This is a mockup of an LR63-AJ-1 liquid fuel rocket motor developed by the Aerojet Engineering Co. as a "Superperformance engine," or built-in JATO (Jet-Assisted-Take-Off), to boost the performance of a U.S. Air Force F-86 jet fighter. It produced 3,500-5,000 pounds of thrust.
During the Korean War, there was an urgent requirement for a Superperformance engine for the F-86 to counter the superior performance of Soviet MiG jets. The LR63 was already being developed experimentally for the F-84 fighter-bomber. It was subsequently modified for use on the F-86. Flight tests on an F-86 were made in 1956 but the war had ended and the YLR63 did not become operational. The motor was donated to the Smithsonian by the Aerojet General Corp. in 1968.