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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Space shuttle phase B extension, volume 1

In order to define a system which would significantly reduce payload delivery costs, activities were extended to modifications of the reusable space shuttle design concept. Considered were systems using orbiters with external propellant tanks and an interim expendable booster which allowed phased development of the usable orbiter and booster. Analyzed were: Merits of internal and external propellant tanks and the impact of external LH2 compared to L02 and LH2; impact of cargo bay size; impact abort; merit of expendable booster options; and merit of a phased development program. Studies showed that external L02/LH2 and the continued use of the J-2S engine on the orbiter reduced program cost and risk.

Source record↗
NASA NTRS1971

Inertial waste separation system for zero G WMS

The design, operation, and flight test are presented for an inertial waste separation system. Training personnel to use this system under simulated conditions is also discussed. Conclusions indicate that before the system is usable in zero gravity environments, a mirror for the user's guidance should be installed, the bounce cycle and bag changing system should be redesigned, and flange clips should be added to improve the user's balance.

Source record↗
NASA NTRS1972

Evaluation of eddy-current proximity devices for measuring thin potassium film thicknesses

Two eddy current proximity probe systems were tested over a range of 0 to 508 micrometers (0 to 20 mils) of simulated potassium film thicknesses for simulated temperatures of 66 C (150 F), 232 C (450 F), and 666 C (1230 F). The results of short time calibration tests are presented. Instrument drift was a problem throughout the testing and, without correction, may limit the use of such systems to short periods of time. Additional development will be required prior to their being usable as practical instrumentation systems.

Asadourian, A. S.↗
NASA NTRS1972

A flight evaluation of VTOL jet transport under visual and simulated instrument conditions

A flight investigation was performed with the Dornier DO-31 VTOL to evaluate the performance, handling qualities, and operating characteristics that are considered to be important in the operation of a commerical VTOL transport in the terminal area. The DO-31, a 20,000 kilogram transport, has a mixed jet propulsion system; main engines with nozzles deflect from a cruise to a hover position, and vertical lift engines operated below 170 knots. This VTOL mode incorporates pitch and roll attitude and yaw rate stabilization. The tests concentrated on the transition, approach, and vertical landing. The mixed jet propulsion system provided a large usable performance envelope that enabled simulated IFR approaches to be made on 7 deg and 12 deg glide slopes. In these approaches management of thrust magnitude and direction was a primary problem, and some form of integrating the controls will be necessary. The handling qualities evaluation pointed out the need for additional research of define flight path criteria. The aircraft had satisfactory control and stability in hover out of ground effect. The recirculation effects in vertical landing were large below 15 meters.

Holzhauser, C. A.↗
NASA NTRS1971

Thermophysical property data and safety information

Precision measurements of the properties of oxygen over a wide range of temperature and pressure are complete. The primary remaining effort, which is in progress, is the representation of these data in the most usable format such as tables, equations, diagrams, and computer programs. In addition, safety data are essential to proper design, operation, and failure analysis. All of the available information on oxygen safety is being reviewed, evaluated and indexed for quick retrieval through the NASA Aerospace Safety Research and Data Institute program. The availability of data, where the major gaps in data occur, and retrieval of bibliographic information are discussed.

Kropschot, R. H.↗
NASA NTRS1972

In-flight aeroacoustic environments on prospective space shuttle vehicles

The problem of in-flight aerodynamic noise has been studied by reliable estimates of full scale surface-pressure fluctuations from scale model tests in wind tunnels. Scaling relationships have been verified, and many details of the fluctuating pressure characteristics such as spatial correlation and convection velocities are understood. The effects of the wind tunnel environmental turbulence and noise have also been investigated sufficiently so that threshold levels of usable data are known.

Dods, J. B., Jr.↗
NASA NTRS1972

Fabrication and evaluation of a weak zone plate for monitoring performance of large orbiting telescopes

An experimental study of the feasibility of monitoring the optical performance of a large telescope by means of a very faint phase hologram imprinted upon the primary mirror is reported. Tests have been made using an f/5 telescope with a 0.3 m aperture. The results indicate that a usable hologram can be so faint and so restricted in area that it will probably not interfere significantly with normal operation of a 3.0 m telescope at wavelengths longer than 100 nm for stars brighter than magnitude 29.

Erickson, K. E.↗
NASA NTRS1972

Photometry of late type stars

Broad band filter photometry for 57 bright stars of spectral type A2 discussed with peak instrument responses at 3320, 2980, 2460 and 1910 A. The data include nearly all usable filter observations of G, K and M types. Sampling is nearly complete for A and F giants and supergiants, with the exception of Cepheid variables. The basic results presented are relative digital counting rates obtained with a field-stop aperture of 10 minutes of arc. Characteristics of the four filter-photometer combinations and errors are discussed. Some observations require substantial correction if they are to represent the visually brightest star in the field. These corrections and the effects of interstellar reddening are discussed. The adjusted counts are then used to construct color-color diagrams and are compared to the recent SAO grid of model atmospheres.

Doherty, L. R.↗
NASA NTRS1972

Analysis of radiation and meteoroid satellite data

The data obtained in earth orbit by the Radiation and Meteoroid Satellite (RMS) were interpreted and reduced to a form which will be usable by future space experimenters. The required tasks are detailed. Computer programs were written which lifted the raw data and associated emphemeris data from the GFE magnetic tapes. The engineering data was then used to evaluate the performance of the spacecraft and the experiments. The radiation data was used to prepare flux, spectral, and dose maps of the South Atlantic magnetic anomaly where possible. The meteoroid data was used to determine a rough estimate of the meteoroid flux and in general evaluate the performance of the thin-film meteoroid sensors. The degree of success of the RMS mission was evaluated in light of the separation anomaly which occurred between RMS and OFO during launch.

Farmer, B. J.↗
NASA NTRS1972

Dynamics of playa lakes in the Texas High Plains

The author has identified the following significant results. Three small playa lake basins on the southern High Plains, Texas, have been examined by geologists, pedologists, hydrologists, and botanists to establish ground truth for correlation with ERTS-1 imagery. Although the sites are recognizable, details of the three playa basins are too small, at present resolution, to be accurately determined by the available MSS imagery. However, a fourth study site, consisting of a dual playa complex approximately 5 miles long in a basin of 9 square miles, does resolve available imagery allowing accurate measurement of water fluctuations and water depth. Of the available MSS imagery, Band 5 is the most usable. Definition of Band 4 is less due to reduced tonal contrast. The greatest tonal contrast appears on Band 6 and Band 7 between dry land and water areas. Band 6 is particularly good for defining large water areas, Band 7 being best for small lake basins, and Band 5 for growing fields.

Reeves, C. C., Jr.↗
NASA NTRS1971

Reflectance and transmittance characteristics of several selected green and blue-green unialgae.

Obtained reflectance properties of green and blue-green unialgae are evaluated for determining the feasibility of using selected wavelengths in differentiating between green and blue-green algae. The attempt is made to establish selected wavelengths and ratios that would delineate relative concentrations of the algal suspensions. The results should prove helpful in the selection of spectral bands usable in conjunction with multispectrum scanners for qualitative and quantitative studies of algae in bodies of water.

Gramms, L. C.↗
NASA NTRS1971

Crop, soil, and geological mapping from digitized multispectral satellite photography.

An experimental study was conducted of digitized multispectral satellite photography to seek answers to the following two questions: what are the data handling problems and requirements of converting photographic density measurements to a usable digital form, and what surface features can be distinguished using multispectral data taken at satellite altitudes. Results include the digitization of three multiband black and white photographs and a color infrared photograph, the conversion of the results of digitization to a useful digital form, and several data analysis experiments. As a whole, they encourage the use of multiband photography as a multispectral data collection instrument.

Anuta, P. E.↗
NASA NTRS1971

Doping explosive materials for neutron radiographic enhancement.

Discussion of studies relating to the selection of doping materials of high neutron absorption usable for enhancing the neutron radiographic imaging of explosive mixtures, without interfering with the proper chemical reaction of the explosives. The results of the studies show that gadolinium oxide is an excellent material for doping explosive mixtures to enhance the neutron radiographic image.

Golliher, K. G.↗
NASA NTRS1972

Electroadhesive devices for zero-g intra/extravehicular activities.

Initial studies of the electroadhesive phenomenon are shown to indicate that electroadhesors are potentially usable as zero-g assistive devices for a range of intra- and extravehicular activities in space missions. These uses generally are related to astronaut and cargo maneuvering, worksite restraint, and tool and equipment tiedown.

Beasley, G. P.↗
NASA NTRS1972

Optimization of self-acting step thrust bearings for load capacity and stiffness.

Linearized analysis of a finite-width rectangular step thrust bearing. Dimensionless load capacity and stiffness are expressed in terms of a Fourier cosine series. The dimensionless load capacity and stiffness were found to be a function of the dimensionless bearing number, the pad length-to-width ratio, the film thickness ratio, the step location parameter, and the feed groove parameter. The equations obtained in the analysis were verified. The assumptions imposed were substantiated by comparing the results with an existing exact solution for the infinite width bearing. A digital computer program was developed which determines optimal bearing configuration for maximum load capacity or stiffness. Simple design curves are presented. Results are shown for both compressible and incompressible lubrication. Through a parameter transformation the results are directly usable in designing optimal step sector thrust bearings.

Hamrock, B. J.↗
NASA NTRS1972

Phased array antenna matching: Simulation and optimization of a planar phased array of circular waveguide elements

A computerized simulation of a planar phased array of circular waveguide elements is reported using mutual coupling and wide angle impedance matching in phased arrays. Special emphasis is given to circular polarization. The aforementioned computer program has as variable inputs: frequency, polarization, grid geometry, element size, dielectric waveguide fill, dielectric plugs in the waveguide for impedance matching, and dielectric sheets covering the array surface for the purpose of wide angle impedance matching. Parameter combinations are found which produce reflection peaks interior to grating lobes, while dielectric cover sheets are successfully employed to extend the usable scan range of a phased array. The most exciting results came from the application of computer aided optimization techniques to the design of this type of array.

Dudgeon, J. E.↗
NASA NTRS1972

Calibration of Lewis hypersonic tunnel facility at Mach 5, 6, and 7

Results of the initial calibration tests and a description of this true simulation facility are presented. Facility nozzles were calibrated over a range of stagnation pressure and temperature from 140 to 700 newtons per square centimeter and 1100 to 1750 K. The Reynolds number varied from 1.77 million to 7.44 million per meter. Mach numbers in the inviscid core of the three nozzles were 5.17 plus or minus 0.03, 6.05 plus or minus 0.02, and 7.25 plus or minus 0.08. Usable core diameters at the nozzle exit plane varied from 69 to 86 centimeters. True simulation with these performance capabilities and the test section size presently make this a unique operating facility.

Cullon, R. R.↗
NASA NTRS1972

Map the distribution of glaciofluvial deposits and associated glacial landforms

The author has identified the following significant results. Relatively little good usable ERTS-1 imagery has been received to date for data extraction. Of three U-2 aircraft support missions flown in Maine, only photography from the 20 September flight is cloud free and of excellent quality. Controlled local contract photography flown in August and September is of generally excellent quality. Low altitude ground truth photography is useful. The system of image and photo filing is discussed, and the limited work involving image and photo comparison is described.

Woodman, R. G.↗