Friday 10th December 1954

To determine if a pilot could eject from an airplane at supersonic speed and live, Lt. Col. John Paul Stapp, a flight surgeon, rode a rocket sled to 632 mph. The Sonic Wind was the rocket powered sled that Stapp rode at Holloman Air Force Base, New Mexico. The sled’s rocket motors generated 40,000 lbs. of thrust and he reached a speed of 632 mph in five seconds. At the end of the ride Stapp was stopped in 1.25 seconds which subjected him to 40 Gs. It was the equivalent of hitting a brick wall in a car traveling at 120 mph. Data from 29 increasingly harsh rocket-sled rides during the 1950s proved invaluable in the design of improved helmets, arm and leg restraints, better aircraft seats, and stronger safety harnesses.