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Lunar Module(LM)

Lunar module, It is the first vehicle to fly only in the space. Because of needless of aerodynamics, peculiarity of the use environment, it's various unique functions, this vehicle has mysterious shape. Then, the development was very difficult.
  • Height : 23ft (7.0104m)
  • Maximum Weight : 36244lb (16.454ton)
  • Manufacturer : Grumman Aircraft Engineering Corp., Bethpage, N.Y.


LM was being called the early days LEM (Lunar Excursion Module). It was stored into SLA (Spacecraft-LM Adapter) : the top of Saturn-V third stage, and carried to the space. When a spaceship goes in orbit to the moon, It docks to the top of CSM, and does a trip to the moon. Then it arrives onto the moon orbit, two astronauts move in LM. The DPS (Descent Propulsion System) engine of the Descent Stage is jetted, and it lands to the surface of the moon. When activities on the moon are finished, Descent Stage of LM is used as a launching pad. Only Ascent Stage is returned to CSM on moon orbit. After astronauts return to CSM, Ascent Stage becomes unnecessary too. The unwanted materials such as a back-pack are crammed in the Ascent Stage, then it is scrapped toward the surface of the moon again. At last, it generates small moonquake (lunar earthquake), gives a chance to examine composition of moon to scientists, it's duty is finished.

Ascent Stage

Ascent Stage is divided into about three parts. One is the part of the cylinder shape at the front, "Crew Compartment". The second is a center unit with docking hatch, "Mid Section". And the last, jutted out to after, "Aft Equipment Bay".

Because of the severe restriction of the weight, LM is being made thoroughly in the light weight. Most part of the body are only being put metal foil on the framework of aluminum.
Crew Compartment and Mid Section are made to unify, it form a cabin. The capacity of the cabin is about 235 cubic feet. This cabin is built by shave an aluminum alloy, and welded together, and epoxy is packed into the gap. Titanium parts are being used for joining.

Crew Compartment is 92 inches in diameter and 42 inches deep. There are two triangular windows and hatch to get off to the moon in front. Command pilot(CDP)'s console is on the left, Lunar Module Pilot(LMP)'s on the right inside, A little docking window is attached to the part of the roof on the CDP side. There is Equipment Storage of the left of CDP and the right of LMP. An environment control device, lithium hydroxide cartridge of the back pack (PLSS : PORTABLELIFESUPPORTSYSTEM), and so on are stored in the CDP side. A camera, food, and so on are stored in the LMP side. Velcro pile is bonded on the deck, and astronaut's shoes can be fixed under the zero gravity conditions. There is no chair in the cockpit because it is used only in the space and the surface of the moon. Astronauts binding a body with the cable and operations LM with standing.
Front hatch is used for get off to the moon, It is a quadrangle in 32 inches square for going in and out with back-pack (PLSS). and opens to the inside on the LMP side. Hinge is being installed in the right, it opens to the inside on the LMP side. By the atmospheric pressure, it is sealed up with silicone sealing. You must operate the valve on the hatch and exhaust air inside the ship completely to open the hatch.

Two triangle windows and a docking window are form of 2 layers. Coating of 59 layer is made outside of the outer layer to shut out ultraviolet rays and so on. And, high efficiency reflection prevention coating is made in the inside and outside of the outer layer. Then, electric heater is provided for prevent dimness, but because it lacks a temperature watch function, astronauts must always check it. A covering board is being installed in all the windows. It is rolled up by side of the window when it isn't used.
The back of the cabin is "Mid Section" of the oval shape of the depth 54 inches, the height 5 feet. In the center of here, ascent engine assembly is installed for takes off from the moon. And on right side, there are environment control device, container which stores moon rocks, water supply machine, life support equipment. On left side, waste treatment device, oxygen purifier, the variety container which stores food, moon shoes, and so on. On after bulkhead, EPS(Electrical Power Subsystem), GN&CS(Guidance, Navigation, and Control Subsystem), e.t.c are installed. Ascent engine is covered with cover of the cylinder shape, and used as astronaut's chair. A fuel tank is being installed outside of Mid Section.

There is an overhead hatch at the top of Mid Section to use for dock with CSM. This is diameter 33-inch circle, the structure is the same as front hatch, it opens inside. Docking tunnel, outside of the hatch, has umbrella shaped parts called "drogue" which can be removed and installed. "probe" of CSM is inserted in this, then, 12 automatic latch installed around the tunnel hang, and it docks. the drogue and probe are removed after the docking by astronaut's hand, and it is stored in CM.

The back area of Mid Section is "Aft Equipment Bay" that is not pressurized. Here is equipped with the electronic machine such as GN&CS, EPS, a communication system. These are cooled down with cold rails by Water-glycol flows. Two gaseous oxygen tanks and two gaseous helium tanks are being installed here.

Descent Stage

Here, all materials unnecessary when leave from the moon are being installed. In the center, DPS (Descent Propulsion System) engine, fuel tanks are surround it. Then, it has four landing gears in the outside.

Descent Stage has the appearance of 8 corner shape. There are five square areas in the center and every direction. And there are four triangular areas in that neighborhood. DPS engine is carried in the central section. As for the square area of the circumference, oxidizer tanks are carried in the front and the back, fuel tanks are carried right and left. The trianglar area which between that, are called quad NO. 1,2,3,4, seen from the top, around the anti-clockwise.

by Thomas J. Kelly:
LM design chief
Quad No.1 has extendable S-band antenna and batteries, and LRV(Lunar Roving Vehicle) at J-mission. Quad No.2 has water tanks, landing rader equipments, science observation machine, atomic power generator. Quad No.3 has oxygen tank and a helium tank, variety materials for the moon investigation Quad No.4 has batteries and MESA(modularized equipment stowage assembly) loads the camera to take pictures of the astronaut who gets off and stands on the moon.
At the tip of three landinbg gears except for the front, five feet length "Lunar Surface Sensing Probe" is being installed. When this probe touches the surface of the moon, LUNARCONTACT lamp of blue is turned on which is in the cockpit. By the way, LM-3 (APOLLO9) and LM-4 (APOLLO10) had 4 probes istalled in all landing gears.

The whole of LM is wrapped in a thing like the seat of gold, silver or black. This is the seat which protects a body from intense heat and the micrometeorite. These are called as "Thermal Blanket" and are piled up to many layer of aluminum or inconel and nickel foil, and mylar and H-film blanket. How to spread this seat varies in any missons. Therefore the color of LM was decided delicately.


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LM-3 Apollo9 Spider
No Thermal Blanket on legs. Four Lunar Surface Sensing Probe are attached at all legs. Scimitar antenna on front face. No RCS Plume Deflectors.

LM-4 Apollo10 Snoopy
No Thermal Blanket on legs. Four Lunar Surface Sensing Probe are attached at all legs. Scimitar antenna on front face. No RCS Plume Deflectors.

LM-5 Apollo11 Eagle
Three Lunar Surface Sensing Probe are attached legs except front. RCS Plume Deflectors are added.

LM-6 Apollo12 Intrepid
Atomic power generator was added at Quad2.

LM-7 Apollo13 Aquarius
About the same specification with LM6.

LM-8 Apollo14 Antares
Made a drastic revision of Descent Stage color.

LM-10 Apollo15 Falcon
J mission version. Lunar Roving Vehicle on Quad1.

LM-11 Apollo16 Orion
About the same specification with LM10.

LM-12 Apollo17 Challenger
About the same specification with LM10.
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