How Astronauts Used the LM (Part 4, Apollo Control Systems)

The space inside the LM was very limited. The crew compartment was about 1 meter long and a round shape with a diameter of about 2 meters. There was additionally some room behind that which was mostly used to store some equipment. The following pictures show how the LM was used for the most important tasks (flying, landing, rendezvous, sleep, exit):

LM Lunar Module (Part 3, Apollo Control Systems)

In LEM or LM there were 2 computers. LM was mostly built by the Grumman Aircraft Engineering company but since MIT was a specialist in IMUs (Inertial Measurement Unit) at that time they got the deal to build the main guidance and navigation section. The main computer was called LGC (LM Guidance Computer) and the secondary computer was in AGS (Abort Guidance Section) which work was to abort the main computer if it had problems.

Apollo Computer in Action (Part 2, Apollo Control Systems)

The LEM (and CSM) computer AGC (Apollo Guidance Computer) was connected to several sensors and controls which it used to get information about the position and situation of the vehicle it controlled.

The following video shows the method to determine the distance of the CSM during the Apollo mission by reading the angle between two known spots in the space. The video shows how to use similar display and keyboard that was used in LEM and CSM. Later in this same video also the method to build the block I AGC is shown in detail. The block I used transistors and the block II computer (the actual computer that was flown to the Moon) used simple intergrated circuitis.

"Computer For Apollo" (1965) - Science Reporter TV Series

The video also shows the "verb - noun" method used to communicate with the AGC. The user could enter verbs and nouns in the pattern "do - something" and the computer then did the requested task and then displayed the results.

The function of the "mark" button is also described. The mark button was used during the actual moon flights.

Some chief designers behind the AGC are also shown in this video: Eldon Hall, Ramon Alonzo and Albert Hopkins.

* * *

LEM Lunar Module (Part 1, Apollo Control Systems)

LEM Lunar Excursion Module, later named LM Lunar Module