These two craft were the only parts of the Apollo-SaturnV to actually reach the moon. The Command module, where the astronauts have been since launch, is a capsule with very little room to spare. (The Lunar Excursion Module is joined nose-to-nose with the C.M. during the trip to the moon; there is a small hatch to move between the vehicles).  Behind the C.M. is the Service module; this contains fuel, oxygen, water supplies, and engines. (It was a short in an electrical circuit in the oxygen tank here that caused the explosion on the Apollo 13 mission). The engine on the Service module must fire to cause the craft to fall into lunar orbit. Then it had to fire again to boost them out of orbit around the moon, and toward earth. |
 The Lunar Excursion Module, or LEM, rode to the moon attached to the nose of the Command module. It was made up of two stages. The lower stage contained the engine that powered them down to the surface of the moon.  The upper stage, where the astronauts stayed, and piloted the LEM down to the moon, also had an engine. This propelled just this upper stage back into lunar orbit, where it rejoined the Command module. The two astronauats who flew this vehicle stood to pilot it, and peered out the tiny windows you see in this photo. |