The A-12, precursor to the SR-71, unveiled to the public 45 years later.

Supersonic A-12 Spy Plane Officially Unveiled at CIA’s Headquarters – Gizmodo

The A-12, a supersonic spy plane which was the precursor of the SR-71 —and according to the CIA, even while they look similar, in some ways it was more advanced than the famous Blackbird. It’s one of the ten that survived the 15-plane OXCART program, one of which is in the USS Intrepid in Manhattan. This one was unveiled today by our dear friends at the CIA in an official ceremony at their Langley HQs. The story of this Mach 3.2 technological wonder starts in 1957 and, like all secret flying things full of gadgets, it’s fascinating.