Tom Mueller

From SpaceWiki

Tom Mueller's bio on the SpaceX People page describes him as "one of the world's foremost rocket engine designers," which is presumably a big part of the reason why they hired him as the Vice President of Propulsion Development. But in addition to his previous professional work for TRW's Propulsion and Combustion Products Department, Mueller was also a rocket hobbyist. That's right, in addition to his rocket-related day job, he built liquid-fueled rockets in his garage in his spare time, as a member of the Reaction Research Society, America’s oldest amateur rocketry club. That kind of dedication no doubt played a big role in getting Mueller hired at SpaceX, though you'll notice they carefully avoid using words like "hobbyist" and "amateur" in his bio.

Now that he's a big player in one of the world's most successful aerospace startups, Mueller probably doesn't have as much free time anymore, but he still gets to work on rockets all the time, which is clearly what he wants. And his work is far more central to both his company and the future of American spaceflight itself, since his rockets will soon be powering essential resupply trips to the International Space Station under NASA's COTS Program. Contrasting with his previous work at "a huge company with a tiny propulsion department," Mueller told Popular Science that at SpaceX, "I’m kind of king."