In later years, Mitchell ran into trouble with NASA, for attempting to auction off a camera he and his team used on the Moon, claiming it was given to him as a souvenir. The camera was eventually donated to the National Air & Space Museum. On September 20, 2012 Congress enacted H.R. 4158, confirming full ownership rights of artifacts to astronauts on Apollo (and Mercury and Gemini) space missions.
Mitchell was the founder of the Institute of Noetic Sciences (IONS) for the purpose of consciousness research and other "related phenomena." He was very interested in UFO's and at one time claimed that he was "90 percent sure that many of the thousands of UFOs, recorded since the 1940s, belong to visitors from other planets."