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At least 1,387 records · Page 77
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Oxygen production processes on the Moon: An overview

The production of oxygen on the Moon utilizing indigenous material is paramount to a successful lunar colonization. Several processes were put forth to accomplish this. The lunar liquid oxygen (LLOX) generation schemes which have received the most study to date are those involving: (1) the reduction of ilmenite (FeTiO3) by H2, C, CO, CH4, CO-Cl2 plasma; (2) magma electrolysis, both unadulterated and fluoride-fluxed, and (3) several others, including carbo-chlorination, HF acid leaching, fluorine extraction, magma oxidation, and vapor pyrolysis. The H2 reduction of ilmenite and magma electrolysis processes have received the most study to date. At this stage of development, they both appear feasible schemes with various pros and cons. However, all processes should be addressed at least at the onset of the considerations. It is ultimatley the energy requirements of the entire process, including the acquisition of feedstock, which will determine the mode of oxygen productions. There is an obvious need for considerably more experimentation and study. Some of these requisite studies are in progress, and several of the most studied and feasible processes for winning oxygen from lunar materials are reviewed.

Taylor, Lawrence A.↗
NASA NTRS1991

Production of solar photovoltaic cells on the Moon

Solar energy is directly available on the sunward lunar surface. Most, if not all, the materials are available on the Moon to make silicon based solar photovoltaic cells. A few additional types are possible. There is a small but growing literature on production of lunar derived solar cells. This literature is reviewed. Topics explored include trade-offs of local production versus import of key materials, processing options, the scale and nature of production equipment, implications of storage requirements, and the end-uses of the energy. Directions for future research and demonstrations are indicated.

Criswell, David R.↗
NASA NTRS1989

Report of the 90-day study on human exploration of the Moon and Mars

The basic mission sequence to achieve the President's goal is clear: begin with Space Station Freedom in the 1990's, return to the Moon to stay early in the Next century, and then journey to Mars. Five reference approaches are modeled building on past programs and recent studies to reflect wide-ranging strategies that incorporate varied program objectives, schedules, technologies, and resource availabilities. The reference approaches are (1) balance and speed; (2) the earliest possible landing on Mars; (3) reduce logistics from Earth; (4) schedule adapted to Space Station Freedom; and (5) reduced scales. The study and programmatic assessment have shown that the Human Exploration Initiative is indeed a feasible approach to achieving the President's goals. Several reasonable alternatives exist, but a long-range commitment and significant resources will be required. However, the value of the program and the benefits to the Nation are immeasurable.

Aaron Cohen↗
NASA NTRS1990

Robotic missions for the moon

In the course of the exploration and settlement of the moon, robotic missions will precede and accompany humans. These robotic missions are defined respectively as precursors and adjuncts. Their contribution is twofold: to generate information about the lunar environment (and system performance in that environment), and to emplace elements of infrastructure for subsequent use. This paper describes information that may be gathered by robotic missions and infrastructure elements that may be deployed by them during an early lunar program phase.

Bourke, R. D.↗
NASA NTRS1989

Options for the human settlement of the moon and Mars

The evolutionary approach to space development is discussed in the framework of three overall strategies encompassing four case studies. The first strategy, human expeditions, places emphasis on highly visible, near-term manned missions to Mars or to one of the two moons of Mars. These expeditions are similar in scope and objectives to the Apollo program, with infrastructure development only conducted to the degree necessary to support one or two short-duration trips. Two such expeditionary scenarios, one to Phobus and the other to the Mars surface, are discussed. The second strategy involves the construction of science outposts, and emphasizes scientific exploration as well as investigation of technologies and operations needed for permanent habitation. A third strategy, evolutionary expansion, would explore and settle the inner solar system in a series of steps, with continued development of technologies, experience, and infrastructure.

Fairchild, Kyle O.↗
NASA NTRS1990

Foundation design for a radio telescope on the moon

A foundation design for a 122 m diameter dish-type radio telescope on the moon is presented. The 1.2 m wide and 43 m diameter circular strip footing was analyzed for settlement due to compaction during installation and also for total and differential settlement under in-service laods. An axisymmetrical finite element code of the uppdated Lagrangian formulation was used. Interface slip elements were also used. The nonlinear hyperbolic stress-strain model parameters for the regolith were derived from load-deflection characteristics of astronauts' bootprints and the Rover tracks.

Chua, Koon Meng↗
NASA NTRS1990

Astrophysics from the moon; Proceedings of the Workshop, Annapolis, MD, Feb. 5-7, 1990

The present conference on astrophysics from the moon encompasses the study of the Galaxy, external planetary systems, solar physics, stars and stellar evolution, the frontiers of Galactic, extragalactic, and cosmological astronomy, an introduction to lunar-based astronomy, concepts for lunar observatories including high-energy observatories, solar observatories, and observatories for particle astrophysics and gravitational studies. Specific issues addressed include the dynamics of Jovian atmospheres, planetary magnetospheres, flare physics, exobiology and SETI from the lunar farside, and the study of interactive stars, star formation, H II regions in absorption at low frequencies, and normal galaxies. Also addressed are the potential lunar investigation of quasars, the formation epoch, and the large-scale structure of the universe, and observational issues related to X-ray large arrays, optical interferometers, VLF radio astronomy, a UV-solar reflecting coronagraph, and a heavy-nucleus detector.

Mumma, Michael J.↗
NASA NTRS1990

Imaging other planetary systems from the moon

This paper studies the problem of using a telescope like the HST, only larger and sensitive to a wider range of wavelengths, to image systems of planets like the solar system around other stars. Both reflected starlight and thermal radiation from the planets are treated. The instrumental effects of aperture diffraction, scattering due to the power spectral density of telescope mirror surface errors, and telescope thermal emission are included. The integration time required to achieve a signal-to-noise ratio is computed at 5 for photon-statistical random errors only, which is a necessary but not sufficient criterion for detection at a confidence level of five standard deviations. A cold telescope on the moon with 16m aperture and the optical quality of HST could detect and characterize planets around nearby stars.

Brown, Robert A.↗
NASA NTRS1991

Implications of convection in the moon and the terrestrial planets

A comprehensive review is made of the thermal chemical evolution of the moon and the terrestrial planets. New results are presented which were obtained for Venus by the Magellan Mission the efforts were concentrated on this planet. Alternative models were examined for the thermal structure of the lithosphere of Venus. The statistical distribution was studied of the locations of the coronae on Venus. Models were examined for the patterns of faulting around the coronae on Venus. A series was considered of viscous models for the development and relaxation of elevation anomalies on Venus. And rates were studied of solidification of volcanic flows on Venus. Both radiative and convective heat transfer were considered.

Turcotte, Donald L.↗
NASA NTRS1991

Observational studies of the exospheres of the Moon and Mercury

The sodium and potassium atmospheres of Mercury and the Moon are mapped using spectroscopic measurements of resonance scattered sunlight. The objective is to define the sources and sinks for these atmospheric constituents, and in doing so, provide a better understanding of atmospheric processes on these bodies. These bodies are unique in that their atmospheres consist solely of an exosphere with the planetary surface at its base.

Potter, Andrew↗
NASA NTRS1991

Development of a moon-based magnetospheric and coronal imager using a large broadband array

The 'Missions to and from Planet Earth' mandated by President Bush in 1989 provide a unique opportunity for magnetospheric and coronal plasma physicists to cooperate with low frequency radio astronomers in the development of an advanced experiment designed for the lunar surface. A large active lunar based array would sound the Earth's magnetosphere at VLF frequencies and the solar corona at decametric wavelengths allowing plasma physicists to map both the Earth's magnetosphere and those regions in the solar corona that trigger precursors to solar flares. With the transmitter silent, the array would become the ideal low frequency radio telescope, examining both geospace emissions such as auroral kilometric radiation and extraterrestrial signals from the planets, pulsars, supernova remnants, and active galactic nuclei. Both experiments satisfy requirements mandated in both 'Mission to Planet Earth' and in 'Mission from Planet Earth.' By proposing a cooperative effort both communities (plasma physicists and radio astronomers) stand to benefit. Jim Green, Director of the NASA Space Science Data Center (NSSDC) at GSFC; Tony Phillips, Research Fellow at California Institute of Technology; T. D. Carr, Director of the University of Florida Radio Observatory (UFRO) and the author are enlisting the cooperation of the scientific community in defining the system specifications. Some components, such as the receivers, will be standard 'off-the-shelf' items, and hence will require little developmental research. However, the individual antenna elements and the phasing and matching networks will require some R&D to satisfy the frequency requirements (20 KHz-40 MHz). By flying the experiment in Earth orbit first, Dr. Green proposes to gather valuable magnetospheric data as well as to prove the principle of the large moon based experiment. He claims that funding for the preliminary ground based studies at the UFRO may be available as early as FY-92.

Lebo, George↗
NASA NTRS1992

The Moon as a solar power satellite

A modified version of the Satellite Solar Power System (SPS) is proposed. The original SPS was conceived by Dr. Peter Glaser of MIT in 1968, as a series of large, photovoltaic solar collectors orbiting at geosynchronous altitude, and converting and beaming the collected solar power to the earth surface using microwave energy (which can pass through cloud cover). This system has been studied extensively in the past. The modified version of the SPS will make use of the moon as the 'satellite'.

Falbel, Gerald↗
NASA NTRS1991

Assessment of potential benefits from lunar/Mars propellant production for support of human exploration of the moon and Mars

This paper describes an assessment of potential benefits offered through use of lunar/Mars in situ propellant production to support manned missions to the moon and Mars. Resources available at each location and processing options for their extraction are discussed. Key infrastructure and support systems needed to sustain the propellant production operation and to deliver the propellants from their point of origin to the point of application are defined. The analysis focuses on reductions of earth launched mass over the course of multiple missions to assess the potential savings offered. Initial results show the impact of requirements for sustaining in situ propellant production systems on benefits offered during steady-state operation.

Jacobs, Mark K.↗
NASA NTRS1991

A taxonomy for the evolution of human settlements on the moon and Mars

A proposed structure is described for partnerships with shared interests and investments to develop the technology and approach for evolutionary surface systems for the moon and Mars. Five models are presented for cooperation with specific references to the technical evolutionary path of the surface systems. The models encompass the standard customer/provider relationship, a concept for exclusive government use, a joint venture with a government-sponsored non-SEI market, a technology joint-development approach, and a redundancy model to insure competitive pricing. The models emphasize the nonaerospace components of the settlement technologies and the decentralized nature of surface systems that make the project suitable for private industrial development by several companies. It is concluded that the taxonomy be considered when examining collaborative opportunities for lunar and Martian settlement.

Roberts, Barney B.↗
NASA NTRS1991

A flat array large telescope concept for use on the moon, earth, and in space

An astronomical optical telescope concept is described which can provide very large collecting areas, of order 1000 sq m. This is an order of magnitude larger than the new generation of telescopes now being designed and built. Multiple gimballed flat mirrors direct the beams from a celestial source into a single telescope of the same aperture as each flat mirror. Multiple images of the same source are formed at the telescope focal plane. A beam combiner collects these images and superimposes them into a single image, onto a detector or spectrograph aperture. This telescope could be used on the earth, the moon, or in space.

Woodgate, Bruce E.↗
NASA NTRS1992

Production of oxygen on the moon - Which processes are best and why

An evaluation of the 20 processes put forth for the liberation of oxygen from lunar materials has resulted in a ranking according to overall feasibility. At this time, the eight processes considered to be the most likely candidates for oxygen production on the moon are: ilmenite reduction with H2, CO, and CH4, glass reduction with H2, molten silicate electrolysis, fluxed molten silicate electrolysis, vapor pyrolysis, and ion plasma pyrolysis.

Taylor, Lawrence A.↗
NASA NTRS1991

Beam power options for the moon

A study to determine the feasibility of providing long-term electrical power to the moon's surface by beaming power from satellites is reported. The model used to develop the reference designs are described, and the major system tradeoffs and reference design characteristics are discussed. The beam power masses and the lunar surface power system masses are compared. In some cases, the beam power system have a quarter of the mass of surface power systems, but the beam power satellites have large space structures that may present complex transportation, deployment, pointing, and control problems.

Fay, E. H.↗
NASA NTRS1992

Apollo 15 impact melts, the age of Imbrium, and the Earth-Moon impact cataclysm

The early impact history of the lunar surface is of critical importance in understanding the evolution of both the primitive Moon and the Earth, as well as the corresponding populations of planetesimals in Earth-crossing orbits. Two endmember hypotheses call for greatly dissimilar impact dynamics. One is a heavy continuous (declining) bombardment from about 4.5 Ga to 3.85 Ga. The other is that an intense but brief bombardment at about 3.85 +/- Ga was responsible for producing the visible lunar landforms and for the common 3.8-3.9 Ga ages of highland rocks. The Apennine Front, the main topographic ring of the Imbrium Basin, was sampled on the Apollo 15 mission. The Apollo 15 impact melts show a diversity of chemical compositions, indicating their origin in at least several different impact events. The few attempts at dating them have generally not produced convincing ages, despite their importance. Thus, we chose to investigate the ages of melt rock samples from the Apennine Front, because of their stratigraphic importance yet lack of previous age definition.

Ryder, Graham↗