FLOWN Apollo 11 LM G/ N Dictionary, PGNS-39/PGNS-40, IMU Alignment
Lot 168
Sold for US$ 33,550 inc. premium
Auction Details
The Space Sale New York
16 Jul 2009 13:00 EDT

Auction 17402
FLOWN Apollo 11 LM G/ N Dictionary, PGNS-39/PGNS-40, IMU Alignment
Lot Details
Apollo 11 LM G & N Dictionary, pp PGNS-39/PGNS-40, a single sheet printed recto and verso, May-June 1969, 5 ½ by 8 inches, inscribed on each side by Buzz Aldrin.

The series of steps performed by Neil Armstrong and Buzz Aldrin to align their navigational equipment based on the celestial measurements made during their use of the lunar surface star chart and on board alignment telescope.
Accompanied by a Typed Letter Signed by Aldrin, which reads: "Enclosed with this letter is a sheet numbered PGNS-39/40 from the Apollo 11 LM G and N Dictionary, Part No. SKB32100074-361, S/N 1001. It is part of the entire manual that was carried to the lunar surface in Lunar Module Eagle on the first lunar landing mission during July 16 to 24, 1969. This sheet is from the Primary Guidance and Navigation Section (PGNS) and has the exact computer procedures for Neil Armstrong and me to perform the P57 or Program 57 'Lunar Surface Alignment.' This alignment determined our exact landing point which was a critical step to enable a successful departure from the lunar surface.
During our descent to the lunar surface, we had several computer program alarms. This caused Neil and I to be preoccupied with a potential abort and slowed the completion of milestones in the landing sequence. It soon appeared that we were headed toward a large boulder-filled crater, but Neil expertly flew Eagle downrange past that looming obstacle. Neil then gently landed on the surface. We had landed well past our target point but made it down safely. After engine shut down, I commanded the computer to give us our landing point. I recorded that information on page 10 of our LM Timeline Book which turned out to be the first writing by human hands on the lunar surface.
Side PGNS-39 has the first three steps for the P51 alignment. Neil lined-out part of step 2 and pulled our reference tables for the Earth and Sun toward the end of this dictionary. After those steps we moved to side PGNS-40 where the real work began. Since we landed long, our current computer position was a concern. Neil and I really wanted the most accurate position determination possible, which the P51 steps would provide.
I started the initial measurements using our Alignment Optical Telescope (AOT). Neil and I worked with the LM TD+2 Star Chart to locate stellar objects using the AOT. Neil logged over 30 measurements I took using the AOT on page 7 of our LM Data Card Book. The entire procedure for the P57 alignment was successful. It enabled us to carry out our complete lunar timeline and allowed Neil Armstrong to become the first human to set foot upon the Moon."

The dictionary sheet has been inscribed on both sides by Aldrin: on one side "Used by Neil Armstrong and me while on the lunar surface during Apollo XI, Buzz Aldrin," and on the other "Carried to the lunar surface in Eagle on Apollo XI, Buzz Aldrin."