Apollo 11 Technical Crew Debriefing: Three Anomalous Observations Outbound and Return, 1969

Source file: nasa-uap-d4-apollo-11-technical-crew-debriefing-1969.pdf Originating agency: NASA Debriefing date: July 31, 1969 Mission date range: July 16–24, 1969 Pages in file: 11 (a targeted excerpt from the original 251 + 216 page debriefing) High-significance pages: 6-33 through 6-39 (Vol. I); 21-1, 21-2 (Vol. II) Original classification: CONFIDENTIAL — declassified 1976

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Official Blurb (from NASA)

Apollo 11 was the third crewed mission to the Moon and the first to land Astronauts on the lunar surface. This document is an excerpt from the Apollo 11 Technical Crew Debriefing (Volumes 1 and 2) from July 31, 1969. The document highlights three observations: one, an object on the way out to the Moon; two, flashes of light inside the cabin; and three, a sighting on the return trip of a bright light tentatively assumed by the crew to be a laser.

Summary

This document — originally classified CONFIDENTIAL and declassified in 1976 — is the anomalous-phenomena excerpt of the Apollo 11 Technical Crew Debriefing. The full debriefing spans two large volumes (251 and 216 pages) recorded on July 31, 1969, seven days after the crew returned to Earth. The excerpt isolates three anomalous observations recorded by the three crew members: Neil Armstrong (mission commander), Michael Collins (command module pilot), and Edwin "Buzz" Aldrin (lunar module pilot).

The first observation (pages 6-33 to 6-36) describes an unidentified object spotted roughly a day out from the Moon, in the vicinity of the spacecraft's trajectory. The crew speculated it might be the third stage of the Saturn V (the S-IVB), but Mission Control reported the S-IVB was 6,000 miles away. Through the sextant, the object appeared as a hollow cylinder, or alternatively as two connected rings; through the monocular, it looked L-shaped or like an "open suitcase." The second observation (pages 6-37 to 6-39) describes flashes of light Aldrin saw inside the darkened cabin on the second night while trying to sleep — single flashes, double flashes separated by about a foot, and directionless streaks. The crew speculated it was the penetration of atomic particles. The third observation (pages 21-1 to 21-2) describes a bright light source Aldrin tentatively attributed to a laser while observing Earth from lunar orbit.

This is one of the most historically significant UAP records in the space environment, both because of the witnesses' identity (the first humans to walk on the Moon) and because the cabin flashes observation led to one of space medicine's important discoveries: the "Cosmic Ray Visual Phenomena," or cosmic-ray light flashes.

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Research Article

Apollo 11, the historic mission

On July 16, 1969 at 13:32 UTC a Saturn V rocket lifted off from Launch Complex 39A at Kennedy Space Center, carrying the three-man Apollo 11 crew toward the Moon. Four days later, on July 20, the lunar module "Eagle" landed in the Sea of Tranquillity, and Armstrong and Aldrin became the first humans to set foot on another celestial body. Collins remained in lunar orbit in the command module "Columbia." On July 24 the crew returned after a mission of eight days, three hours, and eighteen minutes. Seven days after splashdown, on July 31, the crew's Technical Crew Debriefing was conducted — a standard operational-technical document for Apollo missions that exhaustively records every aspect of the flight: spacecraft systems, crew performance, unexpected events, and scientific observations.

The first observation: an object on the way to the Moon

The discussion on page 6-33 (Vol. I) opens with mental preparation for lunar-surface activity, and then Aldrin abruptly introduces a new topic: "The first unusual thing that we saw, I guess, was one day out or something pretty close to the Moon. It had a sizable dimension to it, so we put the monocular on it." In context this likely means a day before lunar arrival — roughly the third or fourth mission day (July 19 or 20).

Collins asks how they noticed it; Aldrin replies they were not sure but it might be the S-IVB — the Saturn V third stage, which after translunar injection separated and was meant to remain on a support trajectory. The crew queried Houston and were told the S-IVB was 6,000 miles away — meaning the object they saw could not have been the third stage. Collins remarks: "There was something. We felt a bump, or maybe I just imagined it." Armstrong notes Collins had wondered whether the lunar module's MESA (Modular Equipment Stowage Assembly) had detached; Collins concludes they did not actually feel anything.

Aldrin continues: every day of the mission the crew dumped urine and watched various small objects drift around the spacecraft, but this particular time they noticed one brighter, larger object. They could think of nothing it could be other than the S-IVB. Through the monocular it looked L-shaped; Armstrong adds, "like an open suitcase." The crew was in PTC (Passive Thermal Control), the slow barbecue roll that balances solar heating, so each of the three could see the object as the spacecraft rotated. Aldrin notes: "It certainly seemed to be in the vicinity of us and of a very sizable dimension."

On page 6-35 Armstrong clarifies the object was at the edge of visual resolution: "It was hard to tell just what it was. And there was no way to tell the size without knowing the range, or the range without knowing the size." This is a basic parallax problem: without distance information, there is no way to determine whether it is a small near object or a large distant one. Aldrin went down to the LEB (Lower Equipment Bay) and used the sextant. With the sextant out of focus the object appeared as a cylinder; Armstrong suggested "or really two rings… two rings. Two rings connected." Collins disagreed: "No, to me it looked like a hollow cylinder. It didn't look like two connected rings. You could see this thing tumbling, and when it went end-over-end, you could look right down into its guts. It was a hollow cylinder. But then you could change the focus on the sextant and it would be replaced by this open-book shape. It was really weird." Aldrin concludes: "I guess there's not much more to say about that, other than that it wasn't a cylinder."

On page 6-36 Collins concedes: "There was a period when we thought it was a cylinder, and we were interested in the S-IVB and almost convinced ourselves that's what it must be. But we have no more conclusions than that, really… We're pretty sure it was not part of the urine dump." Collins suggests a piece of Mylar or other material that came off the lunar module: "It might have been part of the high-gain antenna. It was about the time we were having trouble with the high-gain antenna. In the back of my mind I have some reason to suspect it came from the spacecraft."

The second observation: the cabin flashes

On page 6-37 Aldrin opens an entirely new topic: "The other observation that I made gradually built up. I don't know whether I saw it the first night, but I'm sure I saw it the second night. I was trying to go to sleep with all the lights out. I observed what I thought were little flashes inside the cabin, spaced a couple of minutes apart…" Aldrin describes a cumulative phenomenon. On the second night, trying to sleep in the dark cabin, he noticed small flashes; he did not think much of it, only noting that they kept appearing, and could not explain why his eyes were seeing them.

During the transearth coast Aldrin had more time to investigate. On two separate occasions, instead of a single flash, he saw double flashes separated by about a foot; other times he saw a streak with no direction of motion. Aldrin's hypothesis: "The only thing that comes to mind is some sort of penetration. At least that's my guess, without much to support it. Some sort of penetration of an object into the spacecraft, causing an emission as it enters the cabin itself." On page 6-38 he reflects he had briefly considered static electricity — by moving his hands on the sleeping restraints he could produce tiny static sparks — but "there was a distinct difference between the two, the more I observed it."

Aldrin tried to correlate the flashes with the Sun's direction; he wrote that they seemed to come from the same general direction but there was not enough evidence to confirm it. He asked the others if they had seen anything similar. Not until the last day did they look. Armstrong: "Buzz, I saw a little light, but I always attributed it to sunlight, because the window covers leak a little light no matter how tight they are. The only time I observed it was on the last night, when we were really looking for it. I devoted about an hour to careful observation inside the spacecraft, and probably made about 50 significant observations during that period." On page 6-39 Aldrin describes the frequency: "Sometimes a minute or two would go by, and then you'd see two within 10 seconds. On average, I'd say just as a guess, it was maybe something like one a minute. Definitely more than enough to convince you it was not an optical illusion. It did give you a rather weird feeling to think that something was 'whizzing' through the cabin. There wasn't anything you could do about it." Armstrong concludes scientifically: "It might be something like Buzz suggested. Mostly a neutron or some sort of atomic particle that would be in the visible spectrum."

The third observation: "a laser?" on the way back (Vol. II, §21.5)

In Volume II, section 21 is devoted to Visual Sightings. On page 21-1 Armstrong notes most items in the section were reported previously. Subsection 21.5 (Lunar Orbit) opens the third observation. Aldrin: "In lunar orbit, after the descent to the lunar surface, we noted and reported to the ground that as we approached CDH and at the same time Earth was rising over the lunar horizon, I observed what appeared to be a relatively bright light source, which we tentatively attributed to a possible laser." The CDH (Constant Delta Height maneuver) was an orbital maneuver the command module performed with the lunar module on July 21, 1969, after lunar liftoff. During it, Earth rose over the lunar horizon and Aldrin noticed a bright light source.

The original guess — a laser — was a serious explanation in the 1969 context. On page 21-2 Aldrin updates: "That seemed the most plausible explanation until we got back in the command module and approached Earth and were able to observe something that gave about the same appearance. When we put the monocular on the light source, it appeared to be a reflection of the Sun off a relatively smooth body of water, like a lake. I think we revised our initial conclusion about the light source we saw from Earth. If nobody admits to firing a laser toward the Moon at that time, it's more likely it was a reflection off a lake." However, Aldrin notes: "I still think it's an unusual phenomenon, at that distance, to see such a bright light source. On film, it doesn't look like it's going to show up at all. Earth was too bright." The final conclusion, then, is not unambiguous: the crew offered "reflection off a lake" as an alternative explanation, but Aldrin noted the light's intensity at that distance was anomalous.

Analysis: Cosmic Ray Visual Phenomena

The flashes Aldrin observed in the cabin are likely the earliest documented observation of what is now known as "Cosmic Ray Visual Phenomena" or "Light Flashes" (LF). The phenomenon was confirmed in follow-up research on later Apollo crews (from Apollo 12 onward) and on International Space Station crews. The physical mechanism: in deep space, outside Earth's magnetosphere, astronauts are exposed to Galactic Cosmic Rays, including protons and heavy ions (HZE particles) at high relativistic speeds. When such a particle penetrates the retina, it excites photoreceptor cells or the neurons behind them, producing a visual "flash" experience even though no physical light was present. The double flashes Aldrin described match an event where a particle crosses the retina twice (entry and exit) or produces a secondary particle shower; the streaks match an angular particle track through the visual field.

Armstrong's debriefing guess — "a neutron or some sort of atomic particle" — was remarkably accurate, though the crew had no way to verify the hypothesis. On Apollo 14 (1971), astronauts Alan Shepard, Stuart Roosa, and Edgar Mitchell performed the first systematic experiments to document the phenomenon, using a light-tight eye mask and verbal flash-rate reports. During ISS preparation, considerable research (the SilEye and Alteino projects) confirmed the source as cosmic radiation. In that sense, Aldrin's Apollo 11 observation is the historical record of a scientific discovery rather than an anomalous phenomenon in the UAP sense — yet it was unidentified at the time, hence its inclusion in the PURSUE UAP archive.

Analysis: the S-IVB and other objects on the way to the Moon

The Saturn V third stage, the S-IVB, was indeed on a lunar trajectory (not an Earth orbit) after Apollo 11's translunar injection. However, it did not remain near the spacecraft. After completing TLI, the S-IVB performed a "slingshot" maneuver involving residual-propellant venting and a trajectory change to place it into a heliocentric orbit, removing it from the mission environment. By the time of the crew's observation the S-IVB was indeed thousands of miles from the spacecraft, as Mission Control confirmed. The object the crew saw therefore remains unidentified: it was not the S-IVB, was "not part of the urine dump," and shifted shape between a hollow cylinder and an open-book / open-suitcase form depending on sextant focus — leaving the crew, by their own account, without a conclusion.

Key People

• Neil Armstrong — mission commander; first to walk on the Moon. Observed the cabin flashes on the final night and contributed the "neutron or atomic particle" hypothesis.
• Michael Collins — command module pilot. Argued the outbound object was a "hollow cylinder" and suspected it originated from the spacecraft (possibly the high-gain antenna).
• Edwin "Buzz" Aldrin — lunar module pilot. Principal observer of all three anomalies: the outbound object via sextant, the cumulative cabin flashes, and the bright "laser?" light source from lunar orbit.

Locations

• Earth–Moon trajectory / Translunar Coast — the first observation, roughly a day out from the Moon.
• Command Module Columbia — interior, the cabin-flash observations.
• Lunar Orbit — the third observation during the CDH maneuver, with Earthrise over the lunar horizon.
• Transearth Coast — extended cabin-flash investigation on the return leg.

Incidents

Mission phase	Observation	Witnesses	Character
~1 day from Moon (Jul 19–20)	Unidentified object near trajectory; hollow cylinder / open suitcase / two rings	Armstrong, Collins, Aldrin	Not S-IVB (6,000 mi away); shape changed with sextant focus
Night 2 onward / Transearth	Cabin light flashes — single, double (~1 ft apart), streaks	Aldrin (primary), Armstrong (final night, ~50 obs.)	~1/minute; later identified as cosmic-ray visual phenomena
Lunar orbit, CDH maneuver (Jul 21)	Bright light source — "laser?"	Aldrin	Later revised to possible sun-glint off a lake; intensity still called unusual

Notable Quotes

"The first unusual thing that we saw, I guess, was one day out or something pretty close to the Moon. It had a sizable dimension to it, so we put the monocular on it." — Aldrin, p. 6-33

"No, to me it looked like a hollow cylinder… you could look right down into its guts. It was a hollow cylinder. But then you could change the focus on the sextant and it would be replaced by this open-book shape. It was really weird." — Collins, p. 6-35

"I observed what I thought were little flashes inside the cabin, spaced a couple of minutes apart… Definitely more than enough to convince you it was not an optical illusion." — Aldrin, pp. 6-37 / 6-39

"It might be something like Buzz suggested. Mostly a neutron or some sort of atomic particle that would be in the visible spectrum." — Armstrong, p. 6-39

"I observed what appeared to be a relatively bright light source, which we tentatively attributed to a possible laser." — Aldrin, p. 21-1

"I still think it's an unusual phenomenon, at that distance, to see such a bright light source." — Aldrin, p. 21-2