Tom Mueller worked for Elon Musk at SpaceX for almost 20 years: 'I learned never to tell him no'

• Tom Mueller helped Elon Musk set up SpaceX in 2002.
• Mueller went from playing with toy rockets in Idaho to shaping one of the world's most innovative firms.
• He now runs his own company, Impulse Space, and is trying to beat Musk in the race to Mars.

Tom Mueller may not be a household name, but he was Elon Musk's righthand man at Space X for about two decades.