The Apollo Applications Program (AAP) was established by USGS in the mid 1960's to simulate astronauts collecting rock samples on the Moon using hardware developed for the Apollo program. AAP was the ultimate development of a number of official and unofficial Apollo follow-on projects studied at various NASA labs. The Apollo Applications Program (AAP) was established by USGS in the mid 1960's to simulate astronauts collecting rock samples on the Moon using hardware developed for the Apollo program. AAP was the ultimate development of a number of official and unofficial Apollo follow-on projects studied at various NASA labs. Initially the AAP office in Flagstaff, Arizona was an offshoot of the Apollo 'X' bureau, also known as the Apollo Extension Series. AES was developing technology concepts for mission proposals based on the Saturn IB and Saturn V boosters. These included a crewed lunar base, an Earth-orbiting space station, the so-called Grand Tour of the Outer Solar System, and the original 'Voyager program' of Mars Lander probes. The Apollo lunar base proposal saw an uncrewed Saturn V used to land a shelter based on the Apollo Command/Service Module (CSM) on the Moon. A second Saturn V would carry a three-person crew and a modified CSM and Apollo Lunar Module (LM) to the Moon. The two-person excursion team would have a surface stay time of nearly 200 days and use of an advanced lunar rover and a lunar flier as well as logistics vehicles to construct a larger shelter. The isolation of the CSM pilot was a concern for mission planners, so proposals that it would be a three-person landing team or that the CSM would rendezvous with an orbiting module were considered.