I would wager that if we get a established research colony on Mars, we're 100 years away from a mostly self-sufficient small city. We're not going to have Mars

I would wager that if we get a established research colony on Mars, we're 100 years away from a mostly self-sufficient small city. We're not going to have Mars colonized in a decade or two, but it's not going to take a thousand years, either. Probably. I'd say thriving colonies within a century or two.