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
John Young (astronaut) Module, the Apollo Lunar Module, and the Space Shuttle. In 1965, Young flew on the first manned Gemini mission, and commanded another Gemini mission the next year. In 1969 during Apollo 10, he became the first person to fly solo around the Moon. He drove the Lunar Roving Vehicle on the Moon's surface during Apollo 16, and is one of only three people to have flown to the Moon twice. He also commanded two Space Shuttle flights, including its first launch in 1981, and served as Chief of the Astronaut Office from 1974 to 1987. Young retired from NASA in