Alfred Worden served as Apollo 15's command module pilot while two crewmates explored the Moon.
Worden remained aboard the command module Endeavour as commander David Scott and lunar module pilot James Irwin descended to the lunar surface. His job included operating the spacecraft, conducting scientific observations from lunar orbit, and preparing for the crew's rendezvous and return.
Apollo 15 launched on July 26, 1971, and became the fourth mission to land astronauts on the Moon. While in orbit, Worden photographed and mapped lunar terrain using instruments in the scientific instrument module. He also performed a deep-space spacewalk during the journey home to retrieve film from the module's cameras.
Worden is sometimes confused with Michael Collins, who performed a similar solo orbital role on Apollo 11. Collins piloted Columbia while Neil Armstrong and Buzz Aldrin were on the surface; Worden performed that role for Apollo 15.