@jannem @futurebird @dx Yep. My point was, complexity of society matters. In the 17th century it was just about possible for a colony with 100-odd families to make a go of things—although they'd be short of stuff like metals for a long time, and would regress somewhat if not resupplied. But there is no easy lower threshold for "no resupply" on Mars, never mind a generation ship: you go with every human skill you might conceivably need, or you all die, no exceptions.