The need for a high altitude reconnaissance aircraft, one that would be immune to interception became apparent during the Korean War. Events in the Soviet Union during the early 1950s led the Defense Department to issue a requirement for a reconnaissance aircraft capable of overflying the Soviet Union at extreme altitude. The requirement (Design Study Requirement No 53WC-16507, dated 27 March, 1953)called for a single seat sub-sonic aircraft, capable of carrying a 700 pound payload over 3000 miles at altitudes over 70,000 feet.

2002, 58-page edition

By Larry Davis