Resource Extraction on the Moon: Everything Including the Squeal

Philip E. Brown
University of Wisconsin, Madison, WI

Life requires a series of trade offs; nowhere more evident than while establishing a permanent settlement on the moon. The deep gravity well that is the Earth essentially requires that most lunar construction, life support, and fuel supplies need to be extracted on the moon. A single highly integrated processing facility that could yield oxygen, hydrogen, water, metals, and a concrete surrogate from the indigenous material is the goal. Are the raw materials there and what might this look like?

The lunar surface is composed of calcic anorthosite, high Ti-basalts, pyroclastic volcanic glasses and meteoritic debris including iron spherules. The only economic, resource driven reason to establish a permanent base on the moon is the extraction of helium-3 for fusion reactors on Earth. Helium-3 extraction will involve the scraping up of 1-4 meters of regolith and heating the unconsolidated material to drive off and collect the solar wind implanted helium. The now captive regolith, composed of plagioclase, olivine, pyroxene, ilmenite and chromite, could then be melted and the “magma” passed on to, for example, an electrolytic cell yielding oxygen. Techniques adapted from the steel industry will allow the magma to be separated into a high silica ‘slag' (that could be cast as ceramic bricks) and a molten Fe-Cr-Ti-Si alloy. The molten metal can be processed to yield structural ‘steel' and other lighter weight metals. Solar power can drive this process during the lunar day; either on-site nuclear power or hydrogen fuel cells will be needed during the lunar nights.