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. He was a veteran of three space shuttle missions.
STS-121 STS-121 was a 2006 NASA Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle " Discovery". The main purposes of the mission were to test new safety and repair techniques introduced following the "Columbia" disaster of February 2003 as well as to deliver supplies, equipment and European Space Agency (ESA) astronaut Thomas Reiter from Germany to the ISS.