What engines did the S-IV stage carry into the sky?
The S-IV stage carried six RL-10A-3 engines. Each engine provided 150,000 pounds of thrust for a total force of about 900,000 pounds.
Questions about S-IV
Short answers, pulled from the story.
Who built the structure for the S-IV upper stage?
Douglas Aircraft Company built the structure to hold these engines and fuel tanks. The company manufactured the original S-IV stage in California before modifying it into the S-IVB variant.
When did the first S-IV mission launch take place?
SA-1 lifted off on the 27th of October 1961 at 15:06:04 UTC. This launch marked the beginning of operational history that spanned through the 30th of July 1965.
How many liquid oxygen and liquid hydrogen tanks were in the S-IV design?
Engineers designed a common bulkhead between the liquid oxygen tank and the liquid hydrogen tank. Liquid oxygen filled the upper section while liquid hydrogen occupied the lower section within this shared boundary.
Why was the S-IV modified into the S-IVB variant?
These modifications created a new stage used on the Saturn IB and Saturn V rockets. The transition allowed NASA to reuse proven technology for lunar missions and support heavier payloads destined for lunar orbits.