Astronaut Thomas P. Stafford, who commanded a dress rehearsal flight for the 1969 moon landing and the first U.S.-Soviet space linkup, died Monday. He was 93.

Stafford, a retired Air Force three-star general, took part in four space missions. Before Apollo 10, he flew on two Gemini flights, including the first rendezvous of two U.S. capsules in orbit. He died in a hospital near his Space Coast Florida home, said Max Ary, director of the Stafford Air & Space Museum in Weatherford, Oklahoma.

Stafford was one of 24 NASA astronauts who flew to the moon, but he did not land on it. Only seven of them are still alive.

“Today General Tom Stafford went to the eternal heavens which he so courageously explored as a Gemini and Apollo astronaut as well as a peacemaker in Apollo Soyuz,” NASA Administrator Bill Nelson said via X, formerly known as Twitter. “Those of us privileged to know him are very sad but grateful we knew a giant.”