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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 181 records · Page 10

Meteorite impact - A suggestion for the origin of some stream channels on Mars

The appearance of many streamlike features on Mars indicates the formation of channels through erosion by liquid water. We suggest that streams originating at meteorite crater boundaries are the result of impact which released subsurface water trapped below the Martian surface by a layer of permafrost. Features indicating surface erosion are the presence of alluvial plains at the downstream ends of channels, an increase in stream width with distance from the meteorite craters, and a direct correlation among several examples between crater diameter and stream length. Water released from the subsurface is preferred over rainfall as a mechanism for the origin of stream channels originating from craters on Mars.

Maxwell, T. A.↗

Environmental surveys in Alaska based upon ERTS data

Alaskan applications of ERTS data are summarized. Areas discussed are: (1) land use; (2) archaeology; (3) vegetation mapping; (4) ice reporting and mapping; (5) permafrost; (6) mineral and oil exploration; (7) geological surveys; (8) seismology; (9) geological faults and structures; (10) hydrology and water resources; (11) glaciology; (12) water circulation in Cook Inlet; and (13) fish and mammal populations.

Miller, J. M.↗

Arctic and subarctic environmental analyses utilizing ERTS-1 imagery

The author has identified the following significant results. ERTS-1 imagery provides a means of distinguishing and monitoring estuarine surface water circulation patterns and changes in the relative sediment load of discharging rivers on a regional basis. Physical boundaries mapped from ERTS-1 imagery in combination with ground truth obtained from existing small scale maps and other sources resulted in improved and more detailed maps of permafrost terrain and vegetation for the same area. Snowpack cover within a research watershed has been analyzed and compared to ground data. Large river icings along the proposed Alaska pipeline route from Prudhoe Bay to the Brooks Range have been monitored. Sea ice deformation and drift northeast of Point Barrow, Alaska have been measured during a four day period in March and shore-fast ice accumulation and ablation along the west coast of Alaska have been mapped for the spring and early summer seasons.

Anderson, D. M.↗

A summary of ERTS data applications in Alaska

ERTS has proven to be an exceedingly useful tool for the preparation of urgently needed resource surveys in Alaska. For this reason the wide utilization of ERTS data by federal, state and industrial agencies in Alaska is increasingly directed toward the solution of operational problems in resource inventories, environmental surveys, and land use planning. Examples of some applications are discussed in connection with surveys of potential agricultural lands; mapping of predicted archaeological sites; permafrost terrain and aufeis mapping; snow melt enhancement from Prudhoe Bay roads; geologic interpretations correlated ith possible new petroleum fields, with earthquake activity, and with plate tectonic motion along the Denali fault system; hydrology in monitoring surging glaciers and the break-up characteristics of the Chena River watershed; sea-ice morphology correlated with marine mammal distribution; and coastal sediment plume circulation patterns.

Miller, J. M.↗

Origin of Martian channels - Clathrates and water

Criticism is directed at the suggestion that Martian channels may have been eroded by liquid water produced by the depressurization of CO2 hydrate. The release of pre-existing subsurface liquid water, such as that trapped under a permafrost layer, by meteorite impact or tectonic activity could produce sufficient flow and would not require heat transfer. The presence of water in a CO2 hydrate is shown to be detrimental to its release from an underground reservoir.

Peale, S. J.↗

Water resources, chapter 2, part B

Various applications and projected applications of active microwave instruments for studying water resources. Most applications involve use of an imaging system operating primarily at wavelengths of less than 30 cm (i.e., K-, X-, and L-bands). Discussion is also included concerning longer wavelength nonimaging systems for use in sounding polar glaciers and icecaps (e.g., Greenland and the Antarctic). The section is divided into six topics: (1) stream runoff, drainage basin analysis, and floods, (2) lake detection and fluctuating levels, (3) coastal processes and wetlands, (4) seasonally and permanently frozen (permafrost) ground, (5) solid water resources (snow, ice, and glaciers), and (6) water pollution.

Source record↗

Heat Pipe Technology: A bibliography with abstracts

This bibliography lists 149 references with abstracts and 47 patents dealing with applications of heat pipe technology. Topics covered include: heat exchangers for heat recovery; electrical and electronic equipment cooling; temperature control of spacecraft; cryosurgery; cryogenic, cooling; nuclear reactor heat transfer; solar collectors; laser mirror cooling; laser vapor cavitites; cooling of permafrost; snow melting; thermal diodes variable conductance; artery gas venting; and venting; and gravity assisted pipes.

Source record↗

Preliminary results from the Viking orbiter imaging experiment

During its first 30 orbits around Mars, the Viking orbiter took approximately 1000 photographic frames of the surface of Mars with resolutions that ranged from 100 meters to a little more than 1 kilometer. Most were of potential landing sites in Chryse Planitia and Cydonia and near Capri Chasma. Contiguous high-resolution coverage in these areas has led to an increased understanding of surface processes, particularly cratering, fluvial, and mass-wasting phenomena. Most of the surfaces examined appear relatively old, channel features abound, and a variety of features suggestive of permafrost have been identified. The ejecta patterns around large craters imply that fluid flow of ejecta occurred after ballistic deposition. Variable features in the photographed area appear to have changed little since observed 5 years ago from Mariner 9. A variety of atmospheric phenomena were observed, including diffuse morning hazes, both stationary and moving discrete white clouds, and wave clouds covering extensive areas.

Carr, M. H.↗

Where do we locate the moon base

Because the lunar polar regions permit continuous solar energy collection and adjacent cryogenic temperature, they may be the preferred sites for early human occupation and use of the moon. If permafrost exists in the polar shaded regions, this preference will become dominant. Though not ideal from the point of view of all-sky coverage for astronomical observations, and also possibly subject to terminator-plane particle hazes near the surface, polar sites (especially the south polar region) may offer enough advantages (e.g., constant cryogenic telescope environments and unlimited tracking time) to be preferred sites for the first lunar observatories.

Burke, J. D.↗

The geology of the Viking Lander 2 site

Models are discussed of several competitive geologic histories that can be hypothesized for the Viking Lander 2 site, none of which is uniquely persuasive. The craft landed on a flat plain of fine-grained sediment overlain by dispersed evenly distributed boulders. The fine-grain material appears to be part of a high-latitude mantle comprising material swept south of the pole regions. The boulders, which are covered by distinctive deep pits, or vesicles, may be the residue of an ejecta deposit from the crater Mie. Alternatively, they may be the remnants of lava flows which formerly covered the region. Polygonal sediment-filled cracks may have been formed by ice wedging, similar to the process that occurs in terrestrial permafrost regions. The possibility that they are desiccation polygons may not be excluded.

Mutch, T. A.↗

Heat pipes in space and on earth

The performance of heat pipes used in the thermal control system of spacecraft such as OAO-III and ATS-6 is discussed, and applications of heat pipes to permafrost stabilization on the Alaska Pipeline and to heat recovery systems are described. Particular attention is given to the ATS-6, launched in 1974, which employs 55 heat pipes to carry solar and internal power loads to radiator surfaces. In addition, experiments involving radiative cooling based on cryogenic heat pipes have been planned for the Long Duration Exposure Facility spacecraft and for Spacelab. The role of heat pipes in Space Shuttle heat rejection services is also mentioned.

Ollendorf, S.↗

Possible fossil H2O liquid-ice interfaces in the Martian crust

The extensive chaotic and fretted terrains in the equatorial regions of Mars are explained on the basis of the vertical distribution of H2O liquid and ice which once existed in the crust. This account assumes that below the permafrost containing water ice, there was a second zone in which liquid water resided for at least a time. Diagenetic alteration and cementation characterized the material in the subpermafrost zone; above, pristine fragmented material with various ice concentrations was found. Later, the ice-laden zone was stripped away by a number of erosional processes, exposing the former ice-liquid water interface.

Soderblom, L. A.↗

Martian intrusions - Possible sites and implications

Both the Moon and Mars exhibit volcanic modification of impact craters characterized by subfloor intrusions that either lift the old crater floor or result in extrusions of lava. Endogenic modification of martian craters, however, probably has involved interactions between such intrusive bodies and permafrost, as suggested by differences between lunar and martian floor-fractured craters. Such interactions raise the interesting possibility for hydrothermally concentrating ores in a manner analogous to the Sudbury structure on the Earth that may be consistent with interpretations of Viking lander results.

Schultz, P. H.↗

Mars - The role of the regolith in volatile storage and atmospheric evolution

Earth-based observations of the optical properties of Mars, laboratory alteration experiments, Mariner 9 data, and Viking lander observations are reviewed which indicate the existence of hydrated minerals on the Martian surface. The problem of estimating the total inventory of H2O, CO2, and other volatiles that may be stored in the Martian regolith is discussed, and morphological evidence is cited which supports the possible occurrence of hard-frozen permafrost in some areas on Mars. Physical adsorption of CO2 in the Martian regolith is considered, buffering of atmospheric pressure by regolith-atmosphere reequilibration is examined, and the problem of the exceedingly low inventory of Ar-36 in the Martian atmosphere is investigated. The possibility is considered that earth's degassing history may have had a larger component of long-diffusion-path degassing from a large hot body while the Martian surface inventory may have received a proportionately greater contribution from volatization of accreting particles.

Fanale, F. P.↗

The Viking results - The case for man on Mars

The Viking landers have provided a number of insights into the composition of the Martian atmosphere and soils (e.g. the high Ar-40/Ar-36 ratio in the atmosphere, and the very low level of organic molecules in the Martian soil). However, a manned mission to Mars could yield much needed additional information on the planet. Seismic and electromagnetic sounding surveys, cloud tracking, drilling for permafrost, and the deduction of geologic field relationships are among the tasks for which a manned research endeavor is particularly suited. Rocket propellant synthesis and the production of food on Mars may be necessary to support such a manned mission.

Clark, B. C.↗

Evidence for explosive volcanic density currents on certain Martian volcanoes

The morphologies of certain of the smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents. An examination of newly-photographed flank and caldera features of the Martian volcanoes Ceraunius Tholus, Uranius Tholus, Uranius Patera and Hecates Tholus, including steep slope angles, Krakatoa-type caldera morphologies, erosional features (radial channels and anastamosing gullies) and constructional features (blanketed flanks and possible lava deltas) reveals their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano. Crater age data from the surface of Martian domes and shields indicates that such explosive activity occurred more frequently early in Martian geologic history, consistent with the view that the volcanic density currents were base surges rather than nuees ardentes, with the melting of permafrost supplying the water required in base surge generation.

Reimers, C. E.↗

Study of sample drilling techniques for Mars sample return missions

To demonstrate the feasibility of acquiring various surface samples for a Mars sample return mission the following tasks were performed: (1) design of a Mars rover-mounted drill system capable of acquiring crystalline rock cores; prediction of performance, mass, and power requirements for various size systems, and the generation of engineering drawings; (2) performance of simulated permafrost coring tests using a residual Apollo lunar surface drill, (3) design of a rock breaker system which can be used to produce small samples of rock chips from rocks which are too large to return to Earth, but too small to be cored with the Rover-mounted drill; (4)design of sample containers for the selected regolith cores, rock cores, and small particulate or rock samples; and (5) design of sample handling and transfer techniques which will be required through all phase of sample acquisition, processing, and stowage on-board the Earth return vehicle. A preliminary design of a light-weight Rover-mounted sampling scoop was also developed.

Mitchell, D. C.↗

Volatiles in the Martian regolith

An inventory of released volatiles on Mars has been derived based upon Viking measurements of atmospheric and surface chemical composition, and upon the inferred mineralogy of a ubiquitous regolith, assumed to average 200m in depth. This model is consistent with the relative abundances of volatiles (except for S) on the earth's surface, but implies one-fifteenth of the volatile release of earth if starting materials were comparable. All constituents are accommodated as chemical components of, or absorbed phases on, regolith materials - without the necessity of invoking unobservable deposits of carbonates, nitrates, or permafrost ice.

Clark, B. C.↗