Apollo Lunar Module

lander used in the Apollo program

The Apollo Lunar Module (LM) is the spidery-looking landing vehicle on the moon. It was built for the US Apollo program to carry a crew of two from lunar orbit to the surface and back.

Apollo Lunar Module
Apollo 16 LM Orion on the lunar surface
ManufacturerGrumman Aircraft
DesignerThomas J. Kelly
Country of originUnited States
ApplicationsManned lunar landing
Design life75 hours (Extended)
Launch mass
  • 33,500 pounds (15,200 kg) std
  • 36,200 pounds (16,400 kg) Extended
Dry mass
  • 9,430 pounds (4,280 kg) std
  • 10,850 pounds (4,920 kg) Extended
Crew capacity2
Dimensions23 feet 1 inch (7.04 m) high
31 feet (9.4 m) wide
31 feet (9.4 m) deep
overall, landing gear deployed
Volume235 cubic feet (6.7 m3)
First launchJanuary 22, 1968
Last launchDecember 14, 1972
Last retirementDecember 15, 1972

Apollo LM diagram
Astronauts practice using Lunar Module

The LM was the last of the Apollo “hardware” to be developed. Its start had been delayed while NASA made up its mind to take the lunar-orbit meeting approach and thus require a vehicle like the LM for a landing. A contract with the prime builder was signed on January, 1963, almost two years after the Apollo project began. The LM was tested several times in space.[1] Finally, on July 20, 1969 the Apollo 11 LM Eagle made the first manned lunar landing.

As Apollo missions progressed, Apollo 12, 14, 15, 16, 17 had lunar landings using their LMs. Apollo 13 had a terribly dangerous accident when an oxygen tank exploded. The Apollo 13 Lunar module, called Aquarius, played an unexpected role in saving the lives of the three astronauts after the explosion.[2]


Drawing of LM

The LM was consisted of an ascent stage and decent stage.

Descent stage


This was the unmanned lower part of the LM. it looked like octagonal-shaped. It was made of aluminum alloy and had four legs for landing. It had a descent rocket engine, and batteries and various supplies and scientific equipment to be used when landing on the moon and during the astronauts’ stay on the moon.

To land on the moon, the descent engine would be fired to begin the LM’s drop from 110 kilometres (68 miles) out in lunar orbit down toward the moon. LM could descend vertically and hover above the surface of moon. After the two men finished their stay on the surface, the ascent stage, sitting on the descent stage, would use its ascent engine firing to lift itself off the moon.

Ascent stage


This was the roundish upper half of the LM, the command center and crew cabin as well as the launching rocket for leaving the moon.

To save weight, there were no seats for the men. They would stand, loosely held in place by straps. In front and on either side of them were control panels for the LM’s guidance, communication, environment and propulsion systems. On the left side, there was a window by which commander could look out to steer the LM. Overhead in the middle section was the 90 centimetres (35 inches) of diameter hatch where the astronauts transferred to and from the Command Module when two vehicles were linked. LM’s ascent rocket to meet Command Module was below the deck of the midsection. Although ascent rocket was small, it was sufficient because the moon’s weak gravity – one-sixth that of earth’s – meant that the LM would not require a strong push to rise from the lunar surface.[source?]

First flight of Lunar Module


On Monday, January 22, 1968, a 16-ton unmanned Lunar Module surrounded by a protective shield stood on top of a two-stage Saturn 1-B rocket called Apollo 5. This flight was made to do two important tests. One was to check separating stage from main rocket. The second was to check test firing of the descent engine, but this mission did not succeed. The Apollo 5 test ended after eight hours, and the LM remained in earth orbit. It eventually dropped into the atmosphere and burned up.



  1. Moon Race: The History of Apollo DVD, Columbia River Entertainment (Portland, Oregon, 2007)
  2. Cass, Stephen (April 1, 2005). "Houston, we have a solution". IEEE. Retrieved August 30, 2019.

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