[Illustration: 40. Apollo 15 Lunar Module, center, on the Moon.
Astronaut Irwin on left and Lunar Roving Vehicle on right.]
The lunar module is one of twelve built for the Apollo moon-landing
program. Although this one never flew because an earlier test flight was
completely successful, two-stage lunar modules like this one have been
used for each manned moon landing.
Lunar modules do not have to be streamlined for flights through the
vacuum of space or to withstand reentry. The lunar module (LM) lifts off
from Earth enclosed in a compartment of the Saturn 5 launch vehicle,
below the command-service module that houses the astronauts. The command
module pulls the LM from its storage area once the spacecraft are on
their way to the Moon, and the two travel together until they arrive in
lunar orbit.
When the crew is ready to land, two of the three astronauts enter the LM
and undock it, leaving the third to pilot the command module. After
touchdown on the Moon, the astronauts exit through the door above the
ladder.
The silver and black ascent stage, containing the astronauts’
pressurized compartment and the clusters of rockets that control the
spacecraft, fits on top of the shiny gold descent stage that actually
touches down on the Moon. The descent stage contains a main, centrally
located rocket engine. This segment of the craft remains on the Moon as
the crew lifts off in the ascent stage to rejoin the command module.
After the crew transfers to the command module, the ascent stage is also
left behind as the three crew members start their return journey.
The LM is displayed just as it would look during a moon-landing mission.
The gold and black materials insulate the spacecraft’s inner structure
from temperature extremes and protect it from micrometeoroids. Thin
sheets of both materials are used in “blankets” to accomplish the
necessary protection in a foreign environment.
The black material is heat-resistant nickel-steel alloy. Each sheet is
only .002 millimeters (1/12,000 of an inch) thick. These absorb heat and
radiate it back into the blackness of space.
The shiny gold material on the descent stage is aluminum that is thinly
coated over plastic film. The thin sheets of plastic and aluminum are
used in blankets of up to 25 layers for protection and insulation of the
spacecraft.
Prime contractor for the lunar module was Grumman Aerospace Corporation.
The lunar module on exhibit is from the National Aeronautics and Space
Administration.
Height 7 m. (22 ft., 11 in.), legs extended
Diameter 9.4 m. (31 ft.) diagonally across landing gear
Weight
Earth launch 14,700 kg. (32,400 lb.)
LM (dry) 3900 kg. (8600 lb.)
Volume
Pressurized 6.7 cu. m. (235 cu. ft.)
Habitable 4.5 cu. m. (160 cu. ft.)
[Illustration: 41. Lunar Module Center Instrument Panel in the
ascent stage.]