This is the Sonic Wind 2 rocket sled powered by three solid fuel rocket motors. Sonic Wind 2 was designed for windblast studies. The windblast tests were important in the Air Force's study of aircraft crash forces and led to the development of improved escape systems from aircraft. Sonic Wind 2 was first used operationally in 1957 in which a chimpanzee in a flying suit was the passenger. The sled was later used at the Air Force's Holloman Air Force Base, N.M., during 1958-1959 for similar runs with chimpanzees. Sonic Wind 2 reached speeds up to Mach 1.7 (1,326 miles per hour). Following the chimpanzee rides, runs were made with anthropormorphic dummies until the conclusion of the windblast program in 1959. The sled was transferred to the Smiithsonian in 1968 from the Air Force.