The obvious way to get He-3 is to synthesize it, by irradiating lithium with neutrons from a fission for fusion reactor. This is where commercial He-3 comes fro

The obvious way to get He-3 is to synthesize it, by irradiating lithium with neutrons from a fission for fusion reactor. This is where commercial He-3 comes from today. Mining it on the moon is an idiotic attempt to rationalize its commercial value. In fact: lunar thorium is 3-4 orders of magnitude more abundant than He-3 [0][1], so if you wanted helium-3 from the moon, it would almost certainly be cheaper to mine lunar thorium instead, and use lunar nuclear fission reactors to synthesize it! Which doesn't fit in anyone's stupid sci-fi fantasy. For what it's worth, [0] estimates the total amount of he-3 in lunar regolith, over the entire surface, as only 2.4 million tons -- barely a fossil fuel. [0] http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2175.pdf http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2175.pdf [1] http://www.nature.com/ngeo/journal/v4/n8/fig_tab/ngeo1225_F1.html http://www.nature.com/ngeo/journal/v4/n8/fig_tab/ngeo1225_F1...