ARMSTRONG AND ALDRIN VERIFY THEIR SPACE SUIT CONDITION AND EAGLE'S FLIGHT STATUS.
FLOWN TO THE LUNAR SURFACE, APOLLO 11 LM ACTIVATION SHEET.
Apollo 11 LM Activation Checklist, pp 3-39, a single sheet printed recto only. NASA/MSC, July 4, 1969. 5½ x 8 inches. With a Typed Letter Signed by Buzz Aldrin.
During this period of the mission, Armstrong and Aldrin were in the final stages of Lunar Module checks before they separated from Command Module Columbia to begin their descent to the lunar surface. They performed a critical spacesuit and LM cabin pressure checkany problems would potentially scrub the planned lunar landing.
Accompanied by BUZZ ALDRIN'S letter, which reads in part: "Enclosed with this letter is a sheet numbered ACT-39 from the Apollo 11 LM Activation Checklist. The entire checklist was carried to the Moon on the flight of Apollo 11 during July 16 to 24, 1969. Then the checklist, including this sheet, was taken to the surface of the Moon in Lunar Module Eagle during the first lunar landing on July 20, 1969.
Side ACT-39 lists the four steps of the Lunar Module 'REGULATOR CHECK.' This required Neil Armstrong and myself to put on our space suit helmets and gloves to start the test. We verified that Command Module Columbia's pressurization equalization valve and the tunnel vent valve were closed, and the tunnel itself was vented to vacuum. We then did step number 2, placing the 'CABIN' and 'SUIT' valves to the desired settings.
With step number 3, we placed the forward 'CABIN DUMP VALVE' to 'OPEN,' then to the automatic setting. At 3.5 pounds per square inch of pressure, we verified that the Master Alarm warning light was illuminated, then that the cabin repressurization was in a range of 4.45 to 3.7 psi. As listed with step 4, we immediately turned 'PRESS REG A' to 'CLOSE,' checking that the cabin warning light went to 'OFF' and the repressurization stopped. The last steps were to set the 'CABIN REPRESS' valve to 'CLOSE' and the forward 'CABIN DUMP VALVE' to 'OPEN' then to 'AUTO.' The final step was to verify our space suit pressure was between 3.6 and 4.3 psi.
We started this test with less than 5 hours before Eagle landed on the lunar surface. If the regulators failed to perform properly, it could have prevented Neil Armstrong and myself from becoming the first humans to land and walk on the Moon....
For this particular page, the 'LM-4' title at the top was not updated to 'LM-5.' The change date of 'July 4' (1969) was added correctly, however....
On side ACT-39, I have written: 'Flown to the lunar surface on Apollo XI' and signed it along the left side."