Humanity's survival depends on planet Earth. The technology for humans to live on Mars isn't remotely ready, and may never be. Why doesn't Musk work on that technology? He can pretend to land in the desert and then live by the tech he brings. Like the biosphere of my childhood. Even thought the rocket part is difficult, it is the least of the problems facing humanity's survival anywhere off Earth. I mean, if people die during a natural disaster on Earthy, why would they survive one on Mars? Think about that.