The speed of sound — historically called the ‘sound barrier’ – has been broken by rockets, various jet-powered aircraft and rocket-boosted land vehicles. Felix Baumgartner wants to break the sound barrier with his body, in freefall from the edge of space. He will travel inside a capsule with a stratospheric balloon to 36,500 meters (120,000 feet) step out and attempt a freefall jump targeted to reach – for the first time in history – supersonic speeds.