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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 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

A study of power conditioning and power distribution and components

A comprehensive simulation and analysis performed on the operation of the regulator part of the Charger/Battery/Regulator Module (CBRM) are detailed. The CBRM is utilized as an integral component of the Skylab/Apollo Telescope Mount (ATM) electrical power system and contains a switching mode electronic regulator. Implementing circuit analysis techniques, pertinent voltages and currents are calculated; these, in turn, are incorporated into the regulator system study. Investigation of the turn-on and turn-off times associated with the switching circuitry is performed and an examination is made on these calculations. A simulation model computer program is utilized to generate graphs that relate various CBRM parameters to one another.

Horton, H. M.↗
NASA NTRS1975

Energy spectrum of galactic electrons in the energy range 2 x 10 to the 10 power - 2 x 10 to the 11th power eV

New experimental data on the energy spectrum of galactic electrons up to the energies approximately 2 x 10 to the 11th power eV were obtained in the summer of 1967 by a scintillation telescope lifted to the stratosphere at 32 km. The geometrical factor of the telescope was 1200 sq cm steradians, i.e., three times as great as the geometrical factor of previously employed installations. The results confirm previous measurements.

Zatsepin, V. I.↗
NASA NTRS1976

Space-based solar power conversion and delivery systems study. Volume 3: Economic analysis of space-based solar power systems

A variety of economic and programmatic issues are discussed concerning the development and deployment of a fleet of space-based solar power satellites (SSPS). The costs, uncertainties and risks associated with the current photovoltaic SSPS configuration, and with issues affecting the development of an economically viable SSPS development program are analyzed. The desirability of a low earth orbit (LEO) demonstration satellite and a geosynchronous (GEO) pilot satellite is examined and critical technology areas are identified. In addition, a preliminary examination of utility interface issues is reported. The main focus of the effort reported is the development of SSPS unit production, and operation and maintenance cost models suitable for incorporation into a risk assessment (Monte Carlo) model (RAM). It is shown that the key technology area deals with the productivity of man in space, not, as might be expected, with some hardware component technology.

Hazelrigg, G. A., Jr.↗
NASA NTRS1977

Solar power satellite system definition study. Part 2, volume 4: Microwave power transmission systems

A slotted waveguide planar array was established as the baseline design for the spaceborne transmitter antenna. Key aspects of efficient energy conversion at both ends of the power transfer link were analyzed and optimized alternate approaches in the areas of antenna and tube design are discussed. An integrated design concept was developed which meets design requirements, observes structural and thermal constraints, exhibits good performance and was developed in adequate depth to permit cost estimating at the subsystem/component level.

Source record↗
NASA NTRS1976

UF6 breeder reactor power plants for electric power generation

The reactor concept analyzed is a U-233F6 core surrounded by a molten salt (Li(7)F, BeF2, ThF4) blanket. Nuclear survey calculations were carried out for both spherical and cylindrical geometries. Thermodynamic cycle calculations were performed for a variety of Rankine cycles. A conceptual design is presented along with a system layout for a 1000 MW stationary power plant. Advantages of the gas core breeder reactor (GCBR) are as follows: (1) high efficiency; (2) simplified on-line reprocessing; (3) inherent safety considerations; (4) high breeding ratio; (5) possibility of burning all or most of the long-lived nuclear waste actinides; and (6) possibility of extrapolating the technology to higher temperatures and MHD direct conversion.

Rust, J. H.↗
NASA NTRS1979

The 25 kW power module evolution study. Part 3: Conceptual designs for power module evolution. Volume 2: Program plans

A plan is presented for the evolutionary development and deployment of the power module system with performance capabilities required to support the 1983 to 1990 user requirements. Aspects summarized include program functional, operational, and hardware elements; program work breakdown and specification items; development plans and schedules for developmental and technology milestones; test concepts and timeliness; and ground and orbit operations concepts.

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NASA NTRS1979

The 25 kW power module evolution study. Part 3: Conceptual design for power module evolution. Volume 6: WBS and dictionary

Program elements of the power module (PM) system, are identified, structured, and defined according to the planned work breakdown structure. Efforts required to design, develop, manufacture, test, checkout, launch and operate a protoflight assembled 25 kW, 50 kW and 100 kW PM include the preparation and delivery of related software, government furnished equipment, space support equipment, ground support equipment, launch site verification software, orbital verification software, and all related data items.

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NASA NTRS1979

Switching transients in high-frequency high-power converters using power MOSFET's

The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

Sloane, T. H.↗
NASA NTRS1980

High-power microwave optics for flexible power transmission systems

A large concave microwave mirror near the transmitter can magnify the apparent size of the Earth as seen from a phased array, and vice versa, permitting a small phased array to be coupled to a small rectenna while preserving the transmission efficiency (the reflection loss is slight) and peak power densities characteristic of the reference system. This augmentation of the phased array aperture with a large mirror gives the system greater resolution (in the optical sense), and opens new degrees of freedom in SPS design. The consequences of such an approach for a prototype satellite were explored. Its consequences for a mature SPS are discussed.

Drexler, K. E.↗
NASA NTRS1982

Develop and test fuel cell powered on-site integrated total energy systems: Phase 3: Full-scale power plant development

The development of a commercially viable and cost-effective phospheric acid fuel cell powered on-site integrated energy system (OS/IES) is described. The fuel cell offers energy efficients in the range of 35-40% of the higher heating value of available fuels in the form of electrical energy. In addition, by utilizing the thermal energy generated for heating, ventilating and air-conditioning (HVAC), a fuel cell OS/IES could provide total energy efficiencies in the neighborhood of 80%. Also, the Engelhard fuel cell OS/IES offers the important incentive of replacing imported oil with domestically produced methanol, including coal-derived methanol.

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NASA NTRS1982

Organic Rankine power conversion subsystem development for the small community solar thermal power system

The development and preliminary test results for an air-cooled, hermetically sealed 20 kW sub E organic Rankine cycle engine/alternator unit for use with point focussing distributed receiver solar thermal power system. A 750 F toluene is the working fluid and the system features a high speed, single-stage axial flow turbine direct-coupled to a permanent magnet alternator. Good performance was achieved with the unit in preliminary tests.

Barber, R. E.↗
NASA NTRS1985

Cost comparisons of solar power satellites versus lunar based power systems

A comparison is made between projected electricity costs of an optimized space solar power station (SPS) in GEO and a moon-based SPS (LPS). A single SPS would receive sunlight on an almost uninterruptible basis. The LPS would be illumined 50 percent of the time, thus requiring two stations on opposite sides of the moon as well as three terrestrial rectennas spaced 120 deg apart. The 5 percent efficient LPS cells would be manufactured from lunar materials and built into arrays mounted on tall mounds. The steerable GEO SPS would have 15 percent efficient cells. Construction costs would be significantly lower on the moon, but the total antenna area would need to be two orders of magnitude larger to produce the same output as the SPS. It is estimated that the LPS would therefore deliver 5 GW electricity to earth stations at a cost of 511.3 mills/kW, compared to 46.8 mills/kW from the SPS. It is concluded that lunar materials are suitable for building an SPS, not a LPS.

Kerwin, E. M.↗
NASA NTRS1986

Photovoltaic conversion of laser power to electrical power

Photovoltaic laser to electric converters are attractive for use with a space-based laser power station. This paper presents the results of modeling studies for a silicon vertical junction converter used with a Nd laser. A computer code was developed for the model and this code was used to conduct a parametric study for a Si vertical junction converter consisting of one p-n junction irradiated with a Nd laser. These calculations predict an efficiency over 50 percent for an optimized converter.

Walker, G. H.↗
NASA NTRS1987

Photovoltaic conversion of laser power to electrical power

Photovoltaic laser to electric converters are attractive for use with a space-based laser power station. The results of modeling studies for a silicon vertical junction converter used with a Nd laser are given. A computer code was developed for the model and this code was used to conduct a parametric study for a Si vertical junction converter consisting of one p-n junction irradiated with a Nd laser. These calculations predict an efficiency over 50 percent for an optimized converter.

Walker, Gilbert H.↗