Apollo 15 went unused, due to the explosion that damaged the Apollo 13 spacecraft. Apollo 14's CMP, Stu Roosa, was enthusiastic about geology, but the mission commander, Alan Shepard, less so. Scott, once assigned as Apollo 15 commander, was determined that his crew bring back the maximum amount of scientific data possible, and met with Silver in April 1970 to begin planning the geological training. The assignment of Schmitt as Apollo 15's backup LMP made him an insider, and allowed him to spark competition between the prime and backup crews. The cancellation of two Apollo missions in September 1970 transformed Apollo 15
Apollo program a small orbital laboratory (workshop). Astronauts would continue to use the CSM as a ferry to the station. This study was followed by design of a larger orbital workshop to be built in orbit from an empty S-IVB Saturn upper stage, and grew into the Apollo Applications Program (AAP). The workshop was to be supplemented by the Apollo Telescope Mount, which could be attached to the ascent stage of the lunar module via a rack. The most ambitious plan called for using an empty S-IVB as an interplanetary spacecraft for a Venus fly-by mission. The S-IVB orbital workshop was the