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. Piers Sellers:  He was a veteran of three space shuttle missions.
i don't know