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Crew health and biomedical performance on Apollo 11

How the crew’s bodies handled the first lunar landing — the human-performance thread that runs through the EVA, the suits, and the quarantine, gathered from the program-wide medical retrospective (Biomedical Results of Apollo, SP-368) and the Mission Report’s biomedical evaluation.

Lunar-surface metabolic rates across Apollo ran lower than pre-mission predictions, and crews moved “easily and confidently” in one-sixth gravity (see surface mobility). The energy profile had a shape: the costliest work was the “overhead” activity — egress, offloading and setting up equipment around the LM, ingress, and sample stowage — while experiment deployment and geology ran cheaper (SP-368).

Within that picture, Aldrin logged the highest average EVA metabolic rate of the entire Apollo program: he had been assigned the task of evaluating modes of locomotion (the loping and kangaroo-hop trials in the mobility article) and “was quite active in performing this task.” Consistently, he was the only Apollo crewman who frequently ran his liquid-cooled garment’s diverter valve at maximum cooling (the Apollo 11-era PLSS offered ~21 °C / 15 °C / 7 °C cooling-water settings). The PLSS was sized for ~250 kcal/hr over long EVAs — margin the 2½-hour moonwalk never threatened (SP-368; Mission Report §10, §12).

The biomedical casualty of the surface stay was the rest period: flown before the EVA in the plan but swapped to after it, then degraded by a cold, bright, noisy cabin — the crew slept little before lunar liftoff (Mission Report §12; Crew Debriefing).

Post-flight findings were small: the Commander had a mild barotitis media (right ear) that cleared without treatment, and during transearth coast the crew reported the streaks and points of light later studied systematically as the “light-flash” phenomenon from Apollo 12 onward (SP-368).

The 21-day isolation that closed the mission was a medical protocol — biological isolation garments, the Mobile Quarantine Facility, the Lunar Receiving Laboratory — and its medical verdict (“no harmful organisms … quarantine was terminated”) is told in quarantine and back-contamination.