In late 1957, around my ninth birthday, the Soviet Union launched the world’s first artificial satellite, called Sputnik. I became entranced with the idea of building a rocket of my own. I imagined the lift-off, the graceful arc of the craft as it careened through space. By the age of 13 or 14 I had started mixing my own rocket fuels. A fuel that burned too fast would explode like a bomb; a fuel that burned too slow would smolder like a barbecue grill.