@gerikson @techtakes Ian is a *very* good writer—but for those books he uncritically adopted the American colonialist ideologues’ idea of an good reason for space colonization: and sure, his Lunar colony is a capitalist hellscape, but that’s not the point. (The P + 11B aneutronic fusion pathway was already known about at the time.)
/1
Anyway, if I was going to go mining 3He in space I’d bear in mind it’s in the regolith because it’s part of the solar wind and gets trapped there. Is it possible to collect it more cheaply using a really huge solar sail (with station-keeping as a side-purpose) made out of a membrane that traps it directly and can be reprocessed to outgas the stuff? That way you’re not grinding up gigatons of fucking rock to extract an incredibly rare volatile.