The mode that Apollo would use to land on the moon was the most studied, analyzed, and debated decision made for the lunar landing program. There were four main choices Direct-ascent, Earth-Orbit Rendezvous, Lunar-Orbit Rendezvous, and Lunar Surface Rendezvous.
Max Faget thought the first stage of the moon rocket should use four solid-fueled engines, 6.6 meters in diameter. He reasoned these could certainly accomplish whatever mission was required of either the Saturn or Nova, and it would be more cost effective. Faget said it made good sense to use cheap solid fuels for expendable rockets and more expensive liquid fuels for reusable engines. Faget called the individual solid rocket ‘the Tiger.’
In May 1961, NASA was not really prepared to direct an enormous Apollo program designed to fly its spacecraft to the moon. New and special facilities would be needed and the aerospace industry would have to be marshaled to develop vehicles not easily adapted to production lines, but at this point no one had even decided just what Apollo’s component parts should be or how they should look.
In January 1960, President Eisenhower directed NASA Administrator Glennan to accelerate the Super Booster Program that had recently been assigned to NASA. This order ensured the transfer of the von Braun group from the Army Ballistic Missile Agency to NASA, and it gave Glennan the launch vehicle development and management capability that he needed.
The goal of the nation’s space program should be the scientific exploration of the moon and the planets but also to recognize that nontechnical factors are vital to public acceptance of a space program. Human exploration of the moon and planets would be potentially the greatest inspirational venture of the 20th century and one in which the world could share; inherent here are great and fundamental philosophical and spiritual values which find a response in man’s questing spirit to explore. Thus the space exploration program must be developed on the premise that man will be included. Failure to adopt this premise will inevitably prevent man’s inclusion, presumably because of the costs involved. From a scientific standpoint there seems little room for dissent that man’s participation in the exploration of the Moon and planets will be essential, if and when it becomes technologically feasible to include him.
President Kennedy proposed the manned lunar landing as the focus of the US space program but, at the time of his address, only one American, Alan B. Shepard, Jr. had been into space, on a suborbital lob shot lasting 15 minutes. No rocket launch vehicle was available for a lunar voyage and there was no agreed upon method for placing any kind of spacecraft safely on the lunar surface and getting it back to the earth. Nor was there agreement within NASA itself on how it should be done.
“The main trouble with the Mercury capsule was that most system components were in the pilot’s cabin; and often, to pack them in this very confined space, they had to be stacked like a layer cake and components of one system had to be scattered about the craft to use all available space. This arrangement generated a maze of interconnecting wires, tubing, and mechanical linkages. To replace one malfunctioning system, other systems had to be disturbed; and then, after the trouble had been corrected, the systems that had been disturbed as well as the malfunctioning system had to be checked out again.” James Chamberlin
This brings us to Project Gemini. Gemini started after Apollo had begun, in part to answer a crucial question for Apollo. Was rendezvous and docking in orbit a feasible basis for a manned lunar landing mission?