Flying at an altitude of 84000 feet and a speed of Mach 3.27, the drone deviated from its planned route because of programming errors in its inertial navigation system, and self-destructed a pre-set altitude after exhausting its fuel supply, and no data was recovered Missions", March 20, 1970 Memorandum from National Reconnaissance Office to National Security Agency, 1970 (declassified and released, August 21, 2006)