Page 62 - Apollo Moonships

60 On bOard apOllO mOOnships
DESIGNED TO BE FUNCTIONAL
The Lunar Excursion Module (LEM) is one of the most remarkable engineering achievements of the space era. To this day, it is the only crewed space vehicle designed to operate solely in the vacuum of space, completely outside of the Earth’s atmosphere in low- or no-gravity conditions. The spaceship design represented an enormous challenge. The LEM not only had to be able to safely carry two astronauts up to the lunar surface and to support them during their stay by serving as a control center and home; the ship also had
to operate as a launch pad and launch vehicle to propel the crew back to
the lunar orbit, where they would rendezvous and dock with the Command- Service Module (CSM) in order to return to Earth. The complexity of the
task was further aggravated by the fact that the ship could never be tested in real flight due to its inability to replicate the lunar environment. Other major obstacles in the design were the weight and size of the LEM, which had to be adapted to requirements such as the payload capacity of the moon rocket—the Saturn V—the space available inside of it, or the amount of fuel needed to land and take off from the moon. As a result of these and other practical considerations, the LEM finally presented an exterior and interior design unique to any other spacecraft. The ship was maybe aesthetically unappealing, but it was reliable and functional.
LANDING ON THE MOON
The Apollo 12 Lunar Excursion Module (LEM) in landing configuration descends towards the surface of the moon on November 24, 1969. During the Apollo Program, six of the 13 lunar modules landed on the moon without a single mishap.
LEM INNER STRUCTURE
1 Docking drogue (removable for access)
2 Reaction Control System (RCS) thruster
3 RCS oxidizer tank A
4 RCS helium tank A
5 RCS fuel tank A
6 Ascent stage engine fuel tank
7 Descent stage engine fuel tank compartment
8 Gaseous oxygen tank (2)
9 Rendezvous radar electronic assembly
10 Signal conditioning electronics replaceable assembly N° 1
11 Pulse code modulation & timing equipment assembly
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NOTE: The lunar module was modified according to
the tasks planned to be performed on the moon. This configuration corresponds to the Lunar Module used by Apollo 11, which carries a set of only two deployable experiments (the Early Apollo Surface Experiments Package) and does not house the Lunar Roving Vehicle..
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