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Results for “LUNAR COMPOSITION”

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
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Compositional variations in lunar spinels.

Electron probe data for spinels from Apollo 11, 12, and 14 are presented and analyzed. A modified Johnstone spinel prism showing the data distribution is given. Three projections of this prism are then presented which illustrate the variations of simple ratios that are present in the prism and permit three different perspectives of the data. The results are summarized as fO2 isobars on the spinel prism.

Haggerty, S. E.↗
NASA NTRS1972

Where on the moon - An Apollo systems engineering problem.

Approaches used in the selection of lunar landing sites are discussed, giving attention to a survey of major constraints affecting site selection. The science objectives of lunar exploration are considered, taking into account exploration goals, the acquisition of required data, mission science planning, orbital science, lunar surface traverse capability, the mare basalts, lunar interior composition, regolith, breccias, lunar chronology, lunar surface processes, and the origin of the moon. Subjects examined in connection with Apollo system capabilities include the Apollo missions, development missions, lunar exploration missions, mission design requirements, navigation, launch vehicle considerations, methods of determining accessibility, lunar module descent considerations, landing site redesignation, and questions of landability.

Source record↗
NASA NTRS1973

Removal of a constraint on the composition of the lunar interior.

Ringwood and Essene (1970) proposed that the CaO and Al2O3 contents of the deep interior of the moon must be less than 6% each. This constraint has been generally accepted and has led to models of the lunar interior that are dominated by ferromagnesium silicates. This constraint is invalid. High CaO and Al2O3 peridotites have broader intermediate-density (3.3-3.4 g/cu cm) fields than the Ringwood-Essene 'lunar pyroxenite,' and the high-density phase occurs at higher pressure. Likewise, the gabbro-eclogite transformation pressure increases with Al2O3 content. The moon can have a thick plagioclase rich outer shell and a high Ca-Al interior.

Anderson, D. L.↗
NASA NTRS1973

ALSEP arrays A, B, C, and A-2

The objectives of the lunar surface exploration packages are defined and the preliminary design of scientific systems hardware is reported. Instrument packages are to collect and transmit to earth scientific data on the lunar interior, the lunar surface composition, and the lunar geomorphology

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NASA NTRS1973

Solar wind and terrestrial atmosphere effects on lunar sample surface composition

Samples returned from the Apollo missions have been shown to have undergone a partial surface oxidation with the degree of oxidation being dependent on the intensity and duration of exposure to a terrestrial or other oxidizing atmosphere. Exposure to atomic hydrogen at room temperature, or molecular hydrogen above 100 C results in a surface reduction. The adsorption of water vapor on a test sample was found to be only slightly dependent on the state of surface oxidation, a situation consistent with the formation of hydroxyl groups on the surface when a sample is exposed to hydrogen. That hydroxyl groups are indeed formed is substantiated by the release of water vapor (and by release of heavy water following exposure to deuterium), indicating that water vapor can be synthesized from solar wind hydrogen and sample oxygen. Observations of trace amounts of methane indicate that the reduction process is by no means restricted to the formation of water vapor.

Cadenhead, D. A.↗
NASA NTRS1975

On the composition of the lunar interior

There is now abundant geophysical and geochemical evidence suggesting that the moon has a thick plagioclase rich outer shell. This is most easily explained by early and extensive melting of a CaO and Al2O3 rich moon followed by fractional crystallization involving plagioclase flotation. Melilite is probably an important constituent of the interior. This model explains the seismic velocities, the mean density, and the moment of inertia of the moon. The moon is 73-88% high-temperature condensate.

Anderson, D. L.↗
NASA NTRS2008

Structural, Physical, and Compositional Analysis of Lunar Simulants and Regolith

Relative to the prior manned Apollo and unmanned robotic missions, planned Lunar initiatives are comparatively complex and longer in duration. Individual crew rotations are envisioned to span several months, and various surface systems must function in the Lunar environment for periods of years. As a consequence, an increased understanding of the surface environment is required to engineer and test the associated materials, components, and systems necessary to sustain human habitation and surface operations. The effort described here concerns the analysis of existing simulant materials, with application to Lunar return samples. The interplay between these analyses fulfills the objective of ascertaining the critical properties of regolith itself, and the parallel objective of developing suitable stimulant materials for a variety of engineering applications. Presented here are measurements of the basic physical attributes, i.e. particle size distributions and general shape factors. Also discussed are structural and chemical properties, as determined through a variety of techniques, such as optical microscopy, SEM and TEM microscopy, Mossbauer Spectroscopy, X-ray diffraction, Raman microspectroscopy, inductively coupled argon plasma emission spectroscopy and energy dispersive X-ray fluorescence mapping. A comparative description of currently available stimulant materials is discussed, with implications for more detailed analyses, as well as the requirements for continued refinement of methods for simulant production.

Greenberg, Paul↗
NASA NTRS1977

Lunar sample analysis

The surface composition of lunar fines, the solar wind sputtering process, and the profile of reduced Fe in lunar samples are reported. Atomic absorption studies of trace metal, especially lead, distribution in lunar fines samples are described.

Housley, R. M.↗
NASA NTRS1982

Lunar anorthosite 60025, the petrogenesis of lunar anorthosites, and the composition of the moon

The mineral chemistry of the lunar anorthosite 60025 is investigated, and a model for the differentiation of the moon is proposed based on these findings. Among other results, it is concluded that 60025 is a mixture of pieces from a related sequence of anorthosites, and that this sequence was generated by near-perfect accumulate growth during strong fractional crystallization. The parent liquid of the most primitive anorthosite was saturated with olivine, plagioclase, pigeonite, and chromite, and evolved to one saturated with plagioclase, pigeonite, high-Ca clinopyroxene, and ilmenite. The steep slope of anorthosites on an Mg (mafics) vs. Ab (plagioclase) diagram is a result of the very low alkali content of the magma and of the original magma ocean. The bulk moon had low Al2O3, a sub-chondritic Ca/Al ratio, and REE abundances and patterns which were probably close to chondritic. In addition, mare basalt sources were found to be too magnesian and some contain too much high Ca clinopyroxene to be directly or simply complementary to a floated anorthosite crust.

Ryder, G.↗