I was looking at NASA saying they might not have enough funds to put humans on Mars by 2040. OK, zoom forward maybe 200 years and the cost might be, maybe, just buy a ticket. Or people might already be working there; they will be paid to go there. So, here's the question. What is the least cost method to to get a self-sustaining space infrastructure? To the point where it doesn't matter what the cost of launch from Earth is? I think it might involve robots on the Moon that can be controlled from Earth and use materials they find there, so we don't have to send so much stuff up from Earth. What do you think?