SpaceX launched its mission to rescue the two Starliner astronauts — but it didn't go entirely according to plan.

The first reason is Elon Musk, whose singular vision and hard-driving leadership propelled SpaceX through its many ups and downs. It was Musk, for example, who pushed relentlessly for SpaceX to master reusable rockets, despite industry doubters and the grumblings of his own engineers.