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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 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Electrochemical Orbital Energy Storage (ECOES) technology program

The versatility and flexibility of a regenerative fuel cell power and energy storage system is considered. The principal elements of a Regenerative Fuel Cell System combine the fuel cell and electrolysis cell with a photovoltaic solar cell array, along with fluid storage and transfer equipment. The power output of the array (for LEO) must be roughly triple the load requirements of the vehicle since the electrolyzers must receive about double the fuel cell output power in order to regenerate the reactants (2/3 of the array power) while 1/3 of the array power supplies the vehicle base load. The working fluids are essentially recycled indefinitely. Any resupply requirements necessitated by leakage or inefficient reclamation is water - an ideal material to handle and transport. Any variation in energy storage capacity impacts only the fluid storage portion, and the system is insensitive to use of reserve reactant capacity.

Mcbryar, H.↗
NASA NTRS1981

Endurance test and evaluation of alkaline water electrolysis cells

Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

Burke, K. A.↗
NASA NTRS1983

Environmental control and life support - Partially closed system will save big money

Although the NASA space station has not yet been completely defined, realistic estimates may be made of the environmental control and life support system requirements entailed by a crew of eight, a resupply interval of 90 days, an initial launch which includes expendables for the first resupply interval, 7.86 lb/day of water per person, etc. An appraisal of these requirements is presented which strongly suggests the utility of a partially closed life support system. Such a scheme would give the crew high quality water to drink, and recycle nonpotable water from hand washing, bathing, clothes and dish washing, and urinal flushing. The excess recovery process water is electrolyzed to provide metabolic and leakage oxygen. The crew would drink electrolysis water and atmospheric humidity control moisture-derived water.

Guy, W. W.↗
NASA NTRS1983

A Preliminary Study of Solar Powered Aircraft and Associated Power Trains

The feasibility of regeneratively powered solar high altitude powered platform (HAPP) remotely piloted vehicles was assessed. Those technologies which must be pursued to make long duration solar HAPPs feasible are recommended. A methodology which involved characterization and parametric analysis of roughly two dozen variables to determine vehicles capable of fulfilling the primary mission are defined. One of these vehicles was then conceptually designed. Variations of each major design parameter were investigated along with state-of-the-art changes in power train component capabilities. The midlatitude mission studied would be attainable by a solar HAPP if fuel cell, electrolyzer and photovoltaic technologies are pursued. Vehicles will be very large and have very lightweight structures in order to attain the combinations of altitude and duration required by the primary mission.

Hall, D. W.↗
NASA NTRS1983

Environmental Control and Life Support for an evolutionary Space Station

The requirements for the Space Station are being defined. The Environmental Control/Life Support System (ECLSS) is one of its 13 systems. The ECLSS is further divided into five functional categories. Major ones are the Air Revitalization and Water Reclamation Systems. The paper presents ECLSS performance requirements, average design loads and fluids interfaces. The major cost savings of regenerable ECLSS techniques versus the open loop approach are quantified. Issues impacting ECLSS design are cited. Priority regenerable ECLSS developments are reviewed including the Electrochemical CO2 Concentrator, Static Feed Electrolyzer and Automated Control/Monitor Instrumentation. Baseline and alternative approaches are cited. The ECLSS planning issues are reviewed including functional boundaries, planning schedule, technology maturity definition and technology gaps. The paper concludes with a review of water electrolysis as a Space Station utility impacting ECLSS design.

Quattrone, P. D.↗
NASA NTRS1984

Hydrogen from renewable energy - Photovoltaic/water electrolysis as an exemplary approach

A feasibility study has been conducted for a NASA Kennedy Space Center liquid hydrogen/liquid oxygen production facility using solar cell arrays as the power source for electrolysis. The 100 MW output of the facility would be split into 67.6 and 32 MW portions for electrolysis and liquefaction, respectively. The solar cell array would cover 1.65 sq miles, and would be made up of 249 modular 400-kW arrays. Hydrogen and oxygen are generated at either dispersed or centralized water electrolyzers. The yearly hydrogen output is projected to be 5.76 million lbs, with 8 times that much oxygen; these fuel volumes can support approximately 18 Space Shuttle launches/year.

Sprafka, R. J.↗
NASA NTRS1985

Electrolysis of simulated lunar melts

Electrolysis of molten lunar soil or rock is examined as an attractive means of wresting useful raw materials from lunar rocks. It requires only hat to melt the soil or rock and electricity to electrolyze it, and both can be developed from solar power. The conductivities of the simple silicate diopside, Mg CaSi2O6 were measured. Iron oxide was added to determine the effect on conductivity. The iron brought about substantial electronic conduction. The conductivities of simulated lunar lavas were measured. The simulated basalt had an AC conductivity nearly a fctor of two higher than that of diopside, reflecting the basalt's slightly higher total concentration of the 2+ ions Ca, Mg, and Fe that are the dominant charge carriers. Electrolysis was shown to be about 30% efficient for the basalt composition.

Lewis, R. H.↗
NASA NTRS1985

Applicability of 100kWe-class of space reactor power systems to NASA manned space station missions

An assessment is made of a manned space station operating with sufficiently high power demands to require a multihundred kilowatt range electrical power system. The nuclear reactor is a competitor for supplying this power level. Load levels were selected at 150kWe and 300kWe. Interactions among the reactor electrical power system, the manned space station, the space transportation system, and the mission were evaluated. The reactor shield and the conversion equipment were assumed to be in different positions with respect to the station; on board, tethered, and on a free flyer platform. Mission analyses showed that the free flyer concept resulted in unacceptable costs and technical problems. The tethered reactor providing power to an electrolyzer for regenerative fuel cells on the space station, results in a minimum weight shield and can be designed to release the reactor power section so that it moves to a high altitude orbit where the decay period is at least 300 years. Placing the reactor on the station, on a structural boom is an attractive design, but heavier than the long tethered reactor design because of the shield weight for manned activity near the reactor.

Silverman, S. W.↗
NASA NTRS1986

Calculations of electric currents in Europa

Electrical currents should flow in the Galilean satellite, Europa, because it is located in Jupiter's corotating magnetosphere. The possible magnitudes of these currents are calculated by assuming that Europa is a differentiated body consisting of an outer H2O layer and a silicate core. Two types of models are considered here: one in which the water is completely frozen and a second in which there is an intermediate liquid layer. For the transverse electric mode (eddy currents), the calculated current density in a liquid layer is approximately 10 to the -5/Am. For the transverse magnetic mode (unipolar generator), the calculated current density in the liquid is severely constrained by the ice layer to a range of only 10 to the -10 to -11th power/ Am, for a total H2O thickness of 100 km, provided that neither layer is less than 4 km thick. The current density is less for a completely frozen H2O layer. If transient cracks were to appear in the ice layer, thereby exposing liquid, the calculated current density could rise to a range of 10 to the -6 to 10 to the -5/Am, depending on layer thicknesses, which would require an exposed area of 10 to the -9 to 10 to the -8 of the Europa surface. The corresponding total current of 2.3x10 to the 5th power A could in 1 yr. electrolyze 7x10 to the 5th power kg of water (and more if the cells were in series), and thereby store up to 10 the 8th power J of energy, but it is not clear how electrolysis can take place in the absence of suitable electrodes. Electrical heating would be significant only if the ice-layer thickness were on the order of 1 m, such as might occur if an exposed liquid surface were to freeze over; the heating under this condition could hinder the thickening of the ice layer.

Colburn, D. S.↗
NASA NTRS1987

Space station propulsion system technology

Two propulsion systems have been selected for the space station: O/H rockets for high thrust applications and the multipropellant resistojets for low thrust needs. These thruster systems integrate very well with the fluid systems on the station. Both thrusters will utilize waste fluids as their source of propellant. The O/H rocket will be fueled by electrolyzed water and the resistojets will use stored waste gases from the environmental control system and the various laboratories. This paper presents the results of experimental efforts with O/H and resistojet thrusters to determine their performance and life capability.

Jones, Robert E.↗
NASA NTRS1987

High-surface-area, dual-function oxygen electrocatalysts for space power applications

The processes of hydration/dehydration and carbonation/decarbonation are investigated as an approach to provide higher surface area mixed metal oxides that are more active electrochemically. These materials are candidates for use as electrocatalysts and electrocatalyst supports for alkaline electrolyzers and fuel cells. For the case of the perovskite, LaCoO3 , higher surface areas were achieved with no change in structure and a more active oxygen electrocatalyst.

Ham, David O.↗
NASA NTRS1987

Space station propulsion

Two propulsion systems have been selected for the space station: gaseous H/O rockets for high thrust applications and the multipropellant resistojets for low thrust needs. These two thruster systems integrate very well with the fluid systems on the space station, utilizing waste fluids as their source of propellant. The H/O rocket will be fueled by electrolyzed water and the resistojets will use waste gases collected from the environmental control system and the various laboratories. The results are presented of experimental efforts with H/O and resistojet thrusters to determine their performance and life capability, as well as results of studies to determine the availability of water and waste gases.

Jones, Robert E.↗
NASA NTRS1987

Space station onboard propulsion system: Technology study

The objective was to prepare for the design of the space station propulsion system. Propulsion system concepts were defined and schematics were developed for the most viable concepts. A dual model bipropellant system was found to deliver the largest amount of payload. However, when resupply is considered, an electrolysis system with 10 percent accumulators requires less resupply propellant, though it is penalized by the amount of time required to fill the accumulators and the power requirements for the electrolyzer. A computer simulation was prepared, which was originally intended to simulate the water electrolysis propulsion system but which was expanded to model other types of systems such as cold gas, monopropellant and bipropellant storable systems.

Mcallister, J. G.↗
NASA NTRS1987

Regenerative fuel cell systems for mid- to high-orbit satellites

An assessment of the present and projected capabilities of selected hydrogen-oxygen and hydrogen-halogen fuel cell and electrolyzer combinations for energy storage systems (ESS) in configurations useful for spacecraft missions operating in the 10- to 50-kW range for many years in midaltitude to geosynchronous orbits has recently been completed. Results of the study indicate that regenerative fuel cell ESS are feasible for the intended application. A computer model was used to provide tradeoff analyses for optimizing the various ESS fuel cell concepts. When appropriately configured to be compatible with the mission needs of the selected model spacecraft, the specific energy for these ESS are intermediate between that presently available for nickel-hydrogen batteries and that expected for the newly emerging sodium-sulfur technology.

Taenaka, R. K.↗
NASA NTRS1987

Environmental control and life support systems analysis for a Space Station life sciences animal experiment

NASA's Langley and Goddard facilities have evaluated the effects of animal science experiments on the Space Station's Environmental Control and Life Support System (ECLSS) by means of computer-aided analysis, assuming an animal colony consisting of 96 rodents and eight squirrel monkeys. Thirteen ECLSS options were established for the reclamation of metabolic oxygen and waste water. Minimum cost and weight impacts on the ECLSS are found to accrue to the system's operation in off-nominal mode, using electrochemical CO2 removal and a static feed electrolyzer for O2 generation.

So, Kenneth T.↗
NASA NTRS1987

Space Station propulsion system technology

Two propulsion systems have been selected for the Space Station: O/H rockets for high thrust applications and the multipropellant resistojets for low thrust needs. These thruster systems integrate very well with the fluid systems on the station. Both thrusters will utilize waste fluids as their source of propellant. The O/H rocket will be fueled by electrolyzed water and the resistojets will use stored waste gases from the environmental control system and the various laboratories. This paper presents the results of experimental efforts with O/H and resistojet thrusters to determine their performance and life capability.

Jones, Robert E.↗
NASA NTRS1989

Space Electrochemical Research and Technology Conference: Abstracts

The objectives of the conference were to examine current technologies, research efforts, and advanced ideas, and to identify technical barriers which affect the advancement of electrochemical energy storage systems for space applications. Papers were presented and workshops were conducted in four technical areas: advanced concepts, hydrogen-oxygen fuel cells and electrolyzers, the nickel electrode, and advanced rechargeable batteries.

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