The H-1 liquid-fuel rocket engine was the first stage powerplant of the Saturn 1 and Saturn 1B launch vehicles, precursors to the Saturn V that took men to the Moon in the Apollo program. The Saturn 1 and Saturn 1B were each fitted with eight H-1 engines in their first stages. The engine used RP-1 (kerosene) and liquid oxygen. The model shown here may be the second variation which produced 188,000 pounds of thrust. The Saturn 1 first flew in 1961 while the last Saturn 1B was flown in 1975 for the low-Earth orbit Apollo-Soyuz Test Project. This cutaway version of the engine was transferred to the Smithsonian in 1970 from the NASA Marshall Space Flight Center.