Is It True That NASA Strapped A 41-Foot Rocket Engine To An SR-71’s Back & Flew It To Mach 1.8?

In 1997, NASA needed an aircraft that could perform an incredibly unique experiment in order to test a revolutionary type of rocket engine. The only plane in the world capable of being the test bed for its linear aerospike experiment, or LASRE, was the Lockheed SR-71 Blackbird. It was the only jet that could carry the seven-ton LASRE pod with its rocket thrust engines to the upper stratosphere and fly at the speed of a single-stage-to-orbit spaceship, or SSTO.