Saturn (rocket family)
[1] In 1963, President John F. Kennedy identified the Saturn I SA-5 launch as being the point where US lift capability would surpass the Soviets, after having been behind since Sputnik.
The requirements, drawn up by the then-unofficial Advanced Research Projects Agency (ARPA), called for a vehicle capable of putting 9,000 to 18,000 kilograms into orbit, or accelerating 2,700 to 5,400 kg to escape velocity.
[6] Since the Wilson memorandum covered only weapons, not space vehicles, the Army Ballistic Missile Agency (ABMA) saw this as a way to continue the development of their own large-rocket projects.
[10] The Centaur had been proposed by General Dynamics (Astronautics Corp.) as an upper stage for the Atlas (also their design) in order to quickly produce a launcher capable of placing loads up to 8,500 lb (3,900 kg) into low Earth orbit.
[citation needed] Given that the Atlas was the higher priority of the two ICBM projects and its production was fully accounted for, ABMA focused on "backup" design, Titan, although they proposed extending it in length in order to carry additional fuel.
[citation needed] In December 1957, ABMA delivered Proposal: A National Integrated Missile and Space Vehicle Development Program to the DoD, detailing their clustered approach.
[13] While the Super-Jupiter program was being drawn up, preparations were underway for the first satellite launch as the US contribution to the International Geophysical Year in 1957.
When asked in November 1954 about the possibility of the Soviets launching a satellite, Defense Secretary Wilson replied: "I wouldn't care if they did.
Vanguard was planned to launch shortly after Sputnik, but a series of delays pushed this into December, when the rocket exploded in spectacular fashion.
Making matters worse, the DoD imposed its own Byzantine procurement and contracting rules, adding considerable overhead.
To address these concerns, the DoD initiated the formation of a new research and development group focused on launch vehicles and given wide discretionary powers that cut across traditional Army/Navy/Air Force lines.
Formalized as Advanced Research Projects Agency (ARPA) on February 7, 1958, the group examined the DoD launcher requirements and compared the various approaches that were currently available.
The Air Force had gained valuable experience working with liquid hydrogen on the Lockheed CL-400 Suntan spy plane project and felt confident in their ability to use this volatile fuel for rockets.
ARPA agreed that the Juno proposal was more likely to meet the timeframes required, although they felt that there was no strong reason to use the E-1, and recommended a lower-risk approach here as well.
[18] Happy with the results of the redesign, on August 15, 1958, ARPA issued Order Number 14-59 that called on ABMA to: This was followed on September 11, 1958, with another contract with Rocketdyne to start work on the H-1.
On September 23, 1958, ARPA and the Army Ordnance Missile Command (AOMC) drew up an additional agreement enlarging the scope of the program, stating "In addition to the captive dynamic firing..., it is hereby agreed that this program should now be extended to provide for a propulsion flight test of this booster by approximately September 1960".
NASA was formed on July 29, 1958, and immediately set about studying the problem of crewed space flight, and the launchers needed to work in this field.
At the time, the NASA panels felt that the direct ascent mission profile was the best approach; this placed a single very large spacecraft in orbit, which was capable of flying to the Moon, landing and returning to Earth.
ABMA's Project Horizon proposed using fifteen Saturn launches to carry up spacecraft components and fuel that would be assembled in orbit to build a single very large lunar craft.
This Earth orbit rendezvous mission profile required the least amount of booster capacity per launch, and was thus able to be carried out using the existing rocket design.
This would be the first step towards a small crewed base on the moon, which would require several additional Saturn launches every month to supply it.
As part of the project, they designed an entirely new rocket series known as the Space Launcher System, or SLS (not to be confused with the Space Launch System part of the Artemis program), which combined a number of solid-fuel boosters with either the Titan missile or a new custom booster stage to address a wide variety of launch weights.
At this point, however, all three stages existed only on paper, and it was realized that it was very likely that the actual lunar spacecraft would be developed and ready for testing long before the booster.
