Editing S-II (section)

==History==
[[Image:Saturn v building seal beach.jpg|left|thumb|200px|S-II assembly building in Seal Beach, CA]]
The beginning of the S-II came in December 1959 when a committee recommended the design and construction of a high-thrust, [[liquid hydrogen]] fueled engine. The contract for this engine was given to [[Rocketdyne]] and it would be later called the [[J-2 (rocket engine)|J-2]]. At the same time the S-II stage design began to take shape. Initially it was to have four J-2 engines and be {{convert|74|ft|m}} in length and {{convert|260|in|m}} in diameter.

In 1961 the [[Marshall Space Flight Center]] began the process to find the contractor to build the stage. Out of the 30 aerospace companies invited to a conference where the initial requirements were laid out, only seven submitted proposals a month later. Three of these were eliminated after their proposals had been investigated. However it was then decided that the initial specifications for the entire rocket were too small and so it was decided to increase the size of the stages used. This raised difficulties for the four remaining companies as [[NASA]] had still not yet decided on various aspects of the stage including size, and the upper stages that would be placed on top.

On September 11, 1961, the contract was awarded to [[North American Aviation]] (who were also awarded the contract for the [[Apollo Command/Service Module]]), with the manufacturing plant built by the government at [[Seal Beach]], [[California]].<ref>{{Cite book|last=Aikens|first=David|url=https://history.nasa.gov/MHR-5/part-2.htm|title="Saturn Illustrated Chronology - Part 2: January 1961 through December 1961"|date=15 May 1965 |publisher=NASA-Marshall Space Flight Center|pages=28}}</ref> 15 flight stages were to be produced.

Plans were also developed to build 10 follow-on stages, S-II-16 through -25, but funding to assemble them never materialized.<ref name="16-25">{{Cite web|title=Manufacturing plan for Saturn S-II, Stages 16-25|url=http://libarchstor2.uah.edu/digitalcollections/items/show/11131|access-date=2023-03-18|website=uah.edu|date=14 June 1967 }}</ref> These stages would have supported later Apollo missions, including those of the [[Apollo Applications Program]].