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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Status and outlook for NASA's Land Remote Sensing Program

Both LANDSAT 2 and LANDSAT 3 are currently in operational status following recovery from technical problems. The LANDSAT D program continues NASA's R&D with the dual objectives of assessing the capabilities of the thematic mapper sensor and evaluating the requirements for an operational land observing system. LANDSAT D' will not be launched until LANDSAT D ceases operation, to provide data continuity through 1988. Future NASA remote sensing programs will continue to emphasize research, technology development, cooperative projects with end users of data and cooperation with the National Oceanic and Atmospheric Administration (NOAA) on transition to an operational land observing system. Technology development should extend the results of research to practical applications through improved ground data processing and information extraction techniques and development of new sensors such as the solid state multi-spectral linear array.

Weinstein, R. H.↗
NASA NTRS1982

Status of the 4 MW WTS-4 wind turbine

The WTS-4 is a four-megawatt, horizontal-axis wind turbine presently being fabricated for the U.S. Department of Interior, Bureau of Reclamation, by United Technologies' Hamilton Standard division. This unit, called the System Verification Unit (SVU) will be installed at Medicine Bow, Wyoming, early next spring. The specifications, characteristics and features of the WTS-4 are discussed. The major components-such as rotor, nacelle and tower-are described and their status in the fabrication phase is presented.

Bussolari, R. J.↗
NASA NTRS1983

The NASA Suborbital Program: A status review

The status of the NASA suborbital program is reviewed and its importance to astrophysical and geophysical programs is assessed. A survey of past scientific and developmental accomplishments, an examination of the trends in program costs, and an analysis of current and future program roles are included. The technical disciplines examined are primarily those of astronomy/astrophysics/solar physics and magnetospheric/ionospheric/ atmospheric physics.

Teeter, R.↗
NASA NTRS1982

IR area array status

Leading array technologies are defined and the status of HgCdTe hybrid focal plane development is reported. The liquid phase epitaxy system for HgCdTe production is also discussed.

Rode, J.↗
NASA NTRS1982

Status of the J-series 30-cm mercury ion thruster

This paper describes the status of the 30-cm J-series mercury ion thruster. This thruster was baselined for the Solar Electric Propulsion System (SEPS) vehicle. This thruster is described and several modifications plus suggested modifications are presented. Some of the modifications resulted from tests performed with the thruster. The operational characteristics of eight J-series thrusters are presented. Isolator contamination and flake formation are also discussed.

Kami, S.↗
NASA NTRS1982

Space Shuttle status and performance improvements

Following nearly a decade of studies and development, the Space Shuttle is beginning its flight test phase. This paper reviews the status of the program, and preparations of the space vehicle and facilities for flight. The launch preparations, including conduct of the Mission Verification Test, which comprises a Flight Readiness Firing prior to the actual launch, is discussed. This simulation was designed to test the readiness of the complete organization and all ground and flight equipment for commitment to the first manned orbital flight. The plan of the orbital flight program is outlined indicating how each succeeding flight is made more complex and severe to incrementally test the Space Shuttle. Completion of this four flight program readies the Space Shuttle for operations in late 1982. Payload performance to orbit is increased as the program progresses through the development flights and on into operations.

Day, L. E.↗
NASA NTRS1982

Theory and status of high performance heterodyne detectors

Both near-ideal heterodyne performance and an enhancement of CO2 laser heterodyne system capabilities have been obtained by means of recently developed wide-bandwidth HgCdTe photodiodes and photoconductors. Design considerations, including limitations due to various HgCdTe material parameters, performance predictions, and the current development status of wide bandwidth HgCdTe photodiodes are presented. Attention is also given to the uses and recent results obtained for p-type HgCdTe photoconductors in the role of elevated temperature photomixers.

Spears, D. L.↗
NASA NTRS1982

Status of joint US/USSR experiments planned for the Cosmos '83 biosatellite mission

The plans and status of the fourth joint US/USSR biosatellite experiment, scheduled to be conducted in the last half of 1983, are discussed. These experiments will be conducted on board an unmanned Soviet spacecraft and will involve two restrained Rhesus monkeys and 10 pregnant rats, as well as a variety of small plant and radiation biology experiments. Three of the joint studies will use the monkeys for studies of biorhythms, calcium homeostasis, and the cardiovascular system. The fourth experiment will study rodent embryogenesis and neonatal behavior and development following in utero exposure to spaceflight. Specialized sensors and battery powered hardware have been designed, fabricated, and qualified for flight.

Souza, K. A.↗
NASA NTRS1982

Magnetically suspended Stirling cryogenic space refrigerator Status report

At the 1979 Cryogenic Engineering Conference, attention was given to conceptual designs of spaceborne cryogenic refrigeration systems which can provide long-term, unattended operation. Since that time, efforts have continued to translate one of those concepts into an engineering model. The present investigation is concerned with a refrigerator which was designed to generate 5 W of cooling power at a temperature of 65 K. The compression heat of the refrigerator is dissipated at a temperature of 300 K, and the output of the system is to be maintained reliably for a period of five years or longer. The refrigerator design is based on the Stirling cycle, which has an ideal efficiency equal to that of the Carnot cycle. Attention is given to some background information concerning a cryogenic refrigerator, the design of the refrigerator components, and the development status. The magnetic bearings and the linear motors have been tested at the component level.

Daniels, A.↗
NASA NTRS1983

Status report - DARPA/NASA convertible turbofan/turboshaft engine program

A development status report is presented for the NASA/Defense Advanced Research Projects Agency convertible turbofan-turboshaft engine, which can power a high speed rotorcraft in vertical flight, as well as in horizontal flight up to speeds of Mach 0.85. The basis for this development program is a modified TF34-GE-400 engine. Program objectives include both the demonstration of dual output mode (jet thrust and shaft horsepower) capability and the development of a control system which will operate the engine in either mode and convert operation between the modes.

Bellin, A. I.↗
NASA NTRS1983

Spacecraft-borne long life cryogenic refrigeration: Status and trends

The status of cryogenic refrigerator development intended for, or possibly applicable to, long life spacecraft-borne application is reviewed. Based on these efforts, the general development trends are identified. Using currently projected technology needs, the various trends are compared and evaluated. The linear drive, non-contacting bearing Stirling cycle refrigerator concept appears to be the best current approach that will meet the technology projection requirements for spacecraft-borne cryogenic refrigerators. However, a multiply redundant set of lightweight, moderate life, moderate reliability Stirling cycle cryogenic refrigerators using high-speed linear drive and sliding contact bearings may possibly suffice.

Johnson, A. L.↗
NASA NTRS1983

Helicopter impulsive noise: Theoretical and experimental status

The theoretical and experimental status of helicopter impulsive noise is reviewed. The two major source mechanisms of helicopter impulsive noise are addressed: high-speed impulsive noise and blade-vortex interaction impulsive noise. A thorough physical explanation of both generating mechanism is presented together with model and full-scale measurements of the phenomena. Current theoretical prediction methods are compared with experimental findings of isolated rotor tests. The noise generating mechanism of high speed impulsive noise are fairly well understood - theory and experiment compare nicely over Mach number ranges typical of today's helicopters. For the case of blade-vortex interaction noise, understanding of noise generating mechanisms and theoretical comparison with experiment are less satisfactory. Several methods for improving theory-experiment are suggested.

Schmitz, F. H.↗
NASA NTRS1984

The status of analytical preparation for 2-dimensional testing at high transonic speeds in the University of Southampton transonic self-streamlining wind tunnel

Validation data from the Transonic Self-Streamlining Wind Tunnel has proved the feasibility of streamlining two dimensional flexible walls at low speeds and up to transonic speeds, the upper limit being the speed where the flexible walls are just supercritical. At this condition, breakdown of the wall setting strategy is evident in that convergence is neither as rapid nor as stable as for lower speeds, and wall streamlining criteria are not always completely satisfied. The only major step necessary to permit the extension of two dimensional testing into higher transonic speeds is the provision of a rapid algorithm to solve for mixed flow in the imagery flow fields. The status of two dimensional high transonic testing in the Transonic Self-Streamlining Wind Tunnel is outlined and, in particular, the progress of adapting an algorithm, which solves the Transonic Small Perturbation Equation, for predicting the imagery flow fields is detailed.

Lewis, M. C.↗
NASA NTRS1984

Review and status of heat-transfer technology for internal passages of air-cooled turbine blades

Selected literature on heat-transfer and pressure losses for airflow through passages for several cooling methods generally applicable to gas turbine blades is reviewed. Some useful correlating equations are highlighted. The status of turbine-blade internal air-cooling technology for both nonrotating and rotating blades is discussed and the areas where further research is needed are indicated. The cooling methods considered include convection cooling in passages, impingement cooling at the leading edge and at the midchord, and convection cooling in passages, augmented by pin fins and the use of roughened internal walls.

Yeh, F. C.↗
NASA NTRS1984

Status of New Direction of Liquid Lubricants

The status of liquid lubricants is discussed. Liquid lubricants which continue to be the predominant form of lubrication for machinery are discussed. Petroleum base lubricants comprise a very high percentage of the liquid lubricants in use today. There is a significant movement toward synthetic lubricants driven by crude oil problems coupled with improved additive response, and low temperature performance for the synthetics. Lubricant degradation mechanisms are included for guidance in the selection of lubricant and additive types.

Klaus, E. E.↗
NASA NTRS1984

Elastohydrodynamic Lubrication. Status of Understanding

The development of elastohydrodynamic lubrication can be divided into three main stages. The first stage is the development of the idealized form of elastohydrodynamic lubrication, namely where the surfaces are smooth, the fluid behavior is assumed to be Newtonian, and isothermal considerations are assumed. Results based on these assumptions are presented for the complete spectrum of contact geometries (rectangular and elliptical), contact materials (hard and soft), and lubricant availability (fully flooded and starved). The status of understanding for the idealized stage of elastohydrodynamic lubrication is fairly well covered in the existing literature. The second stage of development separately incorporates the effects of a non-Newtonian fluid model, thermal effects, and surface roughness effects into the elastohydrodynamic lubrication model developed in stage 1. Results showing recent developments in this stage are presented. The third stage collectively considers the items considered in stage 2 in investigating the lubrication of real surfaces in their operating environments.

Bernard J Hamrock↗
NASA NTRS1984

Status of Solar Measurements and Data Reduction for Erb-nimbus 7

The status of the Total Solar Irradiance data obtained using the cavity radiometer aboard the Earth Radiation Budget experiment of the Nimbus 7 satellite is described. The ERB experiment has a number of sensors which measure the radiative fluxes (both shortwave and infrared) leaving the Earth as well as the solar channels. The complexity of the processing of the Earth-flux data, both wide and narrow angle has necessitated a reprocessing effort which produces the final data. Since the solar data is embedded in the same data stream and tape product as the Earth-flux data, it was not generally available in a format convenient for analysis as a separate product. Values for the final data product only are presented and a few remarks concerning the basic features of the data. There is no scientific conclusions presented here other than those directly related to the measurement results. A set of tabulated values is appended.

Hickey, J. R.↗