Astronaut Group 4 (The Scientists) was the fourth group of astronauts selected by NASA in June 1965. While the astronauts of the first two groups were required to have college and some advanced degrees, they were chosen for their experience as test pilots. Test pilot experience was waived as a requirement for the third group, but military jet fighter aircraft experience could be substituted. Group 4 was the first group chosen for research and academic backgrounds (Doctorate degrees) rather than pilot training, which NASA provided as necessary. Of the six, four had previous military experience, with Garriott also having completed the USAF Pilot Training Program; Schmitt, a geologist, walked on the Moon, while Garriott, Gibson and Kerwin all flew to Skylab. Garriott also flew on the Space Shuttle. Graveline and Michel left NASA without flying in space.
A chart showing Group 4 assignments in relation to other astronaut groups. Graphed this way, it clearly shows how Group 5 military pilots were assigned ahead of Group 4, with most of Group 4 required to spend a full year at UPT to get qualified as jet pilots (which all of Group 5 and prior groups had done early in their military careers). The requirement for scientists to get qualified as jet pilots was eventually lifted with the creation of the Mission Specialist position in the shuttle program