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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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NASA NTRS1989

Properties of the moon, Mars, Martian satellites, and near-earth asteroids

Environments and surface properties of the moon, Mars, Martian satellites, and near-earth asteroids are discussed. Topics include gravity, atmospheres, surface properties, surface compositions, seismicity, radiation environment, degradation, use of robotics, and environmental impacts. Gravity fields vary from large fractions of the earth's field such as 1/3 on Mars and 1/6 on the moon to smaller fractions of 0.0004 g on an asteroid 1 km in diameter. Spectral data and the analogy with meteor compositions suggest that near-earth asteroids may contain many resources such as water-rich carbonaceous materials and iron-rich metallic bodies. It is concluded that future mining and materials processing operations from extraterrestrial bodies require an investment now in both (1) missions to the moon, Mars, Phobos, Deimos, and near-earth asteroids and (2) earth-based laboratory research in materials and processing.

Taylor, Jeffrey G.↗
NASA NTRS1991

Use of mercuric iodide X-ray detectors with alpha backscattering spectrometers for space applications

The authors present X-ray fluorescence (XRF) spectra of different extraterrestrial samples taken with a mercuric iodide (HgI2) spectrometer inserted into an alpha backscattering instrument identical to that used in the Soviet Phobos mission. The results obtained with the HgI2 ambient temperature detector are compared with those obtained using an Si(Li) cryogenically cooled detector. Efforts to design an optimized instrument for space application are also described. The results presented indicate that the energy resolution and sensitivity of HgI2 detectors are adequate to meet the performance needs of a number of proposed space applications, particularly those in which cooled silicon X-ray detectors are impractical or even not usable, such as for the target science programs on geoscience opportunities for lunar surface, Mars surface, and other comet and planetary missions being planned by NASA and ESA.

Iwanczyk, J. S.↗
NASA NTRS1991

Interplanetary magnetic field control of the Mars bow shock - Evidence for Venuslike interaction

The Mars bow shock location and shape have been determined by examining the Phobos spacecraft magnetometer data. Observations show that the position of the terminator bow shock varies with interplanetary magnetic field orientation in the same way as at Venus. The shock is farthest from Mars in the direction of the interplanetary electric field, consistent with the idea that mass loading plays an important role in the solar wind interaction with Mars. The shock cross section at the terminator plane is asymmetric and is controlled by the interplanetary magnetic field. The shock is farther from Mars during solar maximum. Thus the solar wind interaction with Mars appears to be Venuslike, with a magnetic moment too small to affect significantly the solar wind interaction.

Zhang, T. L.↗
NASA NTRS1991

Planetary atlases

Two kinds of planetary map atlases are in production. Atlases of the first kind contain reduced-scale versions of maps in hard-bound books with dimensions of 11 x 14 inches. These new atlases are intended to: (1) provide concise but comprehensive references to the geography of the planets needed by planetary scientists and others; and (2) allow inexpensive access to the planetary map dataset without requiring acquisition and examination of tens or hundreds of full-size map sheets. Two such atlases have been published and a third is in press. Work was begun of an Atlas of the Satellite of the Outer Planets. The second kind of atlas is a popular or semi-technical version designed for commercial publication and distribution. The first edition, The Atlas of the Solar System, is nearly ready for publication. New funding and contracting constraints now make it unlikely that the atlas can be published in the format originally planned. Currently, the possibility of publishing the maps through the U.S. Geological Survey as a series of folios in the I-map series is being explored. The maps are global views of each solid-surface body of the Solar System. Each map shows airbrushed relief, albedo, and, where available, topography. A set of simplified geologic maps is also included. All of the maps are on equal-area projections. Scales are 1:40,000,000 for the Earth and Venus; 1:2,000,000 for the Saturnian satellites Mimas and Enceladus and the Uranian satellite Miranda; 1:100,000 for the Martian satellites, Phobos and Deimos; and 1:10,000,000 for all other bodies.

Batson, R. M.↗
NASA NTRS1991

Arecibo S-band radar program

The high powered 12.6 cm wavelength radar on the 1000 ft Arecibo reflector is used for a variety of studies of solar system bodies. These include: (1) the radar mapping of the surfaces of Mercury, Venus, the moon and Mars in both senses (usually the two circulars) of received polarization; (2) high time resolution ranging measurements to Mercury and Mars to obtain height profiles and scattering parameters in the equatorial region and to test relativistic and gravitational theories; (3) measurements of the orbital parameters, scattering properties, figure and spin vectors of asteroids and comets; and (4) observations of the satellites of Mars, Phobos and Deimos, and the Galilean satellites of Jupiter.

Campbell, Donald B.↗
NASA NTRS1992

Thermally distinct ejecta blankets from Martian craters

The study of ejecta blankets on Mars gives information about the Martian surface, subsurface, geologic history, atmospheric history, and impact process. In Feb. and Mar. 1989, the Termoskan instrument on board the Phobos 1988 spacecraft of the USSR acquired the highest spatial resolution thermal data ever obtained for Mars, ranging in the resolution from 300 meters to 3 km per pixel. Termoskan simultaneously obtained broad band visible channel data. The data covers a large portion of the equatorial region from 30 degrees S latitude to 6 degrees N latitude. Utilizing the data set we have discovered tens of craters with thermal infrared distinct ejecta (TIDE) in the equatorial regions of Mars. In order to look for correlations within the data, we have compiled a database which currently consists of 110 craters in an area rich in TIDE's and geologic unit variations. For each crater, we include morphologic information from Barlow's Catalog of Large Martian Impact Craters in addition to geographic, geologic, and physical information and Termoskan thermal infrared and visible data.

Betts, B. H.↗
NASA NTRS1992

Infrared photometric behavior and opposition effect of Mars

Although the instrument wasn't designed for this purpose, data from the imaging spectrometer ISM may be used for studying photometric variations of Mars reflectance, that are related to the surface materials and aerosols physical properties. ISM flew aboard the Phobos-2 spacecraft which orbited Mars from January to March, 1989. About 40,000 spectra were acquired in 128 channels ranging from 0.76 to 3.16 micro-m, with a spatial resolution of 25 km and a signal-to-noise ratio ranging up to 1000. Analysis of the results leads to the following conclusions: width variations of the opposition surge can be related to differences in porosity or grain size distribution on the various domains, with little or no effect from suspended dust. As the biggest effects are observed on dark and bright materials, intermediate behaviors on average-bright regions cannot result from a mixing process, but are more likely to come from either cementation processes or modification of the grain size distribution under the influence of wind, which under Martian conditions preferentially removes the biggest particles. Thus, a surface dust consisting in big bright and small dark grains could explain the observations.

Erard, S.↗
NASA NTRS1992

Orbital transfer rocket engine technology: Advanced engine study

An advanced LOX/LH2 engine study for the use of NASA and vehicle prime contractors in developing concepts for manned missions to the Moon, Mars, and Phobos is documented. Parametric design data was obtained at five engine thrusts from 7.5K lbf to 50K lbf. Also, a separate task evaluated engine throttling over a 20:1 range and operation at a mixture ratio of 12 plus or minus 1 versus the 6 plus or minus 1 nominal. Cost data was also generated for DDT&E, first unit production, and factors in other life cycle costs. The major limitation of the study was lack of contact with vehicle prime contractors to resolve the issues in vehicle/engine interfaces. The baseline Aerojet dual propellant expander cycle was shown capable of meeting all performance requirements with an expected long operational life due to the high thermal margins. The basic engine design readily accommodated the 20:1 throttling requirement and operation up to a mixture ratio of 10 without change. By using platinum for baffled injector construction the increased thermal margin allowed operation up to mixture ratio 13. An initial engine modeling with an Aerojet transient simulation code (named MLETS) indicates stable engine operation with the baseline control system. A throttle ratio of 4 to 5 seconds from 10 percent to 100 percent thrust is also predicted. Performance predictions are 483.1 sec at 7.5K lbf, 487.3 sec at 20K lbf, and 485.2 sec at 50K lbf with a mixture ratio of 6 and an area ratio of 1200. Engine envelopes varied from 120 in. length/53 in. exit diameter at 7.5K lbf to 305 in. length/136 in. exit diameter at 50 K lbf. Packaging will be an important consideration. Continued work is recommended to include more vehicle prime contractor/engine contractor joint assessment of the interface issues.

Hayden, Warren R.↗
NASA NTRS1991

Joint US-USSR Long duration Antarctic Mars calibration Balloon (LAMB) mission

The Long duration Antarctic Mars calibration Balloon (LAMB) project has been established at Goddard Space Flight Center for the evaluation and cross calibration of U.S. and USSR remote sensing gamma-ray and neutron detectors. These detectors are analogs of those flown on the Soviet Phobos mission around Mars and those to be flown on the upcoming U.S. Mars Observer mission. Cosmic rays, which are normally filtered out by the atmosphere, and the earth's magnetic field, will induce gamma-ray and neutron emissions from about a half ton of simulated Mars soil aboard the gondola. The cross calibration of these instruments should greatly facilitate the data analysis from both missions and play a role in U.S.-USSR cooperation in space.

Floyd, S. R.↗
NASA NTRS1992

Proceedings of Lunar and Planetary Science, Volume 22; Conference, Houston, TX, Mar. 18-22, 1991

Various papers on lunar and planetary science are presented. Individual topics addressed include: analysis of Phobos Mission Gamma ray spectra from Mars, comparison of volcanic and modified landforms from Tharsis Montes on Mars, polygenetic origin of Hrad Vallis region of Mars, new evidence of lacustrine basins on Mars, flood surge through the Lunae Planum Outflow Complex on Mars, interpretation of canyon materials and flood sources on Kasei Valles on Mars, geochemistry of Manson Impact structure rocks, micrometer-sized glass spheres in Apollo 16 soil 61181, isotopic abundances in Pesyanoe of solar-type xenon, mineralogy of 12 large 'chondritic' interplanetary dust particles. Also discussed are: trace elements in chondritic stratospheric particles, evolution of isotopic signatures in lunar regolith nitrogen, pyroclastic deposits on the western limb of the moon, origin of picritic green glass magmas by polybaric fractional fusion, origin of yellow glasses associated with Apollo 15 KREEP basalt fragments, trace elements in 59 mostly highland moon rocks, mineralization on the moon, relation between diogenite cumulates and eucrite magmas.

Ryder, Graham↗
NASA NTRS1992

Unusually distant bow shock encounters at Venus

The location of the Venus bow shock on two days (July 6, 1981 and August 4, 1971) when the IMF was strong and the Mach number low is examined. When the solar wind Mach number approaches unity the bow shock appears to be greatly detached from the obstacle. Thus inferences from observations of shocks near planets should be treated cautiously, especially if the Mach number is small or not well known. The case of the Phobos mission to Mars is examined as an example of such a situation.

Russell, C. T.↗
NASA NTRS1992

Vertical structure and size distributions of Martian aerosols from solar occultation measurements

Phobos 2 spectrometer measurements of solar occultations close to the evening terminator have furnished data on the vertical structure of the Martian aerosols near the northern spring equinox. Since the thermal structure derived from saturated IR profiles of water vapor does not allow the reaching of the CO2 frost point at cloud altitudes, said clouds' particles may be formed by H2O ice. Dust was also monitored at two wavelengths; it is assumed that the dust particles are levitated by eddy mixing. A parallel is drawn between these thin clouds and the polar mesospheric clouds observed on earth.

Chassefiere, E.↗
NASA NTRS1992

Calculated ionization rates, ion densities, and airglow emission rates due to precipitating electrons in the nightside ionosphere of Mars

The calculations presented in this paper clearly establish that the electron fluxes measured by the HARP instrument, carried on board Phobos 2, could cause significant electron impact ionization and excitation in the nightside atmosphere of Mars, if these electrons actually do precipitate. The calculated peak electron densities were found to be about a factor of 2 larger than the mean observed nightside densities, indicating that if a significant fraction of the measured electrons actually precipitate, they could be the dominant mechanism responsible for maintaining the nightside ionosphere. The calculated zenith column emission rates of the O I 5577-A and 6300-A and CO Cameron band emissions, due to electron impact and dissociative recombination mechanisms, were found to be significant.

Haider, S. A.↗
NASA NTRS1991

Automation of vehicle processing at Space Station Freedom

A methodology for applying the Kennedy Space Center vehicle processing experience to similar operations at Space Station Freedom is described. First, the required on-orbit processing tasks are identified. These tasks are then evaluated for automation suitability, and robotic manipulator and artificial intelligence technologies are investigated to automate selected physical and cognitive tasks. Effects on processing times, extra-vehicular activity savings, and required resources for incorporating these automation enhancements are identified. Results of the following case studies are included: Phobos Gateway Vehicle On-Orbit Assembly and Launch, Lunar Evolution Vehicle On-Orbit Refurbishment, and Mars Mission Vehicle On-Orbit Assembly and Launch.

Vargo, Rick↗
NASA NTRS1992

Bow shocks and magnetotails of Venus and Mars - A comparison

Observations of the bow shock location and the structure of the magnetotail of Mars by the Phobos spacecraft and of Venus by the Pioneer Venus Orbiter reveal the solar wind interactions with these two planets to be quite similar. The subsolar bow shocks of both Venus and Mars lie at 1.47 planetary radii while at the terminator they are at 2.40 and 2.65 planetary radii, respectively. Both bow shocks have oval cross sections when viewed from the sun whose major axes are controlled by the orientation of the interplanetary magnetic field. The tail lobes of both planets are similarly controlled by the IMF orientation. The strength of the solar/antisolar component of the magnetic field is 17 nT at Venus and 14 nT at Mars. The component perpendicular to the tail axis is about 1/2 the corresponding IMF component at Venus and 2 times this component at Mars. However, when these measurements are compared in terms of the distance down the tail at which each were taken, the data from the two planets are quite consistent. Hence both Venus and Mars have principally induced magnetospheres and magnetotails which stand off the solar wind flow.

Russell, C. T.↗
NASA NTRS1992

Water and cheese from the lunar desert: Abundances and accessibility of H, C, and N on the Moon

The Moon has been underrated as a source of H, N, C, and other elements essential to support life and to provide fuel for rockets. There is enough of these elements in each cubic meter of typical lunar soil to provide a substantial lunch for two, if converted to edible forms. The average amount of C per square meter of the lunar surface to a depth of 2 m is some 35 percent of the average amount per square meter tied up in living organisms on Earth. The water equivalent of H in the upper 2 m of the regolith averages at least 1.3 million liters per square kilometer. Mining of H from a small fraction of the regolith would provide all the rocket fuel needed for thousands of years. These elements can be removed from the soil by heating it to high temperature. Some favor the unproven resources of Phobos, Deimos, or near-Earth asteroids instead of the Moon as a source of extraterrestrial material for use in space, or Mars over the Moon as a site for habitation, partly on the basis that the chemical elements needed for life support and propellant are readily abundant on those bodies, but not on the Moon. Well, the Moon is not as barren of H, C, and N as is commonly perceived. In fact, the elements needed for life support and for rocket fuel are plentiful there, although the ore grades are low. Furthermore, the proximity of the Moon and consequent lower cost of transportation and shorter trip and communication times favor that body as the logical site for early acquisition of resources and extraterrestrial living.

Haskin, L. A.↗
NASA NTRS1992

Cartography of asteroids and comet nuclei from low resolution data

High resolution images of non-spherical objects, such as Viking images of Phobos and the anticipated Galileo images of Gaspra, lend themselves to conventional planetary cartographic procedures: control network analysis, stereophotogrammetry, image mosaicking in 2D or 3D, and airbrush mapping. There remains the problem of a suitable map projection for bodies which are extremely elongated or irregular in shape. Many bodies will soon be seen at lower resolution (5-30 pixels across the disk) in images from speckle interferometry, the Hubble Space Telescope, ground-based radar, distinct spacecraft encounters, and closer images degraded by smear. Different data with similar effective resolutions are available from stellar occultations, radar or lightcurve convex hulls, lightcurve modeling of albedo variations, and cometary jet modeling. With such low resolution, conventional methods of shape determination will be less useful or will fail altogether, leaving limb and terminator topography as the principal sources of topographic information. A method for shape determination based on limb and terminator topography was developed. It has been applied to the nucleus of Comet Halley and the jovian satellite Amalthea. The Amalthea results are described to give an example of the cartographic possibilities and problems of anticipated data sets.

Stooke, Philip J.↗
NASA NTRS1993

A Remote Laser-mass Spectrometer for Determination of Elemental Composition

Determination of the elemental composition of lunar, asteroid, and planetary surfaces is a major concern for science and resource utilization of space. The science associated with the development of a satellite or lunar rover laser-mass spectrometer instrument is presented here. The instrument would include a pulsed laser with sufficient energy to create a plasma on a remote surface. Ions ejected from this plasma travel back to the spacecraft or rover, where they are analyzed by a time-of-flight mass spectrometer, giving the elemental and isotope composition. This concept is based on the LIMA-D instrument on board the former Soviet Union Phobos-88 spacecraft sent to Mars. A laser-mass spectrometer placed on a rover or satellite would substantially improve the data return over alternative techniques. The spatial resolution would be centimeters, and a complete mass spectrum could be achieved in one laser shot. An experiment is described that demonstrates these features. A 400 mj Nd:YAG laser is focused, to an intensity of 10(exp 11) w/sq cm, onto a Al, Ag, Cu, Ge, or lunar simulant target. A plasma forms from which ions are ejected. Some of these ions travel down an 18-m evacuated flight tube to a microchannel plate detector. Alternatively, the ions are captured by an ion trap where they are stored until pulsed into a 1-m time-of-flight mass spectrometer, giving the elemental composition of the remote surface. A television camera monitors the plasma plume shape, and a photodiode monitors the temporal plasma emission . With this system, ions of Al, Ag, Cu, Ge, and lunar simulant have been detected at 18 m. The mass spectrum from the ion trap and 1-m time-of-flight tube will be presented.

Deyoung, R. J.↗