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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Technology survey of electrical power generation and distribution for MIUS application

Candidate electrical generation power systems for the modular integrated utility systems (MIUS) program are described. Literature surveys were conducted to cover both conventional and exotic generators. Heat-recovery equipment associated with conventional power systems and supporting equipment are also discussed. Typical ranges of operating conditions and generating efficiencies are described. Power distribution is discussed briefly. Those systems that appear to be applicable to MIUS have been indicated, and the criteria for equipment selection are discussed.

Gill, W. L.↗
NASA NTRS1975

Economic analysis of materials processing in space: Introduction

Space processing concepts investigated included an unmanned space factory, and a permanently launched factory. Product lines chosen for analysis were: (1) turbine blades, (2) tungsten targets for X-ray machines, (3) 1 sub G subclass separation by electrophoresis, and (4) high-price exotic crystals. The turbine blade, and 1 sub G products are considered promising candidates.

Source record↗
NASA NTRS1975

Lunar science - The Apollo legacy

The progress made in answering a list of fundamental lunar problems is considered, taking into account the nature of the differences in highlands and mare materials, the chemical composition of the moon, the density and internal structure of the moon, and the state of evolution of the moon. Attention is also given to a number of unanticipated results provided by lunar science. Findings concerning an ancient paleomagnetic field are discussed along with the characteristics of exotic components in the regolith, fundamental material differences observed in lunar surface layers, microcraters, and questions regarding an enhanced iron emission in solar flares.

Burnett, D. S.↗
NASA NTRS1975

Origin and evolution of the lunar regolith; Proceedings of the Symposium, Houston, Tex., November 13-15, 1974

The papers consider the origin and evolution of the lunar regolith utilizing data obtained during American and Soviet manned and unmanned lunar missions as well as surface and orbital observations, photography, sample collections, and experimental studies. Topics include the transport and emplacement of crater and basin deposits, development of the mare regolith, the shallow lunar structure as determined from the passive seismic experiment, horizontal transport of the regolith, the origin of the exotic component and KREEP-rich materials, the influx of interplanetary materials onto the moon, stratification in the lunar regolith, catastrophic rupture of lunar rocks, cosmic-ray exposure ages of surface features, breccia formation by sintering and crystallization, evolution of the lunar soil, and effects of maturation on the reflectance of the regolith. Individual items are announced in this issue.

Source record↗
NASA NTRS1975

Development of the mare regolith - Some model considerations

This investigation uses results obtained in an earlier Monte Carlo study by Oberbeck et al. (1973) to shed light on the consequences of mare-regolith origin by impact comminution of primarily local basaltic rocks by evaluating regolith growth and mixing as a function of time. The study demonstrates that regolith growth is self-regulated and has the same trend and nearly the same terminal growth rates whatever the history of bombardment: rapid initial accumulation followed by diminishing rates of growth. Mixing and all other processes investigated are growth regulated. Mixing increases as growth slows, but never to the extent that the regolith is homogenized. Because the average regolith is never homogenized, products of growth-regulated processes are preserved in the stratigraphy. This model indicates that deeper levels contain thinner depositional units, lesser quantities of meteoritic and exotic components, and more debris derived from shallow levels in the mare basalts than material in near-surface layers.

Quaide, W.↗
NASA NTRS1975

Grown organic matter as a fuel raw material resource

An extensive search was made on biomass production from the standpoint of climatic zones, water, nutrients, costs and energy requirements for many species. No exotic species were uncovered that gave hope for a bonanza of biomass production under culture, location, and management markedly different from those of existing agricultural concepts. A simulation analysis of biomass production was carried out for six species using conventional production methods, including their production costs and energy requirements. These estimates were compared with data on food, fiber, and feed production. The alternative possibility of using residues from food, feed, or lumber was evaluated. It was concluded that great doubt must be cast on the feasibility of producing grown organic matter for fuel, in competition with food, feed, or fiber. The feasibility of collecting residues may be nearer, but the competition for the residues for return to the soil or cellulosic production is formidable.

Roller, W. L.↗
NASA NTRS1975

Major and trace element chemistry of Boulder 1 at Station 2, Apollo 17

Twenty-seven samples from Boulder 1 at Station 2 are analyzed for major and trace elements by atomic absorption spectrophotometry and neutron activation analysis. Two types of matrix and several types of clast materials are characterized on the basis of their chemistry. It is shown that one matrix type is a common material at the Apollo 17 site, while the other is probably exotic to that site. The most unusual clast materials found are coarse norite (an old rock no longer found in millimeter fragments at the site) and pigeonite basalt (possibly a highland volcanic rock). It is concluded that the boulder-forming process combined materials from at least two different localities or vertical strata.

Blanchard, D. P.↗
NASA NTRS1976

Shuttle wave experiments

Wave experiments on shuttle are needed to verify dispersion relations, to study nonlinear and exotic phenomena, to support other plasma experiments, and to test engineering designs. Techniques based on coherent detection and bistatic geometry are described. New instrumentation required to provide modules for a variety of missions and to incorporate advanced signal processing and control techniques is discussed. An experiment for Z to 0 coupling is included.

Calvert, W.↗
NASA NTRS1977

Techniques of Global analysis applied to gravitation theories: A cosmological black hole?

An elementary model of freely falling observers and emitters within a black hole's radius is examined to determine the redshift spectrum reaching a typical observer. The model is independent of scale, the fundamental unit being the radius (mass) of the black hole. The observers/emitters all follow the same kinds of trajectories: radially inward and starting from rest at spatial infinity. The test-particle role is assumed throughout; i.e., the observers/emitters do not themselves contribute to the gravitational field of the system. By means of redshift formulas and luminosity distance to the emitters, a picture of actual redshifts and blueshifts, with their intensities, emerges for an observer within the black hole's radius. No luminosity distances greater than approximately one-half the radius are considered in this particular study; nevertheless, redshifts and blueshifts up to approximately 0.6 are seen in portions of the observer's celestial sphere. An exotic application can be made, as a curiosity, to a black hole the size of the universe, resulting in a particular anisotropic "cosmology."

Debney, G.↗
NASA NTRS1977

Low-temperature condensates in comets

Recent observational data on the volatile fraction of comets are confronted with a model based on the fractional condensation, in the 80-100 K range, of a higher-temperature equilibrium obtained from a solar mixture, more or less depleted in oxygen and in hydrogen. It is possible to almost duplicate the observational data, only by assuming that the solar ratio of C/O is at least as large as 0.66 and that the hydrogen was drastically depleted by an unknown process in the primitive solar nebula. Although none of these two assumptions is at variance with present knowledge, the latter is sufficiently exotic to propose a simpler explanation, namely that comets could be made of interstellar grains relatively unprocessed by heat.

Delsemme, A. H.↗
NASA NTRS1978

Infrared, optical, and X-ray properties of the nuclei of nearby galaxies

The paper considers nuclear activity of galaxies and models for violent activity and surveys observations that the nucleus of almost every galaxy is able to release energy in many exotic forms. Observations of galaxies characterized by obscured nuclei, powerful infrared sources, or ejection of large gas masses from nuclei are described. It is suggested that, although the nucleus is active for a large fraction of the life of the galaxy, it may, for long periods operate at a low level of activity.

Burbidge, G.↗
NASA NTRS1978

How thick are lunar mare basalts

It is argued that De Hon's estimates of the thickness of lunar mare basalts, made by analyzing 'ghost' craters on mare surfaces, were inflated as the result of the crater morphometric data of Pike (1977) to reconstruct rim heights of degraded craters. Crater rim heights of 82 randomly selected highland craters of various states of degradation were determined, and median rim height was compared to that of corresponding fresh impact structures. Results indicate that the thickness estimates of De Hon may be reduced by a factor of 2, and that the total volume of mare basalt produced throughout lunar history could be as little as 1-2 million cubic kilometers. A survey of geochemical and petrographic evidence indicates that lateral transport of regolith components over distances of much greater than 10 km is relatively inefficient; it is suggested that vertical mixing of a highland substrate underlying the basaltic fill may have had a primordial role in generating the observed mare width distributions and high concentrations of exotic components in intrabasin regoliths.

Hoerz, F.↗
NASA NTRS1980

Containerless materials processing in the laboratory

Drop tube makes possible preparation of exotic materials. The 100 foot tube is oriented precisely vertical to prevent free-falling drop from hitting tube walls. Inert-gas supply, evacuation pumps, viewing ports, and flexibility in choice of melt technique allow precise control and monitoring of solidification.

Lacy, L. L.↗
NASA NTRS1979

The Apollo 17 drill core - Petrologic systematics and the identification of a possible Tycho component

Modal data support a five-unit stratigraphy for the Apollo 17 drill core. The upper unit E (0-22 cm depth) is marked by high content of fused soil, brown glass, and mare basalt fragments. This unit corresponds with a portion of the core excavated and refilled within the last 2 m.y. The underlying unit D (22071 cm depth) has a low abundance of fused soil (i.e., low maturity) and is rich in coarse (less than 200 microns) mare fragments. A large section of the core, unit C (71-224 cm depth), is finer-grained, more mature (richer in agglutinates), more feldspathic and has more highland lithic, mineral and glass fragments than unit D. The next underlying unit, B (224-256 cm depth), has yellow/colorless KREEP glasses with a high Si, low-alkali composition unlike the common Apollo 15 or Apollo 17 KREEP series. The petrologic (fused soil) and Is/FeO maturity of this layer is also lower than the units above and below. The deepest unit, A (256-284 cm depth), is marked by its relatively higher maturity and lower yellow/colorless KREEP glass content. The most prominent petrographic/stratigraphic indicators are the pyroxene-rich immature mare unit D and the abundance of KREEP glass in unit B. This KREEP glass is distinctive petrographically and compositionally, and is probably exotic to the Apollo 17 site. It is suggested here that the KREEP glass in unit B is derived from Tycho, which implies widespread distribution of KREEP on the lunar nearside.

Vaniman, D. T.↗
NASA NTRS1979

Primordial heating of asteroidal parent bodies

Most meteorites show evidence of thermal processing either because of metamorphic changes or as a result of melting and differentiation. Proposed mechanisms for supplying this energy generally rely upon short-lived radioisotopes or electrical induction, though accretion is sometimes mentioned, and more exotic models have been discussed. Interest in isotopic heating has been heightened by the discovery of Al-26 in Allende inclusions and also by the proposal that a lunar core and dynamo resulted from the radioactive decay of superheavy elements during the early solar system. Electrical induction as a heat source can be scaled to a broad range of solar system conditions, but corroborative evidence for these conditions is inconclusive. The accretion mechanism is probably not viable for the asteroidal and meteorite parent bodies, because the high kinetic energy requirement is inconsistent with the formation of the objects and their regoliths in the presence of a weak gravitational field.

Sonett, C. P.↗
NASA NTRS1980

Carbynes - Carriers of primordial noble gases in meteorites

Five carbynes (triply bonded allotropes of carbon) have been found by electron diffraction in the Allende and Murchison carbonaceous chondrites: carbon VI, VIII, X, XI, and (tentatively) XII. From the isotopic composition of the associated noble-gas components, it appears that the carbynes in Allende (C3V chondrite) are local condensates from the solar nebula, whereas at least two carbynes in Murchison (C2 chondrite) are of exotic, presolar origin. They may be dust grains that condensed in stellar envelopes and trapped isotropically anomalous matter from stellar nucleosynthesis.

Whittaker, A. G.↗
NASA NTRS1982

The W Serpentis binaries with a few words on epsilon Aurigae

The Algol systems, U-Cephei and V356 Sagittarii, which should be included among the W Serpentis stars, characterized by strong ultraviolet emission lines are discussed. The spectra of the W-Ser stars are similar to those of the T-Tauri stars, and a similarity of physical conditions is indicated. A model of W-Serpentis, a B-star embedded in a thick disk, may be relevant to other exotic eclipsing systems, possibly even to obliquity of ecliptic Aurigae. The obliquity of ecliptic and the relationship to Aur, BM Orionis is reviewed; the system probably contains a pre main sequence star highly flattened by differential rotation.

Plavec, M. J.↗
NASA NTRS1981

Thermal history of mesosiderites revisited

The results of a fission track study of uranium-rich merrillite crystals in a number of mesosiderites are clearly incompatible with cooling rates as low as approximately 0.1 C/million years which have previously been inferred for these meteorites. Classical metallographic techniques thus appear to give erroneous results when applied to this type of meteorites. There appears to be no reason to advocate exotic scenarios to explain the thermal history of mesosiderites.

Crozaz, G.↗