The Lockheed D-21 Mach 3 Drone

In the 1960s, Lockheed engineer Kelly Johnson was given an almost impossible task by the U.S. Air Force and CIA. He needed to create a spy drone with range, speed, and altitude capabilities that could match the supersonic A-12. The hope was that Lockheed’s Skunk Works team could build an unmanned reconnaissance aircraft unlike any other in order to replace the increasingly vulnerable U-2 spy plane. The result was the D-21. It was a ramjet with wings and a camera, built to self-destruct after its mission. Early tests were promising, but failures to execute correctly when released over China resulted in several missteps and even a Soviet clone.