[Apollo 11]

Directly from the Personal Collection of Apollo 11 Lunar Module Pilot Buzz Aldrin

FLOWN TO THE LUNAR SURFACE ON APOLLO 11. This Lunar surface flown checklist sheet details the pressurization and checkout of the Lunar Module Eagle's descent propulsion system, one of the last steps the crew took before the historic Lunar landing.

Two copies of the Apollo 11 LM Systems Activation Checklist, the Launch Operations Checklist and the Entry Operations Checklist were carried to the Moon in the Command Module Columbia, and then both copies were transferred from the Command Module into the Lunar Module Eagle and then carried down to the Lunar surface, where both Armstrong and Aldrin made notations on both copies. One of these two copies was supposed to have been jettisoned and left on the Lunar surface (and indeed the Apollo 11 Stowage List lists a quantity of 2 being loaded into the CSM for launch, a quantity of 2 being transferred to the LM from the CSM for the descent, and then a quantity of only one be transferred back into the CSM from the LM for the return ) but Aldrin decided to keep both copies. (The complete copy that was to be jettisoned was sold in these rooms in 2022, as lot 16 in the "Buzz Aldrin: American Icon" sale for $567,000)

BUZZ ALDRIN's provenance letter reads, in full:

"Enclosed with this letter is a sheet numbered ACT-60 and ACT-61 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-60 refers to the pressurization and checkout of the Descent Propulsion System (DPS), the propulsion system on the Lunar Module Eagle used to carry Neil and I to the lunar surface safely from orbit. Neil was scheduled to begin pressurization at the Ground Elapsed Time (GET) of 99:55, but we were running about three minutes ahead of schedule. The tanks of the DPS were pressurized by helium stored in two tanks. In one tank, the helium was stored at ambient (AMB) temperature. In the other, the gas was supercritical (SUPCRIT) – in an extremely cold, high-pressure state. The supercritical helium was so cold that it could not flow to the propellant tanks until after the engine had started, or the fuel would freeze. To keep this from happening, the initial pressurization process used helium stored in the ambient tank.

Side ACT-61 refers to updating the Abort Guidance Subsystem (AGS). The AGS was the system backup to the Primary Guidance and Navigation System (PGNS), in case PGNS failed. One of my main tasks as LMP was to operate the AGS, comparing the AGS information of our trajectory with the information given by the PGNS.

This LM Systems Activation Checklist sheet from Apollo 11 is one of the few objects used both in lunar orbit and on the Sea of Tranquility. It is a rare example of an astronaut flight-certified object used on the first landing on the Moon."

REFERENCES:

NASA. Apollo 11 Stowage List. Mission AS 506 CM 107/LM-5. Houston, Texas: Manned Spacecraft Center, July 15, 1969, pp. 3, 51, 57, 74, and 83