Well before he founded Space Exploration Technologies in 2002, which put the first big (180-foot-tall), privately constructed and launched rocket into orbit, the 39-year-old Musk was part of the dot-com boom: “At 25 I was building part of the early Internet with Zip2, an early version of what Google Maps is today, and helped bring newspapers online. Two and a half years later, Zip2 was acquired for over $300 million in cash. I put the proceeds I received from that sale towards creating PayPal.” In 2002, eBay bought PayPal for $1.5 billion in stock, and from then on, Musk turned his attention to electric cars and spaceflight.
Photos from: "What Were They Doing at 25?" »