After a Soviet surface-to-air missile battery showdown with a USAF U-2 spy plane near the closed city of Sverdlovsk in 1960, the US government realised they needed a reconnaissance plane that could fly even higher – and outrun any missile and fighter launched against it.

The answer was the SR-71 Blackbird. It was closer to a spaceship than an aircraft, made of titanium to withstand the enormous temperatures from flying at 2,200mph (3,540kph). Its futuristic profile made it difficult to detect on radar – even the black paint used, full of radar-absorbing iron, helped hide it. (click)