According to SpaceX, more than 200,000 people from around the world want to be the first to travel to Mars. But the rocket maker cautions that (1) this isn't a Moon quickie; the trip will take roughly six months; and (2) the company has no plans to bring its astronauts back to Earth ... ever. That danger aside, reportedly there are 100 finalists vying for a shot at blasting off for the Red Planet.