Harrison Schmitt credits the image to the entire Apollo 17 crew. While on the Moon's surface, Schmitt — the only geologist in the astronaut corps — collected the rock sample designated Troctolite 76535, which has been called "without doubt the most interesting sample returned from the Moon". Among other distinctions, it is the central piece of evidence suggesting that the Moon once possessed an active magnetic field. As he returned to the Lunar Module before Cernan, Schmitt is the next-to-last person to have walked on the Moon's surface. After the completion of Apollo 17, Schmitt played an active role in documenting the
NASA Astronaut Group 7 also given support assignments for Skylab and the Apollo-Soyuz Test Project, with Bobko and Crippen participating in the Skylab Medical Experiment Altitude Test. Group 7 went on to form the core of early Space Shuttle pilots, upgrading to commander after their first flight, flying 17 STS missions between them, plus the Approach and Landing Tests of . NASA Astronaut Group 7 Astronaut Group 7, referred to in some documents as the USAF MOL Transfer, was a group of seven astronauts announced by NASA on August 14, 1969, and was the last group to be selected during the Apollo era. After