Apollo 17 Technical Crew Debriefing, 1973
Harrison Schmitt's post-mission debriefing captures something genuinely strange from Apollo 17: near-continuous light flashes perceived by the crew throughout the flight, including what Schmitt believed was a flash on the lunar surface itself. The account is particularly interesting because it references the ALFMED experiment — an onboard detector designed to study exactly this phenomenon — suggesting NASA was already investigating these visual anomalies as a scientific question, not dismissing them. Whether cosmic ray interactions with the retina, something else entirely, or a mix of both, this excerpt shows astronauts methodically describing unusual perceptual experiences in the matter-of-fact language of engineers.
Apollo 17 was the ninth crewed U.S. mission to the Moon, and the sixth to land Astronauts on the lunar surface. This document is an excerpt from the Apollo 17 Technical Crew Debriefing on January 4, 1973, in which astronaut Harrison Schmitt reported seeing light flashes. • Page 24-4. [Lunar Module Pilot Harrison Schmitt]: “We had light flashes just about continuously during the whole flight when we were dark adapted. I had one which I thought was a flash on the lunar surface. That one period of time when we had the blindfolds on for the ALFMED [Apollo Light Flash Moving Emulsion Detector] experiment there were just no visible flashes, although that evening, that night, before I went to sleep, I noticed that I was seeing the light flashes again.”