Apollo 9 astronauts, left to right, James McDivitt, David Scott and Russell Schweickart pause in front of the Apollo/Saturn V space vehicle that will launch Apollo 8 space pilots Frank Borman, James Lovell and William Anders on a planned lunar orbital mission. The 363-foot-high space vehicle will lift off from the Kennedy Space Center's Launch Complex 39A. Gaseous liquid oxygen is venting from the vehicle's first stage during recent Countdown Demonstration Test. Photo credit: NASA