I know this theory, and that's why I put a time limit of 10 years! There's a whole community of people who play around with orbital simulators, and I'm curious

I know this theory, and that's why I put a time limit of 10 years! There's a whole community of people who play around with orbital simulators, and I'm curious if we can get some realistic-looking numbers on what such an endeavor would require. Because, of course the next question is "where are you going to find all of that fuel" and I'm guessing that the answer is probably something like "a 40-mile asteroid rich in hydrocarbons."