Rocket Engine, Liquid Fuel, J-2

The J-2 rocket engine, using liquid hydrogen and liquid oxygen fuel, was the power plant for the second and third stages of the Saturn V launch vehicle which took astronauts to the Moon in the Apollo program. The engine shown here produced 230,000 pounds of thrust and was used in three tests for a total firing duration of 655 seconds.

The Saturn V's second (S-II) stage used a cluster of five J-2s, while the third (S-IVB) stage was fitted with a single J-2 with restart capability since it was to restart the Apollo spacecraft for a translunar trajectory, as well as accelerate the craft to the necessary lunar orbit escape velocity. The first manned flight with the J-2 engine was made on October 11, 1968 in the Saturn 1B Apollo 7 test mission.

The Rocketdyne Division of Rockwell International gave this J-2 engine to the Smithsonian Institution in 1976.