On the road to the moon, the mission of Apollo 9 stands as an important gateway in experience and procedures - leading directly to the confidence gained to place a man on the moon less than a half a year later. The first manned mission of the CSM and LM together, astronauts left the safety of the command module and separated in a craft not able to return to Earth. Working through rendezvous and docking procedures, including burn procedures which would later be used to help Apollo 13 return to Earth, the voyage of Apollo 9 was a spectacular achievement in the history of spaceflight.