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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Genesis lunar outpost criteria and design

This design study--the third in the space architecture series--focused on the requirements of an early stage lunar outpost. The driving assumptions of the scenario was that the base would serve as a research facility and technology testbed for future Mars missions, a habitat supporting 12 persons for durations of up to 20 months, and would sustain the following five experimental facilities: Lunar surface mining and production analysis facility, construction technology and materials testbed, closed environmental life support system (CELSS) test facility, lunar farside observatory, and human factors and environment-behavior research facility. Based upon the criteria set forth in a previous programming document, three preliminary lunar base designs were developed. Each of the three schemes studied a different construction method and configuration. The designs were then evaluated in terms of environmental response, human habitability, transportability, constructability, construction dependability and resilience, and their suitability in carrying out the desired scientific research. The positive points of each scheme were then further developed by the entire project team, resulting in one integrated lunar outpost design.

Hansmann, Timothy↗
NASA NTRS1990

Genesis lunar outpost: An evolutionary lunar habitat

Students at the University of Wisconsin-Milwaukee Department of Agriculture undertook a series of studies of lunar habitats during the 1989 to 1990 academic year. Undergraduate students from architecture and mechanical and structural engineering with backgrounds in interior design, biology and construction technology were involved in a seminar in the fall semester followed by a design studio in the spring. The studies resulted in three design alternatives for lunar habitation and an integrated design for an early stage lunar outpost.

Moore, Gary T.↗
NASA NTRS1990

Geochemistry and genesis of the angrites

The major and trace elements were analyzed in samples of LEW86010, LEW87051, and Angra dos Reis angrites were analyzed using INAA and fused-bead EMP techniques. Results suggest that all three angrites originated on a volatile-depleted (Na-poor) but oxidized parent body or on several bodies. The combination of low Na and high FeO/MnO found in these samples suggests that the extreme Na depletion was caused by parent-body outgassing during differentiation, rather than by nebular processes. It was also found that the refractory-element abundances observed in LEW86010 and LEW87051 are related via olivine control; it is suggested that LEW86010 may be a residual melt from a LEW87051-like precursor or that LEW87051 formed from a LEW86010-like precursor via olivine accumulation. On the other hand, the Angra dos Reis displayed an unusual refractory element pattern suggesting that either the angrite parent body was heterogeneous or that Angra dos Reis was formed on a parent body different from that of the other two angrites.

Mittlefehldt, David W.↗
NASA NTRS1991

Space architecture monograph series. Volume 4: Genesis 2: Advanced lunar outpost

This research and design study investigated advanced lunar habitats for astronauts and mission specialists on the Earth's moon. Design recommendations are based on environmental response to the lunar environment, human habitability (human factors and environmental behavior research), transportability (structural and materials system with least mass), constructability (minimizing extravehicular time), construction dependability and resilience, and suitability for NASA launch research missions in the 21st century. The recommended design uses lunar lava tubes, with construction being a combination of Space Station Freedom derived hard modules and light weight Kevlar laminate inflatable structures. The proposed habitat includes research labs and a biotron, crew quarters and crew support facility, mission control, health maintenance facility, maintenance work areas for psychological retreat, privacy, and comtemplation. Furniture, specialized equipment, and lighting are included in the analysis and design. Drawings include base master plans, construction sequencing, overall architectural configuration, detailed floor plans, sections and axonometrics, with interior perspectives.

Fieber, Joseph P.↗
NASA NTRS1992

Genesis of compositional characteristics of Stillwater AN-I and AN-II thick anorthosite units

Compositional variations among samples of the thick Stillwater anorthosite units are used here to model the mechanism by which the anorthosite formed. Suspended plagioclase, on reaching a volumetric crystal concentration of about 65 percent, formed a plagioclase framework here called cumulus plagioclase (CP). Within the interstices among the crystals, some plagioclase and pyroxene precipitated, producing what is here called adcumulus plagioclase and pyroxene (APP). The final materials consists mainly of plagioclase and pyroxene formed from complete crystallization of trapped supporting liquid and called intercumulus plagioclase and pyroxene (IPP). Where the CP framework was relatively open initially, bulk liquid communicated with the interior of the framework to produce APP. Where this communication with the bulk liquid stopped or was prevented initially, the intercumulus liquid froze. Where the CP framework was more tightly packed initially, a relatively higher proportion of IPP to APP was produced.

Haskin, Larry A.↗
NASA NTRS1991

GENESIS 2: Advanced lunar outpost

Advanced, second-generation lunar habitats for astronauts and mission specialists working on the Moon are investigated. The work was based on design constraints set forth in previous publications. Design recommendations are based on environmental response to the lunar environment, habitability, safety, near-term technology, replaceability and modularity, and suitability for NASA lunar research missions in the early 21st century. Scientists, engineers, and architects from NASA/JSC, Wisconsin aeronautical industry, and area universities gave technical input and offered critiques at design reviews throughout the process. The recommended design uses a lunar lava tube, with construction using a combination of Space Station Freedom-derived modules and lightweight Kevlar-laminate inflatables. The outpost includes research laboratories and biotron, crew quarters and support facility, mission control, health maintenance facility, and related areas for functional and psychological requirements. Furniture, specialized equipment, and lighting are included in the design analysis.

Moore, Gary T.↗
NASA NTRS1992

Genesis of mobile troughs in the upper westerlies

Stability calculations on basic-state velocity profiles representative of the preferred regions for the development of the upper-level disturbances active in Type B cyclogenesis show that conditions in these regions (weak low-level baroclinicity, large low-level static stability, and large surface roughness) are favorable for the growth of baroclinic waves with maximum amplitude near the tropopause. The structure of these waves compares favorably with observations of developing short-wavelength upper-level troughs in the atmosphere. Basic states characteristic of the storm track regions (strong low-level baroclinicity and small surface roughness) favor the development of baroclinic waves with maximum amplitude at the surface. The dynamics of both the surface-trapped and the upper-tropospheric waves can be interpreted concisely using concepts of potential vorticity. Based on these results, a possible mechanism for Type B cyclogenesis in the storm track regions is proposed that involves the propagation and structural modification of baroclinic wave packets in a zonally varying basic flow.

Whitaker, Jeffrey S.↗
NASA NTRS1992

Quantitative modeling of soil genesis processes

For fine spatial scale simulation, a model is being developed to predict changes in properties over short-, meso-, and long-term time scales within horizons of a given soil profile. Processes that control these changes can be grouped into five major process clusters: (1) abiotic chemical reactions; (2) activities of organisms; (3) energy balance and water phase transitions; (4) hydrologic flows; and (5) particle redistribution. Landscape modeling of soil development is possible using digitized soil maps associated with quantitative soil attribute data in a geographic information system (GIS) framework to which simulation models are applied.

Levine, E. R.↗
NASA NTRS1993

The genesis of starbursts and infrared emission in the centers of galaxies

We present 10.8-micron maps of the central regions of 21 IR-luminous galaxies. Each map, obtained using the NASA MSFC bolometer array at the IRTF, has a resolution of about 4 arcsec and spans typically 25 x 20 arcsec. Some of the galaxies have also been mapped at 12.5, 19.2, and 30/microns. The sample consists primarily of starburst galaxies but includes several Seyferts and LINERs. On average, the flux detected in each map is about 58 percent of that detected at 12 microns by IRAS. We see a variety of morphologies, including compact and elongated sources and more complex distributions exhibiting such features as kiloparsec-size rings and double lobes. The mid-IR radiation is emitted by dust particles, and for two of the galaxies we see spatial color variations attributable to the presence of very small grains and consistent with their depletion in the starbursts. The mid-IR emission traces the dust heated by the youngest stars. Comparison of the distributions of intense star formation and the dense neutral interstellar medium for eight of these galaxies demonstrates that the two are intimately linked.

Telesco, C. M.↗
NASA NTRS1993

Genesis of a planet in Messier 4

The anomalous spin period second derivative of the binary millisecond pulsar PSR 1620-26 in the globular cluster M4 is best explained by a sub-Jovian mass planet in a moderately eccentric about 7 AU orbit about the pulsar binary. We consider formation scenarios for PSR 1620-26. A planet scavenged from a single main-sequence star during an exchange encounter naturally produces systems such as PSR 1620-26. The position of the pulsar just outside the core of M4 is shown to fit naturally with the preferred formation scenario and permit a planet to have survived in the inferred orbit about the binary. It is possible that the orbital eccentricity of the binary was induced by the planet. A confirmation of a planet in eccentric orbit about PSR 1620-26 would strongly suggest that planets form ubiquitously around low-mass main-sequence stars, even stars of low metallicity.

Sigurdsson, Steinn↗
NASA NTRS1993

Chronology and genesis of high-Ti mare volcanism: Melting of cogenetic depleted and enriched reservoirs

An understanding of the chronology and petrogenesis of volcanic rocks is paramount to unravelling the complexities of the composition and structure of the mantle of the Moon. High-Ti mare basalts represent the best-sampled suite of lunar volcanic rocks and likely represent melts of the uppermost mantle of the Moon. Compiled Nd and Sr isotopic data for high-Ti basalts, combined with weighted average ages determiend by various techniques, yield a complex melting history for the high-Ti mantle source. Melting occurred during three distinct episodes (3.84 Ga, 3.75-3.69 Ga, and 3.56 Ga) separated by hiatuses of 100 Ma or more. The first episode included the melting of a relatively trapped liquid (KREEPy)-rich source beneath the A-11 landing site. Later melting of this source produced magmas which were relatively trapped liquid-free at the A-11 site. Synchronous melting at the A-17 landing site produced magmas with variable proportions of this evolved trapped liquid component. The final phase of volcanism occurred at the A-11 site and involved the assimilation of an evolved 'neuKREEP' component. Continued melting of a similar source, which was nearly exhausted of its ilmenite component, beneath the A-12 landing site may have lead to production of magmas parental to the A-12 ilmenite basalts.

Snyder, Gregory A.↗
NASA NTRS1993

Ancient Martian valley genesis and paleoclimatic inference: The present as a key to the past

I offer here the speculative genetic hypothesis that the flat-floored landforms represent episodically active, sediment-laden valley glaciers formed by localized geothermal melting of abundant interstitial ice (permafrost) in a fine-grained sedimentary terrain. Geothermal melting may also localize spring heads for the narrow deep, high-gradient valleys, or the collapse process itself may result in the generation of decanted, relatively sediment-poor overland water flows (some local evidence of fluid overtopping of the localized depressions exists). Whatever the generic mechanisms for the suite of valley landforms, perhaps the most interesting observation is simply their youth. In aggregate, the morphologies are similar to the ancient valley systems cited as evidence for a previously much denser atmosphere on Mars.

Brakenridge, G. R.↗
NASA NTRS1993

Genesis of the IIICD iron meteorites - Evidence from silicate-bearing inclusions

Our studies of the silicate-bearing inclusions in the IIICD iron meteorites Maltahohe, Carlton, and Dayton suggest that their mineralogy and mineral compositions are related to the composition of the metal in the host meteorites. An inclusion in the low-Ni Maltahohe is similar in mineralogy to those in IAB irons, which contain olivine, pyroxene, plagioclase, graphite, and troilite. With increasing Ni concentration of the metal, silicate inclusions become poorer in graphite, richer in phosphates, and the phosphate and silicate assemblages become more complex. Dayton contains pyroxene, plagioclase, SiO2, brianite, panethite, and whitlockite, without graphite. In addition, mafic silicates become more FeO-rich with increasing Ni concentration of the hosts. In contrast, silicates in IAB irons show no such correlation with host Ni concentration, nor do they have the complex mineral assemblages of Dayton. These trends in inclusion composition and mineralogy in IIICD iron meteorites have been established by reactions between the S-rich metallic magma and the silicates, but the physical setting is uncertain. Of the two processes invoked by other authors to account for groups IAB and IIICD, fractional crystallization of S-rich cores and impact generation of melt pools, we prefer core crystallization. We suggest that the solidification of the IIICD core may have been very complex, involving fractional crystallization, nucleation effects and, possibly, liquid immiscibility.

Mccoy, Timothy J.↗
NASA NTRS1995

Enchanted rendezvous: John C. Houbolt and the genesis of the lunar-orbit rendezvous concept

This is the fourth publication of the 'Monographs in Aerospace History' series, prepared by the NASA History Office. These publications are intended to be tightly focused in terms of subject, relatively short in length, and reproduced to allow timely and broad dissemination to researchers in aerospace history. This publication details the arguments of John C. Houbolt, an engineer at the Langley Research Center in Hampton, Virginia, in his 1961-1962 campaign to support the lunar-orbit rendezvous (LOR). The LOR was eventually selected during Project Apollo as the method of flying to the Moon, landing on the surface, and returning to Earth. The LOR opted to send the entire lunar spacecraft up in one launch, enter into the lunar orbit, and dispatch a small lander to the lunar surface. It was the simplest of the various methods, both in terms of development and operational costs, but it was risky. There was no room for error or the crew could not get home; and the more difficult maneuvers had to be done when the spacecraft was committed to a circumlunar flight. Houbolt was one of the most vocal people supporting the LOR.

Hansen, James R.↗
NASA NTRS2000

On The Genesis of Tropical Cyclones: Role of Mesoscale Interactions

Before the last decades of the 20th century, observations were rarely adequate to assess the role of mesoscale circulations in the formation of tropical cyclones. Recent developments in remote-sensing technology have allowed routine collection of measurements that reveal the small- and mesoscale structure of forming tropical cyclones. Additional information is contained in the original extended abstract.

Ritchie, Elizabeth↗
NASA NTRS1998

Oxygen Isotopic Constraints on the Genesis of Carbonates from Martian Meteorite ALH84001

Ion microprobe oxygen isotopic measurements of a chemically diverse suite of carbonates from Martian meteorite ALH84001 are reported. The delta(sup 18)O values are highly variable, ranging from +5.4 to + 25.3%, and are correlated with major element compositions of the carbonate. The earliest forming (Ca-rich) carbonates have the lowest delta(sup 18)O values and the late-forming (Mg-rich) carbonates have the highest delta(sup 18)O values. Two models are presented which can explain the isotopic variations. The carbonates could have formed in a water rich environment at relatively low, but highly variable temperatures. In this open-system case the lower limit to the temperature variation is approx. 125 C, with fluctuations of over 250 C possible within the constraints of the model. Alternatively, the data can be explained by a closed-system model in which the carbonates precipitated from a limited amount of CO2-rich fluid. This scenario can reproduce the isotopic variations observed at a range of temperatures, including relatively high temperatures (less than 500 C). Thus the oxygen isotopic compositions do not provide unequivocal evidence for formation of the carbonates at low temperature. Although more information is needed in order to distinguish between the models, neither of the implied environments is consistent with biological activity. Thus, we suggest that features associated with the carbonates which have been interpreted to be the result of biological activity were most probably formed by inorganic processes.

Leshin, Laurie A.↗
NASA NTRS1999

Isotopic Constraints on the Genesis of Carbonates in Martian Meteorite ALH 84001

Oxygen isotopic analyses in approximately 20 micrometer spots in a chemically diverse suite of carbonates from ALH 84001 show highly variable delta(exp 18)O values from +5.4 to +25.3%. The isotopic data are correlated with the major element composition of the carbonate. The earliest forming (Ca-rich) carbonates have the lowest delta(exp 18)O values and the late-forming Mg-rich carbonates have the highest delta(exp 18)O values. Two models that can explain the isotopic variation were investigated. The carbonates could have formed in a water-rich environment at relatively low, but highly variable temperatures. In this open-system case the lower limit to the temperature variation is approximately 125 C, with fluctuations of over 250 C possible within the constraints of the model, depending on fluid composition. Alternatively the data can be explained by a closed-system model in which carbonates precipitated from a limited amount of a CO2-rich fluid. This scenario can reproduce the range of isotopic values observed, even at relatively high temperatures (greater than 500 C). Thus, the oxygen isotopic compositions do not provide unequivocal evidence for formation of the carbonates at low temperature. Neither of these scenarios is consistent with a biological origin of the carbonates and their associated features. Olivine from ALH 84001 occurs as clusters within orthopyroxene adjacent to fractures containing disrupted carbonate globules and feldspathic shock glass. The inclusions are irregular in shape and range in size from approximately 40 micrometers to submicrometer. The olivine exhibits a limited range of chemical composition from Fo(sub 65) to Fo(sub 66). We measured delta(exp 18)O values of the olivine to be +5.1 +/- 1.4%, indistinguishable within uncertainty from the host orthopyroxene. The data suggest that the olivine formed at high temperature (greater than 800 C), and is probably unrelated to carbonate formation. Instead the olivine probably formed by metamorphic reactions involving either dehydration of hydrous silicates or reduction of opx + spinel. If the reactions took place after carbonate formation, they could have caused devolatilization of siderite, producing the magnetite in the ALH carbonate globules. This scenario is also inconsistent with a biological origin for the features in ALH 84001.

Leshin, Laurie A.↗