I totally respect and admire Elon Musk. Tesla makes the best cars on the road. I drive one of them and it's super-cool, and I own stock in both Tesla and Solar City. But like the namesake of his company, Musk has at least one idea that's totally nuts: Colonization of Mars. Ain't gonna happen. Nobody is going to invest that kind of money without a financial incentive, and there isn't one. I do expect that we'll send people there to do science, and maybe some day we'll have a research station there with rotating staff. But a permanent colony with cities, nope.
And to correct one mistake Steve made: Tesla does make a profit. It does not pay dividends because all the profits are going back into R&D and building plant. It's a growth company. And plowing your profits back into growth is different than not making a profit.
A bit off topic, I just recently got my shareholder proxy from both Tesla and Solar City to vote on the merger of the two companies. I voted for, because that's the recommendation of the board, and while I think that Musk is nuts on the subject of Mars, I trust his business judgement on electric cars and solar electricity production.