Interesting that both Branson and Bezos are going up this month, but Musk is staying on the ground. This is where we see if Musk is actually a Bond villain or not, consolidating his power. 
He just turned 50 and he has stated in the past that he intends to die on Mars, just hopefully not on impact.
It would not surprise me if he has been grooming a replacement for a few years and he's on either the first or second manned crews to work on the Mars propellant plant.