Who flew on more Space Shuttle missions, meteorologist Piers Sellers or chemical engineer Lodewijk van den Berg?
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. Piers Sellers:  He was a veteran of three space shuttle missions.
i don't know