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.
Ken Bowersox Kenneth Dwane "Sox" Bowersox (born November 14, 1956) is a United States Navy officer, and a former NASA astronaut. He is a veteran of five Space Shuttle missions and an extended stay aboard the International Space Station.