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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Preliminary design of an auxiliary power unit for the space shuttle. Volume 4: Selected system supporting studies

Selected system supporting analyses in conjunction with the preliminary design of an auxiliary power unit (APU) for the space shuttle are presented. Both steady state and transient auxiliary power unit performance, based on digital computer programs, were examined. The selected APU provides up to 400 horsepower out of the gearbox, weighs 227 pounds, and requires 2 pounds per shaft horsepower hour of propellants.

Hamilton, M. L.↗
NASA NTRS1972

NASA work unit system file maintenance manual

The NASA Work Unit System is a management information system for research tasks (i.e., work units) performed under NASA grants and contracts. It supplies profiles on research efforts and statistics on fund distribution. The file maintenance operator can add, delete and change records at a remote terminal or can submit punched cards to the computer room for batch update. The system is designed for file maintenance by a person with little or no knowledge of data processing techniques.

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NASA NTRS1972

NASA work unit system users manual

The NASA Work Unit System is a management information system for research tasks (i.e., work units) performed under NASA grants and contracts. It supplies profiles to indicate how much effort is being expended to what types of research, where the effort is being expended, and how funds are being distributed. The user obtains information by entering requests on the keyboard of a time-sharing terminal. Responses are received as video displays or typed messages at the terminal, or as lists printed in the computer room for subsequent delivery by messenger.

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NASA NTRS1972

Auxiliary engine digital interface unit (DIU)

This auxiliary propulsion engine digital unit controls both the valving of the fuel and oxidizer to the engine combustion chamber and the ignition spark required for timely and efficient engine burns. In addition to this basic function, the unit is designed to manage it's own redundancy such that it is still operational after two hard circuit failures. It communicates to the data bus system several selected information points relating to the operational status of the electronics as well as the engine fuel and burning processes.

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NASA NTRS1974

Rechargeable, silver-zinc battery conditioner/monitor unit and state-of-charge indicator

Unit automatically charges batteries to desired state-of-charge levels, monitors functional battery parameter data both on meters and printer, and automatically activates alarm in event of battery malfunctions. Unit consists of state-of-charge indicator panel, control panel, monitor panel, power panel, charging-current power supply, and load panel.

Thomas, C. E.↗
NASA NTRS1972

Test report: Vibration testing of the electron/proton spectrometer structural test unit

The structural test unit of the electron-proton spectrometer was tested to a random vibration spectra and to a sinusoidal resonant search to comply with the requirements of a verification plan for the spectrometer. The test item consisted of mass simulated electronic and printed circuit boards mounted in a flight type electronic housing. The arrangement, center of gravity, and weight were as proposed for flight units.

Vincent, D. L.↗
NASA NTRS1973

Precision annotation of predetermined primary sampling units on ERTS-1 MSS images

Resectioning programs were developed for projecting the boundary corners of sample units, management units, and counties into U2 RC-10 and ERTS-1 MSS images. The technique used includes corrections for earth curvature, terrain elevation, and MSS distortions. The minimum standard error obtained was about 0.15 mm or 150 meters on the ground. This technique now makes it possible to include land ownership as an integral part of forest resource sampling plans using ERTS imagery.

Vanroessel, J. W.↗
NASA NTRS1973

H2-O2 auxiliary power unit for space shuttle vehicles

A program to establish technology readiness of hydrogen-oxygen (H2-O2) auxiliary power units for use on board the space shuttle orbiter vehicle is discussed. Fundamental objectives include experimentally establishing an acceptable propellant flow control method, verification of combustor stability, and adequate thermal management. An initial APU configuration with recycled hydrogen flow has been studied and revised towards greater simplicity and scaling ease. The selected APU is a recuperated open-cycle, turbine-driven unit. Series flow of cryogenic hydrogen removes internally-generated heat and from the hydraulic system. Steady-state test of the combustor has been successful.

Joyce, J. P.↗
NASA NTRS1972

An H2-O2 auxiliary power unit for Space Shuttle.

Auxiliary power units operating on hydrogen and oxygen have the potential for significantly improved performance and payload for the Space Shuttle vehicles. In order to identify the technologies required for these units and to identify promising system configurations, contracted studies provided component and system-configuration screening analysis and detailed analysis of two preliminary system layouts. From these studies, Lewis Research Center has selected for further investigation a recuperated open-cycle hydrogen-oxygen turbine-driven APU concept with pressure-modulated reactant control. This paper discusses the reference system, the control mode, component arrangement, performance potential, and the technology program for this system.

Beremand, D. G.↗
NASA NTRS1973

Algebraic criteria for positive realness relative to the unit circle.

A definition is presented of the circle positive realness of real rational functions relative to the unit circle in the complex variable plane. The problem of testing this kind of positive reality is reduced to the algebraic problem of determining the distribution of zeros of a real polynomial with respect to and on the unit circle. Such reformulation of the problem avoids the search for explicit information about imaginary poles of rational functions. The stated algebraic problem is solved by applying the polynomial criteria of Marden (1966) and Jury (1964), and a completely recursive algorithm for circle positive realness is obtained.

Siljak, D. D.↗
NASA NTRS1973

A comparison of results from two simulators used for studies of astronaut maneuvering units

A comparison of the results from a fixed-base, six-degree-of -freedom simulator and a moving-base, three-degree-of-freedom simulator was made for a close-in, EVA-type maneuvering task in which visual cues of a target spacecraft were used for guidance. The maneuvering unit (the foot-controlled maneuvering unit of Skylab Experiment T020) employed an on-off acceleration command control system operated entirely by the feet. Maneuvers by two test subjects were made for the fixed-base simulator in six and three degrees of freedom and for the moving-base simulator in uncontrolled and controlled, EVA-type visual cue conditions. Comparisons of pilot ratings and 13 different quantitative parameters from the two simulators are made. Different results were obtained from the two simulators, and the effects of limited degrees of freedom and uncontrolled visual cues are discussed.

Stewart, E. C.↗
NASA NTRS1974

Mariner Mars 1971 inertial reference unit

The design concept of an inertial reference unit is reported that uses the gyroscope in a rate mode in conjunction with a unique application of a drift compensated and temperature stabilized solid state integrator for the inertial mode. A typical test program and results for an inertial reference unit as applied to the Mariner Mars 1971 program to achieve highly reliable spacecraft operation are also described.

Starks, G. T.↗
NASA NTRS1974

Experimental probability density distributions for optical and infrared cross-beam units

A series of cross beam experiments for measuring meteorological parameters was conducted. Both optical and infrared sensors were tested for comparison. The test configuration and experiment identification are provided. A data report is presented for an approximate analysis of the probability density distributions of the signals from both the optical and the infared units. Two runs representing each of the two types of cross-beam units were selected for analysis. Probability density functions are also presented for the instantaneous product of the signals for each of the runs.

Huff, L. L.↗
NASA NTRS1974

Check out of rebuilt optical cross-beam units

Preliminary evaluations of limited cross beam data taken with the rebuilt optical cross beam units at the Gun Barrel Hill Test Site of ESSA are presented. The evaluations were made using the analogue Princeton Time Correlator. A study of these evaluations indicates that the rebuilt units are performing satisfactorily. However, there are indications that, in order to obtain useful information from the cross-correlations, it is essential to make judicious choices of computation time and frequency band pass filtering for the analysis of the data.

Huff, L. L.↗
NASA NTRS1974

Mare Serenitatis - A preliminary definition of surface units by remote observations

Mare Serenitatis is a ringed mare about 600 km in diameter situated in the northeast quadrant of the moon. The floor of the mare is comprised of several units. Remote observations of Mare Serenitatis are presented. Color difference photographs were produced by photographing the moon at two wavelength bands. Radar images were obtained by delay-Doppler mapping of radar echoes. The definition of surface units is discussed together with surface properties obtained from remote observations.

Thompson, T. W.↗
NASA NTRS1975

A structural and thermal packaging approach for power processing units for 30-cm ion thrusters

Solar Electric Propulsion (SEP) is currently being studied for possible use in a number of near earth and planetary missions. The thruster subsystem for these missions would consist of 30 centimeter ion thrusters with Power Processor Units (PPU) clustered in assemblies of from two to ten units. A preliminary design study of the electronic packaging of the PPU has been completed at Lewis Research Center of NASA. This study evaluates designs meeting the competing requirements of low system weight and overall mission flexibility. These requirements are evaluated regarding structural and thermal design, electrical efficiency, and integration of the electrical circuits into a functional PPU layout.

Maloy, J. E.↗
NASA NTRS1974

MAS2-8 radar and digital control unit

The design of the MAS 2-8 (2 to 8 GHz microwave-active spectrometer), a ground-based sensor system, is presented. A major modification in 1974 to the MAS 2-8, that of a control subsystem to automate the data-taking operation, is the prime focus. The digital control unit automatically changes all system parameters except FM rate and records the return signal on paper tape. The overall system operation and a detailed discussion of the design and operation of the digital control unit are presented.

Oberg, J. M.↗