No one thinks bigger than Elon Musk. In this article Wired talks to him about is plan to send a ship to Mars and a multi-stage rocket that can achieve orbit, return to earth and land vertically.

All entrepreneurs have an aptitude for risk, but more important than that is their capacity for self-delusion. Indeed, psychological investigations have found that entrepreneurs aren’t more risk-tolerant than non-entrepreneurs. They just have an extraordinary ability to believe in their own visions, so much so that they think what they’re embarking on isn’t really that risky. They’re wrong, of course, but without the ability to be so wrong—to willfully ignore all those naysayers and all that evidence to the contrary—no one would possess the necessary audacity to start something radically new.

I have never met an entrepreneur who fits this model more than Elon Musk.