Apollo astronauts Buzz Aldrin Walt Cunningham Edgar Mitchell and Al Worden applaud during the introduction of Charlie Duke.

At the Apollo/Saturn V Center at NASA's Kennedy Space Center in Florida, Apollo astronauts Buzz Aldrin, Walt Cunningham, Edgar Mitchell and Al Worden applaud during the introduction of Charlie Duke at NASA's 40th Anniversary of Apollo Celebration of the July 1969 launch and landing on the moon. Eight Apollo astronauts participated in the ceremony. Photo credit: NASA/Kim Shiflett