and liquid oxygen
burning rocket engine
used in the first stage (the S-IC
) of the Apollo project
's Saturn V
The F-1 existed before any vehicle or mission had been created that would use it. In 1955, with great foresight, the U.S. Air Force recognized there would be a need for an engine that could lift large payloads into space and awarded a development contract for the F-1 to Rocketdyne. The F-1 program was inherited by NASA in 1958 and it awarded a new contract to Rocketdyne in 1959.
Although the F-1 used conventional propellants - a kerosene based fuel called RP-1 and liquid oxygen, rather than a liquid hydrogen and oxygen combination - the sheer size of the engine was responsible for most of the development headaches. In particular, engine instability proved to be a major headache, but the 'bomb' technique used in the development of the Saturn I and Saturn IB's H-1 engine proved invaluable. This allowed an instability, normally an intermittent problem, to be created on demand through the explosion of a small bomb in the combustion chamber.
The F-l propellant turbopump was another stumbling block. The turbopump repeatedly had structural failures, which were solved by new materials and improved welding and manfacturing processes.
The giant combustion chamber also posed difficulties. The chamber walls were not solid, but contained a network of tubing through which RP-1 fuel flowed, cooling the chamber and pre-heating the RP-1. A specialized brazing furnace had to be made to allow the entire chamber to be brazed at once, as traditional torch brazing failed to produce reliable chambers.
The first flight of the F-1 occured onboard an unmanned Saturn V in 1967. The Saturn V used a cluster of five F-1s arranged in a cross, and each F-1 burnt one metric ton of RP-1 and two metric tons of liquid oxygen per second for over 160 seconds. The F-1 delivered 6.78 million Newtons of thrust, was 3.7 meters wide and stood 5.6 meters tall.