Edgar Mitchell, the sixth man to walk on the moon, has died just a day before the 45th anniversary of his landing on the moon with crewmate Alan Shepard. He was 85 years old.

All of Apollo’s astronauts were extraordinary individuals, but Mitchell stood out for a number of reasons, according to a Spaceflight Now report.

He was famous for doing an experiment in extra-sensory perception on his way back from his lunar visit. He eventually founded the Institute of Noetic Sciences in 1973 to help “promote awareness of evolving human consciousness,” a lifelong interest of his.

Mitchell’s post-NASA career was like no other. He was fascinated with the question of consciousness and the nature of it. More than perhaps anyone else, he was truly changed by looking back at Earth while in space, feeling the enormousness of the universe and his awareness as an intelligent organism within it.

Mitchell had always been curious about psychic phenomena, and devoted a lot of his time after leaving NASA to see if science could explain consciousness, and whether it could be transmitted through the universe. It is what made him a truly unique personality.

Apollo 14 was the eighth manned mission of the Apollo program, and the third to land on the moon. It was the last of the missions to include two-day stay on the moon and two moonwalks. It was commanded by Alan Shepard, and Mitchel was the lunar module pilot. The mission launched on January 31st, 1971, and they landed on the moon on February 5th.