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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Aerospace Vehicle Design, Spacecraft Section. Volume 1: Project Groups 3-5

Three groups of student engineers in an aerospace vehicle design course present their designs for a vehicle that can be used to resupply the Space Station Freedom and provide an emergency crew return to earth capability. The vehicle's requirements include a lifetime that exceeds six years, low cost, the capability for withstanding pressurization, launch, orbit, and reentry hazards, and reliability. The vehicle's subsystems are analyzed. These subsystems are structures, communication and command data systems, attitude and articulation control, life support and crew systems, power and propulsion, reentry and recovery systems, and mission management, planning, and costing.

Source record↗
NASA NTRS1973

Vapor phase growth of group 3, 4, and 5 compounds by HCl transport of elements

Technique has been devised for vapor-phase epitaxial growth of group 3, 4, and 5 binary, ternary, or quaternary compounds by HCl transport of the constituent elements or dopants. Technique uses all the constituents of the alloy system in their elemental form. Transport of these elements by an HCl + H2 carrier gas facilitates their transport as subchlorides.

Tyagi, R. C.↗
NASA NTRS1976

OAST Space Theme Workshop. Volume 3: Working group summary. 3: Sensors (E-3). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2). D. Additional assessment

Developments required to support the space power, SETI, solar system exploration and global services programs are identified. Instrumentation and calibration sensors (rather than scientific) are needed for the space power system. Highly sophisticated receivers for narrowband detection of microwave sensors and sensors for automated stellar cataloging to provide a mapping data base for SETI are needed. Various phases of solar system exploration require large area solid state imaging arrays from UV to IR; a long focal plane telescope; high energy particle detectors; advanced spectrometers; a gravitometer; and atmospheric distanalyzer; sensors for penetrometers; in-situ sensors for surface chemical analysis, life detection, spectroscopic and microscopic analyses of surface soils, and for meteorological measurements. Active and passive multiapplication sensors, advanced multispectral scanners with improved resolution in the UV and IR ranges, and laser techniques for advanced probing and oceanographic characterization will enhance for global services.

Source record↗
NASA NTRS1980

Working group 3: Space measurements

Solar variability regarding spectral irradiance, with significant variations in the extreme UV and at cm wavelengths and changes in total luminosity were discussed. The question of time scales of solar variations and the problem of establishing past variability were raised, since direct measurements of variability have begun. Enough data have been acquired to begin intercomparison of results, review of different techniques and interaction with theoreticians. The need to establish solar variability as a function of time scale and spectral domain and to relate this variability with such indices as sunspot number, radio flux (10.7 cm), solar diameter, photospheric temperature was addressed. The need for continued long term solar measurements, ozone measurements, stratospheric and mesospheric temperatures and stratospheric trace species was stressed.

Rasool, S. I.↗
NASA NTRS1981

Group 3: Performance evaluation and assessment

Line-oriented flight training provides a unique learning experience and an opportunity to look at aspects of performance other types of training did not provide. Areas such as crew coordination, resource management, leadership, and so forth, can be readily evaluated in such a format. While individual performance is of the utmost importance, crew performance deserves equal emphasis, therefore, these areas should be carefully observed by the instructors as an rea for discussion in the same way that individual performane is observed. To be effective, it must be accepted by the crew members, and administered by the instructors as pure training-learning through experience. To keep open minds, to benefit most from the experience, both in the doing and in the follow-on discussion, it is essential that it be entered into with a feeling of freedom, openness, and enthusiasm. Reserve or defensiveness because of concern for failure must be inhibit participation.

Frink, A.↗
NASA NTRS1980

JANTX1N3893 diode

Diodes manufactured by Siemens and Motorola were tested. Testing of Motorola diodes was stopped in all 3 groups because 50% failure-rate limit was reached. Siemens lot endured more testing in groups 1 and 2 and completed testing on group 3. Failure analysis was performed for group 2 testing.

Source record↗
NASA NTRS1974

Report of the Plasma Physics and Environmental Perturbation Laboratory (PPEPL) working groups. Volume 3: Magnetospheric experiments working group

A number of general studies that were proposed for the PPEPL-SHUTTLE program are considered in qualitative detail from both the theoretical and practical points of view. The selection of experimental programs was restricted to those which may be considered active as opposed to refinements of the passive observational programs done previously. It is concluded that, while these new studies were scientifically worthwhile and could be performed in principle, in most cases insufficient attention was paid to the practical details of the experiments. Several specific areas of study, stressing in particular the practical feasibility of the proposed experiments, are recommended. In addition, recommendations are made for further theoretical study, where appropriate. For Vol. 1, see N74-28169; for Vol. 2, see N74-28170.

Source record↗
NASA NTRS1973

Ultrastructural pathogenesis of lesions produced by exposure to oxygen difluoride with correlative light microscopy

The lungs of rats exposed to OF2 were examined by light and electron microscopy. The exposures were for 30 to 60 minutes to an average of 4.5 ppm OF2, the minimal lethal dose. Animals were sacrificed after 30 (group 1) and 60 minutes (group 2) exposure and 1 (group 3) and 2 (group 4) hours following 60 minutes exposure. Mild gross changes were observed in groups 3 and 4, but no light microscopic lesions were found. Alterations were noted in all four groups using electron microscopy. These were mostly indicative of fluid change and consisted of blebbing of the endothelial and epithelial layers of the alveolocapillary wall and rarification of the cytoplasm of these cells. The lamellar bodies of the Type II cells showed an increasing and consistent loss of matrix structure and density. These fine structural changes increased in quantity and severity as time of exposure or post-exposure period increased. (Modified author abstract)

Harrison, G.↗
NASA NTRS1985

Process thresholds: Report of Working Group Number 3

The Process Thresholds Working Group concerned itself with whether a geomorphic process to be monitored on satellite imagery must be global, regional, or local in its effect on the landscape. It was pointed out that major changes in types and magnitudes of processes operating in an area are needed to be detectable on a global scale. It was concluded from a review of geomorphic studies which used satellite images that they do record change in landscape over time (on a time-lapse basis) as a result of one or more processes. In fact, this may be one of the most important attributes of space imagery, in that one can document land form changes in the form of a permanent historical record. The group also discussed the important subject of the acquisition of basic data sets by different satellite imaging systems. Geomorphologists already have available one near-global basis data set resulting from the early LANDSAT program, especially images acquired by LANDSATs 1 and 2. Such historic basic data sets can serve as a benchmark for comparison with landscape changes that take place in the future. They can also serve as a benchmark for comparison with landscape changes that have occurred in the past (as recorded) by images, photography and maps.

Williams, R. S., Jr.↗
NASA NTRS2017

Microstructural Study of an 18-O-Poor Presolar Silicate Grain from The Meteorite Hills 00426 Cr2 Chondrite

The majority of presolar silicate and oxide grains derive from low-mass red giant and asymptotic giant branch (AGB) stars of approximately solar metallicity (Z). A small subclass of presolar O-rich grains (less than 7%) is thought to originate from stars having lower-than-solar Z. These "Group 3" [1] grains have depletions in 18O and 17O that typically fall along or above the Galactic chemical evolution (GCE) line. Other Group 3 grains show greater 17O than 18O depletions and most likely have supernova (SN) origins. Owing to their rarity, only two Group 3 silicates have been mineralogically examined in detail [2, 3]. Here we present a mineralogical study of a Group 3 presolar silicate to explore its formation conditions and interstellar history.

Nguyen, A. N.↗
NASA NTRS1994

Physiological Anatomical Rodent Experiment (PARE) .04 feasibility test 2

The objective of this feasibility study was to subject pregnant rats of the same age, strain, and size that will be utilized in a shuttle flight experiment to all flight conditions except the unique microgravity of space flight and determine the feasibility of the proposed experimental design to meet the experimental objectives. The study utilized facilities at NASA, Ames Research Center, Moffett Field, CA to subject the rats to the gravitational stresses of a simulated shuttle launch and simulated shuttle landing. One hundred pregnant rats were received on gestation day (G) 2 (day 1 = day of vaginal sperm) and on G7, eighty rats were laparotomized to determine the condition of pregnancy and allow assignment to test groups. The five test groups (N=10 each group) were as follows: Group 1, Nominal Flight; Group 2, Laparotomy Control; Group 3, Hysterectomy Control; Group 4, Vivarium Control; Group 5, Delayed Recovery. On G9, animals in groups 1,2,3, and 5 were subjected to a shuttle launch simulation. On G18, groups 1,2, and 3 were subjected to a shuttle landing simulation and on this same day groups 1 and 2 were subjected to unilateral hysterectomy to obtain fetuses and placentas for evaluation. Fetal crown-rump length and fetal weight of the Nominal Flight group was significantly less than the Laparotomy Control group, but placentas were similar. On G20, group 5 was subjected to a shuttle landing simulation and on this day this group received a unilateral hysterectomy and fetuses and placentas were weighed. Animals in all groups were allowed to go to term and all animals delivered between 06:00 hours G22 and 18:00 hours G23. After delivery, a blood sample was taken from each experimental dam, and they were euthanized and the thymus and adrenal glands weighed. The thymus weight from all experimental group dams was decreased relative to the Vivarium Control group but adrenal glands and hormone values in dam plasma was similar in all groups. Pups from experimental groups were tattooed for identification, the anogenital distance of male pups was measured, and all pups placed with foster dams and litter sizes were standardized to 10. There was no difference in anogenital distances between male pups from different test groups. Pups delivered from Delayed Recovery animals were smaller than pups delivered from Nominal Flight animals. On neonatal day 7, all pups were euthanized and pup adrenal glands and thymus weighed. There was no difference in weights of thymus and adrenal glands in pups euthanized at neonatal day 7. Collectively, these data confirm the feasibility of the experimental design to meet objectives of the studies proposed for shuttle flight.

Burden, Hubert W.↗
NASA NTRS2014

Long Term Displacement Data of Woven Fabric Webbings Under Constant Load for Inflatable Structures

Inflatable modules for space applications offer weight and launch volume savings relative to current metallic modules. Limited data exist on the creep behavior of the restraint layer of inflatable modules. Long-term displacement and strain data of two high strength woven fabric webbings, Kevlar and Vectran, under constant load is presented. The creep behavior of webbings is required by designers to help determine service life parameters of inflatable modules. Four groups of different webbings with different loads were defined for this study. Group 1 consisted of 4K Kevlar webbings loaded to 33% ultimate tensile strength and 6K Vectran webbings loaded to 27% ultimate tensile strength, group 2 consisted of 6K Kevlar webbings loaded to 40% and 43% ultimate tensile strength, and 6K Vectran webbings loaded to 50% ultimate tensile strength, group 3 consisted of 6K Kevlar webbings loaded to 52% ultimate tensile strength and 6K Vectran webbings loaded to 60% ultimate tensile strength, and group 4 consisted of 12.5K Kevlar webbings loaded to 22% ultimate tensile strength, and 12.5K Vectran webbings loaded to 22% ultimate tensile strength. The uniquely designed test facility, hardware, displacement measuring devices, and test data are presented. Test data indicate that immediately after loading all webbings stretch an inch or more, however as time increases displacement values significantly decrease to fall within a range of several hundredth of an inch over the remainder of test period. Webbings in group 1 exhibit near constant displacements and strains over a 17-month period. Data acquisition was suspended after the 17th month, however webbings continue to sustain load without any local webbing damage as of the 21st month of testing. Webbings in group 2 exhibit a combination of initial constant displacement and subsequent increases in displacement rates over a 16-month period. Webbings in group 3 exhibit steady increases in displacement rates leading to webbing failure over a 3-month period. Five of six webbings experienced local damage and subsequent failure in group 3. Data from group 4 indicates increasing webbing displacements over a 7-month period. All webbings in groups 1, 2, and 4 remain suspended without any local damage as of the writing of this paper. Variations in facility temperatures over test period seem to have had limited effect on long-term webbing displacement data.

Kenner, Winfred S.↗
NASA NTRS2001

Dietary n-3 polyunsaturated fatty acids affect the development of renovascular hypertension in rats

The consequences of a dietary n-3 PUFA supply was investigated on the blood pressure (BP) increase elicited by left renal artery stenosis in rats distributed in 3 groups (n = 8) fed for 8 weeks a semi-purified diet either as control diet or enriched diets (docosahexaenoic acid, DHA, or eicosapentaenoic acid, EPA). The PUFA intake induced large alterations in heart and kidney phospholipid fatty acid profile, but did not influence body weight, cardiac hypertrophy, renal left atrophy and right hypertrophy. Within 4 weeks, BP raised from 120-180 +/- 2 mm Hg in the control group, but only to 165 +/- 3 mm Hg in the n-3 PUFA groups. After stabilization of BP in the 3 groups, the rats received a short administration of increasing dose of perindopril. The lower dose (0.5 mg/kg) moderately decreased BP only in the control group. With higher doses (1, 5 and 10 mg/kg) BP was normalized in the 3 groups, with a higher amplitude of the BP lowering effect in the control group. A moderate n-3 PUFA intake can contribute to prevent the development of peripheral hypertension in rats by a mechanism that may involve angiotensin converting enzyme.

Hypertension, Renovascular/etiology/pathology/phys↗
NASA NTRS1993

MACH 3: Past and future approaches to intelligent tutoring

In 1986, the U.S. Army Research Institute created an intelligent tutoring system as a proof-of-concept for artificial intelligence applications in Army training. The Maintenance Aid Computer HAWK Intelligent Institutional Instructor (MACH 3) taught student mechanics to maintain and troubleshoot the AN/MPQ-57 High Power Illuminator Radar (HPIR) of the HAWK Air Defense Missile System. In 1989, TRADOC Analysis Command compared the effectiveness of MACH 3 to traditional paper-based troubleshooting drills. For the study, all students received lecture and hands-on training as usual. However, during troubleshooting drills, students traced faults using either MACH 3 or the traditional paper-based method. Class records showed that the MACH 3 group completed significantly more troubleshooting tasks and progressed through tasks of greater difficulty than the paper-based group. Upon completion of training, students took written, practical, and oral essay tests. Mean test scores showed that students performed similarly regardless of the drill method used. However, significantly different standard deviations showed that the MACH 3 group performed more consistently than the paper-based group. Furthermore, significantly different time measures showed that the MACH 3 group reached faster troubleshooting solutions on the actual radar transmitter than the paper-based group. We will present the study results and discuss how updating the design of the MACH 3 can include desktop computing in a virtual environment.

Acchione-Noel, Sylvia↗
NASA NTRSDate not supplied

Autonomous Control for Arbitrary Thruster Configurations and Mass Properties in Special Euclidean Group SE(3)

Most current methods for determining maneuvers and thrust firing sequences depend on explicit and predetermined commands generated by a combination of on-board systems and ground-based human-in-the-loop methods. For spacecraft and space structures with changing mass properties and thruster configurations, such as the Deep Space Gateway as it changes configurations throughout its lifetime, determining these commands can be time-consuming and computationally intensive. However, recent work within the Lie group SE(3) has offered ways of autonomously determining the location, power, precision, and capabilities of thrusters in any arbitrary position. Furthermore, a method for determining thruster firing sequences based on an arbitrary control input (both translational and rotational in a coupled, 6-element vector) and arbitrary thruster configurations has also recently been developed. When combining these methods, any spacecraft with any mass properties and thruster configurations can be understood in terms of controllability limits and thruster firing sequences can be generated quickly and with low computational load, thus extending the autonomous capabilities of deep space missions. In this work, this method is presented and explored in terms of convergence time to the desired pose. The capabilities of this method are also examined in the case of the Deep Space Gateway both in fully controllable configurations and uncontrollable configurations.

SE(3)↗
NASA NTRSDate not supplied

Discriminative Methodology using the Unscented Transform in Special Euclidean Group SE(3) for Autonomous GN&C

Kalman filtering techniques usually compare a known dynamic model with some process noise to an updated, noisy measurement. Both sources of noise are generally assumed to be Gaussian and are filtered to obtain a more accurate estimate of the state of the system of interest. However, these methods assume that a relatively accurate dynamical model already exists. By including discriminative methodology to interpret differences in the predictive model and the measured states over time, an incorrect model can be corrected overtime, allowing a spacecraft to learn about its environment and adapt to changing conditions. In this paper, a discriminative unscented Kalman filter (DUKF) is introduced on the special Euclidean group SE(3) formulation framework. A spacecraft is initialized near a small body with no knowledge of its parameters, and using several consecutive conditional models the environment is studied and the filter is updated. The case study of a spacecraft in a slightly elliptical, inclined, relatively tight orbit around the irregular moon Phobos is simulated and discussed. The accuracy of this approach is quantifying the differences between the true state, the UKF with a poor model, and the DUKF.

GN&C↗
NASA NTRS1973

The space shuttle payload planning working groups. Volume 3: High energy astrophysics

The findings of the High Energy Astrophysics working group of the space shuttle payload planning activity are presented. The objectives to be accomplished during space shuttle missions are defined as: (1) X-ray astronomy, (2) hard X-ray and gamma ray astronomy, and (3) cosmic ray astronomy. The instruments and test equipment required to accomplish the mission are identified. Recommendations for managing the installation of the equipment and conducting the missions are included.

Source record↗
NASA NTRS1971

Investigation of electrode materials for alkaline batteries

A number of amalgam electrode systems were investigated for possible use as high rate anodes and cathodes. The systems examined include: lithium, sodium, and potassium in Group 1, magnesium, calcium, and barium in Group 2, aluminum in Group 3, lead in Group 4, copper in Group 1b, and zinc and cadmium in Group 2b. The K(Hg) and Na(Hg) anodes in 10 VF and 15 VF (an unambiguous expression of concentration that indicates the number of formula weights of solute dissolved in a liter of solution) hydroxide solutions have proven satisfactory; some of these have produced current densities of more than 8 A/sq cm. None of the amalgam cathodes have approached this performance although the TI(Hg) has delivered 1 A/sq cm. Se(Hg) and Te(Hg) cathodes have given very stable discharges. Zn(Hg) and Cd(Hg) electrodes did not show good high rate characteristics, 200 to 300 mA/sq cm being about the maximum current densities obtainable. Both anodes are charged through a two-step process in which M(Hg) is first formed electrochemically and subsequently reduces Zn(II or Cd(II) to form the corresponding amalgam. The second step is extremely rapid for zinc and very slow for cadmium.

Arcand, G. M.↗