information:classification
Selection for Apollo lunar landing

Early in the planning process, NASA considered three methods for the Moon mission: Earth orbit rendezvous (EOR), direct ascent, and lunar orbit rendezvous (LOR). A direct ascent configuration would require an extremely large rocket to send a three-man spacecraft to land directly on the lunar surface. An EOR would launch the direct-landing spacecraft in two smaller parts which would combine in Earth orbit. A LOR mission would involve a single rocket launching two spacecraft: a mother ship, and a smaller, two-man landing module which would rendezvous back with the main spacecraft in lunar orbit. The lander would be discarded and the mother ship would return home.

At first, NASA dismissed LOR as a riskier option, as a space rendezvous had yet to be performed in Earth orbit, much less in lunar orbit. Several NASA officials, including Langley Research Center engineer John Houbolt and NASA Administrator George Low, argued that a lunar orbit rendezvous provided the simplest landing on the Moon with the most cost–efficient launch vehicle, and the best chance to accomplish the lunar landing within the decade. Other NASA officials became convinced, and LOR was then officially selected as the mission configuration for the Apollo program and announced by NASA administrator James E. Webb on November 7, 1962. Arthur Rudolph became the project director of the Saturn V rocket program in August 1963. He developed the requirements for the rocket system and the mission plan for the Apollo program. The first Saturn V launch lifted off from Kennedy Space Center and performed flawlessly on November 9, 1967, Rudolph's birthday. He was then assigned as the special assistant to the director of MSFC in May 1968 and subsequently retired from NASA on January 1, 1969. On July 16, 1969, the Saturn V launched Apollo 11, putting the first men on the Moon.