Conclusions

1. The type and range of lunar material resources are defined to a first approximation on the basis of analysis of samples returned, remote sensing, and theoretical considerations. Major uncertainties remain as to the presence of cryotrapped volatiles in the permanently dark and thus cold areas of the lunar polar regions and the presence of fumarolic deposits containing material rich in volatile elements or compounds.

2. Early exploitation of lunar material resources will be for shielding purposes and for local use of phases or elements that do not require extensive processing. Present knowledge suggests that this activity will be confined primarily to the minerals (plagioclase feldspars and ilmenite) ,and rock types that result from igneous processes, to meteoritic and cometary debris, and to regolith fines that are significantly affected by solar wind implantation.

3. Lunar regolith fines are an important source of (a) silicate minerals such as plagioclase feldspars, olivines, and pyroxenes; (b) oxide minerals such as ilmenite and spinels; (c) metallic iron-nickel-cobalt alloys; and (d) solar-wind- implanted elements such as H, N, C, and 3He.

4. Lunar regolith fines meet the basic requirement for beneficiation because a major portion of the elements implanted by the solar wind occurs in the less-than-20- micrometer size fraction, which is a relatively small part of the lunar regolith fines.

5. Early exploitation of the lunar regolith fines for hydrogen probably will be limited to hydrogen obtained as a byproduct or coproduct from the mining and processing of other materials, because it takes at least 20 000 metric tons of typical lunar regolith fines to produce 1 metric ton of hydrogen.

6. There is no evidence, direct or theoretical, for significant base metal sulfide or precious metal vein deposits on the Moon.

7. Lack of free water on the Moon eliminates the classes of ore deposits that are most exploitable on Earth; namely, (a) hydrothermal, (b) secondary mobilization and enrichment, (c) direct precipitation from a body of water, and (d) placer.

Table of Contents

WebWork: Al Globus, Bryan Yager, and Tugrul Sezen