Once known as “the fastest man on Earth”, Stapp is best known as “the guy on the rocket sled” — countless photos and movies have circulated over the years of Stapp, strapped into a chair with a rocket on the back mounted on a track, shooting down the track and withstanding forces up to 40 Gs — 40 times the sea-level force of gravity.
A doctor in the U.S. Air Force, Stapp took 29 high-speed rides on the rocket sled in the 1950s to test the effects of high acceleration on the human body. The data he gathered is still used to help in the design of safety systems for everything from automobiles to spacecraft cabins. Stapp died in New Mexico November 13, apparently from emphysema and diabetes. He was 89.