This Month in Air Force Medical Service History Published Dec. 1, 2015 By Kevin M. Hymel Air Force Surgeon General Public Affairs FALLS CHURCH, Va. -- December 1954: Dr. John Paul Stapp (Colonel, USAF, Ret.) conducted the last of his 29 rocket-propelled sled experiments at Holloman Air Force Base in New Mexico, studying the biomedical results of pilot ejection from aircraft traveling at supersonic speeds. During his sled rides, Stapp attained speeds up to 632 miles per hour, experiencing gravity 40 times the normal pull, before coming to full stop in 1.4 seconds. The experiments earned him the designation, “the fastest man on Earth.”