He wants to make tons of money to fund SpaceX and go to Mars. I hope this happens sooner rather than later to show people Mars isn't viable for long term survival. Speaking of which, I hope he's on one of the first trips to demonstrate that. We've evolved for 1g gravity and 24 hour days. Those issues alone will screw up human biology a ton. Then there is the fact there is no geomagnetic field around Mars, so no protection from solar wind. That means two things, dangerously irradiated on the surface, and no chance to rebuild an atmosphere (as much lower gravity and stripping of atmosphere by solar winds are the blockers). Pie in the sky dream, push high metal asteroids into orbit around Mars to form a moon big enough to create crust flexing on Mars to warm up the interior by friction. Maybe that would melt the interior enough to get a rotating core to generate a magnetic field. Wake me up in a million years when that's ready.