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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Comparison of metal oxide absorbents for regenerative carbon dioxide and water vapor removal for advanced portable life support systems

Metal-oxide absorbents (MOAs) have a demonstrated capability for removal of both metabolic CO2 and H2O from breathing atmospheres, simplifying portable life support system (PLSS) design and affording reversible operation for regeneration. Attention is presently given to the comparative performance levels obtained by silver-oxide-based and silver/zinc-oxide-based systems, which also proved to be longer-lasting than the silver oxide-absorber system. The silver/zinc system is found to substantially simplify the ventilation loop of a prospective Space Station Freedom PLSS.

Stonesifer, Greg T.↗
NASA NTRS1991

Neutral Buoyancy Portable Life Support System performance study

The Neutral Buoyancy Portable Life Support System (NBPSS) has been designed to support astronaut underwater training activities associated with EVA operations. The performance of competing NBPSS configurations has been analyzed on the basis of a modified 'Metabolic Man' program. NBPSS success is dependent on the development of novel cryogen supply tank and liquid-cooling garment vaporizer. Attention is given to mass and thermal balances and the evaluation results for the vent-loop ejector and heat-exchanger designs.

Chang, Chi-Min↗
NASA NTRS1992

Portable microwave test packages for beam-waveguide antenna performance evaluations

Portable microwave test packages used to evaluate a new 34-m-diameter beam-waveguide (BWG) antenna are described. The experimental methodology involved transporting test packages to different focal points of the BWG system and making noise temperature, antenna efficiency, and holography measurements. Comparisons of data measured at the different focal points enabled determinations of performance degradations caused by various mirrors in the BWG system. It is shown that, due to remarkable stabilities and accuracies of radiometric data obtained through the use of the microwave test packages, degradations caused by the BWG system were successfully determined.

Otoshi, Tom Y.↗
NASA NTRS1991

A dynamic isotope power system portable generator for the moon or Mars

The dynamic isotope power systems (DIPS) demonstration program is focused on a standardized 2.5 kWe portable generator for multiple uses on the lunar or Martian surface. A variety of potential remote or mobile applications has been identified by NASA. These applications include remote power to science packages, surface rovers for both short and extended duration missions, and backup to central base power. Reviews conducted on alternative power sources for these applications are described. These include the comparison of DIPS to regenerative fuel cells (RFCs). Recent work is presented refining the 2.5 kWe design to assure compatibility with the Martian environment while imposing only a minor mass penalty on lunar operations. This was accomplished by limiting temperatures, except in the heat source unit (HSU), to the nonrefractory materials regime and protecting the necessary refractories in the HSU from the environment. Design changes to the HSU are described. Work related to recent concerns regarding astronaut radiation doses is described. This work includes the bases for the calculations to determine the necessary shielding or operational limitations.

Johnson, Richard A.↗
NASA NTRS1993

Portable Lifting Seat

Portable lifting machine assists user in rising from seated position to standing position, or in sitting down. Small and light enough to be carried like briefcase. Used on variety of chairs and benches. Upholstered aluminum box houses mechanism of lifting seat. Springs on outer shaft-and-arm subassembly counterbalance part of user's weight to assist motor.

Weddendorf, Bruce↗
NASA NTRS1992

Design and initial performance evaluation of a portable short wave infrared spectroradiometer

The design, initial calibration, and performance evaluations of a portable short wave infrared (SWIR) spectroradiometer are described. The spectroradiometer covers the range from 1.1 to 2.5 microns with a spectral resolution that may be varied from less than 10 nm to more than 100 nm. A single spectrum is acquired in about 2 sec. The SNR is about 230 at a wavelength of 2.2 microns for a Lambertian surface of 90-percent reflectance illuminated by the sun at normal incidence with 14.8-nm resolution, a 25 C background temperature, and no atmospheric attenuation. FOV-defining optics are coupled by a flexible fiber-optics bundle to the spectroradiometer, which consists of a concave holographic diffraction grating with a flat focal field imaged onto a 1024-element platinum silicide linear-array detector.

Smith, Mark W.↗
NASA NTRS1992

Portable life support system regenerative carbon dioxide and water vapor removal by metal oxide absorbents preprototype hardware development and testing

NASA-Johnson has acquired a preprototype/full-scale metal oxide CO2 and humidity remover (MOCHR), together with its regeneration module. Tests conducted prior to delivery by the MOCHR's manufacturer have demonstrated the concurrent removal of H2O and CO2 at rates, and under conditions, that are applicable to EVA Portable Life Support Systems.

Hart, Joan M.↗
NASA NTRS1992

Role of a microbore capillary column in the development of a portable gas chromatograph-mass spectrometer

An approach to the development of a high-performance, field portable gas chromatograph-mass spectrometer is presented which is based on a combination of a short microbore capillary column and a miniaturized, light-weight focal plane mass spectrograph. Performance results of the short microbore column for the mixture separation of the major pollutants and data on time-resolved mass spectral measurements of overlapped gas chromatograph peaks are reported.

Sinha, Mahadeva P.↗
NASA NTRS1943

A Portable Calibrator for Dynamic Strain Gages

A portable device for calibrating dynamic strain gages is described. The device contains a motor-driven cam, which applies alternating tensile loads to a metal strip 5/8 inch wide and 6 1/4 inches long. The cam is designed to produce a nearly sinusoidal variation of strain with time. Dynamic strain gages with gage lengths up to 5 inches may be calibrated by mounting them on the strip and by changing the frequency and the amplitude of the tensile load. The frequency may be varied from 15 to 30 cycles per second and the strain amplitude from 0 to 10x10-4 in steps of 2x10-4.

Mcpherson, Albert E↗
NASA NTRS1994

Portable Presentation And Instruction Unit

Proposed electronic display unit reminiscent of kiosk serves as portable, interactive, multimedia information terminal. Used as traveling science exhibit, aid for teaching science in schools, or training and skill-refresher device for space flight crews. Provides interactive video and audio displays, including three-dimensional-appearing video simulations. Speeds learning and improves retention by applying principles of scientific visualization. Also helps previously trained but recently unpracticed personnel relearn special skills and procedures quickly.

Christman, L.↗
NASA NTRS1990

TROJID: A portable software package for upper-stage trajectory optimization

Performance optimization for upper-stage exoatmospheric vehicles often is performed within the framework of a full capability trajectory simulation package requiring either a large mainframe computer or powerful work-station. Since these software packages tend to include capabilities providing for high-fidelity boost and reentry simulations, the programs usually are quite large and not very portable. The program TROJID is an attempt to provide an environment for the optimization of upper-stage trajectories within a small package capable of being run on a standard desktop microcomputer. Utilizing a state-of-the-art nonlinear programming algorithm and a trajectory simulator implementing impulsive burns and an analytic coast phase propagator, TROJID is capable of producing trajectories for optimal multi-burn upper-stage orbit transfers. The package has been designed to allow full generality in definition of both the trajectory simulator and the parameter optimization problem.

Hammes, Steven M.↗
NASA NTRS1993

Spacecraft signal sources portable test system

There is a frequent need to measure the frequency stability and phase noise levels of very high performance signal sources that are required for certain spacecraft missions. These measurements need to be done at different locations as the spacecraft subsystems progress through the various stages of development, assembly, test, and integration. Allan Deviation and Phase Noise of high performance sources are generally measured by comparing the unit under test to a reference standard. Five basic requirements are associated with making these kind of measurements: (1) the reference standard performance needs to be equal or better than the unit under test; (2) the measurement system needs to accommodate odd, nonstandard measurement frequencies that can range from 4 MHz to 35 GHz; (3) warm-up frequency drift and aging can corrupt a measurement and must be dealt with; (4) test equipment generated noise must be understood and prevented from limiting the measurements; (5) test equipment noise performance must be verifiable in the field as needed. A portable measurement system that was built by JPL and used in the field is described. The methods of addressing the above requirements are outlined and some measurement noise floor values are given. This test set was recently used to measure state of the art crystal oscillator frequency standards on the TOPEX and MARS OBSERVER spacecraft during several stages of acceptance tests.

Kirk, Albert↗
NASA NTRS1991

Development of a portable multispectral thermal infrared camera

The purpose of this research and development effort was to design and build a prototype instrument designated the 'Thermal Infrared Multispectral Camera' (TIRC). The Phase 2 effort was a continuation of the Phase 1 feasibility study and preliminary design for such an instrument. The completed instrument designated AA465 has application in the field of geologic remote sensing and exploration. The AA465 Thermal Infrared Camera (TIRC) System is a field-portable multispectral thermal infrared camera operating over the 8.0 - 13.0 micron wavelength range. Its primary function is to acquire two-dimensional thermal infrared images of user-selected scenes. Thermal infrared energy emitted by the scene is collected, dispersed into ten 0.5 micron wide channels, and then measured and recorded by the AA465 System. This multispectral information is presented in real time on a color display to be used by the operator to identify spectral and spatial variations in the scenes emissivity and/or irradiance. This fundamental instrument capability has a wide variety of commercial and research applications. While ideally suited for two-man operation in the field, the AA465 System can be transported and operated effectively by a single user. Functionally, the instrument operates as if it were a single exposure camera. System measurement sensitivity requirements dictate relatively long (several minutes) instrument exposure times. As such, the instrument is not suited for recording time-variant information. The AA465 was fabricated, assembled, tested, and documented during this Phase 2 work period. The detailed design and fabrication of the instrument was performed during the period of June 1989 to July 1990. The software development effort and instrument integration/test extended from July 1990 to February 1991. Software development included an operator interface/menu structure, instrument internal control functions, DSP image processing code, and a display algorithm coding program. The instrument was delivered to NASA in March 1991. Potential commercial and research uses for this instrument are in its primary application as a field geologists exploration tool. Other applications have been suggested but not investigated in depth. These are measurements of process control in commercial materials processing and quality control functions which require information on surface heterogeneity.

Osterwisch, Frederick G.↗
NASA NTRS1993

Open environments to support systems engineering tool integration: A study using the Portable Common Tool Environment (PCTE)

A study of computer engineering tool integration using the Portable Common Tool Environment (PCTE) Public Interface Standard is presented. Over a 10-week time frame, three existing software products were encapsulated to work in the Emeraude environment, an implementation of the PCTE version 1.5 standard. The software products used were a computer-aided software engineering (CASE) design tool, a software reuse tool, and a computer architecture design and analysis tool. The tool set was then demonstrated to work in a coordinated design process in the Emeraude environment. The project and the features of PCTE used are described, experience with the use of Emeraude environment over the project time frame is summarized, and several related areas for future research are summarized.

Eckhardt, Dave E., Jr.↗
NASA NTRS1993

Preliminary results from the portable standard satellite laser ranging intercomparison with MOBLAS-7

Conventional Satellite Laser Ranging (SLR) instrumentation has been configured and successfully used to provide high-accuracy laboratory measurements on the LAGEOS-2 and TOPEX cube-corner arrays. The instrumentation, referred to as the Portable Standard, has also been used for field measurements of satellite ranges in tandem with MOBLAS-7. Preliminary results of the SLR measurements suggest that improved range accuracy can be achieved using this system. Results are discussed.

Selden, Michael↗
NASA NTRS1992

Portable Habitat for Antarctic Scientific Research (PHASR)

The Portable Habitat for Antarctic Scientific Research, PHASR, is designed as a versatile, general purpose habitat system that addresses the problem of functional space and environmental soundness in a partially fabric-covered shelter. PHASR is used for remote field site applications that can be quickly deployed. PHASR will also provide four scientists with a comfortable and efficient use of interior space. PHASR is a NASA/USRA Advanced Design Program project conducted at the University of Houston College of Architecture, Sasadawa International Center for Space Architecture (SICSA). This report is prepared for NASA/USRA.

Griswold, Samantha S.↗