The Lunar Module

The words

1. Apollo Five

   Apollo 5 tested the lunar module without astronauts in Earth orbit on January 22, 1968. The flight exercised both engines before crews were allowed aboard.

   Did you know?

   LM-1 carried no landing legs. Since the test craft would stay in space and never land, leaving them off saved weight.

   NASA: Apollo 5’s uncrewed test (opens a new tab)

2. Ascent Engine

   The ascent engine lifted the crew cabin from the Moon. It returned the astronauts to lunar orbit, where they would meet the waiting command module.

   NASA: Apollo 5’s uncrewed test (opens a new tab)

3. Bethpage

   Bethpage, New York, was home to Grumman’s lunar-module team. Kelly’s nameplate recollection, quoted in print, linked the descent stages left on the Moon to the people who built them.

   Cradle of Aviation: Kelly’s recollection (opens a new tab)

4. Descent Stage

   The descent stage carried the landing engine, legs and surface experiments beneath the crew cabin. It stayed on the Moon when the ascent stage lifted off.

   Smithsonian: lunar-module structure (opens a new tab) · Cradle of Aviation: Kelly’s recollection (opens a new tab)

5. Drop Test

   Engineers dropped models to study whether the lunar module would remain stable at touchdown. These tests helped them design legs for uneven ground and uncertain lunar soil.

   p. 152 (PDF p. 170) · NASA: designing the lunar module (opens a new tab)

6. Eight Ball

   The eight ball showed the lander’s orientation, giving the pilots an attitude reference. Astronauts pressed to keep the instrument in the cockpit during the design debate.

   pp. 148–149 (PDF pp. 166–167) · NASA: designing the lunar module (opens a new tab)

7. Fire in the Hole

   Apollo 5 tested starting the ascent engine while the two stages were still together. This checked a way to separate the crew cabin during an aborted landing.

   NASA: Apollo 5’s uncrewed test (opens a new tab)

8. Footpads

   Broad pads at the ends of the lunar module’s legs supported it on the surface. Their width helped spread the lander’s weight across the soil.

   p. 103 (PDF p. 107) · NASA: Apollo 11 lander and landing gear (opens a new tab)

9. Forward Hatch

   The forward hatch opened onto a small porch and a ladder down a landing leg. It was the astronauts’ doorway between the cabin and the lunar surface.

   Did you know?

   Early designs used a round hatch. Tests with astronauts in pressurized suits and backpacks led engineers to make the opening rectangular.

   p. 151 (PDF p. 169) · NASA: designing the lunar module (opens a new tab)

10. Gold Foil

    Gold-colored blankets helped insulate the lunar module’s equipment. They included metallized plastic films such as Mylar and Kapton, part of the lander’s thermal protection.

    Smithsonian: lunar-module structure (opens a new tab) · NASA: Apollo 11 lander and landing gear (opens a new tab)

11. Grumman

    Grumman designed and built the lunar module. Its two-stage lander carried two astronauts between lunar orbit and the surface, while the command module remained above the Moon.

    Smithsonian: lunar-module structure (opens a new tab) · NASA: Apollo 5’s uncrewed test (opens a new tab)

12. Joe Gavin

    Joseph G. Gavin Jr. directed Grumman’s lunar-module program. He later recalled working closely with engine suppliers and electronics contractors while keeping the whole project moving.

    pp. 8–9 · NASA oral history: Joe Gavin (opens a new tab)

13. Landing Gear

    Four folding legs supported the lunar module at touchdown. Crushable aluminum honeycomb inside the main struts absorbed compression loads, helping soften the impact of landing.

    NASA: designing the lunar module (opens a new tab) · NASA: Apollo 11 lander and landing gear (opens a new tab)

14. Peter Pan Rig

    Cables in the Peter Pan rig supported much of an astronaut’s weight. Grumman used it to test ways of climbing out of the lander in simulated lunar gravity.

    p. 151 (PDF p. 169) · NASA: designing the lunar module (opens a new tab)

15. Tom Kelly

    Thomas J. Kelly led Grumman’s lunar-module engineering. In 1967, he moved into manufacturing, assembly and testing, taking responsibility for building the spacecraft he had helped design.

    PDF pp. 45–46 · NASA oral history: Tom Kelly (opens a new tab)