Who flew on more Space Shuttle missions, meteorologist Piers Sellers or chemical engineer Lodewijk van den Berg?
Lodewijk van den Berg Lodewijk van den Berg (] ; born March 24, 1932) is a Dutch American chemical engineer, specializing in crystal growth, who flew on a 1985 Space Shuttle "Challenger" mission as a Payload Specialist.
Rex J. Walheim Rex Joseph Walheim (born October 10, 1962) is a United States Air Force officer, engineer and a NASA astronaut. He has flown three space shuttle missions, STS-110, STS-122, and STS-135. Rex has logged over 566 hours in space, including 36 hours and 23 minutes of spacewalk (EVA) time. He was assigned as mission specialist and flight engineer on STS-135, the final space shuttle mission.