NASA issued this Omega Speedmaster chronograph to astronaut Tom Stafford for use during the Apollo Soyuz Test Project mission of July 1975.
Selected after a series of rigorous tests demonstrated its high level of precision and reliability, the Speedmaster chronograph was chosen by NASA for the U.S. space program in 1964. Program requirements called for a manual-winding wrist chronograph that was water-proof, shock-proof, anti-magnetic, able to withstand temperatures ranging from 0 to 200 degrees Farenheit, and accelerations of up to 12 g's. NASA first certified the Omega Speedmaster as the chronograph for the Gemini program and made successive purchases for both the Apollo and the Skylab/ASTP missions.
NASA transferred Stafford's chronograph to the Museum in 1977.