Thomas K. Mattingly II, a NASA astronaut who helped bring Apollo 13 home, is dead at 87.

Mattingly II died on Oct. 31, according to a press release from NASA.

NASA selected him as an astronaut in 1966.

He served as a support member for astronauts flying Apollo 8 and 11 missions.

Mattingly, a designated command module pilot for Apollo 13, was removed from the flight due to exposure to measles.

Although he couldn’t make the flight, the Chicago-born aviator was vital to “successfully bring(ing) home the wounded spacecraft and the crew of Apollo 13 – NASA astronauts James Lovell, Jack Swigert, and Fred Haise,” according to NASA.

Mattingly said when he was in orbit, he had a “palpable fear that if I saw too much, I couldn’t remember.”

“TK’s contributions have allowed for advancements in our learning beyond that of space,” said a NASA spokesperson. “As a leader in exploratory missions, TK will be remembered for braving the unknown for the sake of our country’s future.”