NASA’s Apollo 11: How the Lander Module worked

The Lander, also known as the Lunar Module (LM), was a two-stage craft built to separate from the Apollo Command and Service Module, and then travel to and from the moon’s surface.

It first landed on the moon on 20 July 1969. Generally the descent stage was left on the moon, while the ascent stage crashed into the moon’s surface once the astronauts returned to the Command Module.

Each of the 15 Apollo LMs had unique names. The Apollo 11 LM was named the Eagle, which explains why Neil Armstrong stated that “the Eagle has landed” when it touched down.

Inside the Apollo Lander

Apollo Lander Module illustration

Apollo Lander Module


The Lander had three different types of antenna: VHF (for communication), S-band steerable (to facilitate control of the Lander) and rendezvous radar (to facilitate rendezvous between the Lander and the Command Module).

Crew compartment

The crew compartment was a pressurised environment that supported two astronauts in about 6.65 square metres.

Ascent stage

The ascent stage of the Lander contained the crew cabin, navigation system, life support, thermal control system and the capability to return itself to the Apollo Command Module in lunar orbit.

Descent stage

The descent stage contained the fuel to land on the moon, landing gear, a ladder to descent to the surface and materials for experiments and sample collection on the moon.


The Lander was powered by a rocket fuel called Aerozine 50. It is still used in spacecraft and rockets because it is a highly stable fuel with a low freezing point.


Aerozine 50 is used in conjunction with a chemical compound called dinitrogen tetroxide, an oxidiser. The Aerozine 50 ignites upon contact with it.

Landing gear

Initial designs had three legs, which could have resulted in a toppling Lander if one was damaged. Five legs were preferred, but they made the Lander too heavy. Four was an acceptable compromise.

The Apollo 11 crew

Neil Armstrong

Neil Armstrong

Neil Armstrong

The first man on the moon and commander of the Apollo mission. This was his second, and last, space flight.

Michael Collins

Michael Collins

Michael Collins

Collins looked after the command modules while Aldrin and Armstrong landed the Eagle on the moon.

Buzz Aldrin

Buzz Aldrin

Buzz Aldrin

The pilot of the Eagle was the second man to ever set to set foot on the moon, following mission commander Neil Armstrong.

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Plus take a look at:

Top 10 videos from the Moon landings

Are Buzz Aldrin’s footprints still on the Moon?

Interview with astronaut Paolo Nespoli