Harrison Schmitt cancelled in September 1970, the community of lunar geologists supporting Apollo felt so strongly about the need to land a professional geologist on the Moon, that they pressured NASA to reassign Schmitt to a remaining flight. As a result, Schmitt was assigned in August 1971 to fly on the last mission, Apollo 17, replacing Joe Engle as Lunar Module Pilot. Schmitt landed on the Moon with commander Gene Cernan in December 1972. Schmitt claims to have taken the photograph of the Earth known as "The Blue Marble", possibly one of the most widely distributed photographic images in existence. NASA officially
Michael Collins (astronaut) astronaut who had already flown a mission, and that on flights with a LM, the CMP should also have some spaceflight experience, something Anders did not yet have. Collins was therefore moved to the CMP position on the Apollo 8 prime crew, and Anders became the LMP. The policy became that the CMP would be the next most senior member of the crew, and that they would go on to command later Apollo flights. Staff meetings were always held on Fridays in the Astronaut Office and it was here that Collins found himself on January 27, 1967. Don Gregory was