Duke, Charles Moss, Jr. (1935-...), a United States astronaut, was the lunar module pilot on the Apollo 16 mission, from April 16 to April 27, 1972. Duke and astronaut John W. Young spent more than 71 hours on the moon. They explored the Descartes region of the moon, performed scientific experiments, and collected about 210 pounds (95 kilograms) of lunar rocks. While Duke and Young investigated the lunar surface, astronaut Thomas K. Mattingly II orbited the moon in the command module.