Shown here is the LR-79 (Model LR-79-NA-9) rocket engine for the U.S. Air Force's Thor intermediate range ballistic missile (IRBM). Development of the Thor began in 1955. The Air Force activated the first Thor batteries in England in 1959 and removed them from service four years later.
Developed and built by the Rocketdyne division of North American Aviation, the LR-79 incorporated a bell-shaped nozzle to improve the engine's overall efficiency. The propellant consisted of RP-1, a type of kerosene, and liquid oxygen. Rocketdyne developed two versions of the LR-79. The MB-1 and MB-3 produced 135,000 and 150,000 pounds of thrust respectively. The engine shown here is an MB-1, used for training purposes at Chanute Air Force Base, Illinois in 1960.
The U.S. Air Force transferred this engine to the Museum in 1965.