Several initial experimental firings of the various stages of Saturn V into earth orbit will precede the planned lunar flight. The astronauts will practice rendezvous techniques in the earth's orbit. … Before they reach the moon the astronauts will have another difficult maneuver to perform—turning their command module around so that its nose is attached to the top of the lunar excursion module. Two of the crew members will transfer from the command module to the lunar excursion module.