Has Piers Sellers or Hans Schlegel been on more Space Shuttle Missions?
Piers Sellers Piers John Sellers OBE (11 April 1955 – 23 December 2016) was a British-American meteorologist, NASA astronaut and Director of the Earth Science Division at NASA/GSFC. He was a veteran of three space shuttle missions.
John Young (astronaut) John Watts Young (born September 24, 1930) is an American former astronaut, naval officer and aviator, test pilot, and aeronautical engineer, who became the ninth person to walk on the Moon as Commander of the Apollo 16 mission in 1972.