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Apollo 11

Apollo 11 Technical Crew Debriefing — Volume 1 (Sections 1–10)

  • Source document: 1969-07-31-apollo-11-technical-crew-debriefing-vol1.pdf

  • Original: NASA, Apollo 11 Technical Crew Debriefing, Manned Spacecraft Center, July 31, 1969 (Volume 1 of 2). Scanned copy from the Apollo Lunar Surface Journal (original file A11TechCrewDebrfV1_ALSJ.pdf). Originally classified CONFIDENTIAL; the classification stamps are blacked out in the scan.

  • Available online: ibiblio.org/apollo — Apollo 11 Technical Crew Debriefing, Vol. 1.

Summary

Section titled “Summary”

The verbatim transcript of the Apollo 11 crew’s post-mission technical debriefing, held eleven days after splashdown. Armstrong (CDR), Collins (CMP), and Aldrin (LMP) walk through the flight phase-by-phase, giving their own first-person account of what actually happened and what should change for later missions — the candid engineering counterpart to the planning documents and the air-to-ground transcript. The full document runs to 27 sections; Volume 1 covers Sections 1–10, from suiting and ingress through the powered descent and the entire lunar-surface EVA. (Volume 2 continues with Sections 11–27.)

Key takeaways

Section titled “Key takeaways”
  • Structure. Chronological by mission phase: §1 Suiting and Ingress, §2 Countdown, §3 Powered Flight, §4 Earth Orbit, §5 TLI, §6 Translunar Coast, §7 LOI through LM Activation, §8 LM Checkout through Separation, §9 DOI through Touchdown, and §10 Lunar Surface — by far the longest section (~80 pages), the crew’s blow-by-blow of the moonwalk.
  • The landing (§9). The “1202” program alarms began ~5 minutes into descent and forced the crew’s attention inside the cockpit (“the concern here was… whether we could continue at all”); they could not study the landing area until below 2000 ft. Armstrong took manual control below ~1500 ft, flew at 20–30 ft/sec across a large crater and boulder field, and set down in a smooth spot. Blowing dust below ~100 ft behaved like “a thin layer of ground fog” moving fast, making lateral- and descent-rate judgment hard; they touched down near the abort fuel limit, settling “like a helicopter.”
  • EVA prep & egress (§10). The crew chose to start the EVA before the planned rest period — adaptation to 1/6 g was “very rapid and very pleasant.” Prep ran ~1 hour long; the RCU-to-PLSS 50-pin Bendix connector took ~10 minutes each to mate (a years-old, unfixed problem); cabin depressurization through the bacteria filter took ~30 minutes; the first ladder step was a 3–3½-ft drop.
  • Mobility & sampling. A “lope” (both feet briefly off the ground) was the natural gait; subjectively the gravity “felt closer to one-tenth” than one-sixth. The bulk sample took ~20 trips into sunlight (away from the MESA’s shadow and the engine plume); core tubes penetrated only ~6 in before the soil turned hard; the PSE bubble level would not settle; the sample-return boxes needed great force to close.
  • Dust. The fine, “graphite-like” powder adhered to everything, made rocks slippery, and was carried back into the cabin by the LEC until “we all looked like chimney sweeps.” A soft top layer over a hard substrate degraded footing and leveling.

Concepts extracted

Section titled “Concepts extracted”