Lockheed’s A-12 needed a powerplant that could sustain Mach 3 flight, leading to the Pratt and Whitney J58, a turbojet-ramjet hybrid burning JP-7. The engine demanded exotic materials to survive ...

Capable of 32,500 pounds of thrust, Lockheed’s J58 engine turned a spy plane into a Mach 3 monster. Built from exotic alloys that glowed white-hot at 2,000°F, it was part turbojet, part ramjet, an ...