Private space companies want to send humans where none have gone before. Big-picture thinkers like Elon Musk, Jeff Bezos, and Richard Branson are developing spacecraft that can take tourists into orbit around the Earth, to vacation on the Moon, or even to build settlements on Mars.

If you’ve been paying attention to this burgeoning industry (or even if you haven’t), SpaceX is hard to ignore. The high-profile company has completed more missions than any of its competition.