Dr. John Paul Stapp earned the title "The Fastest Man Alive" when he rode the Sonic Wind I rocket-propelled sled on December 10, 1954 to a land record speed of 632 mph in five seconds. He sustained the greatest G-forces endured by man in recorded deceleration tests up to that time, 46.2 Gs, when the sled stopped in 1.4 seconds.
