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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Electric and hybrid vehicle environmental control subsystem study

An environmental control subsystem (ECS) in electric and hybrid vehicles is studied. A combination of a combustion heater and gasoline engine (Otto cycle) driven vapor compression air conditioner is selected. The combustion heater, the small gasoline engine, and the vapor compression air conditioner are commercially available. These technologies have good cost and performance characteristics. The cost for this ECS is relatively close to the cost of current ECS's. Its effect on the vehicle's propulsion battery is minimal and the ECS size and weight do not have significant impact on the vehicle's range.

Heitner, K. L.↗
NASA NTRS1981

Preprototype nitrogen supply subsystem development

A nitrogen supply subsystem based on the dissociation of hydrazine into a mixture of hydrogen and nitrogen is developed. The latter is separated to provide makeup nitrogen to control the composition of spacecraft atmospheres. Specific hardware developments resulted in the design and fabrication of a nominal 3.6 kg/d nitrogen generation module. The design integrates a hydrazine catalytic dissociator, three ammonia dissociation stages and four hydrogen separation stages into a 33 kg, 14 cu dm module. A technique was devised to alternate the ammonia dissociation and hydrogen separation stages to give high nitrogen purity in the end product stream. Tests show the product stream to contain less than 0.5 percent hydrogen and 10 parts per million ammonia. The design and development of a test stand for the nitrogen generation module and a series of tests which verified its operation and performance capability are described.

Heppner, D. B.↗
NASA NTRS1982

OAO-C end-of-mission power subsystem engineering evaluation

The battery performance on both Orbiting Astronomical Observatory missions was excellent. The end-of-mission power subsystem tests on the battery and the solar arrays provides a real-time degradation analysis for these two components.

Tasevoli, M.↗
NASA NTRS1982

The development version control and visibility subsystem

A prototype development version control and programming environment visibility subsystem (DVCS) is described. DVCS provides an implementation/management interface serving both the implementor and management. The DVCS provides the implementor listings annotated with change bars, detects errors in the block structure of the design and indicates when standards requiring the use of structured programming constructs in the design of software are violated.

Hawley, L. R.↗
NASA NTRS1982

Preprototype nitrogen supply subsystem development

The design and development of a test stand for the Nitrogen Generation Module (NGM) and a series of tests which verified its operation and performance capability are described. Over 900 hours of parametric testing were achieved. The results from this testing were then used to design an advanced NGM and a self contained, preprototype Nitrogen Supply Subsystem. The NGM consists of three major components: nitrogen generation module, pressure controller and hydrazine storage tank and ancillary components. The most important improvement is the elimination of all sealing surfaces, achieved with a total welded or brazed construction. Additionally, performance was improved by increasing hydrogen separating capability by 20% with no increase in overall packaging size.

Heppner, D. B.↗
NASA NTRS1981

Preprototype Vapor Compression Distillation Subsystem development

Vapor Compression Distillation (VCD) has evolved as the most promising approach to reclaim potable water from wastewater for future long-term manned space missions. Life Systems, Inc. (LSI), working with NASA, has developed a preprototype Vapor Compression Distillation Subsystem (VCDS) which processes wastewater at 1.4 kg/h. The preprototype unit weighs 143 kg, occupies a volume of 0.47 cu m, and will reclaim 96 percent of the available wastewater. This unit has been tested by LSI and is scheduled for further testing at NASA-JSC. This paper presents the preprototype VCDS design, configuration, performance data, test results and flight system projections.

Thompson, C. D.↗
NASA NTRS1982

Space Shuttle Orbiter - Reusable surface insulation subsystem thermal performance

The thermal performance of the reusable surface insulation (RSI) subsystem consisting of silica tiles, silicone coated nylon felt insulation, and ceramic cloth gap fillers and thermal barriers is discussed. Thermal response predictions for the components are compared with measured flight data, which indicates that the RSI thermal performance can meet or exceed design requirements for the majority of the RSI. Visual inspections and the maximum temperature conditions observed in structural components after data acquisition suggest that the flight environment was not as severe as the worst case preflight prediction.

Dotts, R. L.↗
NASA NTRS1982

Development of the Galileo Attitude and Articulation Control Subsystem flight software

The ongoing design and implementation of the Project Galileo Attitude and Articulation Control Subsystem (AACS) flight software is outlined, as well as the more important problems that were experienced in the development of this software. The important characteristics of the Galileo spacecraft are described, as are the major requirements driving the software design. The important features of the design are stated and discussed, and a modes and tasks transition diagram is presented. The AACS software implementation is covered, and the algorithms active in each task are shown. Finally, some of the design and management techniques used in the course of the software development are discussed.

Krasner, S. M.↗
NASA NTRS1983

MV-3 communication subsystem

The operational mobile VLBI data acquisition system (MV-3) requires that a voice link be established between the mobile data system and a fixed site. A communications subsystem was incorporated in the MV-3 design which consists of HF radio, VHF mobile radio telephone and conventional land line telephone. The HF antenna design was optimized for short and long range transmission using both inverted V and yagi antennas mounted on a self-supporting telescoping mast.

Parks, G. S.↗
NASA NTRS1982

LANDSAT-D accelerated payload correction subsystem output computer compatible tape format

The NASA GSFC LANDSAT-D Ground Segment (GS) is developing an Accelerated Payload Correction Subsystem (APCS) to provide Thematic Mapper (TM) image correction data to be used outside the GS. This correction data is computed from a subset of the TM Payload Correction Data (PCD), which is downlinked from the spacecraft in a 32 Kbps data stream, and mirror scan correction data (MSCD), which is extracted from the wideband video data. This correction data is generated in the GS Thematic Mapper Mission Management Facility (MMF-T), and is recorded on a 9-track 1600 bit per inch computer compatible tape (CCT). This CCT is known as a APCS Output CCT (AOT). The AOT follows standardized corrections with respect to data formats, record construction and record identification. Applicable documents are delineated; common conventions which are used in further defining the structure, format and content of the AOT are defined; and the structure and content of the AOT are described.

Source record↗
NASA NTRS1982

Thematic mapper flight model preshipment review data package. Volume 2, part A: Subsystem data

Performance and acceptance data are presented for the multiplexer, scan mirror, power supply, mainframe/top mechanical and the aft optics, assemblies. Other major subsystems evaluated include the relay optics, the electronic module, the radiative cooler, and the cable harness. Reference lists of nonconforming materials reports, failure reports, and requests for deviation/waiver are also given.

Source record↗
NASA NTRS1982

Thematic mapper flight model preshipment review data package. Volume 2, part B: Subsystem data

Summarized performance data are presented for the following major subsystems of the thematic mapper: the focal plane assembly, the radiative cooler, the radiative cooler door assembly, the top optical assembly, and the telescope assembly. Reference lists of the configurations status and of nonconforming material reports, failure reports, and requests for deviation/waiver are included.

Source record↗
NASA NTRS1983

Antenna Microwave Subsystem Controller

The development of a new microwave subsystem controller is discussed, and results of installing the equipment at the DSS 13 R&D station are reported. This controller is serving as the prototype for a new generation of microwave controllers for the DSN.

Freiley, A.↗
NASA NTRS1983

Space Shuttle Orbiter Leading Edge Structural Subsystem development

The development of the Space Shuttle Orbiter Leading Edge Structural Subsystem (LESS) is traced from concept definition, through technical development, to final design, qualification testing and flight performance. A detailed description of the LESS is presented to support a discussion of the design, material development and thermal/structural integration. Extensive development/qualification tests and analytical studies were performed to verify the thermal/structural system performance and to certify the LESS for flight. Flight data and detailed post-flight inspection results are presented which support the conclusion that the LESS system performance has been outstanding.

Curry, D. M.↗
NASA NTRS1983

Use of Seasat synthetic aperture radar and Landsat multispectral scanner subsystem data for Alaskan glaciology studies

Three Seasat synthetic aperture radar (SAR) and three Landsat multispectral scanner subsystem (MSS) scenes of three areas of Alaska were analyzed for hydrological information. The areas were: the Dease Inlet in northern Alaska and its oriented or thaw lakes, the Ruth and Tokositna valley glaciers in south central Alaska, and the Malaspina piedmont glacier on Alaska's southern coast. Results for the first area showed that the location and identification of some older remnant lake basins were more easily determined in the registered data using an MSS/SAR overlay than in either SAR or MSS data alone. Separately, both SAR and MSS data were useful for determination of surging glaciers based on their distinctive medial moraines, and Landsat data were useful for locating the glacier firn zone. For the Malaspina Glacier scenes, the SAR data were useful for locating heavily crevassed ice beneath glacial debris, and Landsat provided data concerning the extent of the debris overlying the glacier.

Hall, D. K.↗
NASA NTRS1983

Simplified power processing for ion-thruster subsystems

A review of the thruster/power-processor-interface requirements for (mercury and inert gas) ion-thrusters, an evaluation of various approaches to simplifying the power-processor circuitry, and the test results of the recently developed 8-cm mercury-ion-thruster simplified power-processor unit (SPPU) are presented. The SPPU demonstrates the feasibility of stable thruster operation using highly simplified power-processing techniques and achieves an approximately tenfold reduction in the electronic parts count when compared to the existing power-processor unit (PPU) used in the Hughes/NASA Lewis Research Center 8-cm-diameter (mercury) Ion Auxiliary Propulsion Subsystem (IAPS).

Wessel, F. J.↗
NASA NTRS1983

Space shuttle orbiter reaction control subsystem flight data anomalies

Shuttle orbiter vehicle flight data obtained during operation of the reaction control subsystem (RCS) were compared with predictions derived from RCS wind tunnel test data. This paper reviews the derivation of the wind tunnel data base and discusses how it was used to predict the full-scale RCS effects. Flight and predicted data comparisons include the lateral and directional aerodynamic effects of firing the side jets, longitudinal aerodynamics for pitch jets, and lateral aerodynamics for roll jets. Flight data anomalies resulting from wind tunnel limitations in representing portions of the entry flight trajectory are presented. The cause of each data anomaly is described, as well as a requirement for additional technical analysis to establish RCS effect simulation parameters that can be used to update jet effect technology.

Stone, J. S.↗