When you're planning a supersonic jump from the edges of space back to the earth, it's probably a good idea to warm up first, which is exactly what 42-year-old Austrian daredevil Felix Baumgartner is doing with his recent test jump from the stratosphere. During his successful completion of the remarkable 13-mile (21-kilometer) jump, Baumgartner experienced three minutes and 43 seconds of free fall, during which his top speed hit 364 miles (586 kilometers) per hour.