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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 91 records · Page 5
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NASA NTRS1972

MIT's role in project Apollo. Volume 2: Optical, radar, and candidate subsystems

The development of optical, radar, and candidate subsystems for Project Apollo is discussed. The design and development of the optical subsystems for both the Apollo command and lunar spacecraft are described. Design approaches, problems, and solutions are presented. The evolution of radar interfaces with the GN&C system is discussed; these interfaces involved both hardware and software in a relatively complex interrelationship. The design and development of three candidate subsystems are also described. The systems were considered for use in Apollo, but were not incorporated into the final GN&C system. The three subsystems discussed are the star tracker-horizon photometer, the map and data viewer and the lunar module optical rendezvous system.

Source record↗
NASA NTRS1975

Automatic control of a primary electric thrust subsystem

A concept for automatic control of the thrust subsystem has been developed by JPL and participating NASA Centers. This paper reports on progress in implementing the concept at JPL. Control of the Thrust Subsystem (TSS) is performed by the spacecraft computer command subsystem, and telemetry data is extracted by the spacecraft flight data subsystem. The Data and Control Interface Unit, an element of the TSS, provides the interface with the individual elements of the TSS. The control philosophy and implementation guidelines are presented. Control requirements are listed, and the control mechanism, including the serial digital data intercommunication system, is outlined. The paper summarizes progress to Fall 1974.

Macie, T. W.↗
NASA NTRS1974

A Statistical Approach to Establishing Subsystem Environmental Test Specifications

Results are presented of a research task to evaluate structural responses at various subsystem mounting locations during spacecraft level test exposures to the environments of mechanical shock, acoustic noise, and random vibration. This statistical evaluation is presented in the form of recommended subsystem test specifications for these three environments as normalized to a reference set of spacecraft test levels and are thus suitable for extrapolation to a set of different spacecraft test levels. The recommendations are dependent upon a subsystem's mounting location in a spacecraft, and information is presented on how to determine this mounting zone for a given subsystem.

Keegan, W. B.↗
NASA NTRS1977

MIUS Integration and Subsystem Test (MIST) data system

A data system for use in testing integrated subsystems of a modular integrated utility system (MIUS) is presented. The MIUS integration and subsystem test (MIST) data system is reviewed from its conception through its checkout and operation as the controlling portion of the MIST facility. The MIST data system provides a real time monitoring and control function that allows for complete evaluation of the performance of the mechanical and electrical subsystems, as well as controls the operation of the various components of the system. In addition to the aforementioned capabilities, the MIST data system provides computerized control of test operations such that minimum manpower is necessary to set up, operate, and shut down subsystems during test periods.

Pringle, L. M.↗
NASA NTRS1976

Integrated testing of an electrochemical depolarized CO2 concentrator /EDC/ and a Bosch CO2 reduction subsystem /BRS/

An oxygen reclamation system (ORS) in a spacecraft has the task to revitalize the spacecraft atmosphere by recovering the elementary oxygen from metabolically produced carbon dioxide and water vapor. Life support subsystems which can form such an ORS are an electrochemical depolarized carbon dioxide concentrator (EDC), a Bosch carbon dioxide reduction subsystem (BRS), and an oxygen generation subsystem (OGS). A total recovery of the oxygen from metabolically generated carbon dioxide can be obtained with the aid of system composed of the considered three subsystems. Attention is given to the control concept which assures an integrated operation of the EDC, BRS, and OGS. A description is presented of the test results obtained during 86 days of testing.

Schubert, F. H.↗
NASA NTRS1977

Spacecraft subsystem checkout by minicomputer

The minicomputer, with its large capacity in a small and inexpensive package, can be an important component in special-purpose test equipment. The Voyager spacecraft flight data subsystem support equipment is an example of computer-based test gear. The subsystem to be tested is a major control and data acquisition element of the Voyager spacecraft, with a large number of interfaces to several other onboard subsystems. This equipment was designed to meet spacecraft subsystem testing requirements while making maximum use of off-the-shelf commercial components. Careful consideration was given to design tradeoffs in the areas of commercial versus specially built hardware and hardware versus software problem solutions. The resulting system is an integrated package of commercial and special-purpose hardware plus software.

Andersen, R. W.↗
NASA NTRS1981

Development status of a preprototype water electrolysis subsystem

A preprototype water electrolysis subsystem was designed and fabricated for NASA's advanced regenerative life support program. A solid polymer is used for the cell electrolyte. The electrolysis module has 12 cells that can generate 5.5 kg/day of oxygen for the metabolic requirements of three crewmembers, for cabin leakage, and for the oxygen and hydrogen required for carbon dioxide collection and reduction processes. The subsystem can be operated at a pressure between 276 and 2760 kN/sq m and in a continuous constant-current, cyclic, or standby mode. A microprocessor is used to aid in operating the subsystem. Sensors and controls provide fault detection and automatic shutdown. The results of development, demonstration, and parametric testing are presented. Modifications to enhance operation in an integrated and manned test are described. Prospective improvements for the electrolysis subsystem are discussed.

Martin, R. B.↗
NASA NTRS1983

Simplified power processing for ion-thruster subsystems

Compared to chemical propulsion, ion propulsion offers distinct payload-mass increases for many future low-thrust earth-orbital and deep-space missions. Despite this advantage, the high initial cost and complexity of ion-propulsion subsystems reduce their attractiveness for most present and near-term spacecraft missions. Investigations have, therefore, been conducted with the objective to attempt to simplify the power-processing unit (PPU), which is the single most complex and expensive component in the thruster subsystem. The present investigation is concerned with a program to simplify the design of the PPU employed in a 8-cm mercury-ion-thruster subsystem. In this program a dramatic simplification in the design of the PPU could be achieved, while retaining essential thruster control and subsystem operational flexibility.

Wessel, F. J.↗
NASA NTRS1983

Electrochemical carbon dioxide concentrator subsystem development

The fabrication of a one-person Electrochemical Depolarized Carbon Dioxide Concentrator subsystem incorporating advanced electrochemical, mechanical, and control and monitor instrumentation concepts is discussed. This subsystem included an advanced liquid cooled unitized core composite cell module and integrated electromechanical components. Over 1800 hours with the subsystem with removal efficiencies between 90%. and 100%; endurance tests with a Fluid Control Assembly which integrates 11 gas handling components of the subsystem; and endurance testing of a coolant control assembly which integrates a coolant pump, diverter valve and a liquid accumulator were completed.

Heppner, D. B.↗
NASA NTRS1984

A 37.5-kW point design comparison of the nickel-cadmium battery, bipolar nickel-hydrogen battery, and regenerative hydrogen-oxygen fuel cell energy storage subsystems for low Earth orbit

Nickel-cadmium batteries, bipolar nickel-hydrogen batteries, and regenerative fuel cell storage subsystems were evaluated for use as the storage subsystem in a 37.5 kW power system for space station. Design requirements were set in order to establish a common baseline for comparison purposes. The storage subsystems were compared on the basis of effective energy density, round trip electrical efficiency, total subsystem weight and volume, and life.

Manzo, M. A.↗
NASA NTRS1984

A 37.5-kW point design comparison of the nickel-cadmium battery, bipolar nickel-hydrogen battery, and regenerative hydrogen-oxygen fuel cell energy storage subsystems for low earth orbit

Nickel-cadmium batteries, bipolar nickel-hydrogen batteries, and regenerative fuel cell storage subsystems were evaluated for use as the storage subsystem in a 37.5 kW power system for Space Station. Design requirements were set in order to establish a common baseline for comparison purposes. The storage subsystems were compared on the basis of effective energy density, round trip electrical efficiency, total subsystem weight and volume, and life.

Manzo, M. A.↗
NASA NTRS1985

Advanced vehicle systems assessment. Volume 2: Subsystems assessment

Volume 2 (Subsystems Assessment) is part of a five-volume report entitled Advanced Vehicle Systems Assessment. Volume 2 presents the projected performance capabilities and cost characteristics of applicable subsystems, considering an additional decade of development. Subsystems of interest include energy storage and conversion devices as well as the necessary powertrain components and vehicle subsystems. Volume 2 also includes updated battery information based on the assessment of an independent battery review board (with the aid of subcontractor reports on advanced battery characteristics).

Hardy, K.↗
NASA NTRS1986

Spacecraft active thermal control subsystem design and operation considerations

Future spacecraft missions will be characterized by high electrical power requiring active thermal control subsystems for acquisition, transport, and rejection of waste heat. These systems will be designed to operate with minimum maintenance for up to 10 years, with widely varying externally-imposed environments, as well as the spacecraft waste heat rejection loads. This paper presents the design considerations and idealized performance analysis of a typical thermal control subsystem with emphasis on the temperature control aspects during off-design operation. The selected thermal management subsystem is a cooling loop for a 75-kWe fuel cell subsystem, consisting of a fuel cell heat exchanger, thermal storage, pumps, and radiator. Both pumped-liquid transport and two-phase (liquid/vapor) transport options are presented with examination of similarities and differences of the control requirements for these representative thermal control options.

Sadunas, J. A.↗
NASA NTRS1987

Automated Subsystem Control for Life Support System (ASCLSS)

The Automated Subsystem Control for Life Support Systems (ASCLSS) program has successfully developed and demonstrated a generic approach to the automation and control of space station subsystems. The automation system features a hierarchical and distributed real-time control architecture which places maximum controls authority at the lowest or process control level which enhances system autonomy. The ASCLSS demonstration system pioneered many automation and control concepts currently being considered in the space station data management system (DMS). Heavy emphasis is placed on controls hardware and software commonality implemented in accepted standards. The approach demonstrates successfully the application of real-time process and accountability with the subsystem or process developer. The ASCLSS system completely automates a space station subsystem (air revitalization group of the ASCLSS) which moves the crew/operator into a role of supervisory control authority. The ASCLSS program developed over 50 lessons learned which will aide future space station developers in the area of automation and controls..

Block, Roger F.↗
NASA NTRS1986

A membrane-based subsystem for very high recoveries of spacecraft waste waters

This paper describes the continued development of a membrane-based subsystem designed to recover up to 99.5 percent of the water from various spacecraft waste waters. Specifically discussed are: (1) the design and fabrication of an energy-efficient reverse-osmosis (RO) breadboard subsystem; (2) data showing the performance of this subsystem when operated on a synthetic wash-water solution - including the results of a 92-day test; and (3) the results of pasteurization studies, including the design and operation of an in-line pasteurizer. Also included in this paper is a discussion of the design and performance of a second RO stage. This second stage results in higher-purity product water at a minimal energy requirement and provides a substantial redundancy factor to this subsystem.

Ray, Roderick J.↗
NASA NTRS1988

Shuttle to Shuttle 2: Subsystem weight reduction potential (estimated 1992 technology readiness date)

The objective of this study was to make estimates of the weight savings that might be realized on all the subsystems on an advanced rocket-powered shuttle (designated Shuttle 2) by using advanced technologies having a projected maturity date of 1992. The current Shuttle with external tank was used as a baseline from which to make the estimates of weight savings on each subsystem. The subsystems with the greatest potential for weight reduction are the body shell and the thermal protection system. For the body shell, a reduction of 5.2 percent in the weight of the vehicle at main engine cutoff is projected through the application of new technologies, and an additional configuration-based reduction of 5 percent is projected through simplification of body shape. A reduction of 5 percent is projected for the thermal protection system through experience with the current Space Shuttle and the potential for reducing thermal protection system thicknesses in selected areas. Main propellant tanks are expected to increase slightly in weight. The main propulsion system is also projected to increase in weight because of the requirement to operate engines at derated power levels in order to accommodate one-engine-out capability. The projections for weight reductions through improvements in the remaining subsystems are relatively small. By summing all the technology factors, a projected reduction of 16 percent in the vehicle weight at main engine cutoff is obtained. By summarizing the configurational factors, a potential reduction of 12 percent in vehicle weight is obtained.

Macconochie, Ian O.↗
NASA NTRS1989

Microgravity sensitivities for Space Station ECLS subsystems

This report presents a review of the Space Station Environmental Control and Life Support subsystems (ECLSS) for sensitivity to low gravity environments. The object of this review is to categorize sensitivity areas and to quantify the risks. This review addresses all processes from a top level view and then examines in more detail those areas which were considered potential risks. The study has concentrated on the primary function of the subsystems which may be significant to the performance of the particular component and does not address integration of the subsystem and/or the mechanical aspects of the designs. The areas of primary concern were the Atmosphere Revitalization (AR), Water Recovery and Management (WRM), and the Waste Management (WM) subsystems.

Bangham, M. E.↗
NASA NTRS1991

Balancing reliability and cost to choose the best power subsystem

A mathematical model is presented for computing total (spacecraft) subsystem cost including both the basic subsystem cost and the expected cost due to the failure of the subsystem. This model is then used to determine power subsystem cost as a function of reliability and redundancy. Minimum cost and maximum reliability and/or redundancy are not generally equivalent. Two example cases are presented. One is a small satellite, and the other is an interplanetary spacecraft.

Suich, Ronald C.↗