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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Active optics simulation system

The active optics simulation system (AOSS) is a set of computer programs and associated software to be used in the development, design, and evaluation of a primary mirror control system for a large space telescope, (e.g., the tentatively proposed 3-meter telescope). The mathematical models of component subsystems and the solution of the physical processes that occur within the mirror surface control system were obtained, and based on these models AOSS simulates the behavior of the entire mirror surface control system as well as the behavior of the component subsystems. The program has a modular structure so that any subsystem module can be replaced or modified with minimum disruption of the rest of the simulation program.

Chi, C. H.↗
NASA NTRS1973

Results of Full-Scale Wind Tunnel Tests on the H.126 Jet Flap Aircraft

The aerodynamic characteristics of the full-scale H.126 jet flap aircraft were studied in a 40- by 80 foot wind tunnel. The H.126 aircraft is designed for research on flight characteristics of an aircraft using the jet flap principle. Static longitudinal, lateral, and directional characteristics were measured at a Reynolds number of 2.5 to 2.7 million. The jet control power as well as the aerodynamic characteristics were measured and are presented herein with limited discussion. The primary configuration variables were flap and aileron deflection.

Aiken, T. N.↗
NASA NTRS1972

A dynamic solar-electric power/thermal control system for spacecraft.

This paper describes a solar-electric power and active thermal control system for spacecraft with solar energy to electricity conversion efficiency of more than 20%. Briefly, the solar heat energy is absorbed by flat plate collectors yielding above 70% of the energy incident for conversion by an organic condensing cycle. The cycle operates between 132 and 6.67 deg C. The working fluid is F-114 which flows through a solar collector to absorb heat, then through a regenerator and into the radiator where it is condensed to a liquid. The cold liquid flows through two paths, one providing regenerator cooling, the other providing spacecraft thermal control. The system total weight is about 170kg/kW of electrical energy produced. The dynamic system replaces batteries by a thermal capacitor for eclipse period energy storage, thereby eliminating many battery charging and control problems as well as improving efficiency and weight characteristics of the system.

Davis, B. K.↗
NASA NTRS1974

Hypersonic stability and control characteristics of the Rockwell International 139-B space shuttle orbiter

The purpose of this study was to determine the hypersonic aerodynamic performance, longitudinal trim, static stability, and the extent of the center-of-gravity boundaries within the design control limits as well as to examine the effect of Reynolds number on the longitudinal stability of the 139-B space shuttle orbiter. A 0.004 scale model (34-0)was tested in helium over an angle-of-attack range of 18 deg to 54 deg at 0 deg and -minus 5 deg sideslip angles. The total pressure was varied for selected configurations to obtain a Reynolds number range, based on model length, from 0.51 million to 3.6 million at Mach numbers between 17.6 and 21.6 Surface oil-flow studies and electron-beam illuminated-flow studies were also conducted at angles-of-attack of 30 deg, 40 deg, and 50 deg for selected Reynolds numbers.

Stone, D. R.↗
NASA NTRS1974

A system to geometrically rectify and map airborne scanner imagery and to estimate ground area

A system of computer programs were developed which performs geometric rectification and line-by-line mapping of airborne multispectral scanner data to ground coordinates and estimates ground area. The system requires aircraft attitude and positional information furnished by ancillary aircraft equipment, as well as ground control points. The geometric correction and mapping procedure locates the scan lines, or the pixels on each line, in terms of map grid coordinates. The area estimation procedure gives ground area for each pixel or for a predesignated parcel specified in map grid coordinates. The results of exercising the system with simulated data showed the uncorrected video and corrected imagery and produced area estimates accurate to better than 99.7%.

Spencer, M. M.↗
NASA NTRS1973

Surface segregation in titanium as monitored by Auger electron spectroscopy

Investigation of the surface diffusion and segregation of bulk impurities in titanium single crystals under well-defined and controlled experimental conditions. It is shown that an atomically clean titanium single-crystal surface can be obtained by argon ion bombardment within the temperature range from 700 to 800 C. It is demonstrated by Auger electron spectroscopy that, if such clean surfaces are subjected to thermal treatment, bulk impurities, especially sulfur, diffuse out to the crystal surface, and that the rate of surface segregation increases with increasing temperature.

Khan, I. H.↗
NASA NTRS1973

Adaptive on-line classification of multi-spectral scanner data

A possible solution to the analysis of the massive amounts of multi-spectral scanner data from the Earth Resource Technical Satellite (ERTS) program is proposed. This solution is offered as an adaptive on-line classification scheme. The classifier is described as well as its controller which is based on ground truth data. Cluster analysis is presented as an alternative approach to the ground truth data. Adaptive feature selection is discussed and possible mini-computer implementations are offered.

Fromm, F. R.↗
NASA NTRS1975

Photographic Equipment Test System (PETS)

The Photographic Equipment Test System is presented. The device is a mobile optical system designed for evaluating performance of various sensors in a laboratory, in a vacuum chamber or on a flight line. The carriage is designed to allow elevation as well as azimuth control of the direction of the light from the collimator. The pneumatic tires provide an effective vibration isolation system. A target/illumination system is mounted on a motor driven linear slide, and focusing and exposure control can be operated remotely from the small electronics control console.

Source record↗
NASA NTRS1975

Flight flutter testing using pulse techniques

A case of flutter developed at a speed lower than had been flown previously. This incident precipitated the routine procedure of pulsing control surfaces as well as the firing of explosive charges during speed build-ups. In the interest of rapid evaluation of results, simple methods of data reduction were used. A case history is presented where in the pulse technique predicted flutter by extrapolating decay rates obtained at subcritical speeds; in addition, a case is presented where no valid extrapolation could be made.

Stringham, R. H., Jr.↗
NASA NTRS1975

A scientific operations plan for the NASA space telescope

A ground system is described which is compatible with the operational requirements of the space telescope. The goal of the ground system is to minimize the cost of post launch operations without seriously compromising the quality and total throughput of space telescope science, or jeopardizing the safety of the space telescope in orbit. The resulting system is able to accomplish this goal through optimum use of existing and planned resources and institutional facilities. Cost is also reduced and efficiency in operation increased by drawing on existing experience in interfacing guest astronomers with spacecraft as well as mission control experience obtained in the operation of present astronomical spacecraft.

West, D. K.↗
NASA NTRS1974

MSFC Skylab corollary experiments

The evolution of the development and integration of Skylab experiments from initial concepts through mission operations is documented. All experiment systems are covered as well as management controls which were developed and exercised to assure acceptable operational capability and optimize data acquisition for final scientific results.

Source record↗
NASA NTRS1977

Method of preparing zinc orthotitanate pigment

Zinc orthotitanate suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by coprecipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400 to 600 C to remove volatiles and is then rapidly heated at 900 to 1200 C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment.

Gates, D. W.↗
NASA NTRS1977

A pulser-sustainer carbon monoxide electric-discharge supersonic laser

Operation of a CW CO electric-discharge supersonic laser with a pulser-sustainer discharge is described. High-power operation as well as independent control over electron energy and density are demonstrated. Maximum input power achieved to date is 100 kW. The maximum output power is 6 kW or 10% of the sustainer positive-column power. Much improved performance appears possible.

Monson, D. J.↗
NASA NTRS1979

Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 deg to 90 deg. 1: High-wing model B

Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance located in a spin tunnel are presented in plotted form for a 1/6.5 scale, single engine, high wing, general aviation airplane model. The configurations tested included the basic airplane, various wing leading-edge devices, tail designs, and rudder control settings as well as airplane components. Data are presented without analysis for an angle of attack range of 8 deg to 90 deg and clockwise and counter-clockwise rotations covering an omega b/2V range from 0 to 0.85.

Bihrle, W., Jr.↗
NASA NTRS1979

Rotary balance data for a single-engine trainer design for an angle-of-attack range of 8 deg to 90 deg

Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance located in the Langley spin tunnel are presented in plotted form for a 1/6 scale, single engine trainer airplane model. The configurations tested included the basic airplane, various wing leading edge devices, elevator, aileron and rudder control settings as well as airplane components. Data are presented without analysis for an angle of attack range of 8 to 90 degrees and clockwise and counter-clockwise rotations.

Pantason, P.↗
NASA NTRS1979

Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 deg to 90 deg. 2: Low-wing model B

Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance located in the spin tunnel are presented in plotted form for a 1/6.5 scale, single engine, low wing, general aviation airplane model. The configurations tested included the basic airplane, various wing leading-edge devices, tail designs, and rudder control settings as well as airplane components. Data are presented without analysis for an angle-of-attack range of 8 deg to 90 deg and clockwise and counter-clockwise rotations covering an (omega)(b)/2V range from 0 to 0.85.

Bihrle, W., Jr.↗
NASA NTRS1979

A model for unsteady effects in lateral dynamics for use in parameter estimation

A mathematical model for the unsteady aerodynamic effects for use in lateral aircraft dynamics has been developed. The approach is to derive approximations to the force and moment coefficients based on Weissinger's arrangement for the trailing vortex pattern for a sideslipped wing. The main thrust of the modeling is for application to estimation of the lateral stability and control derivatives.

Wells, W. R.↗
NASA NTRS1979

Flight control systems development of highly maneuverable aircraft technology /HiMAT/ vehicle

The highly maneuverable aircraft technology (HiMAT) program was conceived to demonstrate advanced technology concepts through scaled-aircraft flight tests using a remotely piloted technique. Closed-loop primary flight control is performed from a ground-based cockpit, utilizing a digital computer and up/down telemetry links. A backup flight control system for emergency operation resides in an onboard computer. The onboard systems are designed to provide fail-operational capabilities and utilize two microcomputers, dual uplink receiver/decoders, and redundant hydraulic actuation and power systems. This paper discusses the design and validation of the primary and backup digital flight control systems as well as the unique pilot and specialized systems interfaces.

Petersen, K. L.↗