> people might be a tad leery of having a large asteroid on a course where if you miss by 100km you kill a billion Fair point! If unsure, we'd better not play

> people might be a tad leery of having a large asteroid on a course where if you miss by 100km you kill a billion Fair point! If unsure, we'd better not play this game too close from home. > I'll say "10 years after we get cheap ($500/kg class) launches" - which might be within the decade, or might be never. I think asteroid mining might still be profitable at far higher launch costs, but the risk and the startup costs would be far higher to the point that it probably won't happen. Thank you for sharing that perspective. One game-changer is to build some sort of structure around or far enough from Earth's gravity (I'm partial to orbital rings); anything that can be built now using earth materials only (at least the basic stages), to kickstart a space industry. Though I suspect there are bigger political and economical challenges than technical ones on the way to cross this upward bound.