Lockheed D-21

D-21
A D-21 on display at the United States Air Force National Museum
Role	High-altitude and high speed reconnaissance drone Type of aircraft
National origin	United States
Manufacturer	Lockheed
First flight	22 December 1964
Introduction	1969
Retired	1971
Primary users	Central Intelligence Agency United States Air Force
Number built	38

The Lockheed D-21 is an American supersonic reconnaissance drone. The D-21 was initially designed to be launched from the back of an M-21 carrier aircraft, a variant of the Lockheed A-12 aircraft. The drone had maximum speed in excess of Mach 3.3 (2,200 miles per hour; 3,600 kilometers per hour) at an operational altitude of 90,000 feet (27,000 meters). Development began in October 1962. Originally known by the Lockheed designation Q-12, the drone was intended for reconnaissance deep into enemy airspace.

The D-21 was designed to carry a single high-resolution photographic camera over a preprogrammed path, then release the camera module into the air for retrieval, after which the drone would self-destruct.^[1] Following a fatal accident when launched from an M-21, the D-21 was modified to be launched from a Boeing B-52 Stratofortress. Several successful test flights were made, followed by at least four unsuccessful operational D-21 flights over the People's Republic of China, before the program was canceled in 1971.