Lockheed CL-400 Suntan

Common card · No. 442944

Suntan was the code-name of a prototype reconnaissance aircraft program, with the goal of creating a much faster and higher-altitude successor to the U-2, enabled by the use of liquid hydrogen (LH2) as aircraft fuel. The program was cancelled in 1958. Starting in 1956, the United States Air Force funded a highly secretive program of research and development on high-speed aircraft for long-range reconnaissance. Lockheed's Skunk Works was the natural partner for this work, having successfully delivered the U-2 and having all the required secrecy and security arrangements to keep the program secret. Lockheed settled on the CL-400 design, which looked like a greatly scaled-up Lockheed F-104 Starfighter. The main change to the layout was the twin engines, mounted on the wing tips. This was done to ensure that the liquid hydrogen, which was stored in the fuselage, would have to pass through the aircraft's hot wings (up to 436 Kelvin) to reach the engines; a vacuum sealed, insulated line was provided...

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