This is the Sonic Wind 1 rocket sled, which was powered by nine solid fuel rockets with 40,000 pounds total thrust for five seconds. Air Force Lt. Col. John Stapp first rode the sled on March 19, 1954, at Holloman Air Force Base, New Mexico, and reached a speed of 613 feet per second. During acceleration, he was subjected to a force of 22 times that of gravity (22 g's). He made his second run on the sled on August 20, 1954 attaining a speed of 735 feet per second.