On December 10, 1954, Col. John P. Stapp propelled down the Holloman High Speed Test Track aboard the Sonic Wind Rocket Sled 1 at a rate of 632 miles per hour. The purpose of this experiment was to see at what speed a pilot could safely eject. The Sonic Wind 1, the sled Stapp used for that test, is now displayed at the New Mexico Museum of Space History. (Courtesy Holloman Air Force Base)