Sensors Supersonic Spy Drone by Stuart F. Brown To light off its ramjet engine, the 2,300-mph D-21 needed a blindingly-fast launch platform. Enter the Lockheed A-12. When is that wild thing coming out? It would question that was driving U.S. national security officials mad: How was the Chinese military progressing in its effort to build and test nuclear weapons? Flying a spy plane over China's remote testing facility at Lop Nor was considered far too risky after a camera-equipped U-2 spy plane piloted by Francis Gary Powers was shot down on a mission over the Soviet Union in 1960. Thus, momentum quickly built for the idea of building a much faster, high-flying aircraft Lockheed via James C. Goodall be a reasonable question for an average reader to ask after looking at a picture of the futuristic D-21 drone, a windowless aircraft with a sharp cone-shaped nose, a delta-shaped wing-fuselage structure and a single vertical tailfin. Code-named 'Tagboard' during its CIA- and Air Force-funded mid-1960s development by Lockheed's secretive Skunk Works advanced-projects group in Burbank, Calif., the D-21 was intended to answer a A D-21 'Tagboard' drone rides piggyback atop a modified A-12/M-21 spy plane at high altitude. 40 May 2019 AUTONOMOUS VEHICLE ENGINEERING