The Apollo 9 astronauts, left to right, James A. McDivitt, David R. Scott, and Russell L. Schweickart, pause in front of the Apollo/Saturn V space vehicle that would launch the Apollo 8 crew. The launch of the Apollo 9 (Saturn V launch vehicle, SA-504) took place on March 3, 1969. The Apollo 9 spacecraft, in the lunar mission configuration, was tested in Earth orbit. The mission was designed to rehearse all the steps and reproduce all the events of the Apollo 11 mission with the exception of the lunar touchdown, stay, and liftoff. The command and service modules, and the lunar module were used in flight procedures identical to those that would later take similar vehicles to the Moon, and a landing. The Apollo 9 crew landed on March 13, 1969.
Image Credit: NASA