Saturn I

Flight testing other, smaller pieces of hardware like the Command Service Module and Lunar Module thus required a smaller, cheaper booster.

Thankfully, in 1957, Dr. Wernher von Braun, and yes this is another space race name commonly mispronounced, but is indeed supposed to be pronounced more or less like Brown, not Braun as most say, confirmed by none other than his daughter if you don't believe me, But in any event, the former Nazi rocket scientist and then-director of the Army Ballistic Missile Agency in Huntsville, Alabama, proposed just such a cheaper system, dubbed the Saturn I.

Built largely from existing rocket hardware, the Saturn I SI stage comprised eight propellant tanks from the PGM-11 Redstone ballistic missile, clustered around a single oxygen tank from the PGM-19 Jupiter missile, a configuration detractors amusingly dubbed Cluster's last stand.

This in turn was topped by an S-IV second stage with six Aerojet Rocketdyne RL-10 engines burning liquid hydrogen and oxygen which produced a maximum thrust of 400 kilonewtons or 90,000 pounds.

Together, these two stages were just powerful enough to loft a crewed Apollo CSM and LEM into low Earth orbit for a fraction of the price of a Saturn V launch.

A total of 10 Saturn I vehicles were launched from Cape Canaveral in Florida, starting with the SA-1 on October 27, 1961, and ending with the SA-10 on July 30, 1965.

Though the main goal of these launches was to prove out the Saturn engine and guidance systems, and the aerodynamics of the Apollo spacecraft, some missions also added secondary objectives.

For example, SA-2 and SA-3 launched on April 25th and November 16th, 1962, respectively, were part of an unusual research program called Project High Water intended to study the effects of releasing large quantities of liquid into the ionosphere.