His Zero Gravity Corporation lets the public experience weightlessness during parabolic flight, and his company Space Adventures has taken four tourists to the International Space Station. But space entrepreneur Peter Diamandis may be best known as the chairman and CEO of the X PRIZE Foundation, which in 2004 awarded the $10 million Ansari X PRIZE to aviation icon Burt Rutan, whose SpaceShipOne was the first private, manned spacecraft to reach suborbital space twice within two weeks. Diamandis is on a mission to open space for all humanity, and he embraces the risk inherent to such an undertaking. "A true breakthrough requires tremendous levels of risk," says Diamandis. "It's really in the entrepreneurial sector that people are willing to risk their lives, risk their fortunes, their reputations, to do something they fundamentally believe they can do." Diamandis is now developing X PRIZES in a variety of fields, including education and medicine.