospheric delay. The relative velocity uncertainty due to the random tropospheric delay depends on the scatter of the random tropospheric delay, and is inversely proportional to the number of acquisitions, and the total time span covered by the SAR acquisitions. InSAR observations across the Chaman fault system shows that relative motion between India and Eurasia in the western boundary is distributed among different faults. The InSAR velocity field indicates strain localization on the Chaman fault and Ghazaband fault with slip rates of ~8 and ~16 mm/yr, respectively. High rate of strain accumulation on the Ghazaband fault and lack of evidence for rupturing the fault during the 1935 Quetta earthquake indicates that enough strain has been accumulated for large (M>7) earthquake, which threatens Balochistan and the City of Quetta. Chaman fault from latitudes ~29.5 N to ~32.5 N is creeping with a maximum surface creep rate of 8 mm/yr, which indicates that Chaman fault is only partially locked and therefore moderate earthquakes (M<7) similar to what has been recorded in last 100 years are expected.

Solid state laser communications in space (SOLACOS) high data rate satellite communication system verification program

NASA Astrophysics Data System (ADS)

Pribil, Klaus; Flemmig, Joerg

1994-09-01

This paper gives an overview on the current development status of the SOLACOS program and presents the highlights of the program. SOLACOS (Solid State Laser Communications in Space) is the national German program to develop a high performance laser communication system for high data rate transmission between LEO and GEO satellites (Inter Orbit Link, IOL). Two experimental demonstrator terminals are designed and developed in the SOLACOS program. The main development objectives are the Pointing Acquisition and Tracking subsystem (PAT) and the high data rate communication system. All key subsystems and components are straightway developed to be upgraded in follow- on projects to full space qualification. The main design objective for the system is a high degree of modularity which allows to easily upgrade the system with new upcoming technologies. Therefore, all main subsystems are interconnected via fibers to ease replacement of subsystems. The system implements an asymmetric data link with a 650 MBit/s return channel and a 10 MBit/s forward channel. The 650 MBit/s channel is based on a diode pumped Nd:YAG, Integrated Optics Modulator and uses the syncbit transmission scheme. In the syncbit system synchronization information which is necessary to maintain phase lock of the local oscillator of the coherent receiver is transmitted time multiplexed into the data stream. The PAT system comprises two beam detection sensors and three beam steering elements. For initial acquisition and tracking of the remote satellite a high speed CCD camera with an integrated image processing unit, the Acquisition and Tracking Sensor (ATS) is used. In the tacking mode the beam position is sensed via the Fibernutator sensor which is also used to couple the incoming signal into the receiver fiber. Incoming and outgoing beams are routed through the telescopes which are positioned with a 2 axis gimbal mechanism and a high speed beam steering mirror. The PAT system is controlled by a digital signal processor. For beam control advanced PAT algorithms are under development.

Development and application of a model for the analysis of trades between space launch system operations and acquisition costs

NASA Astrophysics Data System (ADS)

Nix, Michael B.

2005-12-01

Early design decisions in the development of space launch systems determine the costs to acquire and operate launch systems. Some sources indicate that as much as 90% of life cycle costs are fixed by the end of the critical design review phase. System characteristics determined by these early decisions are major factors in the acquisition cost of flight hardware elements and facilities and influence operations costs through the amount of maintenance and support labor required to sustain system function. Operations costs are also dependent on post-development management decisions regarding how much labor will be deployed to meet requirements of market demand and ownership profit. The ability to perform early trade-offs between these costs is vital to the development of systems that have the necessary capacity to provide service and are profitable to operate. An Excel-based prototype model was developed for making early analyses of trade-offs between the costs to operate a space launch system and to acquire the necessary assets to meet a given set of operational requirements. The model, integrating input from existing models and adding missing capability, allows the user to make such trade-offs across a range of operations concepts (required flight rates, staffing levels, shifts per workday, workdays per week and per year, unreliability, wearout and depot maintenance) and the number, type and capability of assets (flight hardware elements, processing and supporting facilities and infrastructure). The costs and capabilities of hypothetical launch systems can be modeled as a function of interrelated turnaround times and labor resource levels, and asset loss and retirement. The number of flight components and facilities required can be calculated and the operations and acquisition costs compared for a specified scenario. Findings, based on the analysis of a hypothetical two stage to orbit, reusable, unmanned launch system, indicate that the model is suitable for the trade-off analyses desired. The minimum turnaround time/maximum labor allocation for specific hardware configurations and characteristics and corresponding asset requirements can be estimated. Either turnaround time or resources can be varied and the resulting operations and acquisition costs can be compared. Asset reliability, wearout and depot maintenance intervals and durations can be varied as well to analyze the effects on costs. Likewise, the effects on operations and acquisitions costs of the introduction of alternative technologies that affect reliability, maintainability and supportability in various hardware configurations can be evaluated.

GPS/REFSAT definition study report for low-cost terminals

NASA Technical Reports Server (NTRS)

1980-01-01

A relay transponder, located either on a satellite in geostationary orbit or on a local tower to relay acquisition-aiding data, ephemerides, etc, from a ground-based remote control station to a GPS civil user terminal located on a ship or land-transportation vehicle is described. Termed REFSAT (Reference Satellite), this concept reduces the circuit complexity and cost of user terminals. The various systems needed to implement the REFSAT concept for low-cost, GPS civil terminals are defined. The GPS/REFSAT system compatible with the NAVSTAR GPS system consists of a geostationary relay satellite, civil user terminals, and the central facility which performs operations common to all users for relay via the space segment. A GPS/REFSAT system utilizing a local tower for the relay transponder is described, results of a study of civil user requirements are presented, and specifications for the GPS/REFSAT system and its individual segments are included.

Evolved Expendable Launch Vehicle: The Air Force Needs to Adopt an Incremental Approach to Future Acquisition Planning to Enable Incorporation of Lessons Learned

DTIC Science & Technology

2015-08-01

expressed interest in competing for national security launches, including ULA, Space Exploration Technologies, Inc. ( SpaceX ), and Orbital Sciences...launch offices, and launch service providers including ULA, SpaceX , and Orbital Sciences Corporation. We also reviewed past GAO reports on EELV...launch until 2019 at the earliest, and will still have to become certified. SpaceX earned certification for its Falcon 9 launch vehicle in May 2015, but

The NASA Meter Class Autonomous Telescope: Ascension Island

NASA Technical Reports Server (NTRS)

Lederer, S. M.; Stansbery, E. G.; Cowardin, H. M.; Hickson, P.; Pace, L. F.; Abercromby, K. J.; Kervin, P. W.

2013-01-01

The Meter Class Autonomous Telescope (MCAT) is the newest optical sensor dedicated to NASA's mission to characterize the space debris environment. It is the successor to a series of optical telescopes developed and operated by the JSC Orbital Debris Program Office (ODPO) to monitor and assess the debris environment in (1) Low Earth Orbit (LEO), (2) Medium Earth Orbit (MEO), and (3) Geosynchronous Orbit (GEO), with emphasis on LEO and GEO altitudes. A joint NASA - Air Force Research Labs project, MCAT is a 1.3m optical telescope dedicated to debris research. Its optical path and sensor yield a large survey fence at the cutting edge of current detector performance. It has four primary operational observing modes, two of which were not computationally feasible a decade ago. Operations are supported by a sophisticated software suite that monitors clouds and weather conditions, and controls everything from data collection to dome rotation to processing tens of gigabytes of image data nightly. With fainter detection limits, precision detection, acquisition and tracking of targets, multi-color photometry, precision astrometry, automated re-acquisition capability, and the ability to process all data at the acquisition rate, MCAT is capable of producing and processing a volume and quality of data far in excess of any current (or prior) ODPO operations. This means higher fidelity population inputs and eliminating the multi-year backlog from acquisition-to-product typical of optical campaigns. All of this is possible given a suitable observing location. Ascension Island offers numerous advantages. As a British overseas territory with a US Air Force base presence, the necessary infrastructure and support already exists. It is located mid-way between Brazil and Africa at 7.93S latitude and 14.37 W longitude. With the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) asset in Moron, Spain shutting down, this presents access to the sky from a unique latitude/longitude for an optical telescope. Constant trade winds from the SSE, originating from Africa, give promise to a steady laminar airflow over an island, a trait sought after to create stable atmospheric and good astronomical 'seeing' conditions with very low annual rainfall values. This combination of attributes created the necessary compelling argument to redirect MCAT to its final destination: Ascension Island.

Doppler Lidar for Wind Measurements on Venus

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Emmitt, George D.; Yu, Jirong; Kavaya, Michael J.

2010-01-01

NASA Langley Research Center has a long history of developing 2-micron laser transmitter for wind sensing. With support from NASA Laser Risk Reduction Program (LRRP) and Instrument Incubator Program (IIP), NASA Langley Research Center has developed a state-of-the-art compact lidar transceiver for a pulsed coherent Doppler lidar system for wind measurement. The transmitter portion of the transceiver employs the high-pulse-energy, Ho:Tm:LuLiF, partially conductively cooled laser technology developed at NASA Langley. The transceiver is capable of 250 mJ pulses at 10 Hz. It is very similar to the technology envisioned for coherent Doppler lidar wind measurements from Earth and Mars orbit. The transceiver is coupled to the large optics and data acquisition system in the NASA Langley VALIDAR mobile trailer. The large optics consists of a 15-cm off-axis beam expanding telescope, and a full-hemispheric scanner. Vertical and horizontal vector winds are measured, as well as relative backscatter. The data acquisition system employs frequency domain velocity estimation and pulse accumulation. It permits real-time display of the processed winds and archival of all data. This lidar system was recently deployed at Howard University facility in Beltsville, Mary-land, along with other wind lidar systems. Coherent Doppler wind lidar ground-based wind measurements and comparisons with other sensors will be presented. A simulation and data product for wind measurement at Venus will be presented.

NASA Tech Briefs, June 2010

NASA Technical Reports Server (NTRS)

2010-01-01

Topics covered include: Situational Awareness from a Low-Cost Camera System; Data Acquisition System for Multi-Frequency Radar Flight Operations Preparation; Mercury Toolset for Spatiotemporal Metadata; Social Tagging of Mission Data; Integrating Radar Image Data with Google Maps; Demonstration of a Submillimeter-Wave HEMT Oscillator Module at 330 GHz; Flexible Peripheral Component Interconnect Input/Output Card; Interface Supports Lightweight Subsystem Routing for Flight Applications; MMIC Amplifiers and Wafer Probes for 350 to 500 GHz; Public Risk Assessment Program; Particle Swarm Optimization Toolbox; Telescience Support Center Data System Software; Update on PISCES; Ground and Space Radar Volume Matching and Comparison Software; Web-Based Interface for Command and Control of Network Sensors; Orbit Determination Toolbox; Distributed Observer Network; Computer-Automated Evolution of Spacecraft X-Band Antennas; Practical Loop-Shaping Design of Feedback Control Systems; Fully Printed High-Frequency Phased-Array Antenna on Flexible Substrate; Formula for the Removal and Remediation of Polychlorinated Biphenyls in Painted Structures; Integrated Solar Concentrator and Shielded Radiator; Water Membrane Evaporator; Modeling of Failure for Analysis of Triaxial Braided Carbon Fiber Composites; Catalyst for Carbon Monoxide Oxidation; Titanium Hydroxide - a Volatile Species at High Temperature; Selective Functionalization of Carbon Nanotubes: Part II; Steerable Hopping Six-Legged Robot; Launchable and Retrievable Tetherobot; Hybrid Heat Exchangers; Orbital Winch for High-Strength, Space-Survivable Tethers; Parameterized Linear Longitudinal Airship Model; and Physics of Life: A Model for Non-Newtonian Properties of Living Systems.

SCIAMACHY In-orbit Operations until 2013

NASA Astrophysics Data System (ADS)

Gottwald, Manfred; Krieg, Eckhart; Lichtenberg, Günter; Noël, Stefan; Bramstedt, Klaus; Bovensmann, Heinrich

In 2010 ENVISAT enters its next mission extension phase when a manoeuvre transfers the plat-form from its nominal into a modified orbit. This modified orbit is not only characterized by the lower altitude but also by slightly drifting parameters such as e.g. the inclination or the Mean Local Solar Time at ascending node crossing. Thus all SCIAMACHY measurements requiring an accurate pointing knowledge are affected. How the line-of-sight evolves along the orbit de-pends on orbit altitude and orbital period. Therefore adjustments to SCIAMACHY's on-board instrument configuration are necessary reflecting this orbit chance. Based on a detailed analysis simulating SCIAMACHY operations in the modified orbit until the end of 2013, the impacts on nadir, limb and solar and lunar occultation measurements when orbiting the Earth at a reduced altitude was studied. By modifying SCIAMACHY's configuration these impacts can be compensated for. Thus the current performance of instrument operations, including the pointing knowledge, can be maintained. It ensures acquisition of high quality measurement data for the entire duration of the mission. This presentation describes how the instrument will be configured for achieving successful operations until the end of 2013. In addition a brief outlook is given how the drifting modified orbit may impact an operations phase even beyond 2013 and potential corrective countermeasures.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1996-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). TMOD also performs work funded by other NASA program offices through and with the cooperation of OSC. The first of these is the Orbital Debris Radar Program funded by the Office of Space Systems Development. It exists at Goldstone only and makes use of the planetary radar capability when the antennas are configured as science instruments making direct observations of the planets, their satellites, and asteroids of our solar system. The Office of Space Sciences funds the data reduction and science analyses of data obtained by the Goldstone Solar System Radar. The antennas at all three complexes are also configured for radio astronomy research and, as such, conduct experiments funded by the National Science Foundation in the U.S. and other agencies at the overseas complexes. These experiments are either in microwave spectroscopy or very long baseline interferometry. Finally, tasks funded under the JPL Director's Discretionary Fund and the Caltech President's Fund that involve TMOD are included. This and each succeeding issue of 'The Telecommunications and Data Acquisition Progress Report' will present material in some, but not necessarily all, of the aforementioned programs.

A Collection of Technical Papers

NASA Technical Reports Server (NTRS)

1995-01-01

Papers presented at the 6th Space Logistics Symposium covered such areas as: The International Space Station; The Hubble Space Telescope; Launch site computer simulation; Integrated logistics support; The Baikonur Cosmodrome; Probabalistic tools for high confidence repair; A simple space station rescue vehicle; Integrated Traffic Model for the International Space Station; Packaging the maintenance shop; Leading edge software support; Storage information management system; Consolidated maintenance inventory logistics planning; Operation concepts for a single stage to orbit vehicle; Mission architecture for human lunar exploration; Logistics of a lunar based solar power satellite scenario; Just in time in space; NASA acquisitions/logistics; Effective transition management; Shuttle logistics; and Revitalized space operations through total quality control management.

Preliminary flight test results from the advanced photovoltaic experiment

NASA Technical Reports Server (NTRS)

Brinker, David J.; Hickey, John R.

1990-01-01

The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight, limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination.

Preliminary results from the advanced photovoltaic experiment flight test

NASA Technical Reports Server (NTRS)

Brinker, David J.; Hart, Russell E., Jr.; Hickey, John R.

1990-01-01

The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight; limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination.

Development of data processing interpretation and analysis system for the remote sensing of trace atmospheric gas species

NASA Technical Reports Server (NTRS)

Casas, J. C.; Koziana, J. V.; Saylor, M. S.; Kindle, E. C.

1982-01-01

Problems associated with the development of the measurement of air pollution from satellites (MAPS) experiment program are addressed. The primary thrust of this research was the utilization of the MAPS experiment data in three application areas: low altitude aircraft flights (one to six km); mid altitude aircraft flights (eight to 12 km); and orbiting space platforms. Extensive research work in four major areas of data management was the framework for implementation of the MAPS experiment technique. These areas are: (1) data acquisition; (2) data processing, analysis and interpretation algorithms; (3) data display techniques; and (4) information production.

Characterization and Modeling of Materials Responsible for Planetary Crustal Magnetism

NASA Astrophysics Data System (ADS)

Strauss, Becky E.

Earth and Mercury are the only terrestrial planets in our solar system with present-day magnetic dipole fields generated by internal dynamo systems. In contrast, Mars and the Moon show evidence of past dipole fields in the form of crustal magnetic anomalies; to hold measurable magnetizations, crustal materials must have been exposed to an applied field. While the physical principles of magnetic recording are consistent between terrestrial planets, the particular conditions at each planet control the mechanisms by which crustal materials may be magnetized and limit the types of minerals that can retain magnetic remanence. As the suite of magnetic materials used for studies of remanence expands, the need for new methods follows. The integration of rock magnetic techniques with microscopy and chemical analyses enables the reconstruction of increasingly comprehensive narratives of remanence acquisition and alteration, even in materials that are challenging to study using traditional methods. This thesis demonstrates the utility of a materials approach to rock magnetism by applying techniques designed for terrestrial use in a planetary context. The first of two case studies focuses on calcite cave deposits as a means to demonstrate how novel techniques can be used to unlock previously inaccessible archives of magnetic information. Tandem magnetic and microscopic analyses improve our understanding of the rock magnetic properties of weakly magnetic stalagmites and their potential for paleomagnetic research, as well as illuminating the pathways of remanence acquisition in cave systems. The second case study addresses the magnetic anomalies recently detected by the MESSENGER orbiter at Mercury. These anomalies are consistent with remanence acquired in a dipole field. However, in the absence of physical samples, the types of magnetic minerals that could be holding remanence in Mercury's hot, highly reducing surface environment have not yet been determined. Orbital data is combined with fundamental rock magnetic principles to constrain the magnetic mineralogy of Mercury and to propose mechanisms of magnetization and remagnetization in the lithosphere.

Proximity operations concept design study, task 6

NASA Technical Reports Server (NTRS)

Williams, A. N.

1990-01-01

The feasibility of using optical technology to perform the mission of the proximity operations communications subsystem on Space Station Freedom was determined. Proximity operations mission requirements are determined and the relationship to the overall operational environment of the space station is defined. From this information, the design requirements of the communication subsystem are derived. Based on these requirements, a preliminary design is developed and the feasibility of implementation determined. To support the Orbital Maneuvering Vehicle and National Space Transportation System, the optical system development is straightforward. The requirements on extra-vehicular activity are such as to allow large fields of uncertainty, thus exacerbating the acquisition problem; however, an approach is given that could mitigate this problem. In general, it is found that such a system could indeed perform the proximity operations mission requirement, with some development required to support extra-vehicular activity.

Reconstruction techniques of holograms from Spacelab 3

NASA Technical Reports Server (NTRS)

Witherow, William K.

1987-01-01

Fluid transport effects in a ground-based laboratory are fairly well known. Bouyancy driven transport occurs when there is a local density change in the fluid. In a low-g environment these density changes become less important, and other transport mechanisms dominate. To better understand fluid flows in a low-g environment, a fluid experiment system (FES) was designed to fly aboard the Shuttle orbiter in Spacelab. The FES is a holographic system designed for acquisition of the maximum amount of data from an experiment. The FES flew for the first time in May 1985 on Spacelab 3 for investigation of triglycine sulfate (TGS) crystal growth in low-g. This paper describes the FES optical system. The reconstruction techniques of the holograms are examined in detail, and the multiuser and reflight capabilities are discussed. Proposed future experiments are mentioned.

A Study of Fluid Interface Configurations in Exploration Vehicle Propellant Tanks

NASA Technical Reports Server (NTRS)

Zimmerli, Gregory A.; Asipauskas, Marius; Chen, Yongkang; Weislogel, Mark M.

2010-01-01

The equilibrium shape and location of fluid interfaces in spacecraft propellant tanks while in low-gravity is of interest to system designers, but can be challenging to predict. The propellant position can affect many aspects of the spacecraft such as the spacecraft center of mass, response to thruster firing due to sloshing, liquid acquisition, propellant mass gauging, and thermal control systems. We use Surface Evolver, a fluid interface energy minimizing algorithm, to investigate theoretical equilibrium liquid-vapor interfaces for spacecraft propellant tanks similar to those that have been considered for NASA's new class of Exploration vehicles. The choice of tank design parameters we consider are derived from the NASA Exploration Systems Architecture Study report. The local acceleration vector employed in the computations is determined by estimating low-Earth orbit (LEO) atmospheric drag effects and centrifugal forces due to a fixed spacecraft orientation with respect to the Earth or Moon, and rotisserie-type spacecraft rotation. Propellant/vapor interface positions are computed for the Earth Departure Stage and Altair lunar lander descent and ascent stage tanks for propellant loads applicable to LEO and low-lunar orbit. In some of the cases investigated the vapor ullage bubble is located at the drain end of the tank, where propellant management device hardware is often located.

Thermal History of Near-Earth Asteroids: Implications for OSIRIS-REx Asteroid Sample Return

NASA Astrophysics Data System (ADS)

Springmann, Alessondra; Lauretta, Dante S.

2016-10-01

The connection between orbital and temperature history of small Solar System bodies has only been studied through modeling. The upcoming OSIRIS-REx asteroid sample return mission provides an opportunity to connect thermal modeling predictions with laboratory studies of meteorites to predict past heating and thus dynamical histories of bodies such as OSIRIS-REx mission target asteroid (101955) Bennu. Bennu is a desirable target for asteroid sample return due to its inferred primitive nature, likely 4.5 Gyr old, with chemistry and mineralogy established in the first 10 Myr of solar system history (Lauretta et al. 2015). Delbo & Michel (2011) studied connections between the temperature and orbital history of Bennu. Their results suggest that the surface of Bennu (assuming no regolith turnover) has a 50% probability of being heated to 500 K in the past. Further, the Delbo & Michel simulations show that the temperature within the asteroid below the top layer of regolith could remain at temperatures ~100 K below that of the surface. The Touch-And-Go Sample Acquisition Mechanism on OSIRIS-REx could access both the surface and near surface regolith, collecting primitive asteroid material for study in Earth-based laboratories in 2023. To quantify the effects of thermal metamorphism on the Bennu regolith, laboratory heating experiments on carbonaceous chondrite meteorites with compositions likely similar to that of Bennu were conducted from 300-1200 K. These experiments show mobilization and volatilization of a suite of labile elements (sulfur, mercury, arsenic, tellurium, selenium, antimony, and cadmium) at temperatures that could be reached by asteroids that cross Mercury's orbit. We are able to quantify element loss with temperature for several carbonaceous chondrites and use these results to constrain past orbital histories of Bennu. When OSIRIS-REx samples arrive for analysis we will be able to measure labile element loss in the material, determine maximum past temperature of the samples, and predict the past orbital and thermal history of Bennu.

Design and simulation of EVA tools for first servicing mission of HST

NASA Technical Reports Server (NTRS)

Naik, Dipak; Dehoff, P. H.

1994-01-01

The Hubble Space Telescope (HST) was launched into near-earth orbit by the Space Shuttle Discovery on April 24, 1990. The payload of two cameras, two spectrographs, and a high-speed photometer is supplemented by three fine-guidance sensors that can be used for astronomy as well as for star tracking. A widely reported spherical aberration in the primary mirror causes HST to produce images of much lower quality than intended. A Space Shuttle repair mission in January 1994 installed small corrective mirrors that restored the full intended optical capability of the HST. The First Servicing Mission (FSM) involved considerable Extra Vehicular Activity (EVA). Special EVA tools for the FSM were designed and developed for this specific purpose. In an earlier report, the details of the Data Acquisition System developed to test the performance of the various EVA tools in ambient as well as simulated space environment were presented. The general schematic of the test setup is reproduced in this report for continuity. Although the data acquisition system was used extensively to test a number of fasteners, only the results of one test each carried on various fasteners and the Power Ratchet Tool are included in this report.

Control of optical systems

NASA Technical Reports Server (NTRS)

Founds, D.

1988-01-01

Some of the current and planned activities at the Air Force Systems Command in structures and controls for optical-type systems are summarized. Many of the activities are contracted to industry; one task is an in-house program which includes a hardware test program. The objective of the in-house program, referred to as the Aluminum Beam Expander Structure (ABES), is to address issues involved in on-orbit system identification. The structure, which appears similar to the LDR backup structure, is about 35 feet tall. The activity to date has been limited to acquisition of about 250 hours of test data. About 30 hours of data per excitation force is gathered in order to obtain sufficient data for a good statistical estimate of the structural parameters. The development of an Integrated Structural Modeling (ISM) computer program is being done by Boeing Aerospace Company. The objective of the contracted effort is to develop a combined optics, structures, thermal, controls, and multibody dynamics simulation code.

Perspectives in remote sensing in Brazil. An approach of the remote sensing applications to Earth resources surveys

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Novaes, R. A.

1982-01-01

Since the systematic use of earth surface data collection by orbital sensor systems started in 1972 with the launching of the North American LANDSAT satellite, a great effort has been made to assimilate, develop and transfer remote sensing technology (data acquisition and analysis) in its many applications in Brazil. The availability of sensor systems and existing data is considered approached, as well as those which will soon be available to the Brazilian researchers. The new systems of the LANDSAT-4, of the Columbia space shuttle and of the French satellites of the SPOT series are discussed. Some characteristics of the sensor system for the first Brazilian remote sensing satellite, to be launched by the end of the decade, are presented. Some LANDSAT-4 and SPOT simulation products are shown, emphasizing how the data obtained by these new satellites can be applied.

Performance Evaluation of Orbit Determination System during Initial Phase of INSAT-3 Mission

NASA Astrophysics Data System (ADS)

Subramanian, B.; Vighnesam, N. V.

INSAT-3C is the second in the third generation of ISRO's INSAT series of satellites that was launched by ARIANE-SPACE on 23 January 2002 at 23 h 46 m 57 s (lift off time in U.T). The ARIANE-4 Flight Nr.147 took off from Kourou in French Guyana and injected the 2750-kg communications satellite in a geostationary transfer orbit of (571 X 35935) km with an inclination of 4.007 deg at 00 h 07 m 48 s U.T on 24 January 2002 (1252 s after lift off). The satellite was successfully guided into its intended geostationary position of 74 deg E longitude by 09 February 2002 after a series of four firings of its Liquid Apogee Motor (LAM) and four station acquisition (STAQ) maneuvers. Six distinct phases of the mission were categorized based on the orbit characteristics of the INSAT- 3C mission, namely, the pre-launch phase, the launch phase, transfer orbit phase, intermediate orbit phase, drift orbit phase and synchronous orbit phase. The orbit with a perigee height of 571 km at injection of the satellite, was gradually raised to higher orbits with perigee height increasing to 9346 km after Apogee Motor Firing #1 (AMF #1), 18335 km after AMF #2, 32448 km after AMF #3 and 35493 km after AMF #4. The North and South solar panels and the reflectors were deployed at this stage of the mission and the attitude of the satellite with respect to the three axes was stabilized. The Orbit Determination System (ODS) that was used in the initial phase of the mission played a crucial role in realizing the objectives of the mission. This system which consisted of Tracking Data Pre-Processing (TDPP) software, Ephemeris Generation (EPHGEN) software and the Orbit Determination (OD) software, performed rigorously and its results were used for planning the AMF and STAQ strategies with a greater degree of accuracy. This paper reports the results of evaluation of the performance of the apogee-motor firings employed to place the satellite in its intended position where it is collocated with INSAT-1D satellite. The orbit of the satellite had to be determined continuously at each stage of the initial phase of the mission at a brisk pace and this study shows that the ODS provided consistent results to meet the stringent requirements of the mission operations. At each stage of the mission the orbit was determined using tracking data obtained over varying periods of time. The orbit solutions obtained from short arc OD's are compared with that obtained using the longest arc OD of each stage of the initial phase of the mission. The results of this study have been tabled in this paper. The performance of the ODS in calibrating the ARIANE-4 launch vehicle has been analyzed. A comparison of the orbit elements obtained from the mission operational ODS with the injection parameters provided by CNES, Centre Spatial Guyanais has been made in this paper which shows that the satellite was injected well within the 1 dispersions quoted by ARIANE-SPACE. A comparison has also been shown between the determined transfer orbit elements with pre-launch nominal orbit elements. For the initial phase of this mission ranging support was provided by Hassan earth station at India and INMARSAT network of stations at LakeCowichan (Canada), Fucino (Italy) and Beijing (China). The performance of the tracking systems employed by these stations has been studied. The quality of tracking data obtained from these stations has also been assessed.

Arm-Locking with the GRACE Follow-On Laser Ranging Instrument

NASA Technical Reports Server (NTRS)

Thorpe, James Ira; Mckenzie, Kirk

2016-01-01

Arm-locking is a technique for stabilizing the frequency of a laser in an inter-spacecraft interferometer by using the spacecraft separation as the frequency reference. A candidate technique for future space-based gravitational wave detectors such as the Laser Interferometer Space Antenna (LISA), arm-locking has been extensive studied in this context through analytic models, time-domain simulations, and hardware-in-the-loop laboratory demonstrations. In this paper we show the Laser Ranging Instrument flying aboard the upcoming Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission provides an appropriate platform for an on-orbit demonstration of the arm-locking technique. We describe an arm-locking controller design for the GRACE-FO system and a series of time-domain simulations that demonstrate its feasibility. We conclude that it is possible to achieve laser frequency noise suppression of roughly two orders of magnitude around a Fourier frequency of 1Hz with conservative margins on the system's stability. We further demonstrate that `pulling' of the master laser frequency due to fluctuating Doppler shifts and lock acquisition transients is less than 100MHz over several GRACE-FO orbits. These findings motivate further study of the implementation of such a demonstration.

Arm locking with the GRACE follow-on laser ranging interferometer

NASA Astrophysics Data System (ADS)

Thorpe, James Ira; McKenzie, Kirk

2016-02-01

Arm locking is a technique for stabilizing the frequency of a laser in an interspacecraft interferometer by using the spacecraft separation as the frequency reference. A candidate technique for future space-based gravitational wave detectors such as the Laser Interferometer Space Antenna, arm locking has been extensive studied in this context through analytic models, time-domain simulations, and hardware-in-the-loop laboratory demonstrations. In this paper we show the laser ranging interferometer instrument flying aboard the upcoming Gravity Recovery and Climate Experiment follow-on (GRACE-FO) mission provides an appropriate platform for an on-orbit demonstration of the arm-locking technique. We describe an arm-locking controller design for the GRACE-FO system and a series of time-domain simulations that demonstrate its feasibility. We conclude that it is possible to achieve laser frequency noise suppression of roughly 2 orders of magnitude around a Fourier frequency of 1 Hz with conservative margins on the system's stability. We further demonstrate that "pulling" of the master laser frequency due to fluctuating Doppler shifts and lock acquisition transients is less than 100 MHz over several GRACE-FO orbits. These findings motivate further study of the implementation of such a demonstration.

Monitoring and telemedicine support in remote environments and in human space flight.

PubMed

Cermack, M

2006-07-01

The common features of remote environments are geographical separation, logistic problems with health care delivery and with patient retrieval, extreme natural conditions, artificial environment, or combination of all. The exposure can have adverse effects on patients' physiology, on care providers' performance and on hardware functionality. The time to definite treatment may vary between hours as in orbital space flight, days for remote exploratory camp, weeks for polar bases and months to years for interplanetary exploration. The generic system architecture, used in any telematic support, consists of data acquisition, data-processing and storage, telecommunications links, decision-making facilities and the means of command execution. At the present level of technology, a simple data transfer and two-way voice communication could be established from any place on the earth, but the current use of mobile communication technologies for telemedicine applications is still low, either for logistic, economic and political reasons, or because of limited knowledge about the available technology and procedures. Criteria for selection of portable telemedicine terminals in remote terrestrial places, characteristics of currently available mobile telecommunication systems, and the concept of integrated monitoring of physiological and environmental parameters are mentioned in the first section of this paper. The second part describes some aspects of emergency medical support in human orbital spaceflight, the limits of telemedicine support in near-Earth space environment and mentions some open issues related to long-term exploratory missions beyond the low Earth orbit.

Intercontinental Bistatic Radar Test Observation of Asteroid 1998 WT24

NASA Technical Reports Server (NTRS)

Righini, S.; Poppi, S.; Montebugnoli, S.; DiMartino, M.; Saba, L.; Delbo, M.; Ostro, S.; Monari, J.; Poloni, M.; Orlati, A.

2002-01-01

We describe the first intercontinental planetary radar test performed in Italy observing the near Earth asteroid (NEA) 33342 (1998 WT24) in December 2001 by means of the bistatic configurations Goldstone (California, USA)-Medicina (Italy) and Evpatoria (Ukraine)-Medicina. The experiment goal was to characterize the system for realtime radar follow-up observations of NEAs and artificial orbiting debris, in the framework of a feasibility study which aims at using the Sardinia Radio Telescope, at present under construction, also as a planetary radar facility. We report the preliminary results of the radar observations carried out by the IRA-CNR (Instituto di Radioastronomia - Consiglio Nazionale delle Ricerche) and the OATo (Osservatorio Astronomico di Torino) groups, aimed at exploring the scientific potentials of a new space radar program, using the existing facilities in Italy. The planetary radar technique is uniquely capable of investigating geometry and surface properties of various solar system objects, demonstrating advantages over the optical methods in its high spatial resolution and ability to obtain three-dimensional images. A single radar detection allows to obtain extremely accurate orbital elements, improving the instantaneous positional uncertainties by orders of magnitude with respect to an optically determined orbit. Radar is a powerful means to spatially resolve NEAs by measuring the distribution of the echo power in time delay (range) and Doppler frequency (line-of-sight velocity) with extreme precision in each coordinate, as it provides detailed information about the target physical properties like size, shape, rotation, near-surface bulk density and roughness and internal density distribution. The Medicina 32m antenna had been successfully used for the first time as the receiving part of a bistatic configuration during a test experiment (September 2001) held to check the capabilities of the entire data acquisition system. This test was possible thanks to the collaboration undertaken with the Evpatoria radar station, and consisted in the observation of the ETALON-1 low orbit satellite

Establishing a Near Term Lunar Farside Gravity Model via Inexpensive Add-on Navigation Payload

NASA Technical Reports Server (NTRS)

Folta, David; Mesarch, Michael; Miller, Ronald; Bell, David; Jedrey, Tom; Butman, Stanley; Asmar, Sami

2007-01-01

The Space Communications and Navigation, Constellation Integration Project (SCIP) is tasked with defining, developing, deploying and operating an evolving multi-decade communications and navigation (C/N) infrastructure including services and subsystems that will support both robotic and human exploration activities at the Moon. This paper discusses an early far side gravitational mapping service and related telecom subsystem that uses an existing spacecraft (WIND) and the Lunar Reconnaissance Orbiter (LRO) to collect data that would address several needs of the SCIP. An important aspect of such an endeavor is to vastly improve the current lunar gravity model while demonstrating the navigation and stationkeeping of a relay spacecraft. We describe a gravity data acquisition activity and the trajectory design of the relay orbit in an Earth-Moon L2 co-linear libration orbit. Several phases of the transfer from an Earth-Sun to the Earth-Moon region are discussed along with transfers within the Earth-Moon system. We describe a proposed, but not integrated, add-on to LRO scheduled to be launched in October of 2008. LRO provided a real host spacecraft against which we designed the science payload and mission activities. From a strategic standpoint, LRO was a very exciting first flight opportunity for gravity science data collection. Gravity Science data collection requires the use of one or more low altitude lunar polar orbiters. Variations in the lunar gravity field will cause measurable variations in the orbit of a low altitude lunar orbiter. The primary means to capture these induced motions is to monitor the Doppler shift of a radio signal to or from the low altitude spacecraft, given that the signal is referenced to a stable frequency reference. For the lunar far side, a secondary orbiting radio signal platform is required. We provide an in-depth look at link margins, trajectory design, and hardware implications. Our approach posed minimum risk to a host mission while maintaining a very low implementation and operations cost.

Landsat 8 on-orbit characterization and calibration system

USGS Publications Warehouse

Micijevic, Esad; Morfitt, Ron; Choate, Michael J.

2011-01-01

The Landsat Data Continuity Mission (LDCM) is planning to launch the Landsat 8 satellite in December 2012, which continues an uninterrupted record of consistently calibrated globally acquired multispectral images of the Earth started in 1972. The satellite will carry two imaging sensors: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). The OLI will provide visible, near-infrared and short-wave infrared data in nine spectral bands while the TIRS will acquire thermal infrared data in two bands. Both sensors have a pushbroom design and consequently, each has a large number of detectors to be characterized. Image and calibration data downlinked from the satellite will be processed by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using the Landsat 8 Image Assessment System (IAS), a component of the Ground System. In addition to extracting statistics from all Earth images acquired, the IAS will process and trend results from analysis of special calibration acquisitions, such as solar diffuser, lunar, shutter, night, lamp and blackbody data, and preselected calibration sites. The trended data will be systematically processed and analyzed, and calibration and characterization parameters will be updated using both automatic and customized manual tools. This paper describes the analysis tools and the system developed to monitor and characterize on-orbit performance and calibrate the Landsat 8 sensors and image data products.

The Ion Propulsion System for the Asteroid Redirect Robotic Mission

NASA Technical Reports Server (NTRS)

Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard; Sekerak, Michael

2016-01-01

The Asteroid Redirect Robotic Mission is a Solar Electric Propulsion Technology Demonstration Mission (ARRM) whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of NASA's future beyond-low-Earth-orbit, human-crewed exploration plans. This presentation presents the conceptual design of the ARRM ion propulsion system, the status of the NASA in-house thruster and power processing development activities, the status of the planned technology maturation for the mission through flight hardware delivery, and the status of the mission formulation and spacecraft acquisition.

An introduction to the global positioning system and some geological applications

NASA Technical Reports Server (NTRS)

Dixon, T. H.

1991-01-01

The fundamental principles of the global positioning system (GPS) are reviewed, with consideration given to geological and geophysical applications and related accuracy requirements. Recent improvements are emphasized which relate to areas such as equipment cost, limitations in the GPS satellite constellation, data analysis, uncertainties in satellite orbits and propagation delays, and problems in resolving carrier phase cycle ambiguities. Earthquake processes and near-fault crustal deformation monitoring have been facilitated by advances in GPS data acquisition and analysis. Horizontal positioning capability has been improved by new satellite constellation, better models, and global tracking networks. New classes of tectonic problems may now be studied through GPS, such as kinematic descriptions of crustal deformation and the measurement of relative plate motion at convergent boundaries. Continued improvements in the GPS are foreseen.

Forward Technology Solar Cell Experiment (FTSCE) for MISSE-5 Verified and Readied for Flight on STS-114

NASA Technical Reports Server (NTRS)

Jenkins, Phillip P.; Krasowski, Michael J.; Greer, Lawrence C.; Flatico, Joseph M.

2005-01-01

The Forward Technology Solar Cell Experiment (FTSCE) is a space solar cell experiment built as part of the Fifth Materials on the International Space Station Experiment (MISSE-5): Data Acquisition and Control Hardware and Software. It represents a collaborative effort between the NASA Glenn Research Center, the Naval Research Laboratory, and the U.S. Naval Academy. The purpose of this experiment is to place current and future solar cell technologies on orbit where they will be characterized and validated. This is in response to recent on-orbit and ground test results that raised concerns about the in-space survivability of new solar cell technologies and about current ground test methodology. The various components of the FTSCE are assembled into a passive experiment container--a 2- by 2- by 4-in. folding metal container that will be attached by an astronaut to the outer structure of the International Space Station. Data collected by the FTSCE will be relayed to the ground through a transmitter assembled by the U.S. Naval Academy. Data-acquisition electronics and software were designed to be tolerant of the thermal and radiation effects expected on orbit. The experiment has been verified and readied for flight on STS-114.

Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.

1985-01-01

The Cryogenic Fluid Management Facility is a reusable test bed which is designed to be carried within the Shuttle cargo bay to investigate the systems and technologies associated with the efficient management of cryogens in space. Cryogenic fluid management consists of the systems and technologies for: (1) liquid storage and supply, including capillary acquisition/expulsion systems which provide single-phase liquid to the user system, (2) both passive and active thermal control systems, and (3) fluid transfer/resupply systems, including transfer lines and receiver tanks. The facility contains a storage and supply tank, a transfer line and a receiver tank, configured to provide low-g verification of fluid and thermal models of cryogenic storage and transfer processes. The facility will provide design data and criteria for future subcritical cryogenic storage and transfer system applications, such as Space Station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, and ground-based and space-based orbit transfer vehicles (OTV).

Satellite services system program plan

NASA Technical Reports Server (NTRS)

Hoffman, Stephen J.

1985-01-01

The purpose is to determine the potential for servicing from the Space Shuttle Orbiter and to assess NASA's role as the catalyst in bringing about routine on-orbit servicing. Specifically this study seeks to determine what requirements, in terms of both funds and time, are needed to make the Shuttle Orbiter not only a transporter of spacecraft but a servicing vehicle for those spacecraft as well. The scope of this effort is to focus on the near term development of a generic servicing capability. To make this capability truly generic and attractive requires that the customer's point of veiw be taken and transformed into a widely usable set of hardware. And to maintain a near term advent of this capability requires that a minimal reliance be made on advanced technology. With this background and scope, this study will proceed through three general phases to arrive at the desired program costs and schedule. The first step will be to determine the servicing requirements of the user community. This will provide the basis for the second phase which is to develop hardware concepts to meet these needs. Finally, a cost estimate will be made for each of the new hardware concepts and a phased hardware development plan will be established for the acquisition of these items based on the inputs obtained from the user community.

Single-event and total-dose effects in geo-stationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite

NASA Astrophysics Data System (ADS)

Koshiishi, H.; Kimoto, Y.; Matsumoto, H.; Goka, T.

The Tsubasa satellite developed by the Japan Aerospace Exploration Agency was launched in Feb 2002 into Geo-stationary Transfer Orbit GTO Perigee 500km Apogee 36000km and had been operated well until Sep 2003 The objective of this satellite was to verify the function of commercial parts and new technologies of bus-system components in space Thus the on-board experiments were conducted in the more severe radiation environment of GTO rather than in Geo-stationary Earth Orbit GEO or Low Earth Orbit LEO The Space Environment Data Acquisition equipment SEDA on board the Tsubasa satellite had the Single-event Upset Monitor SUM and the DOSimeter DOS to evaluate influences on electronic devices caused by radiation environment that was also measured by the particle detectors of the SEDA the Standard DOse Monitor SDOM for measurements of light particles and the Heavy Ion Telescope HIT for measurements of heavy ions The SUM monitored single-event upsets and single-event latch-ups occurred in the test sample of two 64-Mbit DRAMs The DOS measured accumulated radiation dose at fifty-six locations in the body of the Tsubasa satellite Using the data obtained by these instruments single-event and total-dose effects in GTO during solar-activity maximum period especially their rapid changes due to solar flares and CMEs in the region from L 1 1 through L 11 is discussed in this paper

Autonomous Closed-Loop Tasking, Acquisition, Processing, and Evaluation for Situational Awareness Feedback

NASA Technical Reports Server (NTRS)

Frye, Stuart; Mandl, Dan; Cappelaere, Pat

2016-01-01

This presentation describes the closed loop satellite autonomy methods used to connect users and the assets on Earth Orbiter- 1 (EO-1) and similar satellites. The base layer is a distributed architecture based on Goddard Mission Services Evolution Concept (GMSEC) thus each asset still under independent control. Situational awareness is provided by a middleware layer through common Application Programmer Interface (API) to GMSEC components developed at GSFC. Users setup their own tasking requests, receive views into immediate past acquisitions in their area of interest, and into future feasibilities for acquisition across all assets. Automated notifications via pubsub feeds are returned to users containing published links to image footprints, algorithm results, and full data sets. Theme-based algorithms are available on-demand for processing.

Observation of ultrahigh-energy cosmic rays and neutrinos from lunar orbit: LORD space experiment

NASA Astrophysics Data System (ADS)

Ryabov, Vladimir; Chechin, Valery; Gusev, German

The problem of detecting highest-energy cosmic rays and neutrinos in the Universe is reviewed. Nowadays, there becomes clear that observation of these particles requires approaches based on novel principles. Projects based on orbital radio detectors for particles of energies above the CZK cut-off are discussed. We imply the registration of coherent Cherenkov radio emission produced by cascades of most energetic particles in radio-transparent lunar regolith. The Luna-Glob space mission proposed for launching in the near future involves the Lunar Orbital Radio Detector (LORD). The feasibility of LORD space instrument to detect radio signals from cascades initiated by ultrahigh-energy particles interacting with lunar regolith is examined. The comprehensive Monte Carlo calculations were carried out within the energy range of 10 (20) -10 (25) eV with the account for physical properties of the Moon such as its density, the lunar-regolith radiation length, the radio-wave absorption length, the refraction index, and the orbital altitude of a lunar satellite. We may expect that the LORD space experiment will surpass in its apertures and capabilities the majority of well-known current and proposed experiments dealing with the detection of both ultrahigh-energy cosmic rays and neutrinos. The design of the LORD space instrument and its scientific potentialities in registration of low-intense cosmic-ray particle fluxes above the GZK cut-off up to 10 (25) eV is discussed as well. The designed LORD module (including an antenna system, amplifiers, and a data acquisition system) now is under construction. The LORD space experiment will make it possible to obtain important information on the highest-energy particles in the Universe, to verify modern models for the origin and the propagation of ultrahigh-energy cosmic rays and neutrinos. Successful completion of the LORD experiment will permit to consider the next step of the program, namely, a multi-satellite lunar systems to increase the statistics and the accuracy of the experiment. Opportunities and prospects of a multi-satellite system for observation of ultrahigh-energy cosmic rays and neutrinos are also investigated. In addition, possibilities of future missions to Jovian satellites are analyzed, insofar as the largest ice planets of the Solar System (Ganymede and Europe) can be considered as convenient targets for registration of ultrahigh-energy particles by orbiting radio detectors. The expected results are compared to those for the lunar target. The conclusion is made that within the Solar System, there are no objects with better registration efficiency for ultrahigh-energy cosmic rays and neutrinos that can be utilized in space experiments of as an alternative to the future space mission Luna-Glob with the LORD orbital radio detector.

Business intelligence modeling in launch operations

NASA Astrophysics Data System (ADS)

Bardina, Jorge E.; Thirumalainambi, Rajkumar; Davis, Rodney D.

2005-05-01

The future of business intelligence in space exploration will focus on the intelligent system-of-systems real-time enterprise. In present business intelligence, a number of technologies that are most relevant to space exploration are experiencing the greatest change. Emerging patterns of set of processes rather than organizational units leading to end-to-end automation is becoming a major objective of enterprise information technology. The cost element is a leading factor of future exploration systems. This technology project is to advance an integrated Planning and Management Simulation Model for evaluation of risks, costs, and reliability of launch systems from Earth to Orbit for Space Exploration. The approach builds on research done in the NASA ARC/KSC developed Virtual Test Bed (VTB) to integrate architectural, operations process, and mission simulations for the purpose of evaluating enterprise level strategies to reduce cost, improve systems operability, and reduce mission risks. The objectives are to understand the interdependency of architecture and process on recurring launch cost of operations, provide management a tool for assessing systems safety and dependability versus cost, and leverage lessons learned and empirical models from Shuttle and International Space Station to validate models applied to Exploration. The systems-of-systems concept is built to balance the conflicting objectives of safety, reliability, and process strategy in order to achieve long term sustainability. A planning and analysis test bed is needed for evaluation of enterprise level options and strategies for transit and launch systems as well as surface and orbital systems. This environment can also support agency simulation based acquisition process objectives. The technology development approach is based on the collaborative effort set forth in the VTB's integrating operations, process models, systems and environment models, and cost models as a comprehensive disciplined enterprise analysis environment. Significant emphasis is being placed on adapting root cause from existing Shuttle operations to exploration. Technical challenges include cost model validation, integration of parametric models with discrete event process and systems simulations, and large-scale simulation integration. The enterprise architecture is required for coherent integration of systems models. It will also require a plan for evolution over the life of the program. The proposed technology will produce long-term benefits in support of the NASA objectives for simulation based acquisition, will improve the ability to assess architectural options verses safety/risk for future exploration systems, and will facilitate incorporation of operability as a systems design consideration, reducing overall life cycle cost for future systems.

Business Intelligence Modeling in Launch Operations

NASA Technical Reports Server (NTRS)

Bardina, Jorge E.; Thirumalainambi, Rajkumar; Davis, Rodney D.

2005-01-01

This technology project is to advance an integrated Planning and Management Simulation Model for evaluation of risks, costs, and reliability of launch systems from Earth to Orbit for Space Exploration. The approach builds on research done in the NASA ARC/KSC developed Virtual Test Bed (VTB) to integrate architectural, operations process, and mission simulations for the purpose of evaluating enterprise level strategies to reduce cost, improve systems operability, and reduce mission risks. The objectives are to understand the interdependency of architecture and process on recurring launch cost of operations, provide management a tool for assessing systems safety and dependability versus cost, and leverage lessons learned and empirical models from Shuttle and International Space Station to validate models applied to Exploration. The systems-of-systems concept is built to balance the conflicting objectives of safety, reliability, and process strategy in order to achieve long term sustainability. A planning and analysis test bed is needed for evaluation of enterprise level options and strategies for transit and launch systems as well as surface and orbital systems. This environment can also support agency simulation .based acquisition process objectives. The technology development approach is based on the collaborative effort set forth in the VTB's integrating operations. process models, systems and environment models, and cost models as a comprehensive disciplined enterprise analysis environment. Significant emphasis is being placed on adapting root cause from existing Shuttle operations to exploration. Technical challenges include cost model validation, integration of parametric models with discrete event process and systems simulations. and large-scale simulation integration. The enterprise architecture is required for coherent integration of systems models. It will also require a plan for evolution over the life of the program. The proposed technology will produce long-term benefits in support of the NASA objectives for simulation based acquisition, will improve the ability to assess architectural options verses safety/risk for future exploration systems, and will facilitate incorporation of operability as a systems design consideration, reducing overall life cycle cost for future systems. The future of business intelligence of space exploration will focus on the intelligent system-of-systems real-time enterprise. In present business intelligence, a number of technologies that are most relevant to space exploration are experiencing the greatest change. Emerging patterns of set of processes rather than organizational units leading to end-to-end automation is becoming a major objective of enterprise information technology. The cost element is a leading factor of future exploration systems.

Ground System Extensibility Considerations

NASA Astrophysics Data System (ADS)

Miller, S. W.; Greene, E.

2017-12-01

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP). The CGS provides a wide range of support to a number of national and international missions, including command and control, mission management, data acquisition and routing, and environmental data processing and distribution. The current suite of CGS-supported missions has demonstrated the value of interagency and international partnerships to address global observation needs. With its established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe how the inherent scalability and extensibility of the CGS enables the addition of these new missions, with an eye on global enterprise needs in the 2020's and beyond.

MSFC Skylab ground-based astronomy program

NASA Technical Reports Server (NTRS)

Duncan, B. J.

1974-01-01

The Skylab Ground-Based Astronomy Program (SGAP) was conducted to enhance the data base of solar physics obtained during the Apollo Telescope Mount (ATM) mission flown in conjunction with the Skylab orbital station. Leading solar physicists from various observatories obtained data from the ground at the same time that orbital data were being acquired by ATM. The acquisition of corollary solar data from the ground simultaneously with the ATM orbital observations helped to provide a broader basis for understanding solar physics by increasing spectral coverage and by the use of additional sophisticated instruments of various types. This report briefly describes the individual tasks and the associated instrumentation selected for this ground-based program and contains as appendices, the final reports from the Principal Investigators.

Submillimeter Wave Astronomy Satellite (SWAS) Launch and Early Orbit Support Experiences

NASA Technical Reports Server (NTRS)

Kirschner, S.; Sedlak, J.; Challa, M.; Nicholson, A.; Sande, C.; Rohrbaugh, D.

1999-01-01

The Submillimeter Wave Astronomy Satellite (SWAS) was successfully launched on December 6, 1998 at 00:58 UTC. The two year mission is the fourth in the series of Small Explorer (SMEX) missions. SWAS is dedicated to the study of star formation and interstellar chemistry. SWAS was injected into a 635 km by 650 km orbit with an inclination of nearly 70 deg by an Orbital Sciences Corporation Pegasus XL launch vehicle. The Flight Dynamics attitude and navigation teams supported all phases of the early mission. This support included orbit determination, attitude determination, real-time monitoring, and sensor calibration. This paper reports the main results and lessons learned concerning navigation, support software, star tracker performance, magnetometer and gyroscope calibrations, and anomaly resolution. This includes information on spacecraft tip-off rates, first-day navigation problems, target acquisition anomalies, star tracker anomalies, and significant sensor improvements due to calibration efforts.

Options for the Further Orbit Evolution of the Swarm Mission

NASA Astrophysics Data System (ADS)

Sieg, Detlef; Diekmann, Frank

2016-08-01

The three satellites of ESA's magnetic field mission Swarm were launched into a common low Earth circular orbit in November 2013 to measure precisely the magnetic signals from Earth's core, mantle, crust and oceans, as well as the ionosphere and magnetosphere. Since completion of the orbit acquisition phase in April 2014 one satellite (Swarm-B) is flying in a higher orbit with an inclination of 87.8deg and an altitude decaying from 520km. The other two satellites are Swarm-A (trailing) and Swarm-C (leading). They form the lower pair with an initial altitude of 473km, an inclination of 87.4 deg and an ascending node difference of 1.4 deg. The original mission analysis foresaw a decay of the lower pair down to 300km altitude within 4 years after launch. The target altitude of the launcher injection orbit was selected accordingly with some margin due to uncertainties in the solar activity prediction. However the final altitude selection had to be provided more than half a year before launch. Following several launch delays, the major part of the mission falls now beyond the maximum of the current solar cycle. Because of the lower radio flux and geomagnetic activity, the air drag forces are now much lower and the actual decay takes longer.As a first countermeasure the target for the inclination difference between Swarm-B and Swarm-A/C was reduced to 0.4deg shortly before the start of the orbit acquisition manoeuvre sequence early 2014 such that the LTAN drift between the orbit planes of B and A/C has been reduced to 1.5h per year to avoid a too large difference towards the end of the mission.First the paper describes the routine orbit determination approach by ESOC flight dynamics, which is used to determine absolute drag scale factors. Based on the in- flight calibrated values, long-term orbit predictions are calculated every half a year and can be compared against the actual observed decay. This gives good confidence for the prediction of the future altitude evolution. The latest results for different confidence levels of the predicted solar activity are given.Then estimated relative differences between the drag scale factors of the lower satellite pair are presented together with the evolution of the lower pair separation and the corresponding maintenance manoeuvres. Finally, the major part of the poster presentation focuses on different options to change the future orbit evolution.

Scheduler software for tracking and data relay satellite system loading analysis: User manual and programmer guide

NASA Technical Reports Server (NTRS)

Craft, R.; Dunn, C.; Mccord, J.; Simeone, L.

1980-01-01

A user guide and programmer documentation is provided for a system of PRIME 400 minicomputer programs. The system was designed to support loading analyses on the Tracking Data Relay Satellite System (TDRSS). The system is a scheduler for various types of data relays (including tape recorder dumps and real time relays) from orbiting payloads to the TDRSS. Several model options are available to statistically generate data relay requirements. TDRSS time lines (representing resources available for scheduling) and payload/TDRSS acquisition and loss of sight time lines are input to the scheduler from disk. Tabulated output from the interactive system includes a summary of the scheduler activities over time intervals specified by the user and overall summary of scheduler input and output information. A history file, which records every event generated by the scheduler, is written to disk to allow further scheduling on remaining resources and to provide data for graphic displays or additional statistical analysis.

Multimode C-arm fluoroscopy, tomosynthesis, and cone-beam CT for image-guided interventions: from proof of principle to patient protocols

NASA Astrophysics Data System (ADS)

Siewerdsen, J. H.; Daly, M. J.; Bachar, G.; Moseley, D. J.; Bootsma, G.; Brock, K. K.; Ansell, S.; Wilson, G. A.; Chhabra, S.; Jaffray, D. A.; Irish, J. C.

2007-03-01

High-performance intraoperative imaging is essential to an ever-expanding scope of therapeutic procedures ranging from tumor surgery to interventional radiology. The need for precise visualization of bony and soft-tissue structures with minimal obstruction to the therapy setup presents challenges and opportunities in the development of novel imaging technologies specifically for image-guided procedures. Over the past ~5 years, a mobile C-arm has been modified in collaboration with Siemens Medical Solutions for 3D imaging. Based upon a Siemens PowerMobil, the device includes: a flat-panel detector (Varian PaxScan 4030CB); a motorized orbit; a system for geometric calibration; integration with real-time tracking and navigation (NDI Polaris); and a computer control system for multi-mode fluoroscopy, tomosynthesis, and cone-beam CT. Investigation of 3D imaging performance (noise-equivalent quanta), image quality (human observer studies), and image artifacts (scatter, truncation, and cone-beam artifacts) has driven the development of imaging techniques appropriate to a host of image-guided interventions. Multi-mode functionality presents a valuable spectrum of acquisition techniques: i.) fluoroscopy for real-time 2D guidance; ii.) limited-angle tomosynthesis for fast 3D imaging (e.g., ~10 sec acquisition of coronal slices containing the surgical target); and iii.) fully 3D cone-beam CT (e.g., ~30-60 sec acquisition providing bony and soft-tissue visualization across the field of view). Phantom and cadaver studies clearly indicate the potential for improved surgical performance - up to a factor of 2 increase in challenging surgical target excisions. The C-arm system is currently being deployed in patient protocols ranging from brachytherapy to chest, breast, spine, and head and neck surgery.

STARSYS: A view after WARC-92

NASA Astrophysics Data System (ADS)

Kaveeshwar, Ashok; Rodriguez, Raul

1993-01-01

The STARSYS system is aimed at providing low cost global positioning and messaging by satellite. STARSYS is a data only system using very brief message transmission times. Code Division Multiple Access (CDMA) is used for frequency sharing; it enables transmitted data to be coded for unique user identification and also to employ Doppler and radio ranging to determine the geographical location of a transmitting terminal. The STARSYS system is composed of the field receiver/transmitter, the Low Earth Orbit (LEO) satellite constellation and the ground station elements. Each message transmission is able to contain up to thirty two digital characters. Market applications are numerous: theft control, vehicle and logistic tracking and messaging, personal communications, utility and environmental data acquisition and transfer. Co-primary frequency allocation at WARC-92 accelerated interest for potential customers and investors, although the amount of frequency allocation (less than 1 GHz) is small.

Automation of Hubble Space Telescope Mission Operations

NASA Technical Reports Server (NTRS)

Burley, Richard; Goulet, Gregory; Slater, Mark; Huey, William; Bassford, Lynn; Dunham, Larry

2012-01-01

On June 13, 2011, after more than 21 years, 115 thousand orbits, and nearly 1 million exposures taken, the operation of the Hubble Space Telescope successfully transitioned from 24x7x365 staffing to 815 staffing. This required the automation of routine mission operations including telemetry and forward link acquisition, data dumping and solid-state recorder management, stored command loading, and health and safety monitoring of both the observatory and the HST Ground System. These changes were driven by budget reductions, and required ground system and onboard spacecraft enhancements across the entire operations spectrum, from planning and scheduling systems to payload flight software. Changes in personnel and staffing were required in order to adapt to the new roles and responsibilities required in the new automated operations era. This paper will provide a high level overview of the obstacles to automating nominal HST mission operations, both technical and cultural, and how those obstacles were overcome.

Lunar Reconnaissance Orbiter (LRO) Command and Data Handling Flight Electronics Subsystem

NASA Technical Reports Server (NTRS)

Nguyen, Quang; Yuknis, William; Haghani, Noosha; Pursley, Scott; Haddad, Omar

2012-01-01

A document describes a high-performance, modular, and state-of-the-art Command and Data Handling (C&DH) system developed for use on the Lunar Reconnaissance Orbiter (LRO) mission. This system implements a complete hardware C&DH subsystem in a single chassis enclosure that includes a processor card, 48 Gbytes of solid-state recorder memory, data buses including MIL-STD-1553B, custom RS-422, SpaceWire, analog collection, switched power services, and interfaces to the Ka-Band and S-Band RF communications systems. The C&DH team capitalized on extensive experience with hardware and software with PCI bus design, SpaceWire networking, Actel FPGA design, digital flight design techniques, and the use of VxWorks for the real-time operating system. The resulting hardware architecture was implemented to meet the LRO mission requirements. The C&DH comprises an enclosure, a backplane, a low-voltage power converter, a single-board computer, a communications interface board, four data storage boards, a housekeeping and digital input/output board, and an analog data acquisition board. The interfaces between the C&DH and the instruments and avionics are connected through a SpaceWire network, a MIL-STD-1553 bus, and a combination of synchronous and asynchronous serial data transfers over RS-422 and LVDS (low-voltage differential-signaling) electrical interfaces. The C&DH acts as the spacecraft data system with an instrument data manager providing all software and internal bus scheduling, ingestion of science data, distribution of commands, and performing science operations in real time.

Shuttle Laser Altimeter (SLA): A pathfinder for space-based laser altimetry and lidar

NASA Technical Reports Server (NTRS)

Bufton, Jack; Blair, Bryan; Cavanaugh, John; Garvin, James

1995-01-01

The Shuttle Laser Altimeter (SLA) is a Hitchhiker experiment now being integrated for first flight on STS-72 in November 1995. Four Shuttle flights of the SLA are planned at a rate of about a flight every 18 months. They are aimed at the transition of the Goddard Space Flight Center airborne laser altimeter and lidar technology to low Earth orbit as a pathfinder for operational space-based laser remote sensing devices. Future alser altimeter sensors such as the Geoscience Laser Altimeter System (GLAS), an Earth Observing System facility instrument, and the Multi-Beam Laser Altimeter (MBLA), the land and vegetation laser altimeter for the NASA TOPSAT (Topography Satellite) Mission, will utilize systems and approaches being tested with SLA. The SLA Instrument measures the distance from the Space Shuttle to the Earth's surface by timing the two-way propagation of short (approximately 10 na noseconds) laser pulses. laser pulses at 1064 nm wavelength are generated in a laser transmitter and are detected by a telescope equipped with a silicon avalanche photodiode detector. The SLA data system makes the pulse time interval measurement to a precision of about 10 nsec and also records the temporal shape of the laser echo from the Earth's surface for interpretation of surface height distribution within the 100 m diam. sensor footprint. For example, tree height can be determined by measuring the characteristic double-pulse signature that results from a separation in time of laser backscatter from tree canopies and the underlying ground. This is accomplished with a pulse waveform digitizer that samples the detector output with an adjustable resolution of 2 nanoseconds or wider intervals in a 100 sample window centered on the return pulse echo. The digitizer makes the SLA into a high resolution surface lidar sensor. It can also be used for cloud and atmospheric aerosol lidar measurements by lengthening the sampling window and degrading the waveform resolution. Detailed test objectives for the STS-72 mission center on the acquisition of sample data sets for land topography and vegetation height, waveform digitizer performance, and verification of data acquisition algorithms. The operational concept of SLA is illustrated in Fig. 1 where a series of 100 m footprints stretch in a profile of Earth surface topography along the nadir track of the Space Shuttle. The location of SLA as a dual canister payload on the Hitchhiker Bridge Assembly in Bay 12 of the Space Shuttle Endeavor can also be noted in this figure. Full interpretation of the SLA range measurement data set requires a 1 m knowledge of the Orbiter trajectory and better than 0.1 deg knowledge of Orbiter pointing angle. These ancillary data sets will be acquired during the STS-72 mission with an on-board Global Positioning System (GPS) receiver, K-band range and range-rate tracking of the Orbiter through TDRSS, and use of on-board inertial measurement units and star trackers. Integration and interpretation of all these different data sets as a pathfinder investigation for accurate determination of Earth surface elevation is the overall science of the SLA investigation.

Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

NASA Technical Reports Server (NTRS)

Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

2001-01-01

NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

Aerosol backscatter lidar calibration and data interpretation

NASA Technical Reports Server (NTRS)

Kavaya, M. J.; Menzies, R. T.

1984-01-01

A treatment of the various factors involved in lidar data acquisition and analysis is presented. This treatment highlights sources of fundamental, systematic, modeling, and calibration errors that may affect the accurate interpretation and calibration of lidar aerosol backscatter data. The discussion primarily pertains to ground based, pulsed CO2 lidars that probe the troposphere and are calibrated using large, hard calibration targets. However, a large part of the analysis is relevant to other types of lidar systems such as lidars operating at other wavelengths; continuous wave (CW) lidars; lidars operating in other regions of the atmosphere; lidars measuring nonaerosol elastic or inelastic backscatter; airborne or Earth-orbiting lidar platforms; and lidars employing combinations of the above characteristics.

Design and testing of the Space Station Freedom Propellant Tank Assembly

NASA Technical Reports Server (NTRS)

Dudley, D. D.; Thonet, T. A.; Goforth, A. M.

1992-01-01

Propellant storage and management functions for the Propulsion Module of the U.S. Space Station Freedom are provided by the Propellant Tank Assembly (PTA). The PTA consists of a surface-tension type propellant acquisition device contained within a welded titanium pressure vessel. The PTA design concept was selected with high reliability and low program risk as primary goals in order to meet stringent NASA structural, expulsion, fracture control and reliability requirements. The PTA design makes use of Shuttle Orbital Maneuvering System and Peacekeeper Propellant Storage Assembly design and analysis techniques. This paper summarizes the PTA design solution and discusses the underlying detailed analyses. In addition, design verification and qualification test activities are discussed.

Ground radar detection of meteoroids in space

NASA Technical Reports Server (NTRS)

Kessler, D. J.; Landry, P. M.; Gabbard, J. R.; Moran, J. L. T.

1980-01-01

A special test to lower the detection threshold for satellite fragments potentially dangerous to spacecraft was carried out by NORAD for NASA, using modified radar software. The Perimeter Acquisition Radar Attack Characterization System, a large, planar face, phased radar, operates at a nominal 430 MHz and produces 120 pulses per second, 45 of which were dedicated to search. In a time period of 8.4 hours of observations over three days, over 6000 objects were detected and tracked of which 37 were determined to have velocities greater than escape velocity. Six of these were larger objects with radar cross sections greater than 0.1 sq m and were probably orbiting satellites. A table gives the flux of both observed groups.

Fast aurora zone analysis

NASA Technical Reports Server (NTRS)

Booker, Mattie

1992-01-01

The Flight Dynamics Facility (FDF) of the Flight Dynamics Division (FDD), of the Goddard Space Flight Center provides acquisition data to tracking stations and orbit and attitude services to scientists and mission support personnel. The following paper explains how a method was determined that found spacecraft entry and exit times of the aurora zone.

A new algorithm for agile satellite-based acquisition operations

NASA Astrophysics Data System (ADS)

Bunkheila, Federico; Ortore, Emiliano; Circi, Christian

2016-06-01

Taking advantage of the high manoeuvrability and the accurate pointing of the so-called agile satellites, an algorithm which allows efficient management of the operations concerning optical acquisitions is described. Fundamentally, this algorithm can be subdivided into two parts: in the first one the algorithm operates a geometric classification of the areas of interest and a partitioning of these areas into stripes which develop along the optimal scan directions; in the second one it computes the succession of the time windows in which the acquisition operations of the areas of interest are feasible, taking into consideration the potential restrictions associated with these operations and with the geometric and stereoscopic constraints. The results and the performances of the proposed algorithm have been determined and discussed considering the case of the Periodic Sun-Synchronous Orbits.

Numerical investigation of performance of vane-type propellant management device by VOF methods

NASA Astrophysics Data System (ADS)

Liu, J. T.; Zhou, C.; Wu, Y. L.; Zhuang, B. T.; Li, Y.

2015-01-01

The orbital propellant management performance of the vane-type tank is so important for the propellant system and it determines the lifetime of the satellite. The propellant in the tank can be extruded by helium gas. To study the two phase distribution in the vane-type surface tension tank and the capability of the vane-type propellant management device (PMD), a large volume vane-type surface tension tank is analysed using 3-D unsteady numerical simulations. VOF methods are used to analyse the location of the interface of the two phase. Performances of the propellant acquisition vanes and propellant refillable reservoir in the tank are investigated. The flow conductivity of the propellant acquisition vanes and the liquid storage capacity of propellant refillable reservoir can be affected by the value of the gravity and the volume of the propellant in the tank. To avoid the large resistance causing by surface tension in an outflow of a small hole, the design of the vanes in a propellant refillable reservoir should have suitable space.

Autonomous support for microorganism research in space

NASA Astrophysics Data System (ADS)

Fleet, M. L.; Smith, J. D.; Klaus, D. M.; Luttges, M. W.

1993-02-01

A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. The payload is designed to be compatible with the COMercial Experiment Transporter (COMET), an orbiter middeck locker interface and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional data acquisition includes optical density measurement, microscopy, video, and film photography. On-board data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, research opportunities are explored to illustrate hardware versatility and function. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

Digital Astronaut Photography: A Discovery Dataset for Archaeology

NASA Technical Reports Server (NTRS)

Stefanov, William L.

2010-01-01

Astronaut photography acquired from the International Space Station (ISS) using commercial off-the-shelf cameras offers a freely-accessible source for high to very high resolution (4-20 m/pixel) visible-wavelength digital data of Earth. Since ISS Expedition 1 in 2000, over 373,000 images of the Earth-Moon system (including land surface, ocean, atmospheric, and lunar images) have been added to the Gateway to Astronaut Photography of Earth online database (http://eol.jsc.nasa.gov ). Handheld astronaut photographs vary in look angle, time of acquisition, solar illumination, and spatial resolution. These attributes of digital astronaut photography result from a unique combination of ISS orbital dynamics, mission operations, camera systems, and the individual skills of the astronaut. The variable nature of astronaut photography makes the dataset uniquely useful for archaeological applications in comparison with more traditional nadir-viewing multispectral datasets acquired from unmanned orbital platforms. For example, surface features such as trenches, walls, ruins, urban patterns, and vegetation clearing and regrowth patterns may be accentuated by low sun angles and oblique viewing conditions (Fig. 1). High spatial resolution digital astronaut photographs can also be used with sophisticated land cover classification and spatial analysis approaches like Object Based Image Analysis, increasing the potential for use in archaeological characterization of landscapes and specific sites.

Non-subjective cataract analysis and its application in space radiation risk assessment

NASA Technical Reports Server (NTRS)

Wu, B.; Medvedovsky, C.; Worgul, B. V.

1994-01-01

Experimental animal studies and human observations suggest that the question is not whether or not prolonged space missions will cause cataracts to appear prematurely in the astronauts, but when and to what degree. Historically the major impediment to radiation cataract follow-up has been the necessarily subjective nature of assessing the degree of lens transparency. This has spurred the development of instruments which produce video images amenable to digital analysis. One such system, the Zeiss Scheimpflug slit lamp measuring system (SLC), was incorporated into our ongoing studies of radiation cataractogenesis. It was found that the Zeiss SLC measuring system has high resolution and permits the acquisition of reproducible images of the anterior segment of the eye. Our results, based on about 650 images of the rats lens, and followed over a period of 91 weeks of radiation cataract development, showed that the Integrated Optical Density (IOD) of the lens correlated well with conventional assessment with the added advantages of objectivity, permanent and transportable records and linearity as cataracts become more severe. This continuous data acquisition, commencing with cataract onset, can proceed through more advanced stages. The SLC exhibits much greater sensitivity reflected in a continuously progressive severity despite the artifactual plateaus in staging which occur using conventional scoring methods. Systems such as the Zeiss SLC should be used to monitor astronauts frequent visits to low earth orbit to obtain a longitudinal data-base on the influence of this activity on the lens.

Evaluation of Parallel and Fan-Beam Data Acquisition Geometries and Strategies for Myocardial SPECT Imaging

NASA Astrophysics Data System (ADS)

Qi, Yujin; Tsui, B. M. W.; Gilland, K. L.; Frey, E. C.; Gullberg, G. T.

2004-06-01

This study evaluates myocardial SPECT images obtained from parallel-hole (PH) and fan-beam (FB) collimator geometries using both circular-orbit (CO) and noncircular-orbit (NCO) acquisitions. A newly developed 4-D NURBS-based cardiac-torso (NCAT) phantom was used to simulate the /sup 99m/Tc-sestamibi uptakes in human torso with myocardial defects in the left ventricular (LV) wall. Two phantoms were generated to simulate patients with thick and thin body builds. Projection data including the effects of attenuation, collimator-detector response and scatter were generated using SIMSET Monte Carlo simulations. A large number of photon histories were generated such that the projection data were close to noise free. Poisson noise fluctuations were then added to simulate the count densities found in clinical data. Noise-free and noisy projection data were reconstructed using the iterative OS-EM reconstruction algorithm with attenuation compensation. The reconstructed images from noisy projection data show that the noise levels are lower for the FB as compared to the PH collimator due to increase in detected counts. The NCO acquisition method provides slightly better resolution and small improvement in defect contrast as compared to the CO acquisition method in noise-free reconstructed images. Despite lower projection counts the NCO shows the same noise level as the CO in the attenuation corrected reconstruction images. The results from the channelized Hotelling observer (CHO) study show that FB collimator is superior to PH collimator in myocardial defect detection, but the NCO shows no statistical significant difference from the CO for either PH or FB collimator. In conclusion, our results indicate that data acquisition using NCO makes a very small improvement in the resolution over CO for myocardial SPECT imaging. This small improvement does not make a significant difference on myocardial defect detection. However, an FB collimator provides better defect detection than a PH collimator with similar spatial resolution for myocardial SPECT imaging.

The Advanced Re-Entry Vehicle (ARV) A Development Step From ATV Toward Manned Transportation Systems

NASA Astrophysics Data System (ADS)

Bottacini, Massimiliano; Berthe, Philippe; Vo, Xavier; Pietsch, Klaus

2011-05-01

The Advanced Re-entry Vehicle (ARV) programme has been undertaken by Europe with the objective to contribute to the preparation of a future European crew transportation system, while providing a valuable logistic support to the ISS through an operational cargo return system. This development would allow: - the early acquisition of critical technologies; - the design, development and testing of elements suitable for the follow up human rated transportation system. These vehicles should also serve future LEO infrastructures and exploration missions. With the aim to satisfy the above objectives a team composed by major European industries and led by EADS Astrium Space Transportation is currently conducting the phase A of the programme under contract with the European Space Agency (ESA). Two vehicle versions are being investigated: a Cargo version, transporting cargo only to/from the ISS, and a Crew version, which will allow the transfer of both crew and cargo to/from the ISS. The ARV Cargo version, in its present configuration, is composed of three modules. The Versatile Service Module (VSM) provides to the system the propulsion/GNC for orbital manoeuvres and attitude control and the orbital power generation. Its propulsion system and GNC shall be robust enough to allow its use for different launch stacks and different LEO missions in the future. The Un-pressurised Cargo Module (UCM) provides the accommodation for about 3000 kg of unpressurised cargo and is to be sufficiently flexible to ensure the transportation of: - orbital infrastructure components (ORU’s); - scientific / technological experiments; - propellant for re-fuelling, re-boost (and de-orbiting) of the ISS. The Re-entry Module (RM) provides a pressurized volume to accommodate active/passive cargo (2000 kg upload/1500 kg download). It is conceived as an expendable conical capsule with spherical heat-shield, interfacing with the new docking standard of the ISS, i.e. it carries the IBDM docking system, on a dedicated adapter. Its thermo-mechanical design, GNC, descent & landing systems take into account its future evolution for crew transportation. The ARV Crew version is also composed of three main modules: - an Integrated Resource Module (IRM) providing the main propulsion and power functions during the on-orbit phases of the mission; - a Re-entry Module (RM) providing the re-entry function and a pressurized environment for four crew members and about 250 kg of passive / active cargo; - a Crew Escape System (CES) providing the function of emergency separation of the RM from the launcher (in case of failure of this latter). The paper presents an overview of the ARV Cargo and Crew versions requirements derived from the above objectives, their mission scenarios, system architectures and performances. The commonality aspects between the ARV Cargo version and future transportation systems (including also the ARV Crew version and logistic carriers) are also highlighted.

On-orbit operations and offline data processing of CALET onboard the ISS

NASA Astrophysics Data System (ADS)

Asaoka, Y.; Ozawa, S.; Torii, S.; Adriani, O.; Akaike, Y.; Asano, K.; Bagliesi, M. G.; Bigongiari, G.; Binns, W. R.; Bonechi, S.; Bongi, M.; Brogi, P.; Buckley, J. H.; Cannady, N.; Castellini, G.; Checchia, C.; Cherry, M. L.; Collazuol, G.; Di Felice, V.; Ebisawa, K.; Fuke, H.; Guzik, T. G.; Hams, T.; Hareyama, M.; Hasebe, N.; Hibino, K.; Ichimura, M.; Ioka, K.; Ishizaki, W.; Israel, M. H.; Javaid, A.; Kasahara, K.; Kataoka, J.; Kataoka, R.; Katayose, Y.; Kato, C.; Kawanaka, N.; Kawakubo, Y.; Krawczynski, H. S.; Krizmanic, J. F.; Kuramata, S.; Lomtadze, T.; Maestro, P.; Marrocchesi, P. S.; Messineo, A. M.; Mitchell, J. W.; Miyake, S.; Mizutani, K.; Moiseev, A. A.; Mori, K.; Mori, M.; Mori, N.; Motz, H. M.; Munakata, K.; Murakami, H.; Nakahira, S.; Nishimura, J.; de Nolfo, G. A.; Okuno, S.; Ormes, J. F.; Pacini, L.; Palma, F.; Papini, P.; Penacchioni, A. V.; Rauch, B. F.; Ricciarini, S. B.; Sakai, K.; Sakamoto, T.; Sasaki, M.; Shimizu, Y.; Shiomi, A.; Sparvoli, R.; Spillantini, P.; Stolzi, F.; Takahashi, I.; Takayanagi, M.; Takita, M.; Tamura, T.; Tateyama, N.; Terasawa, T.; Tomida, H.; Tsunesada, Y.; Uchihori, Y.; Ueno, S.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Yuda, T.

2018-07-01

The CALorimetric Electron Telescope (CALET), launched for installation on the International Space Station (ISS) in August, 2015, has been accumulating scientific data since October, 2015. CALET is intended to perform long-duration observations of high-energy cosmic rays onboard the ISS. CALET directly measures the cosmic-ray electron spectrum in the energy range of 1 GeV to 20 TeV with a 2% energy resolution above 30 GeV. In addition, the instrument can measure the spectrum of gamma rays well into the TeV range, and the spectra of protons and nuclei up to a PeV. In order to operate the CALET onboard ISS, JAXA Ground Support Equipment (JAXA-GSE) and the Waseda CALET Operations Center (WCOC) have been established at JAXA and Waseda University, respectively. Scientific operations using CALET are planned at WCOC, taking into account orbital variations of geomagnetic rigidity cutoff. Scheduled command sequences are used to control the CALET observation modes on orbit. Calibration data acquisition by, for example, recording pedestal and penetrating particle events, a low-energy electron trigger mode operating at high geomagnetic latitude, a low-energy gamma-ray trigger mode operating at low geomagnetic latitude, and an ultra heavy trigger mode, are scheduled around the ISS orbit while maintaining maximum exposure to high-energy electrons and other high-energy shower events by always having the high-energy trigger mode active. The WCOC also prepares and distributes CALET flight data to collaborators in Italy and the United States. As of August 31, 2017, the total observation time is 689 days with a live time fraction of the total time of ∼ 84%. Nearly 450 million events are collected with a high-energy (E > 10 GeV) trigger. In addition, calibration data acquisition and low-energy trigger modes, as well as an ultra-heavy trigger mode, are consistently scheduled around the ISS orbit. By combining all operation modes with the excellent-quality on-orbit data collected thus far, it is expected that a five-year observation period will provide a wealth of new and interesting results.

In-Space Propellant Production Using Water

NASA Technical Reports Server (NTRS)

Notardonato, William; Johnson, Wesley; Swanger, Adam; McQuade, William

2012-01-01

A new era of space exploration is being planned. Manned exploration architectures under consideration require the long term storage of cryogenic propellants in space, and larger science mission directorate payloads can be delivered using cryogenic propulsion stages. Several architecture studies have shown that in-space cryogenic propulsion depots offer benefits including lower launch costs, smaller launch vehicles, and enhanced mission flexibility. NASA is currently planning a Cryogenic Propellant Storage and Transfer (CPST) technology demonstration mission that will use existing technology to demonstrate long duration storage, acquisition, mass gauging, and transfer of liquid hydrogen in low Earth orbit. This mission will demonstrate key technologies, but the CPST architecture is not designed for optimal mission operations for a true propellant depot. This paper will consider cryogenic propellant depots that are designed for operability. The operability principles considered are reusability, commonality, designing for the unique environment of space, and use of active control systems, both thermal and fluid. After considering these operability principles, a proposed depot architecture will be presented that uses water launch and on orbit electrolysis and liquefaction. This could serve as the first true space factory. Critical technologies needed for this depot architecture, including on orbit electrolysis, zero-g liquefaction and storage, rendezvous and docking, and propellant transfer, will be discussed and a developmental path forward will be presented. Finally, use of the depot to support the NASA Science Mission Directorate exploration goals will be presented.

The impact of acquisition times on the accuracy of microwave soil moisture retrievals over the contiguous U.S.

USDA-ARS?s Scientific Manuscript database

Satellite-derived soil moisture products have become an important data source for the study of land surface processes and related applications. For satellites with sun-synchronous orbits, these products are typically derived separately for ascending and descending overpasses with different local acq...

Sentinel-3 coverage-driven mission design: Coupling of orbit selection and instrument design

NASA Astrophysics Data System (ADS)

Cornara, S.; Pirondini, F.; Palmade, J. L.

2017-11-01

The first satellite of the Sentinel-3 series was launched in February 2016. Sentinel-3 payload suite encompasses the Ocean and Land Colour Instrument (OLCI) with a swath of 1270 km, the Sea and Land Surface Temperature Radiometer (SLSTR) yielding a dual-view scan with swaths of 1420 km (nadir) and 750 km (oblique view), the Synthetic Aperture Radar Altimeter (SRAL) working in Ku-band and C-band, and the dual-frequency Microwave Radiometer (MWR). In the early stages of mission and system design, the main driver for the Sentinel-3 reference orbit selection was the requirement to achieve a revisit time of two days or less globally over ocean areas with two satellites (i.e. 4-day global coverage with one satellite). The orbit selection was seamlessly coupled with the OLCI instrument design in terms of field of view (FoV) definition driven by the observation zenith angle (OZA) and sunglint constraints applied to ocean observations. The criticality of the global coverage requirement for ocean monitoring derives from the sunglint phenomenon, i.e. the impact on visible channels of the solar ray reflection on the water surface. This constraint was finally overcome thanks to the concurrent optimisation of the orbit parameters, notably the Local Time at Descending Node (LTDN), and the OLCI instrument FoV definition. The orbit selection process started with the identification of orbits with short repeat cycle (2-4 days), firstly to minimise the time required to achieve global coverage with existing constraints, and then to minimise the swath required to obtain global coverage and the maximum required OZA. This step yielded the selection of a 4-day repeat cycle orbit, thus allowing 2-day coverage with two adequately spaced satellites. Then suitable candidate orbits with higher repeat cycles were identified in the proximity of the selected altitudes and the reference orbit was ultimately chosen. Rationale was to keep the swath for global coverage as close as possible to the previous optimum value, but to tailor the repeat cycle length (i.e. the ground-track grid) to optimise the topography mission performances. The final choice converged on the sun-synchronous orbit 14 + 7/27, reference altitude ∼800 km, LTDN = 10h00. Extensive coverage analyses were carried out to characterise the mission performance and the fulfilment of the requirements, encompassing revisit time, number of acquisitions, observation viewing geometry and swath properties. This paper presents a comprehensive overview of the Sentinel-3 orbit selection, starting from coverage requirements and highlighting the close interaction with the instrument design activity.

Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Baud, Guillaume; Bruce, Roderik; Gasior, Marek; Mereghetti, Alessio; Mirarchi, Daniele; Olexa, Jakub; Redaelli, Stefano; Salvachua, Belen; Valloni, Alessandra; Wenninger, Jorg

2017-08-01

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also allow for reducing operational margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts, therefore decreasing the β* and increasing the luminosity reach of the LHC. In this paper, the results from the commissioning of the embedded BPMs in the LHC are presented. The data acquisition and control software architectures are reviewed. A comparison with the standard alignment technique is provided, together with a fill-to-fill analysis of the measured orbit in different machine modes, which will also be used to determine suitable beam interlocks for a tighter collimation hierarchy.

Entry, Descent, and Landing Communications for the 2011 Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Abilleira, Fernando; Shidner, Jeremy D.

2012-01-01

The Mars Science Laboratory (MSL), established as the most advanced rover to land on the surface of Mars to date, launched on November 26th, 2011 and arrived to the Martian Gale Crater during the night of August 5th, 2012 (PDT). MSL will investigate whether the landing region was ever suitable to support carbon-based life, and examine rocks, soil, and the atmosphere with a sophisticated suite of tools. This paper addresses the flight system requirement by which the vehicle transmitted indications of the following events using both X-band tones and UHF telemetry to allow identification of probable root causes should a mission anomaly have occurred: Heat-Rejection System (HRS) venting, completion of the cruise stage separation, turn to entry attitude, atmospheric deceleration, bank angle reversal commanded, parachute deployment, heatshield separation, radar ground acquisition, powered descent initiation, rover separation from the descent stage, and rover release. During Entry, Descent, and Landing (EDL), the flight system transmitted a UHF telemetry stream adequate to determine the state of the spacecraft (including the presence of faults) at 8 kbps initiating from cruise stage separation through at least one minute after positive indication of rover release on the surface of Mars. The flight system also transmitted X-band semaphore tones from Entry to Landing plus one minute although since MSL was occulted, as predicted, by Mars as seen from the Earth, Direct-To-Earth (DTE) communications were interrupted at approximately is approx. 5 min after Entry ( approximately 130 prior to Landing). The primary data return paths were through the Deep Space Network (DSN) for DTE and the existing Mars network of orbiting assets for UHF, which included the Mars Reconnaissance Orbiter (MRO), Mars Odyssey (ODY), and Mars Express (MEX) elements. These orbiters recorded the telemetry data stream and returned it back to Earth via the DSN. The paper also discusses the total power received during EDL and the robustness of the telecom design strategy used to ensure EDL communications coverage.

Potential for calibration of geostationary meteorological satellite imagers using the Moon

USGS Publications Warehouse

Stone, T.C.; Kieffer, H.H.; Grant, I.F.; ,

2005-01-01

Solar-band imagery from geostationary meteorological satellites has been utilized in a number of important applications in Earth Science that require radiometric calibration. Because these satellite systems typically lack on-board calibrators, various techniques have been employed to establish "ground truth", including observations of stable ground sites and oceans, and cross-calibrating with coincident observations made by instruments with on-board calibration systems. The Moon appears regularly in the margins and corners of full-disk operational images of the Earth acquired by meteorological instruments with a rectangular field of regard, typically several times each month, which provides an excellent opportunity for radiometric calibration. The USGS RObotic Lunar Observatory (ROLO) project has developed the capability for on-orbit calibration using the Moon via a model for lunar spectral irradiance that accommodates the geometries of illumination and viewing by a spacecraft. The ROLO model has been used to determine on-orbit response characteristics for several NASA EOS instruments in low Earth orbit. Relative response trending with precision approaching 0.1% per year has been achieved for SeaWiFS as a result of the long time-series of lunar observations collected by that instrument. The method has a demonstrated capability for cross-calibration of different instruments that have viewed the Moon. The Moon appears skewed in high-resolution meteorological images, primarily due to satellite orbital motion during acquisition; however, the geometric correction for this is straightforward. By integrating the lunar disk image to an equivalent irradiance, and using knowledge of the sensor's spectral response, a calibration can be developed through comparison against the ROLO lunar model. The inherent stability of the lunar surface means that lunar calibration can be applied to observations made at any time, including retroactively. Archived geostationary imager data that contains the Moon can be used to develop response histories for these instruments, regardless of their current operational status.

Pulsed Plasma Thrusters for Small Spacecraft Attitude Control

NASA Technical Reports Server (NTRS)

McGuire, Melissa L.; Myers, Roger M.

1996-01-01

Pulsed plasma thrusters (PPT's) are a new option for attitude control of a small spacecraft and may result in reduced attitude control system (ACS) mass and cost. The primary purpose of an ACS is to orient the spacecraft configuration to the desired accuracy in inertial space. The ACS functions for which the PPT system will be analyzed include disturbance torque compensation and slewing maneuvers such as sun acquisition for which the small impulse bit and high specific impulse of the PPT offers unique advantages. The NASA Lewis Reserach Center (LeRC) currently has a contracted flight PPT system development program in place with Olin Aerospace and a delivery date of October 1997. The PPT system in this study are based upon the work being done under the NASA LeRC program. Analysis of the use of PPT's for ACS showed that the replacement of the standard momentum wheels and torque rods systems with a PTT system to perform the altitude control maneuvers on a small low Earth orbiting spacecraft reduced the ACS mass by 50 to 75 percent with no increase in required power level over comparable wheel-based systems.

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems...) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems licensed on... placed in the authorized orbital location or non-geostationary orbit(s) and that in-orbit operation of...

48 CFR 304.7001 - Numbering acquisitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Numbering acquisitions. 304.7001 Section 304.7001 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATIVE MATTERS Acquisition Instrument Identification Numbering System 304.7001 Numbering acquisitions. (a...

Heat transfer tests of an 0.006-scale thin-skin space shuttle thermocouple model (141-OT) in the Langley Research Center Freon tunnel at M-6 (IH18). [wind tunnel tests

NASA Technical Reports Server (NTRS)

Walstad, D. G.

1976-01-01

Ascent heating data were obtained at conditions simulating real gas effects at hypersonic Mach numbers. The configurations tested were Orbiter alone, external tank alone, and mated Orbiter and external tank. A boundary layer trip investigation was conducted for all configurations. The test was conducted at Mach 6 and Reynolds number of one half million per foot for 0 deg and -5 deg angle-of-attack. Selected thermocouples were chosen from the Orbiter and external tank to be used for obtaining heat transfer measurements. A maximum of 42 thermocouples could be measured by the facility data acquisition at one time and no attempt was made to record the excess thermocouples located on the model. Photographs of the test configurations are shown.

Impact gages for detecting meteoroid and other orbital debris impacts on space vehicles.

NASA Technical Reports Server (NTRS)

Mastandrea, J. R.; Scherb, M. V.

1973-01-01

Impacts on space vehicles have been simulated using the McDonnell Douglas Aerophysics Laboratory (MDAL) Light-Gas Guns to launch particles at hypervelocity speeds into scaled space structures. Using impact gages and a triangulation technique, these impacts have been detected and accurately located. This paper describes in detail the various types of impact gages (piezoelectric PZT-5A, quartz, electret, and off-the-shelf plastics) used. This description includes gage design and experimental results for gages installed on single-walled scaled payload carriers, multiple-walled satellites and space stations, and single-walled full-scale Delta tank structures. A brief description of the triangulation technique, the impact simulation, and the data acquisition system are also included.

AAFE man-made noise experiment project. Volume 2: Project and experiment discussions

NASA Technical Reports Server (NTRS)

1974-01-01

An experiment for the acquisition and processing of man-made noise interference data on earth orbital altitudes is discussed. The objectives of the project are to confirm the results of analytical studies concerning radio frequency man-made noise in space. It is stated that the measurements of the amounts and types of noise in frequency bands of interest could allow the allocation and utilization of frequencies to be optimized and would also contribute to the engineering objective of optimizing flight receiving systems. A second objective of the project was to design and fabricate a noise measuring receiver which would demonstrate the feasibility of the experiment design under the project. The procedures for acquiring and processing the electromagnetic radiation data are discussed.

ROSAT in-orbit attitude measurement recovery

NASA Astrophysics Data System (ADS)

Kaffer, L.; Boeinghoff, A.; Bruederle, E.; Schrempp, W.; Wullstein, P.

After about 7 months of nearly perfect Attitude Measurement and Control System (AMCS) functioning, the ROSAT mission was influenced by gyro degradations which complicated the operation and after one year the nominal mission could no longer be maintained. The reestablishment of the nominal mission by the redesign of the attitude measurement using inertial reference generation from coarse Sun sensor and magnetometer together with a new star acquisition procedure is described. This success was only possible because sufficient reprogramming provisions in the onboard computer were available. The new software now occupies nearly the complete Random Access Memory (RAM) area and increases the computation time from about 50 msec to 300 msec per 1 sec cycle. This proves that deficiencies of the hardware can be overcome by a more intelligent software.

48 CFR 201.301 - Policy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Policy. 201.301 Section 201.301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition Regulations 201.301 Policy. (a...

Machine Vision for Relative Spacecraft Navigation During Approach to Docking

NASA Technical Reports Server (NTRS)

Chien, Chiun-Hong; Baker, Kenneth

2011-01-01

This paper describes a machine vision system for relative spacecraft navigation during the terminal phase of approach to docking that: 1) matches high contrast image features of the target vehicle, as seen by a camera that is bore-sighted to the docking adapter on the chase vehicle, to the corresponding features in a 3d model of the docking adapter on the target vehicle and 2) is robust to on-orbit lighting. An implementation is provided for the case of the Space Shuttle Orbiter docking to the International Space Station (ISS) with quantitative test results using a full scale, medium fidelity mock-up of the ISS docking adapter mounted on a 6-DOF motion platform at the NASA Marshall Spaceflight Center Flight Robotics Laboratory and qualitative test results using recorded video from the Orbiter Docking System Camera (ODSC) during multiple orbiter to ISS docking missions. The Natural Feature Image Registration (NFIR) system consists of two modules: 1) Tracking which tracks the target object from image to image and estimates the position and orientation (pose) of the docking camera relative to the target object and 2) Acquisition which recognizes the target object if it is in the docking camera Field-of-View and provides an approximate pose that is used to initialize tracking. Detected image edges are matched to the 3d model edges whose predicted location, based on the pose estimate and its first time derivative from the previous frame, is closest to the detected edge1 . Mismatches are eliminated using a rigid motion constraint. The remaining 2d image to 3d model matches are used to make a least squares estimate of the change in relative pose from the previous image to the current image. The changes in position and in attitude are used as data for two Kalman filters whose outputs are smoothed estimate of position and velocity plus attitude and attitude rate that are then used to predict the location of the 3d model features in the next image.

48 CFR 246.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 246.404 Section 246.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE...

48 CFR 246.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 246.404 Section 246.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE...

48 CFR 246.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 246.404 Section 246.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE...

48 CFR 246.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 246.404 Section 246.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE...

48 CFR 246.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 246.404 Section 246.404 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE...

Study of an orbiting tethered dumbbell system having positive orbital energy

NASA Technical Reports Server (NTRS)

Arnold, David A.

1988-01-01

For very long tethered systems the sum of the kinetic and potential energy can be positive. The system remains in a circular orbit as long as the masses remain vertically aligned. The system is unstable without constant control of the alignment. If the upper mass rotates forward in the direction of the orbital motion, the system escapes out of orbit. If the upper mass rotates backward, the system falls out of orbit and the lower mass impacts the body around which the system is orbiting.

The Ion Propulsion System for the Asteroid Redirect Robotic Mission

NASA Technical Reports Server (NTRS)

Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard R.; Sekerak, Michael J.

2016-01-01

The Asteroid Redirect Robotic Mission is a Solar Electric Propulsion Technology Demonstration Mission (ARRM) whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of NASA'a future beyond-low-Earth-orbit, human-crewed exploration plans. Under the NASA Space Technology Mission Directorate the critical electric propulsion and solar array technologies are being developed. This paper presents the conceptual design of the ARRM ion propulsion system, the status of the NASA in-house thruster and power processing development activities, the status of the planned technology maturation for the mission through flight hardware delivery, and the status of the mission formulation and spacecraft acquisition.

Tracking and data relay satellite system (TDRSS) capabilities

NASA Astrophysics Data System (ADS)

Spearing, R. E.

1985-10-01

The Tracking and Data Relay Satellite System (TDRSS) is the latest implementation to tracking and data acquisition network for near-earth orbiting satellite support designed to meet the requirements of the current and projected (to the year 2000) satellite user community. The TDRSS consists of a space segment (SS) and a ground segment (GS) that fit within NASA's Space Network (SN) complex controlled at the Goddard Space Flight Center. The SS currently employs a single satellite, TDRS-1, with two additional satellites to be deployed in January 1986 and July 1986. The GS contains the communications and equipment required to manage the three TDR satellites and to transmit and receive information to and from TDRSS user satellites. Diagrams and tables illustrating the TDRSS signal characteristics, the situation of TDRSS within the SN, the SN operations and element interrelationships, as well as future plans for new missions are included.

Tracking and data relay satellite system (TDRSS) capabilities

NASA Technical Reports Server (NTRS)

Spearing, R. E.

1985-01-01

The Tracking and Data Relay Satellite System (TDRSS) is the latest implementation to tracking and data acquisition network for near-earth orbiting satellite support designed to meet the requirements of the current and projected (to the year 2000) satellite user community. The TDRSS consists of a space segment (SS) and a ground segment (GS) that fit within NASA's Space Network (SN) complex controlled at the Goddard Space Flight Center. The SS currently employs a single satellite, TDRS-1, with two additional satellites to be deployed in January 1986 and July 1986. The GS contains the communications and equipment required to manage the three TDR satellites and to transmit and receive information to and from TDRSS user satellites. Diagrams and tables illustrating the TDRSS signal characteristics, the situation of TDRSS within the SN, the SN operations and element interrelationships, as well as future plans for new missions are included.

Calibration and operation of the Faint Object Spectrograph

NASA Technical Reports Server (NTRS)

Harms, R.; Beaver, E.; Burbidge, E.; Hier, R.; Allen, R.; Angel, R.; Bartko, F.; Bohlin, R.; Ford, H.; Davidson, A.

1984-01-01

The design and basic performance characteristics of the Faint Object Spectrograph (FOS), one of five instruments built for use on the Space Telescope observatory, is summarized briefly. The results of the recently completed instrument-level calibration are presented with special emphasis on issues affecting plans for FOS astronomical observations. Examples include such fundamental characteristics as: limiting magnitudes (system sensitivity and noise figures), spectral coverage and resolution, scattered light properties, and instrumental polarization and modulation efficiencies. Also gated toward intended users, a rather detailed description of FOS operating modes is given. The discussion begins with the difficulties anticipated during target acquisition and their hoped-for resolution. Both the 'normal' spectroscopic operating modes of the FOS and its 'exotic' features (e.g. spectropolarimetric, time-tagged, and time-resolved modes) are presented. The paper concludes with an overview of the activities to assure proper alignment and operation of the FOS within the entire Space Telescope system (orbital and ground-based).

The role of space borne imaging radars in environmental monitoring: Some shuttle imaging radar results in Asia

NASA Technical Reports Server (NTRS)

Imhoff, M.; Vermillion, C.

1986-01-01

The synoptic view afforded by orbiting Earth sensors can be extremely valuable for resource evaluation, environmental monitoring and development planning. For many regions of the world, however, cloud cover has prevented the acquisition of remotely sensed data during the most environmentally stressful periods of the year. This paper discusses how synthetic aperture imaging radar can be used to provide valuable data about the condition of the Earth's surface during periods of bad weather. Examples are given of applications using data from the Shuttle Imaging Radars (SIR) A and B for agriculture land use and crop condition assessment, monsoon flood boundary and flood damage assessment, water resource monitoring and terrain modeling, coastal forest mapping and vegetation penetration, and coastal development monitoring. Recent SIR-B results in Bangladesh are emphasized, radar system basics are reviewed and future SAR systems discussed.

The role of space borne imaging radars in environmental monitoring: Some shuttle imaging radar results in Asia

NASA Technical Reports Server (NTRS)

Imhoff, Marc L.; Vermillion, C. H.

1986-01-01

The synoptic view afforded by orbiting Earth sensors can be extremely valuable for resource evaluation, environmental monitoring and development planning. For many regions of the world, however, cloud cover has prevented the acquisition of remotely sensed data during the most environmentally stressful periods of the year. How synthetic aperture imaging radar can be used to provide valuable data about the condition of the Earth's surface during periods of bad weather is discussed. Examples are given of applications using data from the Shuttle Imaging Radars (SIR) A and B for agricultural land use and crop condition assessment, monsoon flood boundary and flood damage assessment, water resource monitoring and terrain modeling, coastal forest mapping and vegetation penetration, and coastal development monitoring. Recent SIR-B results in Bangladesh are emphasized, radar system basics are reviewed and future SAR systems are discussed.

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

Dwyer, Morgan Maeve

This report summarizes the results of doctoral research that explored the cost impact of acquiring complex government systems jointly. The report begins by reviewing recent evidence that suggests that joint programs experience greater cost growth than non-joint programs. It continues by proposing an alternative approach for studying cost growth on government acquisition programs and demonstrates the utility of this approach by applying it to study the cost of jointness on three past programs that developed environmental monitoring systems for low-Earth orbit. Ultimately, the report concludes that joint programs' costs grow when the collaborating government agencies take action to retain ormore » regain their autonomy. The report provides detailed qualitative and quantitative data in support of this conclusion and generalizes its findings to other joint programs that were not explicitly studied here. Finally, it concludes by presenting a quantitative model that assesses the cost impacts of jointness and by demonstrating how government agencies can more effectively architect joint programs in the future.« less

The Block V Receiver fast acquisition algorithm for the Galileo S-band mission

NASA Technical Reports Server (NTRS)

Aung, M.; Hurd, W. J.; Buu, C. M.; Berner, J. B.; Stephens, S. A.; Gevargiz, J. M.

1994-01-01

A fast acquisition algorithm for the Galileo suppressed carrier, subcarrier, and data symbol signals under low data rate, signal-to-noise ratio (SNR) and high carrier phase-noise conditions has been developed. The algorithm employs a two-arm fast Fourier transform (FFT) method utilizing both the in-phase and quadrature-phase channels of the carrier. The use of both channels results in an improved SNR in the FFT acquisition, enabling the use of a shorter FFT period over which the carrier instability is expected to be less significant. The use of a two-arm FFT also enables subcarrier and symbol acquisition before carrier acquisition. With the subcarrier and symbol loops locked first, the carrier can be acquired from an even shorter FFT period. Two-arm tracking loops are employed to lock the subcarrier and symbol loops parameter modification to achieve the final (high) loop SNR in the shortest time possible. The fast acquisition algorithm is implemented in the Block V Receiver (BVR). This article describes the complete algorithm design, the extensive computer simulation work done for verification of the design and the analysis, implementation issues in the BVR, and the acquisition times of the algorithm. In the expected case of the Galileo spacecraft at Jupiter orbit insertion PD/No equals 14.6 dB-Hz, R(sym) equals 16 symbols per sec, and the predicted acquisition time of the algorithm (to attain a 0.2-dB degradation from each loop to the output symbol SNR) is 38 sec.

48 CFR 3401.000 - Scope of part.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Scope of part. 3401.000 Section 3401.000 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM 3401.000 Scope of part. The Federal Acquisition Regulation System...

The NASA Space Shuttle Earth Observations Office

NASA Technical Reports Server (NTRS)

Helfert, Michael R.; Wood, Charles A.

1989-01-01

The NASA Space Shuttle Earth Observations Office conducts astronaut training in earth observations, provides orbital documentation for acquisition of data and catalogs, and analyzes the astronaut handheld photography upon the return of Space Shuttle missions. This paper provides backgrounds on these functions and outlines the data constraints, organization, formats, and modes of access within the public domain.

Evolved Expendable Launch Vehicle: DOD Is Assessing Data on Worldwide Launch Market to Inform New Acquisition Strategy

DTIC Science & Technology

2016-07-22

Launch Services (ILS) of a Proton M launch vehicle and one provided by Space Exploration Technologies ( SpaceX ) of a Falcon 9 launch vehicle — and...U.S. based providers are United Launch Alliance (ULA), Space Exploration Technologies Corporation ( SpaceX ), and Orbital ATK. Countries we reviewed

Project UM-HAUL: A self-unloading reusable lunar lander

NASA Technical Reports Server (NTRS)

1991-01-01

The establishment of a lunar base is technologically and financially challenging. Given the necessary resources and political support, it can be done. In addition to the geopolitical obstacles, however, there are logistical problems involved in establishing such bases that can only be overcome with the acquisition of a significant transportation and communications network in the Earth-Moon spatial region. Considering the significant number of payloads that will be required in this process, the mass-specific cost of launching these payloads, and the added risk and cost of human presence in space, it is clearly desirable to automate major parts of such an operation. One very costly and time-consuming factor in this picture is the delivery of payloads to the Moon. Foreseeable payloads would include atmospheric modules, inflatable habitat kits, energy and oxygen plant elements, ground vehicles, laboratory modules, crew supplies, etc. The duration of high-risk human presence on the Moon could be greatly reduced if all such payloads were delivered to the prospective base site in advance of crew arrival. In this view, the idea of a 'Self-Unloading Reusable Lunar Lander' (SURLL) arises naturally. The general scenario depicts the lander being brought to low lunar orbit (LLO) from Earth atop a generic Orbital Transfer Vehicle (OTV). From LLO, the lander shuttles payloads down to the lunar surface, where, by means of some resident, detachable unloading device, it deploys the payloads and returns to orbit. The general goal is for the system to perform with maximum payload capability, automation, and reliability, while also minimizing environmental hazards, servicing needs, and mission costs. Our response to this demand is UM-HAUL, or the UnManned Heavy pAyload Unloader and Lander. The complete study includes a system description, along with a preliminary cost analysis and a design status assessment.

Project UM-HAUL: A self-unloading reusable lunar lander

NASA Astrophysics Data System (ADS)

The establishment of a lunar base is technologically and financially challenging. Given the necessary resources and political support, it can be done. In addition to the geopolitical obstacles, however, there are logistical problems involved in establishing such bases that can only be overcome with the acquisition of a significant transportation and communications network in the Earth-Moon spatial region. Considering the significant number of payloads that will be required in this process, the mass-specific cost of launching these payloads, and the added risk and cost of human presence in space, it is clearly desirable to automate major parts of such an operation. One very costly and time-consuming factor in this picture is the delivery of payloads to the Moon. Foreseeable payloads would include atmospheric modules, inflatable habitat kits, energy and oxygen plant elements, ground vehicles, laboratory modules, crew supplies, etc. The duration of high-risk human presence on the Moon could be greatly reduced if all such payloads were delivered to the prospective base site in advance of crew arrival. In this view, the idea of a 'Self-Unloading Reusable Lunar Lander' (SURLL) arises naturally. The general scenario depicts the lander being brought to low lunar orbit (LLO) from Earth atop a generic Orbital Transfer Vehicle (OTV). From LLO, the lander shuttles payloads down to the lunar surface, where, by means of some resident, detachable unloading device, it deploys the payloads and returns to orbit. The general goal is for the system to perform with maximum payload capability, automation, and reliability, while also minimizing environmental hazards, servicing needs, and mission costs. Our response to this demand is UM-HAUL, or the UnManned Heavy pAyload Unloader and Lander. The complete study includes a system description, along with a preliminary cost analysis and a design status assessment.

Milliwatt radioisotope power supply for the PASCAL Mars surface stations

NASA Astrophysics Data System (ADS)

Allen, Daniel T.; Murbach, Marcus S.

2001-02-01

A milliwatt power supply is being developed based on the 1 watt Light-Weight Radioisotope Heater Unit (RHU), which has already been used to provide heating alone on numerous spacecraft. In the past year the power supply has been integrated into the design of the proposed PASCAL Mars Network Mission, which is intended to place 24 surface climate monitoring stations on Mars. The PASCAL Mars mission calls for the individual surface stations to be transported together in one spacecraft on a trajectory direct from launch to orbit around Mars. From orbit around Mars each surface station will be deployed on a SCRAMP (slotted compression ramp) probe and, after aerodynamic and parachute deceleration, land at a preselected location on the planet. During descent sounding data and still images will be accumulated, and, once on the surface, the station will take measurements of pressure, temperature and overhead atmospheric optical depth for a period of 10 Mars years (18.8 Earth years). Power for periodic data acquisition and transmission to orbital then to Earth relay will come from a bank of ultracapacitors which will be continuously recharged by the radioisotope power supply. This electronic system has been designed and a breadboard built. In the ultimate design the electronics will be arrayed on the exterior surface of the radioisotope power supply in order to take advantage of the reject heat. This assembly in turn is packaged within the SCRAMP, and that assembly comprises the surface station. An electrically heated but otherwise prototypical power supply was operated in combination with the surface station breadboard system, which included the ultracapacitors. Other issues addressed in this work have been the capability of the generator to withstand the mechanical shock of the landing on Mars and the effectiveness of the generator's multi-foil vacuum thermal insulation. .

Satisfaction with ophthalmology residency training from the perspective of recent graduates: a cross-sectional study

PubMed Central

2013-01-01

Background Few studies have evaluated satisfaction with medical residency programs from the perspective of residents or recent graduates. Knowledge of current conditions of teaching might help to identify deficiencies and to provide adequate training. So, the aim of this study was to assess the satisfaction with residency training and to identify deficiencies in this training from the perspective of recent graduates in ophthalmology residency. Methods For this purpose, we developed a questionnaire and gaved it to recent graduates in ophthalmology residency in São Paulo, Brazil, from January to December 2010. The questions contained demographic information (age, sex and time of practice in ophthalmology), a Likert scale to evaluate the level of satisfaction with medical residency concerning clinical knowledge, surgical skills and doctor-patient relationship and questions about deficiency in clinical and surgical areas. Results The areas in which recent residency graduates were very or extremely satisfied were: acquisition of clinical knowledge (89.1%), acquisition of surgical skills (93.4%) and the development of doctor-patient relationship (74.9%). Specific areas of clinical knowledge in which they perceived more deficiency were orbit (48.3%) and ophthalmic pathology (47.9%), and in surgical skills were refractive surgery (65.9%) and orbit (59.2%) Conclusions The assessment of the satisfaction with residency training in ophthalmology from the perspective of recent graduates showed high level of satisfaction and identified specific deficiencies in ophthalmic pathology, refractive surgery and orbit. PMID:23706136

Issues With Access to Acquisition Data and Information in the Department of Defense: Doing Data Right in Weapon System Acquisition

DTIC Science & Technology

2016-04-30

Defense: Doing Data Right in Weapon System Acquisition Nancy Moore, Senior Management Scientist, RAND Megan McKernan, Defense Research Analyst...Access to Acquisition Data & Information in the Department of Defense: Doing Data Right in Weapon System Acquisition Nancy Moore, Senior Management...With Access to Acquisition Data and Information in the Department of Defense: Doing Data Right in Weapon System Acquisition Nancy Y. Moore—is a

48 CFR 1601.301 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Policy. 1601.301 Section 1601.301 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition...

48 CFR 1601.301 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Policy. 1601.301 Section 1601.301 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition...

The National Polar-orbiting Operational Environmental Satellite System

NASA Astrophysics Data System (ADS)

Hoffman, C. W.; Mango, S.; Schneider, S.; Duda, J.; Haas, J.; Bloom, H.

2005-12-01

Over the last decade, the tri-agency Integrated Program Office (IPO), comprised of the National Oceanic and Atmospheric Administration (NOAA), the Department of Defense (DoD), and the National Aeronautics and Space Administration (NASA), has been managing the development of the National Polar-orbiting Operational Environmental Satellite System (NPOESS). Once operational later this decade, NPOESS will replace NOAA's Polar-orbiting Operational Environmental Satellites (POES) and DoD's Defense Meteorological Satellite Program (DMSP) systems. The IPO, through its Acquisition and Operations contractor, Northrop Grumman, will launch NPOESS spacecraft into three orbital planes to provide a single, national system capable of satisfying both civil and national security requirements for space-based, remotely sensed environmental data. With the development of NPOESS, we are evolving the existing 'weather' satellites into integrated environmental observing systems by expanding our capabilities to observe, assess, and predict the total Earth system - ocean, atmosphere, land, and the space environment. NPOESS will transform today's short-term, space-based ocean research missions into a sustained, operational ocean remote sensing observation program. Ocean measurements comprise one-fourth of the 55 user-validated requirements for geophysical measurements that will be made by NPOESS sensors. In 1997, the IPO initiated a robust sensor risk reduction effort for early development of the critical sensor suites and algorithms necessary to support NPOESS. In 2001, preliminary design efforts were completed for the last of five critical imaging/sounding instruments for NPOESS. Ocean requirements have directly and substantially 'driven' the design of three NPOESS sensors: the Visible/Infrared Imager Radiometer Suite (VIIRS); the Conical-scanning Microwave Imager/Sounder (CMIS); and the Altimeter. With these instruments, NPOESS will deliver higher resolution (spatial and temporal) and more accurate measurements of sea surface temperature (SST), ocean surface wind vectors/stress, ocean color and suspended matter, sea ice (edge motion, age, surface temperature, thickness), oceanic heat flux, significant wave height, and sea surface topography. Infrared and microwave measurements of sea surface temperature from VIIRS and CMIS, respectively, will be combined to produce 'all weather' SST products. VIIRS imagery and altimeter measurements will be used to derive ocean circulation parameters to meet monitoring requirements for both operational and research purposes. The advanced technology visible, infrared, and microwave imagers and sounders that will fly on NPOESS will deliver higher spatial and temporal resolution oceanic, atmospheric, terrestrial, climatic, and solar-geophysical data, enabling more accurate short-term weather forecasts and severe storm warnings and improved real-time monitoring of coastal and open ocean phenomena. NPOESS will also provide continuity of critical data for monitoring, understanding, and predicting climate change and assessing the impacts of climate change on seasonal and longer time scales. The NPOESS team is well along the path to creating a high performance, polar-orbiting satellite system that will be more responsive to user requirements, deliver more capability at less cost, and provide sustained, space-based measurements as a cornerstone of an Integrated Global Observing System.

48 CFR 7.102 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Policy. 7.102 Section 7.102 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Plans 7.102 Policy. (a) Agencies shall perform acquisition planning and...

48 CFR 7.102 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Policy. 7.102 Section 7.102 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Plans 7.102 Policy. (a) Agencies shall perform acquisition planning and...

Auxiliary Propulsion Activities in Support of NASA's Exploration Initiative

NASA Technical Reports Server (NTRS)

Best, Philip J.; Unger, Ronald J.; Waits, David A.

2005-01-01

The Space Launch Initiative (SLI) procurement mechanism NRA8-30 initiated the Auxiliary Propulsion System/Main Propulsion System (APS/MPS) Project in 2001 to address technology gaps and development risks for non-toxic and cryogenic propellants for auxiliary propulsion applications. These applications include reaction control and orbital maneuvering engines, and storage, pressure control, and transfer technologies associated with on-orbit maintenance of cryogens. The project has successfully evolved over several years in response to changing requirements for re-usable launch vehicle technologies, general launch technology improvements, and, most recently, exploration technologies. Lessons learned based on actual hardware performance have also played a part in the project evolution to focus now on those technologies deemed specifically relevant to the Exploration Initiative. Formal relevance reviews held in the spring of 2004 resulted in authority for continuation of the Auxiliary Propulsion Project through Fiscal Year 2005 (FY05), and provided for a direct reporting path to the Exploration Systems Mission Directorate. The tasks determined to be relevant under the project were: continuation of the development, fabrication, and delivery of three 870 lbf thrust prototype LOX/ethanol reaction control engines; the fabrication, assembly, engine integration and testing of the Auxiliary Propulsion Test Bed at White Sands Test Facility; and the completion of FY04 cryogenic fluid management component and subsystem development tasks (mass gauging, pressure control, and liquid acquisition elements). This paper presents an overview of those tasks, their scope, expectations, and results to-date as carried forward into the Exploration Initiative.

STS-70 mission highlights

NASA Astrophysics Data System (ADS)

1995-09-01

The highlights of the STS-70 mission are presented in this video. The flight crew consisted of Cmdr. John Hendricks, Pilot Kevin Kregel, Flight Engineer Nancy Curie, and Mission Specialists Dr. Don Thomas and Dr. Mary Ellen Weber. The mission's primary objective was the deployment of the 7th Tracking Data and Relay Satellite (TDRS), which will provide a communication, tracking, telemetry, data acquisition, and command services space-based network system essential to low Earth orbital spacecraft. Secondary mission objectives included activating and studying the Physiological and Anatomical Rodent Experiment/National Institutes of Health-Rodents (PARE/NIH-R), The Bioreactor Demonstration System (BDS), the Commercial Protein Crystal Growth (CPCG) studies, the Space Tissue Loss/National Institutes of Health-Cells (STL/NIH-C) experiment, the Biological Research in Canisters (BRIC) experiment, Shuttle Amateur Radio Experiment-2 (SAREX-2), the Visual Function Tester-4 (VFT-4), the Hand-Held, Earth Oriented, Real-Time, Cooperative, User-Friendly, Location-Targeting and Environmental System (HERCULES), the Microcapsules in Space-B (MIS-B) experiment, the Windows Experiment (WINDEX), the Radiation Monitoring Equipment-3 (RME-3), and the Military Applications of Ship Tracks (MAST) experiment. There was an in-orbit dedication ceremony by the spacecrew and the newly Integrated Mission Control Center to commemorate the Center's integration. The STS-70 mission was the first mission monitored by this new control center. Earth views included the Earth's atmosphere, a sunrise over the Earth's horizon, several views of various land masses, some B/W lightning shots, some cloud cover, and a tropical storm.

HSI in NASA: From Research to Implementation

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Plaga, John A.

2016-01-01

As NASA plans to send human explorers beyond low Earth orbit, onward to Mars and other destinations in the solar system, there will be new challenges to address in terms of HSI. These exploration missions will be quite different from the current and past missions such as Apollo, Shuttle, and International Space Station. The exploration crew will be more autonomous from ground mission control with delayed, and at times, no communication. They will have limited to no resupply for much longer mission durations. Systems to deliver and support extended human habitation at these destinations are extremely complex and unique, presenting new opportunities to employ HSI practices. In order to have an effective and affordable HSI implementation, both research and programmatic efforts are required. Currently, the HSI-related research at NASA is primarily in the area of space human factors and habitability. The purpose is to provide human health and performance countermeasures, knowledge, technologies, and tools to enable safe, reliable, and productive human space exploration beyond low Earth orbit, and update standards, requirements, and processes to verify and validate these requirements. In addition, HSI teams are actively engaged in technology development and demonstration efforts to influence the mission architecture and next-generation vehicle design. Finally, appropriate HSI references have been added to NASA' s systems engineering documentation, and an HSI Practitioner's Guide has been published to help design engineers consider HSI early and continuously in the acquisition process. These current and planned HSI-related activities at NASA will be discussed in this panel.

Spacecraft attitude impacts on COLD-SAT non-vacuum jacketed LH2 supply tank thermal performance

NASA Technical Reports Server (NTRS)

Arif, Hugh

1990-01-01

The Cryogenic On-Orbit Liquid Depot - Storage, Acquisition and Transfer (COLD-SAT) spacecraft will be launched into low earth orbit to perform fluid management experiments on the behavior of subcritical liquid hydrogen (LH2). For determining the optimum on-orbit attitude for the COLD-SAT satellite, a comparative analytical study was performed to determine the thermal impacts of spacecraft attitude on the performance of the COLD-SAT non-vacuum jacketed LH2 supply tank. Tank thermal performance was quantitied by total conductive and radiative heat leakage into the pressure vessel due to the absorbed solar, earth albedo and infra-red on-orbit fluxes, and also by the uniformity of the variation of this leakage on the vessel surface area. Geometric and thermal analysis math models were developed for the spacecraft and the tank as part of this analysis, based on their individual thermal/structural designs. Two quasi-inertial spacecraft attitudes were investigated and their effects on the tank performance compared. The results are one of the criteria by which the spacecraft orientation in orbit was selected for the in-house NASA Lewis Research Center design.

Spacecraft attitude impacts on COLD-SAT non-vacuum jacketed LH2 supply tank thermal performance

NASA Technical Reports Server (NTRS)

Arif, Hugh

1990-01-01

The Cryogenic On-Orbit Liquid Depot - Storage, Acquisition and Transfer (COLD-SAT) spacecraft will be launched into low earth orbit to perform fluid management experiments on the behavior of subcritical liquid hydrogen (LH2). For determining the optimum on-orbit attitude for the COLD-SAT satellite, a comparative analytical study was performed to determine the thermal impacts of spacecraft attitude on the performance of the COLD-SAT non-vacuum jacketed LH2 supply tank. Tank thermal performance was quantified by total conductive and radiative heat leakage into the pressure vessel due to the absorbed solar, earth albedo and infra-red on-orbit fluxes, and also by the uniformity of the variation of this leakage on the vessel surface area. Geometric and thermal analysis math models were developed for the spacecraft and the tank as part of this analysis, based on their individual thermal/structural designs. Two quasi-inertial spacecraft attitudes were investigated and their effects on the tank performance compared. The results are one of the criteria by which the spacecraft orientation in orbit was selected for the in-house NASA Lewis Research Center design.

The Attitude Control System for the Wilkinson Microwave Anisotropy Probe

NASA Technical Reports Server (NTRS)

Markley, F. Landis; Andrews, Stephen F.; ODonnell, James R., Jr.; Ward, David K.

2003-01-01

The Wilkinson Microwave Anisotropy Probe mission produces a map of the cosmic microwave background radiation over the entire celestial sphere by executing a fast spin and a slow precession of its spin axis about the Sun line to obtain a highly interconnected set of measurements. The spacecraft attitude is sensed and controlled using an inertial reference unit, two star trackers, a digital sun sensor, twelve coarse sun sensors, three reaction wheel assemblies, and a propulsion system. Sufficient attitude knowledge is provided to yield instrument pointing to a standard deviation (l sigma) of 1.3 arc-minutes per axis. In addition, the spacecraft acquires and holds the sunline at initial acquisition and in the event of a failure, and slews to the proper orbit adjust orientations and to the proper off-sunline attitude to start the compound spin. This paper presents an overview of the design of the attitude control system to carry out this mission and presents some early flight experience.

Earth Observing System (EOS) Aqua Launch and Early Mission Attitude Support Experiences

NASA Technical Reports Server (NTRS)

Tracewell, D.; Glickman, J.; Hashmall, J.; Natanson, G.; Sedlak, J.

2003-01-01

The Earth Observing System (EOS) Aqua satellite was successfully launched on May 4,2002. Aqua is the second in the series of EOS satellites. EOS is part of NASA s Earth Science Enterprise Program, whose goals are to advance the scientific understanding of the Earth system. Aqua is a three-axis stabilized, Earth-pointing spacecraft in a nearly circular, sun-synchronous orbit at an altitude of 705 km. The Goddard Space Flight Center (GSFC) Flight Dynamics attitude team supported all phases of the launch and early mission. This paper presents the main results and lessons learned during this period, including: real-time attitude mode transition support, sensor calibration, onboard computer attitude validation, response to spacecraft emergencies, postlaunch attitude analyses, and anomaly resolution. In particular, Flight Dynamics support proved to be invaluable for successful Earth acquisition, fine-point mode transition, and recognition and correction of several anomalies, including support for the resolution of problems observed with the MODIS instrument.

Exploration Requirements Development Utilizing the Strategy-to-Task-to-Technology Development Approach

NASA Technical Reports Server (NTRS)

Drake, Bret G.; Josten, B. Kent; Monell, Donald W.

2004-01-01

The Vision for Space Exploration provides direction for the National Aeronautics and Space Administration to embark on a robust space exploration program that will advance the Nation s scientific, security, and economic interests. This plan calls for a progressive expansion of human capabilities beyond low earth orbit seeking to answer profound scientific and philosophical questions while responding to discoveries along the way. In addition, the Vision articulates the strategy for developing the revolutionary new technologies and capabilities required for the future exploration of the solar system. The National Aeronautics and Space Administration faces new challenges in successfully implementing the Vision. In order to implement a sustained and affordable exploration endeavor it is vital for NASA to do business differently. This paper provides an overview of the strategy-to-task-to-technology process being used by NASA s Exploration Systems Mission Directorate to develop the requirements and system acquisition details necessary for implementing a sustainable exploration vision.

48 CFR 18.113 - Interagency acquisitions under the Economy Act.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Interagency acquisitions under the Economy Act. 18.113 Section 18.113 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.113 Interagency acquisitions under...

Observation planning algorithm of a Japanese space-borne sensor: Hyperspectral Imager SUIte (HISUI) onboard International Space Station (ISS) as platform

NASA Astrophysics Data System (ADS)

Ogawa, Kenta; Konno, Yukiko; Yamamoto, Satoru; Matsunaga, Tsuneo; Tachikawa, Tetsushi; Komoda, Mako

2017-09-01

Hyperspectral Imager Suite (HISUI) is a Japanese future space-borne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI). HISUI will be launched in 2019 or later onboard International Space Station (ISS) as platform. HISUI has 185 spectral band from 0.4 to 2.5 μm with 20 by 30 m spatial resolution with swath of 20 km. Swath is limited as such, however observations in continental scale area are requested in HISUI mission lifetime of three years. Therefore we are developing a scheduling algorithm to generate effective observation plans. HISUI scheduling algorithm is to generate observation plans automatically based on platform orbit, observation area maps (we say DAR; "Data Acquisition Request" in HISUI project), their priorities, and available resources and limitation of HISUI system such as instrument operation time per orbit and data transfer capability. Then next we need to set adequate DAR before start of HISUI observation, because years of observations are needed to cover continental scale wide area that is difficult to change after the mission started. To address these issues, we have developed observation simulator. The simulator's critical inputs are DAR and the ISS's orbit, HISUI limitations in observation minutes per orbit, data storage and past cloud coverage data for term of HISUI observations (3 years). Then the outputs of simulator are coverage map of each day. Areas with cloud free image are accumulated for the term of observation up to three years. We have successfully tested the simulator and tentative DAR and found that it is possible to estimate coverage for each of requests for the mission lifetime.

The Evolution of System Safety at NASA

NASA Technical Reports Server (NTRS)

Dezfuli, Homayoon; Everett, Chris; Groen, Frank

2014-01-01

The NASA system safety framework is in the process of change, motivated by the desire to promote an objectives-driven approach to system safety that explicitly focuses system safety efforts on system-level safety performance, and serves to unify, in a purposeful manner, safety-related activities that otherwise might be done in a way that results in gaps, redundancies, or unnecessary work. An objectives-driven approach to system safety affords more flexibility to determine, on a system-specific basis, the means by which adequate safety is achieved and verified. Such flexibility and efficiency is becoming increasingly important in the face of evolving engineering modalities and acquisition models, where, for example, NASA will increasingly rely on commercial providers for transportation services to low-earth orbit. A key element of this objectives-driven approach is the use of the risk-informed safety case (RISC): a structured argument, supported by a body of evidence, that provides a compelling, comprehensible and valid case that a system is or will be adequately safe for a given application in a given environment. The RISC addresses each of the objectives defined for the system, providing a rational basis for making informed risk acceptance decisions at relevant decision points in the system life cycle.

48 CFR 1.303 - Publication and codification.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Publication and codification. 1.303 Section 1.303 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition Regulations 1.303 Publication and codification...

48 CFR Appendix - Federal Acquisition Regulation (FAR) Index

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Federal Acquisition Regulation (FAR) Index Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT USE OF GOVERNMENT SOURCES BY CONTRACTORS Contractor Use of Interagency Fleet Management System...

48 CFR 252.211-7000 - Acquisition streamlining.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Acquisition streamlining. 252.211-7000 Section 252.211-7000 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text...

48 CFR 1.303 - Publication and codification.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Publication and codification. 1.303 Section 1.303 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition Regulations 1.303 Publication and codification...

48 CFR 1.303 - Publication and codification.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Publication and codification. 1.303 Section 1.303 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition Regulations 1.303 Publication and codification...

48 CFR 207.471 - Funding requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Funding requirements. 207.471 Section 207.471 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE ACQUISITION PLANNING ACQUISITION PLANNING Equipment Lease or Purchase 207.471 Funding...

48 CFR 207.471 - Funding requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Funding requirements. 207.471 Section 207.471 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE ACQUISITION PLANNING ACQUISITION PLANNING Equipment Lease or Purchase 207.471 Funding...

48 CFR 207.471 - Funding requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Funding requirements. 207.471 Section 207.471 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE ACQUISITION PLANNING ACQUISITION PLANNING Equipment Lease or Purchase 207.471 Funding...

48 CFR 207.471 - Funding requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Funding requirements. 207.471 Section 207.471 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE ACQUISITION PLANNING ACQUISITION PLANNING Equipment Lease or Purchase 207.471 Funding...

48 CFR 3401.304 - Agency control and compliance procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Agency control and compliance procedures. 3401.304 Section 3401.304 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations...

48 CFR 3046.790 - Use of warranties in major systems acquisitions by the USCG (USCG).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Use of warranties in major systems acquisitions by the USCG (USCG). 3046.790 Section 3046.790 Federal Acquisition Regulations System DEPARTMENT OF HOMELAND SECURITY, HOMELAND SECURITY ACQUISITION REGULATION (HSAR) CONTRACT MANAGEMENT QUALITY...

Integrated orbital servicing study for low-cost payload programs. Volume 2: Technical and cost analysis

NASA Technical Reports Server (NTRS)

Cody, E. R.; Deats, C. L.; Derocher, W. L., Jr.; Kyrias, G. M.; Snodgrass, M. R.; Sosnay, R. D.; Spencer, R. A.; Wudell, A. E.

1975-01-01

Orbital maintenance concepts were examined in an effort to determine a cost effective orbital maintenance system compatible with the space transportation system. An on-orbit servicer maintenance system is recommended as the most cost effective system. A pivoting arm on-orbit servicer was selected and a preliminary design was prepared. It is indicated that orbital maintenance does not have any significant impact on the space transportation system.

The HARPS search for southern extra-solar planets . XXXII. New multi-planet systems in the HARPS volume limited sample: a super-Earth and a Neptune in the habitable zone

NASA Astrophysics Data System (ADS)

Lo Curto, G.; Mayor, M.; Benz, W.; Bouchy, F.; Hébrard, G.; Lovis, C.; Moutou, C.; Naef, D.; Pepe, F.; Queloz, D.; Santos, N. C.; Segransan, D.; Udry, S.

2013-03-01

The vast diversity of planetary systems detected to date is defying our capability of understanding their formation and evolution. Well-defined volume-limited surveys are the best tool at our disposal to tackle the problem, via the acquisition of robust statistics of the orbital elements. We are using the HARPS spectrograph to conduct our survey of ≈850 nearby solar-type stars, and in the course of the past nine years we have monitored the radial velocity of HD 103774, HD 109271, and BD-061339. In this work we present the detection of five planets orbiting these stars, with msin (i) between 0.6 and 7 Neptune masses, four of which are in two multiple systems, comprising one super-Earth and one planet within the habitable zone of a late-type dwarf. Although for strategic reasons we chose efficiency over precision in this survey, we have the capability to detect planets down to the Neptune and super-Earth mass range as well as multiple systems, provided that enough data points are made available. Based on observations made with the HARPS instrument on the ESO 3.6 m telescope at La Silla (Chile), under the GTO program ID 072.C-0488 and the regular programs: 085.C-0019, 087.C-0831 and 089.C-0732. RV data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A59

48 CFR 225.7303-3 - Government-to-government agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Government-to-government agreements. 225.7303-3 Section 225.7303-3 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Acquisitions for Foreign...

48 CFR 205.301 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false General. 205.301 Section 205.301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... acquisition threshold that are for the acquisition of any clothing, fiber, yarn, or fabric items described in...

48 CFR 205.301 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false General. 205.301 Section 205.301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... acquisition threshold that are for the acquisition of any clothing, fiber, yarn, or fabric items described in...

48 CFR 237.7001 - Method of acquisition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Method of acquisition. 237.7001 Section 237.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... contract exists, use DD Form 1155, Order for Supplies or Services, to obtain mortuary services. ...

48 CFR 1.304 - Agency control and compliance procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Agency control and compliance procedures. 1.304 Section 1.304 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Agency Acquisition Regulations 1.304 Agency control...

Demonstration of various rotor instabilities (exhibit of Bently Rotor Dynamics Research Corporation Laborator rigs at symposium on instability in rotaing machinery)

NASA Technical Reports Server (NTRS)

Muszynska, A.

1985-01-01

The operation of rotor rigs used to demonstrate various instability phenomena occurring in rotating machines is described. The instability phenomena demonstrated included oil whirl/whip antiswirl, rub, loose rotating parts, water-lubricated bearing instabilities, and cracked shaft. The rotor rigs were also used to show corrective measures for preventing instabilities. Vibrational response data from the rigs were taken with modern, computerized instrumentation. The rotor nonsynchronous perturbation rig demonstrated modal identification techniques for rotor/bearing systems. Computer-aided data acquisition and presentation, using the dynamic stiffness method, makes it possible to identify rotor and bearing parameters for low modes. The shaft mode demonstrator presented the amplified modal shape line of the shaft excited by inertia forces of unbalance (synchronous perturbation). The first three bending modes of the shaft can be demonstrated. The user-friendly software, Orbits, presented a simulation of rotor precessional motion that is characteristic of various instability phenomena. The data presentation demonstration used data measured on a turbine driven compressor train as an example of how computer aided data acquisition and presentation assists in identifying rotating machine malfunctions.

OSIRIS-REx Asteroid Sample-Return Mission

NASA Astrophysics Data System (ADS)

DellaGiustina, D. N.; Lauretta, D. S.

2016-12-01

Launching in September 2016, the primary objective of the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission is to return a pristine sample of asteroid (101955) Bennu to Earth for sample analysis. Bennu is a carbonaceous primitive near-Earth object, and is expected to be rich in volatile and organic material leftover from the formation of the Solar System. OSIRIS-REx will return a minimum of 60 g of bulk surface material from this body using a novel "touch-and-go" sample acquisition mechanism. Analyses of these samples will provide unprecedented knowledge about presolar history, from the initial stages of planet formation to the origin of life. Before sample acquisition, OSIRIS-REx will perform global mapping of Bennu, detailing the asteroid's composition and texture, resolving surface features, revealing its geologic and dynamic history, and providing context for the returned samples. The mission will also document the sampling site in situ at sub-centimeter scales, as well as the asteroid sampling event. In addition, OSIRIS-REx will measure the Yarkovsky effect, a non-Keplerian force affecting the orbit of this potentially hazardous asteroid, and provide a ground truth data for the interpretation of telescopic observations of carbonaceous asteroids.

Continental-Scale Validation of Modis-Based and LEDAPS Landsat ETM + Atmospheric Correction Methods

NASA Technical Reports Server (NTRS)

Ju, Junchang; Roy, David P.; Vermote, Eric; Masek, Jeffrey; Kovalskyy, Valeriy

2012-01-01

The potential of Landsat data processing to provide systematic continental scale products has been demonstratedby several projects including the NASA Web-enabled Landsat Data (WELD) project. The recent freeavailability of Landsat data increases the need for robust and efficient atmospheric correction algorithms applicableto large volume Landsat data sets. This paper compares the accuracy of two Landsat atmospheric correctionmethods: a MODIS-based method and the Landsat Ecosystem Disturbance Adaptive ProcessingSystem (LEDAPS) method. Both methods are based on the 6SV radiative transfer code but have different atmosphericcharacterization approaches. The MODIS-based method uses the MODIS Terra derived dynamicaerosol type, aerosol optical thickness, and water vapor to atmospherically correct ETM+ acquisitions ineach coincident orbit. The LEDAPS method uses aerosol characterizations derived independently from eachLandsat acquisition and assumes a fixed continental aerosol type and uses ancillary water vapor. Validationresults are presented comparing ETM+ atmospherically corrected data generated using these two methodswith AERONET corrected ETM+ data for 95 10 km10 km 30 m subsets, a total of nearly 8 million 30 mpixels, located across the conterminous United States. The results indicate that the MODIS-based methodhas better accuracy than the LEDAPS method for the ETM+ red and longer wavelength bands.

Earth orbit navigation study. Volume 2: System evaluation

NASA Technical Reports Server (NTRS)

1972-01-01

An overall systems evaluation was made of five candidate navigation systems in support of earth orbit missions. The five systems were horizon sensor system, unkown landmark tracking system, ground transponder system, manned space flight network, and tracking and data relay satellite system. Two reference missions were chosen: a low earth orbit mission and a transfer trajectory mission from low earth orbit to geosynchronous orbit. The specific areas addressed in the evaluation were performance, multifunction utilization, system mechanization, and cost.

Remote observations of reentering spacecraft including the space shuttle orbiter

NASA Astrophysics Data System (ADS)

Horvath, Thomas J.; Cagle, Melinda F.; Grinstead, Jay H.; Gibson, David M.

Flight measurement is a critical phase in development, validation and certification processes of technologies destined for future civilian and military operational capabilities. This paper focuses on several recent NASA-sponsored remote observations that have provided unique engineering and scientific insights of reentry vehicle flight phenomenology and performance that could not necessarily be obtained with more traditional instrumentation methods such as onboard discrete surface sensors. The missions highlighted include multiple spatially-resolved infrared observations of the NASA Space Shuttle Orbiter during hypersonic reentry from 2009 to 2011, and emission spectroscopy of comparatively small-sized sample return capsules returning from exploration missions. Emphasis has been placed upon identifying the challenges associated with these remote sensing missions with focus on end-to-end aspects that include the initial science objective, selection of the appropriate imaging platform and instrumentation suite, target flight path analysis and acquisition strategy, pre-mission simulations to optimize sensor configuration, logistics and communications during the actual observation. Explored are collaborative opportunities and technology investments required to develop a next-generation quantitative imaging system (i.e., an intelligent sensor and platform) with greater capability, which could more affordably support cross cutting civilian and military flight test needs.

Quantitative analysis of geomorphic processes using satellite image data at different scales

NASA Technical Reports Server (NTRS)

Williams, R. S., Jr.

1985-01-01

When aerial and satellite photographs and images are used in the quantitative analysis of geomorphic processes, either through direct observation of active processes or by analysis of landforms resulting from inferred active or dormant processes, a number of limitations in the use of such data must be considered. Active geomorphic processes work at different scales and rates. Therefore, the capability of imaging an active or dormant process depends primarily on the scale of the process and the spatial-resolution characteristic of the imaging system. Scale is an important factor in recording continuous and discontinuous active geomorphic processes, because what is not recorded will not be considered or even suspected in the analysis of orbital images. If the geomorphic process of landform change caused by the process is less than 200 m in x to y dimension, then it will not be recorded. Although the scale factor is critical, in the recording of discontinuous active geomorphic processes, the repeat interval of orbital-image acquisition of a planetary surface also is a consideration in order to capture a recurring short-lived geomorphic process or to record changes caused by either a continuous or a discontinuous geomorphic process.

Remote Observations of Reentering Spacecraft Including the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Horvath, Thomas J.; Cagle, Melinda F.; Grinstead, jay H.; Gibson, David

2013-01-01

Flight measurement is a critical phase in development, validation and certification processes of technologies destined for future civilian and military operational capabilities. This paper focuses on several recent NASA-sponsored remote observations that have provided unique engineering and scientific insights of reentry vehicle flight phenomenology and performance that could not necessarily be obtained with more traditional instrumentation methods such as onboard discrete surface sensors. The missions highlighted include multiple spatially-resolved infrared observations of the NASA Space Shuttle Orbiter during hypersonic reentry from 2009 to 2011, and emission spectroscopy of comparatively small-sized sample return capsules returning from exploration missions. Emphasis has been placed upon identifying the challenges associated with these remote sensing missions with focus on end-to-end aspects that include the initial science objective, selection of the appropriate imaging platform and instrumentation suite, target flight path analysis and acquisition strategy, pre-mission simulations to optimize sensor configuration, logistics and communications during the actual observation. Explored are collaborative opportunities and technology investments required to develop a next-generation quantitative imaging system (i.e., an intelligent sensor and platform) with greater capability, which could more affordably support cross cutting civilian and military flight test needs.

Introduction to Defense Acquisition Management

DTIC Science & Technology

1989-03-01

the system after Most new systems follow the same formatted and its usefullness in the weapon inventory predictable life cycle, and fit the model...natives for system concept development Statement (MNS) setting forth requirements need- -An acquisition strategy is developed to guide ed to meet the...6 BUSINESS, FINANCIAL AND TECHNICAL ASPECTS OF SYSTEMS ACQUISITION Management of the systems acquisition process The acquisition planning phase of the

48 CFR 234.003 - Responsibilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Responsibilities. 234.003 Section 234.003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION 234.003 Responsibilities. DoDD...

Three dimensional dose distribution comparison of simple and complex acquisition trajectories in dedicated breast CT

PubMed Central

Shah, Jainil P.; Mann, Steve D.; McKinley, Randolph L.; Tornai, Martin P.

2015-01-01

Purpose: A novel breast CT system capable of arbitrary 3D trajectories has been developed to address cone beam sampling insufficiency as well as to image further into the patient’s chest wall. The purpose of this study was to characterize any trajectory-related differences in 3D x-ray dose distribution in a pendant target when imaged with different orbits. Methods: Two acquisition trajectories were evaluated: circular azimuthal (no-tilt) and sinusoidal (saddle) orbit with ±15° tilts around a pendant breast, using Monte Carlo simulations as well as physical measurements. Simulations were performed with tungsten (W) filtration of a W-anode source; the simulated source flux was normalized to the measured exposure of a W-anode source. A water-filled cylindrical phantom was divided into 1 cm3 voxels, and the cumulative energy deposited was tracked in each voxel. Energy deposited per voxel was converted to dose, yielding the 3D distributed dose volumes. Additionally, three cylindrical phantoms of different diameters (10, 12.5, and 15 cm) and an anthropomorphic breast phantom, initially filled with water (mimicking pure fibroglandular tissue) and then with a 75% methanol-25% water mixture (mimicking 50–50 fibroglandular-adipose tissues), were used to simulate the pendant breast geometry and scanned on the physical system. Ionization chamber calibrated radiochromic film was used to determine the dose delivered in a 2D plane through the center of the volume for a fully 3D CT scan using the different orbits. Results: Measured experimental results for the same exposure indicated that the mean dose measured throughout the central slice for different diameters ranged from 3.93 to 5.28 mGy, with the lowest average dose measured on the largest cylinder with water mimicking a homogeneously fibroglandular breast. These results align well with the cylinder phantom Monte Carlo studies which also showed a marginal difference in dose delivered by a saddle trajectory in the central slice. Regardless of phantom material or filled fluid density, dose delivered by the saddle scan was negligibly different than the simple circular, no-tilt scans. The average dose measured in the breast phantom was marginally higher for saddle than the circular no tilt scan at 3.82 and 3.87 mGy, respectively. Conclusions: Not only does nontraditional 3D-trajectory CT scanning yield more complete sampling of the breast volume but also has comparable dose deposition throughout the breast and anterior chest volume, as verified by Monte Carlo simulation and physical measurements. PMID:26233179

48 CFR 34.000 - Scope of part.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Scope of part. 34.000... CONTRACTING MAJOR SYSTEM ACQUISITION General 34.000 Scope of part. This part describes acquisition policies... of an Earned Value Management System in acquisitions designated as major acquisitions consistent with...

48 CFR 34.000 - Scope of part.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Scope of part. 34.000... CONTRACTING MAJOR SYSTEM ACQUISITION General 34.000 Scope of part. This part describes acquisition policies... of an Earned Value Management System in acquisitions designated as major acquisitions consistent with...

48 CFR 34.000 - Scope of part.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Scope of part. 34.000... CONTRACTING MAJOR SYSTEM ACQUISITION General 34.000 Scope of part. This part describes acquisition policies... of an Earned Value Management System in acquisitions designated as major acquisitions consistent with...

48 CFR Appendix - Federal Acquisition Regulation (FAR) Index

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Federal Acquisition Regulation (FAR) Index Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT USE OF GOVERNMENT SOURCES BY CONTRACTORS Contractor Use of Interagency Fleet Management System (IFMS) Contract clause. FAR Index Federal...

48 CFR Appendix - Federal Acquisition Regulation (FAR) Index

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Federal Acquisition Regulation (FAR) Index Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT USE OF GOVERNMENT SOURCES BY CONTRACTORS Contractor Use of Interagency Fleet Management System (IFMS) Contract clause. FAR Index Federal...

Conceptual design of the ITER fast-ion loss detector.

PubMed

Garcia-Munoz, M; Kocan, M; Ayllon-Guerola, J; Bertalot, L; Bonnet, Y; Casal, N; Galdon, J; Garcia Lopez, J; Giacomin, T; Gonzalez-Martin, J; Gunn, J P; Jimenez-Ramos, M C; Kiptily, V; Pinches, S D; Rodriguez-Ramos, M; Reichle, R; Rivero-Rodriguez, J F; Sanchis-Sanchez, L; Snicker, A; Vayakis, G; Veshchev, E; Vorpahl, Ch; Walsh, M; Walton, R

2016-11-01

A conceptual design of a reciprocating fast-ion loss detector for ITER has been developed and is presented here. Fast-ion orbit simulations in a 3D magnetic equilibrium and up-to-date first wall have been carried out to revise the measurement requirements for the lost alpha monitor in ITER. In agreement with recent observations, the simulations presented here suggest that a pitch-angle resolution of ∼5° might be necessary to identify the loss mechanisms. Synthetic measurements including realistic lost alpha-particle as well as neutron and gamma fluxes predict scintillator signal-to-noise levels measurable with standard light acquisition systems with the detector aperture at ∼11 cm outside of the diagnostic first wall. At measurement position, heat load on detector head is comparable to that in present devices.

The FRALIT teledetection program, using the ERTS-A satellite, for the oceanic littoral of France

NASA Technical Reports Server (NTRS)

Verger, F. (Principal Investigator); Cazabat, C.; Demathieu, P.; Dupuis, J.

1972-01-01

There are no author-identified significant results in this report. The French Atlantic Littoral program, utilizing data from the ERTS-1 satellite, is considered. It involves teledetection of the French shoreline along the Atlantic Ocean and English Channel. A description is given of the ERTS-1 orbit and the satellite itself, including the attitude control system, and the data acquisition and transmission equipment. The geographic extent of the area covered by the program is delineated and the subjects studied are enumerated. These include the geomorphology, pedology, hydrology, and vegetation of the maritime marshes; sedimentology, morphology, and hydrology of the intertidal zones; and transport of material in suspension to the mouths of the Seine, the Loire, and the Gironde as a part of the coastal waters study.

Wave-particle interactions on the FAST satellite

NASA Technical Reports Server (NTRS)

Temerin, M. A.; Carlson, C. W.; Cattell, C. A.; Ergun, R. E.; Mcfadden, J. P.

1990-01-01

NASA's Fast Auroral Snapshot, or 'FAST' satellite, scheduled for launch in 1993, will investigate the plasma physics of the low altitude auroral zone from a 3500-km apogee polar orbit. FAST will give attention to wave, double-layer, and soliton production processes due to electrons and ions, as well as to wave-wave interactions, and the acceleration of electrons and ions by waves and electric fields. FAST will employ an intelligent data-handling system capacle of data acquisition at rates of up to 1 Mb/sec, in addition to a 1-Gbit solid-state memory. The data need be gathered for only a few minutes during passes through the auroral zone, since the most interesting auroral phenomena occur in such narrow regions as auroral arcs, electrostatic shocks, and superthermal electron bursts.

48 CFR 12.101 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Policy. 12.101 Section 12.101 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING ACQUISITION OF COMMERCIAL ITEMS Acquisition of Commercial Items-General 12.101 Policy. Agencies shall— (a...

Automatic Overset Grid Generation with Heuristic Feedback Control

NASA Technical Reports Server (NTRS)

Robinson, Peter I.

2001-01-01

An advancing front grid generation system for structured Overset grids is presented which automatically modifies Overset structured surface grids and control lines until user-specified grid qualities are achieved. The system is demonstrated on two examples: the first refines a space shuttle fuselage control line until global truncation error is achieved; the second advances, from control lines, the space shuttle orbiter fuselage top and fuselage side surface grids until proper overlap is achieved. Surface grids are generated in minutes for complex geometries. The system is implemented as a heuristic feedback control (HFC) expert system which iteratively modifies the input specifications for Overset control line and surface grids. It is developed as an extension of modern control theory, production rules systems and subsumption architectures. The methodology provides benefits over the full knowledge lifecycle of an expert system for knowledge acquisition, knowledge representation, and knowledge execution. The vector/matrix framework of modern control theory systematically acquires and represents expert system knowledge. Missing matrix elements imply missing expert knowledge. The execution of the expert system knowledge is performed through symbolic execution of the matrix algebra equations of modern control theory. The dot product operation of matrix algebra is generalized for heuristic symbolic terms. Constant time execution is guaranteed.

48 CFR 225.7704-1 - Applicability of trade agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Applicability of trade agreements. 225.7704-1 Section 225.7704-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Acquisitions in Support of Operations in Afghanistan 225.7704-1...

48 CFR 225.7704-1 - Applicability of trade agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Applicability of trade agreements. 225.7704-1 Section 225.7704-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Acquisitions in Support of Operations in Iraq or Afghanistan...

48 CFR 225.7704-1 - Applicability of trade agreements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Applicability of trade agreements. 225.7704-1 Section 225.7704-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Acquisitions in Support of Operations in Afghanistan 225.7704-1...

48 CFR 213.302 - Purchase orders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Purchase orders. 213.302 Section 213.302 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Acquisition Methods 213.302 Purchase orders. ...

KSC-04pd0950

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is lowered toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0948

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is maneuvered toward the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

48 CFR 201.105-3 - Copies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Copies. 201.105-3 Section 201.105-3 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 201.105-3 Copies. The...

A study of an orbital radar mapping mission to Venus. Volume 3: Parametric studies and subsystem comparisons

NASA Technical Reports Server (NTRS)

1973-01-01

Parametric studies and subsystem comparisons for the orbital radar mapping mission to planet Venus are presented. Launch vehicle requirements and primary orbiter propulsion system requirements are evaluated. The systems parametric analysis indicated that orbit size and orientation interrelated with almost all of the principal spacecraft systems and influenced significantly the definition of orbit insertion propulsion requirements, weight in orbit capability, radar system design, and mapping strategy.

48 CFR 3034.004 - Acquisition strategy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Acquisition strategy. 3034.004 Section 3034.004 Federal Acquisition Regulations System DEPARTMENT OF HOMELAND SECURITY, HOMELAND... Acquisition strategy. See (HSAR) 48 CFR 3009.570 for policy applicable to acquisition strategies that consider...

48 CFR 34.004 - Acquisition strategy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Acquisition strategy. 34... CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION General 34.004 Acquisition strategy. The program manager, as specified in agency procedures, shall develop an acquisition strategy tailored to the particular...

48 CFR 46.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 46.404 Section 46.404 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance...

48 CFR 46.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 46.404 Section 46.404 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance...

48 CFR 46.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 46.404 Section 46.404 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance...

48 CFR 46.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 46.404 Section 46.404 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance...

48 CFR 46.404 - Government contract quality assurance for acquisitions at or below the simplified acquisition...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Government contract quality assurance for acquisitions at or below the simplified acquisition threshold. 46.404 Section 46.404 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance...

76 FR 71464 - Defense Federal Acquisition Regulation Supplement; Transition to the System for Award Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... Regulation Supplement for the transition of the Integrated Acquisition Environment systems to the new System... Acquisition Environment (IAE) is an electronic Government initiative that aggregates Federal acquisition...

48 CFR 201.201-1 - The two councils.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false The two councils. 201.201-1 Section 201.201-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Administration 201.201-1 The two...

48 CFR 201.201-1 - The two councils.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false The two councils. 201.201-1 Section 201.201-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Administration 201.201-1 The two...

48 CFR 201.201-1 - The two councils.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false The two councils. 201.201-1 Section 201.201-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Administration 201.201-1 The two...

48 CFR 201.201-1 - The two councils.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false The two councils. 201.201-1 Section 201.201-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Administration 201.201-1 The two...

48 CFR 201.201-1 - The two councils.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false The two councils. 201.201-1 Section 201.201-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Administration 201.201-1 The two...

48 CFR 908.7101-3 - Direct acquisition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Direct acquisition. 908.7101-3 Section 908.7101-3 Federal Acquisition Regulations System DEPARTMENT OF ENERGY COMPETITION ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Special Items 908.7101-3 Direct...

CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

NASA Technical Reports Server (NTRS)

Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

2012-01-01

The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

Data Acquisition, Management, and Analysis in Support of the Audiology and Hearing Conservation and the Orbital Debris Program Office

NASA Technical Reports Server (NTRS)

Dicken, Todd

2012-01-01

My internship at Johnson Space Center, Houston TX comprised of working simultaneously in the Space Life Science Directorate (Clinical Services Branch, SD3) in Audiology and Hearing Conservation and in the Astromaterials Research and Exploration Sciences Directorate in the Orbital Debris Program Office (KX). The purpose of the project done to support the Audiology and Hearing Conservation Clinic (AuHCon) is to organize and analyze auditory test data that has been obtained from tests conducted onboard the International Space Station (ISS) and in Johnson Space Center's clinic. Astronauts undergo a special type of auditory test called an On-Orbit Hearing Assessment (OOHA), which monitors hearing function while crewmembers are exposed to noise and microgravity during long-duration spaceflight. Data needed to be formatted to assist the Audiologist in studying, analyzing and reporting OOHA results from all ISS missions, with comparison to conventional preflight and post-flight audiometric test results of crewmembers. Orbital debris is the #1 threat to manned spacecraft; therefore NASA is investing in different measurement techniques to acquire information on orbital debris. These measurements are taken with telescopes in different parts of the world to acquire brightness variations over time, from which size, rotation rates and material information can be determined for orbital debris. Currently many assumptions are taken to resolve size and material from observed brightness, therefore a laboratory (Optical Measurement Center) is used to simulate the space environment and acquire information of known targets suited to best model the orbital debris population. In the Orbital Debris Program Office (ODPO) telescopic data were acquired and analyzed to better assess the orbital debris population.

48 CFR 7.300 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false [Reserved] 7.300 Section 7.300 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING ACQUISITION PLANNING Contractor Versus Government Performance 7.300 [Reserved] ...

The anticoincidence system of the PAMELA satellite experiment: Design of the data acquisition system and performance studies

NASA Astrophysics Data System (ADS)

Lunquist, Johan

PAMELA is a satellite-borne cosmic ray experiment. Its primary scientific objective is to study the antiproton and positron components of the cosmic radiation. This will be done with unprecedented statistics over a wide energy range (~10MeV to ~100GeV). The PAMELA experiment consists of a permanent magnetic spectrometer, an electromagnetic calorimeter, a Time-of-Fight system, a neutron detector and a shower tail catcher. An anticoincidence (AC) system surrounds the spectrometer to detect particles which do not pass cleanly through the acceptance of the spectrometer. PAMELA will be mounted on a Russian Earth-observation satellite, and the launch is scheduled for 2006. The anticoincidence system for PAMELA has been developed by KTH, and consists of plastic scintillator detectors with photomultiplier tube read-out. Extensive testing has been performed during the development phase. Results are presented for environmental tests, tests with cosmic-rays and particle beams. The design of the digital part of the AC electronics has been realised on an FPGA (Field Programmable Gate Array) and a DSP (Digital Signal Processor). It records signals from the 16 AC photomultipliers and from various sensors for over-current and temperature. It also provides functionality for setting the photomultiplier discrimination thresholds, system testing, issuing alarms and communication with the PAMELA main data acquisition system. The design philosophy and functionality needs to be reliable and suitable for use in a space environment. To evaluate the performance of the AC detectors, a test utilizing cosmic-rays has been performed. The primary aim of the test was to calibrate the individual channels to gain knowledge of suitable discriminator levels for flight. A secondary aim was to estimate the AC detector efficiency. A lower limit of (99.89±0.04)% was obtained. An in-orbit simulation study was performed using protons to estimate trigger rates and investigate the AC system performance in a second level trigger. The average orbital trigger rate was estimated to be (8.4±0.6)Hz, consisting of (2.0±0.2)Hz good triggers and (6.4±0.5)Hz background. Inclusion of the AC system in the trigger condition to reduce background (for the purpose of data handling capacity) leads to losses of good triggers due to backscattering from the calorimeter (90% loss for 300GeV electrons and 25% for 100GeV protons). A method, using the calorimeter, for identifying backscattering events was investigated and found to reduce the loss of good events to below 1% (300GeV electrons) and 5% (100GeV protons), while maintaining a background reduction of 70%.

48 CFR 1601.102 - Authority.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Authority. 1601.102 Section 1601.102 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.103 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Applicability. 1601.103 Section 1601.103 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.103 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Applicability. 1601.103 Section 1601.103 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.103 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Applicability. 1601.103 Section 1601.103 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.103 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Applicability. 1601.103 Section 1601.103 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.102 - Authority.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Authority. 1601.102 Section 1601.102 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.102 - Authority.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Authority. 1601.102 Section 1601.102 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.102 - Authority.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Authority. 1601.102 Section 1601.102 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 1601.103 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Applicability. 1601.103 Section 1601.103 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority...

48 CFR 2001.301 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Policy. 2001.301 Section 2001.301 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION GENERAL NUCLEAR REGULATORY COMMISSION ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2001.301 Policy. Policy...

48 CFR 2001.301 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Policy. 2001.301 Section 2001.301 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION GENERAL NUCLEAR REGULATORY COMMISSION ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2001.301 Policy. Policy...

48 CFR 2001.301 - Policy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Policy. 2001.301 Section 2001.301 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION GENERAL NUCLEAR REGULATORY COMMISSION ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2001.301 Policy. Policy...

48 CFR 208.7001 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Program. Integrated materiel management means assignment of acquisition management responsibility to one... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Definitions. 208.7001 Section 208.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 208.7001 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Program. Integrated materiel management means assignment of acquisition management responsibility to one... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Definitions. 208.7001 Section 208.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 208.7001 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Program. Integrated materiel management means assignment of acquisition management responsibility to one... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Definitions. 208.7001 Section 208.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 208.7001 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Program. Integrated materiel management means assignment of acquisition management responsibility to one... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Definitions. 208.7001 Section 208.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 208.7001 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Program. Integrated materiel management means assignment of acquisition management responsibility to one... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Definitions. 208.7001 Section 208.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 3401.104 - Issuance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Issuance. 3401.104 Section 3401.104 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Purpose, Authority, Issuance 3401.104 Issuance. ...

48 CFR 3401.601 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false General. 3401.601 Section 3401.601 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Contracting Authority and Responsibilities 3401.601 General...

Blueprint for Acquisition Reform, Version 3.0

DTIC Science & Technology

2008-07-01

represents a substantial and immediate step forward in establishing the Coast Guard as a model mid-sized federal agency for acquisition processes...Blueprint for Acquisition Reform in the U. S. Coast Guard “The Coast Guard must become the model for mid-sized Federal agency acquisition in process...acquisition (DoD 5000 model >CG Major Systems Acquisition Manual) • Deepwater Program Executive Officer (PEO): System of Systems performance-based

AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

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

WHITE, D.A.

1999-12-29

This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS).

48 CFR 215.407-5 - Estimating systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Estimating systems. 215.407-5 Section 215.407-5 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM....407-5 Estimating systems. ...

48 CFR 215.407-5 - Estimating systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Estimating systems. 215.407-5 Section 215.407-5 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM....407-5 Estimating systems. ...

48 CFR 215.407-5 - Estimating systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Estimating systems. 215.407-5 Section 215.407-5 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM....407-5 Estimating systems. ...

48 CFR 215.407-5 - Estimating systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Estimating systems. 215.407-5 Section 215.407-5 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM....407-5 Estimating systems. ...

48 CFR 215.407-5 - Estimating systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Estimating systems. 215.407-5 Section 215.407-5 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM....407-5 Estimating systems. ...

77 FR 2653 - Defense Federal Acquisition Regulation Supplement; Pilot Program for Acquisition of Military...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-19

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Parts 212 and 252 RIN 0750-AH27 Defense Federal Acquisition Regulation Supplement; Pilot Program for Acquisition of Military-Purpose Nondevelopmental Items (DFARS Case 2011-D034) AGENCY: Defense Acquisition Regulations System...

Development of an integrated spacecraft Guidance, Navigation, & Control subsystem for automated proximity operations

NASA Astrophysics Data System (ADS)

Schulte, Peter Z.; Spencer, David A.

2016-01-01

This paper describes the development and validation process of a highly automated Guidance, Navigation, & Control subsystem for a small satellite on-orbit inspection application, enabling proximity operations without human-in-the-loop interaction. The paper focuses on the integration and testing of Guidance, Navigation, & Control software and the development of decision logic to address the question of how such a system can be effectively implemented for full automation. This process is unique because a multitude of operational scenarios must be considered and a set of complex interactions between subsystem algorithms must be defined to achieve the automation goal. The Prox-1 mission is currently under development within the Space Systems Design Laboratory at the Georgia Institute of Technology. The mission involves the characterization of new small satellite component technologies, deployment of the LightSail 3U CubeSat, entering into a trailing orbit relative to LightSail using ground-in-the-loop commands, and demonstration of automated proximity operations through formation flight and natural motion circumnavigation maneuvers. Operations such as these may be utilized for many scenarios including on-orbit inspection, refueling, repair, construction, reconnaissance, docking, and debris mitigation activities. Prox-1 uses onboard sensors and imaging instruments to perform Guidance, Navigation, & Control operations during on-orbit inspection of LightSail. Navigation filters perform relative orbit determination based on images of the target spacecraft, and guidance algorithms conduct automated maneuver planning. A slew and tracking controller sends attitude actuation commands to a set of control moment gyroscopes, and other controllers manage desaturation, detumble, thruster firing, and target acquisition/recovery. All Guidance, Navigation, & Control algorithms are developed in a MATLAB/Simulink six degree-of-freedom simulation environment and are integrated using decision logic to autonomously determine when actions should be performed. The complexity of this decision logic is the primary challenge of the automated process, and the Stateflow tool in Simulink is used to establish logical relationships and manage data flow between each of the individual hardware and software components. Once the integrated simulation is fully developed in MATLAB/Simulink, the algorithms are autocoded to C/C++ and integrated into flight software. Hardware-in-the-loop testing provides validation of the Guidance, Navigation, & Control subsystem performance.

KSC-04pd0942

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (seen from the back) is lifted off its transporter. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0949

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers stand by as the left-hand Orbital Maneuvering System (OMS) pod is maneuvered toward the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0944

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is lifted at an angle from the transporter below. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0947

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (top of photo) is poised behind the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0946

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers on an upper level watch as the left-hand Orbital Maneuvering System (OMS) pod is lifted high to maneuver it toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0943

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers check the lifting of the left-hand Orbital Maneuvering System (OMS) pod. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0941

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (seen from the front) is lifted off its transporter. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

KSC-04pd0945

NASA Image and Video Library

2004-04-21

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a worker on an upper level watches as the left-hand Orbital Maneuvering System (OMS) pod is lifted high to maneuver it toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

Feasibility of Whole-Body Functional Mouse Imaging Using Helical Pinhole SPECT

PubMed Central

Metzler, Scott D.; Vemulapalli, Sreekanth; Jaszczak, Ronald J.; Akabani, Gamal; Chin, Bennett B.

2010-01-01

Purpose Detailed in vivo whole-body biodistributions of radiolabeled tracers may characterize the longitudinal progression of disease, and changes with therapeutic interventions. Small-animal imaging in mice is particularly attractive due to the wide array of well characterized genetically and surgically created models of disease. Single Photon Emission Computed Tomography (SPECT) imaging using pinhole collimation provides high resolution and sensitivity, but conventional methods using circular acquisitions result in severe image truncation and incomplete sampling of data which prevent the accurate determination of whole-body radiotracer biodistributions. This study describes the feasibility of helical acquisition paths to mitigate these effects. Procedures Helical paths of pinhole apertures were implemented using an external robotic stage aligned with the axis of rotation (AOR) of the scanner. Phantom and mouse scans were performed using helical paths and either circular or bi-circular orbits at the same radius of rotation (ROR). The bi-circular orbits consisted of two 360-degree scans separated by an axial shift to increase the axial field of view (FOV) and to improve the complete-sampling properties. Results Reconstructions of phantoms and mice acquired with helical paths show good image quality and are visually free of both truncation and axial-blurring artifacts. Circular orbits yielded reconstructions with both artifacts and a limited effective FOV. The bi-circular scans enlarged the axial FOV, but still suffered from truncation and sampling artifacts. Conclusions Helical paths can provide complete sampling data and large effective FOV, yielding 3D full-body in vivo biodistributions while still maintaining a small distance from the aperture to the object for good sensitivity and resolution. PMID:19521736

48 CFR 225.7003 - Restrictions on acquisition of specialty metals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restrictions on acquisition of specialty metals. 225.7003 Section 225.7003 Federal Acquisition Regulations System DEFENSE... Restrictions on acquisition of specialty metals. ...

48 CFR 225.7003 - Restrictions on acquisition of specialty metals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restrictions on acquisition of specialty metals. 225.7003 Section 225.7003 Federal Acquisition Regulations System DEFENSE... Restrictions on acquisition of specialty metals. ...

48 CFR 1807.7201 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Definitions. 1807.7201 Section 1807.7201 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COMPETITION AND ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Forecasting 1807.7201 Definitions. Class...

48 CFR 13.304 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false [Reserved] 13.304 Section 13.304 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Simplified Acquisition Methods 13.304 [Reserved] ...

Two Demonstrations with a New Data-Acquisition System

ERIC Educational Resources Information Center

Kraftmakher, Yaakov

2014-01-01

Nowadays, the use of data-acquisition systems in undergraduate laboratories is routine. Many computer-assisted experiments became possible with the PASCO scientific data-acquisition system based on the 750 Interface and DataStudio software. A new data-acquisition system developed by PASCO includes the 850 Universal Interface and Capstone software.…

75 FR 65439 - Defense Federal Acquisition Regulation Supplement; Electronic Subcontracting Reporting System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-25

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Parts 219 and 252 [DFARS Case... System AGENCY: Defense Acquisition Regulations System, Department of Defense (DoD). ACTION: Interim rule... Supplement (DFARS) to conform to the Federal Acquisition Regulation (FAR) by providing Department of Defense...

48 CFR 1601.104 - Issuance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Issuance. 1601.104 Section 1601.104 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 1601.104 - Issuance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Issuance. 1601.104 Section 1601.104 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 1601.104 - Issuance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Issuance. 1601.104 Section 1601.104 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 1601.102 - Authority.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Authority. 1601.102 Section 1601.102 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 1601.104 - Issuance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Issuance. 1601.104 Section 1601.104 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 1601.104 - Issuance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Issuance. 1601.104 Section 1601.104 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance...

48 CFR 241.201 - Policy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Policy. 241.201 Section 241.201 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING ACQUISITION OF UTILITY SERVICES Acquiring Utility Services 241...

48 CFR 2401.301 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Policy. 2401.301 Section 2401.301 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL FEDERAL ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2401.301 Policy. (a)(1...

48 CFR 2401.301 - Policy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Policy. 2401.301 Section 2401.301 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL FEDERAL ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2401.301 Policy. (a)(1...

48 CFR 2401.301 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Policy. 2401.301 Section 2401.301 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL FEDERAL ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 2401.301 Policy. (a)(1...

48 CFR 1.403 - Individual deviations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Individual deviations. 1.403 Section 1.403 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Deviations from the FAR 1.403 Individual deviations. Individual...

48 CFR 1.403 - Individual deviations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Individual deviations. 1.403 Section 1.403 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Deviations from the FAR 1.403 Individual deviations. Individual...

48 CFR 1.403 - Individual deviations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Individual deviations. 1.403 Section 1.403 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Deviations from the FAR 1.403 Individual deviations. Individual...

48 CFR 225.7603 - Exceptions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Exceptions. 225.7603 Section 225.7603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7603...

48 CFR 225.7602 - Procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

48 CFR 225.7602 - Procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

48 CFR 225.7602 - Procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

48 CFR 225.7603 - Exceptions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Exceptions. 225.7603 Section 225.7603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7603...

48 CFR 225.7603 - Exceptions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Exceptions. 225.7603 Section 225.7603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7603...

48 CFR 225.7603 - Exceptions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Exceptions. 225.7603 Section 225.7603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7603...

48 CFR 225.7602 - Procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

48 CFR 3401.403 - Individual deviations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Individual deviations. 3401.403 Section 3401.403 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Deviations 3401.403 Individual deviations. An individual...

48 CFR 3401.103 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Applicability. 3401.103 Section 3401.103 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Purpose, Authority, Issuance 3401.103 Applicability. The FAR and...

48 CFR 225.7603 - Exceptions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Exceptions. 225.7603 Section 225.7603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7603...

48 CFR 225.7602 - Procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

48 CFR 13.005 - Federal Acquisition Streamlining Act of 1994 list of inapplicable laws.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Federal Acquisition Streamlining Act of 1994 list of inapplicable laws. 13.005 Section 13.005 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION...

76 FR 21849 - Defense Federal Acquisition Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card® and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-19

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Part 213 RIN 0750-AH07 Defense Federal Acquisition Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card[supreg] and Aircraft Ground Services (DFARS Case 2009-D019) AGENCY: Defense Acquisition Regulations System, Department of...

76 FR 58149 - Defense Federal Acquisition Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card® and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Part 213 RIN 0750-AH07 Defense Federal Acquisition Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card[supreg] and Aircraft Ground Services (DFARS Case 2009-D019) AGENCY: Defense Acquisition Regulations System, Department of...

48 CFR 13.005 - Federal Acquisition Streamlining Act of 1994 list of inapplicable laws.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Federal Acquisition Streamlining Act of 1994 list of inapplicable laws. 13.005 Section 13.005 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION...

48 CFR 13.005 - Federal Acquisition Streamlining Act of 1994 list of inapplicable laws.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Federal Acquisition Streamlining Act of 1994 list of inapplicable laws. 13.005 Section 13.005 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION...

48 CFR 13.005 - Federal Acquisition Streamlining Act of 1994 list of inapplicable laws.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Federal Acquisition Streamlining Act of 1994 list of inapplicable laws. 13.005 Section 13.005 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION...

48 CFR 1.102-3 - Acquisition team.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Acquisition team. 1.102-3... ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 1.102-3 Acquisition team. The purpose of defining the Federal Acquisition Team (Team) in the Guiding Principles is to ensure that participants in the...

48 CFR 1.102-3 - Acquisition team.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Acquisition team. 1.102-3... ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 1.102-3 Acquisition team. The purpose of defining the Federal Acquisition Team (Team) in the Guiding Principles is to ensure that participants in the...

48 CFR 1.102-3 - Acquisition team.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Acquisition team. 1.102-3... ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 1.102-3 Acquisition team. The purpose of defining the Federal Acquisition Team (Team) in the Guiding Principles is to ensure that participants in the...

48 CFR 1.102-3 - Acquisition team.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Acquisition team. 1.102-3... ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 1.102-3 Acquisition team. The purpose of defining the Federal Acquisition Team (Team) in the Guiding Principles is to ensure that participants in the...

48 CFR 1.102-3 - Acquisition team.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Acquisition team. 1.102-3... ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 1.102-3 Acquisition team. The purpose of defining the Federal Acquisition Team (Team) in the Guiding Principles is to ensure that participants in the...

48 CFR 3409.570 - Certification at or below the simplified acquisition threshold.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Certification at or below the simplified acquisition threshold. 3409.570 Section 3409.570 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant...

48 CFR 3409.570 - Certification at or below the simplified acquisition threshold.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Certification at or below the simplified acquisition threshold. 3409.570 Section 3409.570 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant...

48 CFR 3409.570 - Certification at or below the simplified acquisition threshold.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Certification at or below the simplified acquisition threshold. 3409.570 Section 3409.570 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant...

Data Acquisition for Modular Biometric Monitoring System

NASA Technical Reports Server (NTRS)

Grodsinsky, Carlos M. (Inventor); Chmiel, Alan J. (Inventor); Humphreys, Bradley T. (Inventor)

2014-01-01

A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to collect data asynchronously, via the bus, from the memory of the plurality of data acquisition modules according to a relative fullness of the memory of the plurality of data acquisition modules.

The Space Shuttle orbiter payload retention systems

NASA Technical Reports Server (NTRS)

Hardee, J. H.

1982-01-01

Payloads are secured in the orbiter payload bay by the payload retention system or are equipped with their own unique retention systems. The orbiter payload retention mechanisms provide structural attachments for each payload by using four or five attachment points to secure the payload within the orbiter payload bay during all phases of the orbiter mission. The payload retention system (PRS) is an electromechanical system that provides standarized payload carrier attachment fittings to accommodate up to five payloads for each orbiter flight. The mechanisms are able to function under either l-g or zero-g conditions. Payload berthing or deberthing on orbit is accomplished by utilizing the remote manipulator system (RMS). The retention mechanisms provide the capability for either vertical or horizontal payload installation or removal. The payload support points are selected to minimize point torsional, bending, and radial loads imparted to the payloads. In addition to the remotely controlled latching system, the passive system used for nondeployable payloads performs the same function as the RMS except it provides fixed attachments to the orbiter.

Internet-to-orbit gateway and virtual ground station: A tool for space research and scientific outreach

NASA Astrophysics Data System (ADS)

Jaffer, Ghulam; Nader, Ronnie; Koudelka, Otto

2011-09-01

Students in higher education, and scientific and technological researchers want to communicate with the International Space Station (ISS), download live satellite images, and receive telemetry, housekeeping and science/engineering data from nano-satellites and larger spacecrafts. To meet this need the Ecuadorian Civilian Space Agency (EXA) has recently provided the civilian world with an internet-to-orbit gateway (Hermes-A/Minotaur) Space Flight Control Center (SFCC) available for public use. The gateway has a maximum range of tracking and detection of 22,000 km and sensitivity such that it can receive and discriminate the signals from a satellite transmitter with power˜0.1 W. The capability is enough to receive the faintest low-earth-orbit (LEO) satellites. This gateway virtually connects participating internet clients around the world to a remote satellite ground station (GS), providing a broad community for multinational cooperation. The goal of the GS is to lower financial and engineering barriers that hinder access to science and engineering data from orbit. The basic design of the virtual GS on a user side is based on free software suites. Using these and other software tools the GS is able to provide access to orbit for a multitude of users without each having to go through the costly setups. We present the design and implementation of the virtual GS in a higher education and scientific outreach settings. We also discuss the basic architecture of the single existing system and the benefits of a proposed distributed system. Details of the software tools and their applicability to synchronous round-the-world tracking, monitoring and processing performed by students and teams at Graz University of Technology, Austria, EXA-Ecuador, University of Michigan, USA and JAXA who have participated in various mission operations and have investigated real-time satellite data download and image acquisition and processing. Students and other remote users at these institutions undergo training with in orbit satellites in preparation for their own use with future university-class nano-satellites' post launch space operations. The exclusive ability of Hermes-A/Minotaur to act as a gateway between remote users (internet) and satellites (in orbit) makes the virtual GS at user-end more feasible for the long-term real-time nano/cubesats space operations. The only requirement is to have a mutual agreement between EXA and participating university/research organization and broadband internet connection at user-end. With successful and remote satellite tracking and downloading of real-time data from many operational satellites, the Hermes has been found a reliable potential GS for current and future university missions and a training platform for individuals pursuing space operations.

48 CFR 13.302 - Purchase orders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Purchase orders. 13.302 Section 13.302 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Simplified Acquisition Methods 13.302 Purchase...

48 CFR 18.119 - Trade agreements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Trade agreements. 18.119 Section 18.119 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.119 Trade agreements...

76 FR 27274 - Defense Federal Acquisition Regulation Supplement; Technical Amendments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Part 225 Defense Federal Acquisition Regulation Supplement; Technical Amendments AGENCY: Defense Acquisition Regulations System... Federal Acquisition Regulation Supplement (DFARS) to direct contracting officers to additional guidance on...

48 CFR 2407.102 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Policy. 2407.102 Section 2407.102 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT COMPETITION AND ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Plans 2407.102 Policy. The Senior...

48 CFR 2407.102 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Policy. 2407.102 Section 2407.102 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT COMPETITION AND ACQUISITION PLANNING ACQUISITION PLANNING Acquisition Plans 2407.102 Policy. The Senior...

48 CFR 18.119 - Trade agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Trade agreements. 18.119 Section 18.119 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.119 Trade agreements...

48 CFR 18.118 - Trade agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Trade agreements. 18.118 Section 18.118 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.118 Trade agreements...

48 CFR 18.119 - Trade agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Trade agreements. 18.119 Section 18.119 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.119 Trade agreements...

48 CFR 8.709 - Payments.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Payments. 8.709 Section 8.709 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition From Nonprofit Agencies Employing People Who Are...

48 CFR 8.702 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false General. 8.702 Section 8.702 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition From Nonprofit Agencies Employing People Who Are...