Earth-produced facilities is matched. It almost certainly would not be; comparatively low technology means would be used where overall productive efficiency is enhanced. Airflow ducting made from cast basalt or sintered ceramic would be selected over metal, for example, if more energy efficient, even though much more massive. Processes for producing oxygen on the Moon can also produce metals. Plausible rates for lunar oxygen production are generally compatible with metals production rates for lunar base build-up; if the selected processes deliver both, resolution of their relative importance can be deferred. Reduction of ilmenite by hydrogen or carbon (Gibson and Knudsen, 1985; Williams, 1985) would produce over 3 tons of iron per ton of oxygen. Waldron (1985) recommends an HF acid leach process that would produce aluminum, titanium, iron and silicon (as well as other materials in smaller quantities) as a byproduct of oxygen production. This process is not as prolific a producer of iron as the ilmenite reduction processes. A thermal process recommended by Steurer (Steurer, 1985) does not produce metals as a byproduct and therefore may be of lesser interest. Goldsworthy (1985) recommends processes for making glass/- glass composites from lunar materials. He notes that fibers made from basalt and moderately beneficiated feldspar have surprisingly good properties. Iron and steels are not as weight efficient as aluminum but are not as much worse as sometimes imagined by aerospace engineers. As noted by Cutler (1985), passably good structural alloys are probably much easier to make on the Moon from iron than from aluminum. In the highly anhydrous lunar environment, glasses and ceramics may take on superior properties (Blacic, 1985). Production rates for lunar oxygen, associated with representative uses, are: Modest lunar base support, 6 trips/year, fueling on lunar surface 250 T/yr Same with lunar oxygen delivery to low earth orbit 550 T/yr Large base support, 40 trips/year, fueling on lunar surface 1700 T/yr Same with lunar oxygen delivery to low earth orbit 3700 T/yr Manned Mars mission fueled with oxygen in lunar vicinity 1000-2000 T/yr Manned GEO missions, 6/year, lunar oxygen to low earth orbit 300 T/yr These are very modest production rates compared to terrestrial plants. A typical terrestrial liquid oxygen plant would be rated at 1000 T/day. A lunar plant at 1000 T/year has about 1/3 of 1% of this capacity (but the process is more complex). The economic value of facilities production on the Moon is substantial, about $3 million per ton according to typical logistics costs reported in Woodcock (1986). This figure assumes a reusable transportation system that accommodates additional cargo at relatively low cost; under other assumptions the value would be much more. Even at this low figure, the value of a 1000 T/yr production rate is $3 billion annually. The plant and equipment needed to attain this production rate would likely be a few shuttle payload equivalents, deliverable to the Moon in less than a dozen trips at 17 T/trip.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==