LOCKHEED D-21B UNMANNED AERIAL VEHICLE (UAV)    

The Lockheed D-21 is an unmanned drone aircraft designed to carry out high-speed high-altitude strategic reconnaissance missions over hostile territory.  It is a product of the Lockheed "Skunk Works" program that developed the A-12, YF-12 and SR-71 "Blackbird" manned aircraft in the 1960s.

Originally, the D-21 was designed to be launched from the back of a modified A-12 (redesignated the M-21) carrier aircraft.  The first flight of the D-21/M21 combination took place on 22 December 1964, but the first D-21 release from an M-21 did not occur until 5 March 1966.  Two more launches were successful, but on 30 July 1966, a D-21 collided with the M-21 after release, destroying both aircraft and resulting in the death of one of the M-21's crewmembers.  No further "piggyback" launches were attempted.

A new launch system was developed using modified B-52H aircraft as carriers. The new D-21 configuration (designated B-21B) had dorsal mounting hooks for the carriage under the B-52s wing, and a solid rocket booster for the initial acceleration required to start the ramjet engine. The first launch from a B-52 took place on 6 November 1967, but the D-21 crashed. Several flights followed in 1968 with mixed success.

The first operational launch was on 9 November 1969, but the D-21B was lost. Several successful operational missions were flown over the next 2 years, but the D-21 program was highly classified and details have not been released. The program was cancelled in 1971 and the D-21s were placed in storage. The D-21 on display was shipped from storage to the Museum in 1995.