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International Concrete Abstracts Portal

Showing 1-5 of 21 Abstracts search results

Document: 

SP125-07

Date: 

May 1, 1991

Author(s):

Philip J. Richter, Richard M.Drake, and Ed Drake, and Ed M. Repic.

Publication:

Symposium Papers

Volume:

125

Abstract:

Provides an overview of engineering studies performed in support of the Space Exploration Institute (SEI). Topics addressed include background on the SEI, lunar construction phases, lunar habitats, lunar oxygen, mechanical concepts, and lunar power. Although the topics do not relate equally to concrete construction, they do identify selected issues that must be addressed before a lunar outpost can evolve to the emplacement and operation phases. In these phases of lunar outpost development, maximum use will be made of native materials, such as lunar concrete.

DOI:

10.14359/3640


Document: 

SP125-10

Date: 

May 1, 1991

Author(s):

P. N. Swanson, J. D. Burke, J. A. Cutts, and J. A. Hendrickson

Publication:

Symposium Papers

Volume:

125

Abstract:

During the NASA 90-day study, in response to the President's statement on the space exploration initiative, the Jet Propulsion Laboratory conducted a study of potential astronomical observatories that could be situated on the lunar surface in conjunction with the lunar outpost. The scientific objectives were derived from the four NASA discipline management and operations working groups, several special workshops and symposia on lunar astrophysics, and the NASA Office of Space Science and Applications (OSSA). The overriding premise in selecting and defining the lunar observatories was that the moon must provide some unique advantage in performance, cost, or other significant parameter, such that the experiment could be executed better there than anywhere else. The unique properties of lunar siting include 1/6 gravity, a large stable platform, long continuous viewing times, and low nighttime temperatures. The four observatories were: a seven-element optical interferometer with a 1- to 2-km baseline; a seven-element submillimeter interferometer with coherent detectors and a 1-km baseline; a very low-frequency interferometer (ó 30 MHz) with 100 elements and a 200-km baseline on the lunar far side; and a gravitational wave detector with two 50-km arms, perhaps operating in conjunction with an earth-based gravitational detector. Advanced technology needs associated with the four observatories have been identified and include advances in optical delay lines and beam combiners, coherent heterodyne detectors, instrument cryogenic systems, and methods for construction on the moon, such as building foundations, trenching building roads, etc. In particular, the problems of construction and civil engineering commonplace on earth present a new class of problem for the lunar surface. The paper addresses some of these civil engineering needs and suggests precursor experiments that should be done to provide a firm basis for the construction of astronomical observatories on the moon.

DOI:

10.14359/3745


Document: 

SP125-20

Date: 

May 1, 1991

Author(s):

H. A. Franklin

Publication:

Symposium Papers

Volume:

125

Abstract:

In July 1989, those who advocate U.S. space programs received a significant boost from President Bush's declaration that the U.S. should return to the moon (this time to stay) and then go on to Mars. Achieving these objectives will thrust engineers of ma

DOI:

10.14359/3806


Document: 

SP125-19

Date: 

May 1, 1991

Author(s):

David Webb, Chris Shove, and T. D. Lin.

Publication:

Symposium Papers

Volume:

125

Abstract:

Presents the concept of Moonbase #1--its objectives, financial structure, facilities, functions, and scientific/engineering merits. In accordance with a Florida state goal of encouraging commercial enterprise, a consortium of corporations is in the proce

DOI:

10.14359/3802


Document: 

SP125-16

Date: 

May 1, 1991

Author(s):

Joseph J. O'Gallagher and T. D. Lin

Publication:

Symposium Papers

Volume:

125

Abstract:

In the lunar environment, the use of solar thermal energy has obvious advantages over any combustion or electrical furnace for driving high-temperature processes. However, extremely high temperatures, in the range of 1700 to 2000 C, will be necessary to produce cement from lunar minerals and will, in turn, require very high levels of solar flux concentration. Such levels can only be achieved in practice with some form of ideal or near-ideal nonimaging concentrator that can approach the maximum concentration permitted by physical conservation laws. In particular, very substantial gains in efficiency can be generated through the incorporation of a properly designed ideal or near-ideal nonimaging secondary concentrator in a two-stage configuration with a long focal ratio primary concentrator. A preliminary design configuration for such a high-flux nonimaging solar concentrating furnace for lunar applications is presented. It employs a tracking heliostat and a fixed, off-axis, two-stage concentrator with a long focal length utilizing a nonimaging trumpet or CPC-type secondary deployed in the focal zone of the primary. An analysis of the benefits associated with this configuration employed as a solar furnace in the lunar environment shows that the thermal conversion efficiency can be about 3 to 5 times that of the corresponding conventional design at 2000 C. Furthermore, this configuration allows the primary collecting aperture to remain unshaded by the furnace or any associated support structure.

DOI:

10.14359/3796


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