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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 1,027 records · Page 57
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Microcomputer-based digital image processing - A tutorial package for exploration geologists

An Apple II microcomputer-based software package for analysis of digital data developed at the University of Oklahoma, the Digital Image Analysis System (DIAS), provides a relatively low-cost, portable alternative to large, dedicated minicomputers for digital image processing education. Digital processing techniques for analysis of Landsat MSS data and a series of tutorial exercises for exploration geologists are described and evaluated. DIAS allows in-house training that does not interfere with computer-based prospect analysis objectives.

Harrington, J. A., Jr.↗
NASA NTRS1985

JPL pulsar timing observations. III - Pulsar rotation fluctuations

Pulsar arrival-time data from a timing program carried out at the Jet Propulsion Laboratory from 1968 to 1982 at 2390 MHz were analyzed to study the precision of neutron star rotation rates. Most of the 24 objects in the sample show 'timing activity' as deviations from the smooth spin-down expected from a simple electromagnetic torque mechanism. About 20 events in both frequency and frequency derivative across the sample of objects are identified, whose properties differ from those of the large-amplitude 'glitches' observed from a few objects. Prospects are good for the millisecond pulsar PSR 1937 + 214 being better than terrestrial maser clocks on time scales of a few years.

Cordes, J. M.↗
NASA NTRS1985

On stellar X-ray emission

Stellar X-ray astronomy represents an entirely new astronomical discipline which has emerged during the past five years. It lies at the crossroads of solar physics, stellar physics, and general astrophysics. The present review is concerned with the main physical problems which arise in connection with a study of the stellar X-ray data. A central issue is the extent to which the extrapolation from solar physics is justified and the definition (if possible) of the limits to such extrapolation. The observational properties of X-ray emission from stars are considered along with the solar analogy and the modeling of X-ray emission from late-type stars, the modeling of X-ray emission from early-type stars, the physics of stellar X-ray emission, stellar X-ray emission in the more general astrophysical context, and future prospects.

Rosner, R.↗
NASA NTRS1984

The future scientific CCD

Since the first introduction of charge-coupled devices (CCDs) in 1970, CCDs have been considered for applications related to memories, logic circuits, and the detection of visible radiation. It is pointed out, however, that the mass market orientation of CCD development has left largely untapped the enormous potential of these devices for advanced scientific instrumentation. The present paper has, therefore, the objective to introduce the CCD characteristics to the scientific community, taking into account prospects for further improvement. Attention is given to evaluation criteria, a summary of current CCDs, CCD performance characteristics, absolute calibration tools, quantum efficiency, aspects of charge collection, charge transfer efficiency, read noise, and predictions regarding the characteristics of the next generation of silicon scientific CCD imagers.

Janesick, J. R.↗
NASA NTRS1985

Project Cassini - A potential collaborative ESA/NASA Saturn Orbiter and Titan Probe mission

Project Cassini is concerned with a potential collaborative mission to Saturn and Titan. The project has been the subject of a joint ESA/NASA Technical Assessment Study from April 1984 to July 1985. The spacecraft consists of a Saturn Orbiter and a Titan entry Probe. Science objectives with respect to Titan include a determination of the abundances of atmospheric constituents and isotope ratios, a study of the distribution of trace gases, cloud physics, and a determination of the state of the surface. Other science objectives are related to Saturn, the rings, icy satellites, the magnetosphere of Saturn, and asteroids. Attention is given to mission design, the spacecraft, and future prospects.

Beckman, J.↗
NASA NTRS1985

Permanent presence - Making it work; Proceedings of the Twenty-second Goddard Memorial Symposium, Greenbelt, MD, March 15, 16, 1984

Among the topics discussed are: electrophoresis operations in space for pharmaceutical processing; Space Station program operations; and Space Station platform configurations. Consideration is also given to: the human role in future space systems; EVA operations; spherical shell applications; and a container material for alloy processing in near-zero gravity. Among additional topics discussed are: Space Station platform thermal control; environmental control and life support for an evolving capability manned Space Station; and the commercial prospects of the Space Station.

Bekey, I.↗
NASA NTRS1985

EOS - The earth observing system of the 1990s

Attention is given to the deliberations of NASA's Earth Observing System (EOS) Science and Mission Requirements Working Group, which has addressed the requirements and prospects for low earth orbit sensor platforms in the 1990s. The proposed EOS network would link data users with mission data repositories. Three EOS instrument packages have been chosen on the basis of synergistic instrument groupings for making simultaneous observations of selected phenomena over a variety of wavelengths.

Arvidson, R. E.↗
NASA NTRS1986

Evolution and status of CFD techniques for scramjet applications

Computational Fluid Dynamics (CFD) methods are presently applied to the design and analysis of scramjet propulsion systems for missiles and aircraft operating at speeds in excess of Mach 5, in forms ranging from simple inviscid codes for parametric studies of inlet geometries to Navier-Stokes codes incorporating chemistry models which address complex scramjet combustion phenomena. Attention is given to the development history of CFD for the hypersonic regime, as well as to scramjet flowfield modeling in inlets, combustors and nozzles, and prospective development trends.

White, M. E.↗
NASA NTRS1986

Current wind tunnel capability and planned improvements at Lewis Research Center

The NASA Lewis 8 x 6-ft and 10 x 10-ft supersonic wind tunnels furnish the capability for propulsion system tests in the Mach 0.4-3.5 range; the 9 x 15-ft wind tunnel at the facility addresses propulsion installation problems at the lower, takeoff and landing speeds, further providing an excellent anechoic environment in which to measure propeller and fan noise. The NASA Lewis Icing Research Tunnel is the largest of its kind in the free world. The currently mothballed Hypersonic Tunnel Facility could furnish the best available simulations of nonvitiated Mach 5-7 test conditions. Studies are underway to identify prospective performance-enhancing modifications for these facilities in the 1990s and beyond.

Bowditch, D. N.↗
NASA NTRS1985

Mass loss from solar-type stars

The present picture of mass loss from solar-type (low-mass) stars is described, with special emphasis on winds from pre-main-sequence stars. Attention is given to winds from T Tauri stars and to angular momentum loss. Prospects are good for further advances in our understanding of the powerful mass loss observed from young stars; ultraviolet spectra obtainable with the Space Telescope should provide better estimates of mass loss rates and a clearer picture of physical conditions in the envelopes of these stars. To understand the mass ejection from old, slowly rotating main-sequence stars, we will have to study the sun.

Hartmann, L.↗
NASA NTRS1985

Lunar bases and space activities of the 21st century

The present conference gives attention to such major aspects of lunar colonization as lunar base concepts, lunar transportation, lunar science research activities, moon-based astronomical researches, lunar architectural construction, lunar materials and processes, lunar oxygen production, life support and health maintenance in lunar bases, societal aspects of lunar colonization, and the prospects for Mars colonization. Specific discussions are presented concerning the role of nuclear energy in lunar development, achromatic trajectories and the industrial scale transport of lunar resources, advanced geologic exploration from a lunar base, geophysical investigations of the moon, moon-based astronomical interferometry, the irradiation of the moon by particles, cement-based composites for lunar base construction, electrostatic concentration of lunar soil minerals, microwave processing of lunar materials, a parametric analysis of lunar oxygen production, hydrogen from lunar regolith fines, metabolic support for a lunar base, past and future Soviet lunar exploration, and the use of the moons of Mars as sources of water for lunar bases.

Mendell, W. W.↗
NASA NTRS1985

Lunar bases - A post-Apollo evaluation

It is presently noted that the moon furnishes a stable and radio-quiet platform for astronomy and space physics, as well as a source for such materials resources as Si, Al, Fe, O, Mg, and Ti, and a base for low cost interplanetary exploration. Attention is given to a vehicle designated the 'Lunar Geochemical Orbiter', and it is recommended that the prospective NASA Space Station's structural modules be designed for lunar as well as orbital use. Further, design studies should be initiated for a manned orbital transfer vehicle (whose propulsion system may be nuclear).

Lowman, P. D., Jr.↗
NASA NTRS1985

Extracting sea ice data from satellite SAR imagery

With the prospect operational satellite SAR's by the end of the decade, there is a clear need to develop automated algorithms for the extraction of geophysical data about sea ice from high resolution radar imagery. To this end, techniques were developed for distinguishing ice from open water and for resolving the details of deformation within areas 100 km square imaged by SEASAT SAR. The classification of ice and open water is based on the creation of two bands of lower resolution image data: local average brightness, and the local variance of brightness. In the space of these two variables, ice and open water are separated into two distinct clusters. The deformation is found on a 3.4 km mesh by local cross-correlations of the brightness. Comparison with manually determined deformation shows room for improvement in regions of high deformation by using smaller areas for cross-correlation. Th concentration and deformation data are used together to determine localized regions of the scene where open water is produced or lost.

Fily, M.↗
NASA NTRS1986

Pioneering the space frontier

The goals and plans of the program for exploration and development of the space frontier recommended by the National Commission on Space for the next 50 years are described. The topics discussed include civilian space goals for 21st-century America, low-cost access to the solar system, opening the space frontier, and American leadership on the space frontier. Papers are presented on advancing science; exploring, prospecting, and settling the solar system; space enterprise and building the technology base; and on an economical, phased approach. In addition, consideration is given to the aspects of conducting an effective science program, government policy and the private sector, international cooperation and competition, 21st-century America, and to what the recommended program will do.

Space Exploration↗
NASA NTRS1986

Application of an InGaAsP diode laser to probe photodissociation dynamics - I(asterisk) quantum yields from n- and i-C3F7I and CH3I by laser gain vs absorption spectroscopy

Initial measurements on I-asterisk yields of alkyl iodides at 266 nm are reported using gain vs. absorption spectroscopy with an InGaAsP diode probe laser. The results are 102 percent + or - 4 percent, 102 percent + or - 7 percent, and 73 percent + or - 4 percent for n-C3F7I, i-C3F7I, and CH3I respectively. Future prospects for the development of diode laser systems and for their use in dynamical studies are discussed.

Hess, W. P.↗
NASA NTRS1985

Working group on chromospheric fields - Canopies

Although there are many points of uncertainty and controversy, the working group on chromospheric fields focussed its discussion on the concept of canopies; i.e., no one disagreed that a central issue relating to magnetic fields and chromospheric models is to learn how the photospheric field spreads with height. However, it quickly became apparent that in the time available, there was little prospect of building new unified models of magnetic field phenomena in the chromosphere beyond the scope of the formal presentations. Thus, the discussion was devoted to formulating questions which seemed both possible to address in future work and important for advancing understanding of the chromosphere. It began by discussing unresolved physical issues (almost everything) and then proceeded to consider means, both observational and synthetic, to address them.

Jones, H. P.↗
NASA NTRS1985

Detectors for high energy cosmic rays on Spacelab

Two instruments designed to determine the spectra of the individual cosmic-ray components at very high energies are described. One of these (CRNE) uses a combination of gas Cerenkov counters and transition radiation detectors for the cosmic-ray nuclei lithium to nickel; the other (TRIC) is optimized for the light cosmic rays (electrons, protons, helium) and uses a transition-radiation/ionization-calorimeter combination. The CRNE instrument, constructed at the University of Chicago, was delivered to NASA for a first Shuttle flight on Spacelab-2 in summer 1985. Some of the technical and programmatic requirements encountered during the hardware construction and integration are discussed, and the expected scientific return and the prospects of using such instrumentation on the Space Station are considered.

Lheureux, J.↗
NASA NTRS1986

SIRTF and the Space Station

An evaluation is made of the technical prospects and scientific goals of the Space IR Telescope Facility (SIRTF), whose telescope is of 1-m aperture and cryogenically cooled and will be able to improve on IRAS performance in such areas as wavelength coverage, spectral and spatial resolution, and sensitivity. Attention is given to the findings of an intensive review of the long-life SIRTF mission, with a view to new determinations on its orbit, scientific performance requirements, and baseline design concepts, as well as the ways in which it will employ elements of the NASA Space Station.

Werner, M. W.↗