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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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Heat flow from an embedded heated wire responds to a change in the ambient environment. The wire is part of a self-balancing bridge system, and heat flow is measured directly in watts. Steady-state and transient thermal coupling can be measured directly and is an indication of the thermal resistance and diffusivity for the system under study. The method is applied to an aerospace electroexplosive component.
The three manned Skylab missions resulted in biomedical experiment data in the areas of neurophysiology, musculoskeletal physiology, biochemistry, hematology, cytology, cardiovascular and respiratory metabolic functions: as well as detailed test objectives involving crew health and environment procedures. Major emphasis was placed on results from the last mission, Skylab 4, which covered 84 days of in-flight data collection. Many new norms were defined for normal man living and operating in a unique environment. While man is quite adaptable to this unique environment, many of the changes observed in Skylab require additional research for future flights lasting very long periods of time such as a Mars mission requiring 18 months.
The three manned Skylab missions resulted in biomedical experiment data in the areas of neurophysiology, musculoskeletal physiology, biochemistry, hematology, cytology, cardiovascular and respiratory metabolic functions: as well as detailed test objectives involving crew health and environment procedures. Major emphasis was placed on results from the last mission, Skylab 4, which covered 84 days of in-flight data collection. Many new norms were defined for normal man living and operating in a unique environment. While man is quite adaptable to this unique environment, many of the changes observed in Skylab require additional research for future flights lasting very long periods of time such as a Mars mission requiring 18 months.
The principal objective of the present work is to identify a variety of strategic approaches which could significantly enhance the rate of commercial development and deployment of total energy systems, fuel cells, and solar conversion. Emphasis is on the need for integration of research, conference, legislation, federal program, and industrial program aspects, leading to a fruitful feedback and follow-through process involving new energy technologies. The discussions are on a general, lay level. Recommendations made feature (1) action which improves the environment for innovation and change, (2) action which decreases risk and creates positive incentives, and (3) action which reflects the distance a particular technology is from commercialization and widespread use, as determined by its position on a development/diffusion scale.
A coordinated microwave applications development program was initiated to improve the capability to: (1) identify, monitor, and assess the earth's resources; and (2) monitor the earth's environment and predict significant changes. The program consists of the scientific, technical, and programmatic activities required to develop microwave remote sensing into an operational tool for systematic earth observations.
Electro-optical extensometer containing optical and electronic components measures displacement in simulated turbine blade thermally cycled into and out of hot-gas stream. Innovation is useful in obtaining accurate strain histories for components subjected to severe thermal environments and other environmental changes.
An investigation was made of the losses encountered in the propagation of CO2 laser radiation through the atmosphere, particularly as it applies to the NASA/Marshall Space Flight Center Pulsed Laser Doppler System. As such it addresses three major areas associated with signal loss: molecular absorption, refractive index changes in a turbulent environment, and aerosol absorption and scattering. In particular, the molecular absorption coefficients of carbon dioxide, water vapor, and nitrous oxide are calculated for various laser lines in the region of 10.6 mu m as a function of various pressures and temperatures. The current status in the physics of low-energy laser propagation through a turbulent atmosphere is presented together with the analysis and evaluation of the associated heterodyne signal power loss. Finally, aerosol backscatter and extinction coefficients are calculated for various aerosol distributions and the results incorporated into the signal-to-noise ratio equation for the Marshall Space Flight Center system.
X-ray photoelectron spectroscopy (XPS) is analytical technique for understanding electronic structure of atoms close to surface in solids, in preference to bulk structure of material. Study found evidence for core-level chemical shifts arising from changes in local structural environment in amorphous SiO2 and at Si/SiO2 interface. Observed XPS spectra may be understood as sequential convolution of several functions, each with well-defined physical interpretation.
The results of study to determine the effects of space plasmas on a large GaAs solar cell array using solar reflectors at a concentration ratio of two in geostationary orbit are summarized. It was concluded that the system could function in the GEO environment if certain design changes were implemented. These included conductive coatings on the solar cells, changing the reflector material from Kapton to a higher conductivity material, and oversizing the array to compensate for a 0.7% parasitic load due to losses from the ambient magnetospheric plasma. The operation of the solar powered earth orbit transfer vehicle (EOTV) was also examined and it was concluded that LEO servere arcing would take place on all high voltage negative portions of the array. The parasitic load loss at LEO was estimated at 3%. Operation of a high voltage array at LEO represents a major problem. Charge exchange ion feedback from argon ion thrusters located near the EOTV solar array was also examined and all problems found were believed to be solvable by the placement of protective ground screens.
A small scale Mach 3.5 wind tunnel incorporating certain novel design features and intended for boundary-layer-transition research has been tested. The free stream noise intensities and spectral distributions were determined throughout the test section for several values of unit Reynolds number and for nozzle boundary layer bleed on and off. The boundary layer transition location on a slender cone and the response of this to changes in the noise environment were determined. Root mean square free stream noise levels ranged from less than one tenth up to values approaching those for conventional nozzles, with the lowest values prevailing at upstream locations within the nozzle. For low noise conditions, cone transition Reynolds numbers were in the range of those for free flight; whereas for high noise conditions, they were in the range of those in conventional tunnels.
The etalon is shown to remain stable to less than 5-m/sec equivalent wind over one orbit and less than 100 m/sec over several months in orbit. The thermal stability considerations for the highly stable etalon are discussed, including the passive thermal control used in flight. The various physical processes which give rise to drifts in the peak transmission wavelength are quantified, and the kinematic mount used to isolate the etalon from large incremental forces caused by changes in the thermal environment is presented. The performance of the etalon in its flight configuration is evaluated.
Space program goals that NASA can best achieve by the construction of a space station in keeping with the 1958 directive to maintain U.S. pre-eminence in space technology are discussed. Science goals that can be satisfied by a suitable equipped space station include a deeper understanding of the earth/sun system and the earth as a planet, the acquisition of new data on the evolution of the solar system, of life, and of the universe, and the extended study of the laws governing the state of matter and energy. Application goals that can be pursued with a space station include assaying all renewable and nonrenewable earth resources, predicting environment, weather, and climatic changes, studying ocean dynamics, using space to develop new processes and materials, and using space for information transmission on a global basis. The space station can serve as a waypoint for voyages by manned or unmanned spacecraft, as a laboratory, observation platform, and technology proving station, and as a base for deployment and repair of other spacecraft.
The guest pilot flight evaluation of the Demonstration Advanced Avionics System (DAAS) is discussed. The results are based on the fifty-nine questionnaires that were completed by the participants. The primary purpose of the pilot evaluation was to expose the Demonstration Advanced Avionics System to the various segments of the general aviation community and solicit comments in order to determine the effectiveness of integrated avionics for general aviation. Segments of the community that were represented in the evaluation are listed. A total of sixty-four (64) flights were conducted in which one hundred and seventeen (117) pilots and observers participated. It was felt that the exposure each subject had with the DAAS was too short to adequately assess the training requirements, pilot workload, and the reconfiguration concept of the DAAS. It is recommended that an operational evaluation of the DAAS be made to assess: the training requirements or varying experience levels, the pilot workload in the ATC environment with unplanned route changes, and the viability of the reconfiguration concept for failures.
Various homeostatic responses of a nonhuman primate, the squirrel monkey (Saimiri sciureus) to acute changes in the acceleration environment were examined. When these animals were exposed to a hyperdynamic field the body temperature was consistently depressed and the animals showed behavioral indications of increased drowsiness. Further, time of day played a significant role in influencing these responses.
The Plasma Diagnostics Package, flown aboard STS-3 as part of the first Shuttle payload (OSS-1), recorded the effects of various chemical releases from the Orbiter. Changes in the plasma environment was observed during flash evaporator system releases, water dumps and maneuvering thruster operations. During flash evaporator operations, broadband Orbiter-generated electrostatic noise was enhanced and plasma density irregularities were observed to increase by 3 to 30 times with a spectrum which rose steeply and peaked below 6 Hz. In the case of water dumps, background electrostatic noise was enhanced at frequencies below about 3 kHz and suppressed at frequencies above 2 kHz. Thruster activity also stimulated electrostatic noise with a spectrum which peaked at approximately 0.5 kHz. In addition, ions with energies up to 1 keV were seen during some thruster events.
A variety of proteolytic and micolytic enzumes, mechanical procedures, and changes in the ionic environment, especially Ca chelation, are used for dispersal of monolayer grown cells. If either chelating agents or mechanical dispersion are used alone, the cell yield is often low and suspensions of single cells are difficult to obtain. Confluent monolayers treated with EDTA tend to be released from their surfaces in sheets, and clumps of cells remain even after further incubation in EDTA. Crude trypsin is the most popular dispersal agent and is known to contain a variety of contaminating enzymes which contribute to the dispersal of cells. A variety of cell injuries resulting from the activity of proteolytic enzymes are reported. It is shown that crystalline trypsin is least harmful to cell integrity as judged by trypan blue uptake.
The Plasma Diagnostics Package, flown aboard STS-3 as part of the first Shuttle payload (OSS-1), recorded the effects of various chemical releases from the Orbiter. Changes in the plasma environment was observed during flash evaporator system releases, water dumps and maneuvering thruster operations. During flash evaporator operations, broadband Orbiter-generated electrostatic noise was enhanced and plasma density irregularities were observed to increase by 3 to 30 times with a spectrum which rose steeply and peaked below 6 Hz. In the case of water dumps, background electrostatic noise was enhanced at frequencies below about 3 kHz and suppressed at frequencies above 2 kHz. Thruster activity also stimulated electrostatic noise with a spectrum which peaked at approximately 0.5 kHz. In addition, ions with energies up to 1 keV were seen during some thruster events.
Problems in the space and earth science programs are examined. Changes in the research environment and requirements for the space and earth sciences, for example from small Explorer missions to multispacecraft missions, have been observed. The need to expand the computational capabilities for space and earth sciences is discussed. The effects of fluctuations in funding, program delays, the limited number of space flights, and the development of the Space Station on research in the areas of astronomy and astrophysics, planetary exploration, solar and space physics, and earth science are analyzed. The recommendations of the Space and Earth Science Advisory Committee on the development and maintenance of effective space and earth sciences programs are described.