CAPE CANAVERAL, Fla. -- The Apollo/Saturn V Center at NASA's Kennedy Space Center in Florida hosted a celebration on the 40th anniversary of NASA's Apollo 15 mission. An elite gathering of Apollo-era astronauts were on hand for the event and panel discussion. Gerry Griffin, Apollo 15 flight director moderates the question-and-answer period with the panel. From left are: Apollo 15 astronaut backup support crew members, Joe Allen, Jack Schmitt, Vance Brand and Dick Gordon; Al Worden and Dave Scott. Worden circled the moon while Scott and the late Jim Irwin, the Lunar Module commander, made history when they became the first humans to drive a vehicle on the surface of the moon. They also provided extensive descriptions and photographic documentation of geologic features in the vicinity of the Hadley Rille landing site during their three days on the lunar surface. Photo credit: NASA/Kim Shiflett