DISCLOSURE / FILE

Apollo 14 Crew Debriefing: Biomedical Sensor Failures

NASA-UAP-D026, Apollo 14 Debriefing, 1971

Segment 1 of 2 of the Apollo 14 post-mission crew debriefing at the Manned Spacecraft Center in Houston, transcribing crew and debriefer discussion of in-flight food, biomedical sensor failures, sleep, and (per the release framing) the cosmic-ray 'light flash phenomena.'

Brief

NASA's Apollo 14 crew debriefing was recorded February 18, 1971 at the Manned Spacecraft Center (now Johnson Space Center) in Houston, Texas, and this file holds the first of two segments. The extractable transcript covers in-flight appetite and weight loss, drink-bag and food-packaging problems, repeated biomedical harness and EKG sensor dropouts and their in-flight fixes, and broken, unsatisfying sleep in the couch and lunar module. The release describes the debriefing's central 'light flash phenomena' discussion, the now well-documented effect of high-energy cosmic rays striking the retina, with the debriefing continuing in NASA-UAP-D027. The transcript pages provided here do not contain the light-flash exchange itself; that material sits in the omitted or overlapping portions.

Metadata

Agency: NASA
Release: 7/10/26
Incident: 2/18/71
Location: Texas
Type: AUDIO • .aud
Length: 1:36:31
Classification: UNCLASSIFIED
Programs: Apollo 14
Tags: light flash phenomena, cosmic rays, Apollo 14, 1971, Manned Spacecraft Center, Houston Texas

Key points

The recording is the Apollo 14 crew's post-mission debriefing, opening with a communications check and references to the prior night's printed debrief and the crew's technical tape debrief.p.23
Crew members debated their in-flight weight loss, with one saying he was three or four pounds overweight going in and doubting zero-G was the cause.p.1748
The crew reported the food's appeal tracked the flight plan's activity level, favoring cans and wet packs during busy periods over time-consuming rehydratable meals.p.1807
The crew ran completely out of the bite-sized sandwich packages, which one member called the best food they had.p.2043
A biomedical sensor harness produced erratic, full-scale-unreadable data after the crew was cinched into the couch pre-launch, then returned to normal over Australia without intervention.p.2233
The crew fixed a failing sensor on the second flight day by pulling it off, cleaning it, refilling it with electrolyte, and reattaching it, rather than swapping the whole harness as ground control assumed.p.2518
All three crew reported broken sleep, never a solid long sleep period, attributed to wanting pressure against the body, suit wear, and the lunar module tilt.p.2779
One crew member described low-back pain from using feet and legs to stabilize in zero-G, which eased after the second day once the crew began deliberate exercise and relaxation.p.3005

Verbatim

We ran completely out of these bite sized packages you know and to me that was the best the best thing we had.
p.2043
There we had data, and we went back to the MSOB from the firing room to catch that pass, and there you were, it was beautiful, just as if nothing had ever happened.
p.2276
But in my case, I felt very strongly that I was on reserves, that physically I was going downhill.
p.2888
But sleeping to me was a very insecure experience.
p.2910
It was really a pleasant experience to be in zero-g during the daytime, I thought.
p.2936

Most interesting

The debriefing's headline topic, per NASA's release, is the 'light flash phenomena': high-energy cosmic rays passing through the eye and striking the retina, perceived by crew as streaks or flashes.
A biomedical sensor went full-scale unreadable after the crew was cinched into the launch couch, then corrected itself over Australia with no crew action, which the crew and ground later attributed to a loosened sensor edge.
Ground control assumed the crew had swapped out an entire biomedical harness in flight; the crew had only cleaned and refilled a single sensor with electrolyte.
All three crew members independently woke the first morning with low-back pain resembling the ache of an 11-hour night, despite having slept far less.
The debriefing continues in NASA-UAP-D027, which contains some overlapping audio content.

Common questions

What is Apollo 14 Crew Debriefing: Biomedical Sensor Failures?

What does Apollo 14 Crew Debriefing: Biomedical Sensor Failures reveal?

The recording is the Apollo 14 crew's post-mission debriefing, opening with a communications check and references to the prior night's printed debrief and the crew's technical tape debrief. Crew members debated their in-flight weight loss, with one saying he was three or four pounds overweight going in and doubting zero-G was the cause. The crew reported…

Which agency produced Apollo 14 Crew Debriefing: Biomedical Sensor Failures?

Apollo 14 Crew Debriefing: Biomedical Sensor Failures is a primary-source record from NASA. Its original classification was UNCLASSIFIED.

When is Apollo 14 Crew Debriefing: Biomedical Sensor Failures dated?

Apollo 14 Crew Debriefing: Biomedical Sensor Failures is dated 1971-02-18. It was disclosed 2026-07-10.

What programs and topics appear in Apollo 14 Crew Debriefing: Biomedical Sensor Failures?

Apollo 14 Crew Debriefing: Biomedical Sensor Failures references Apollo 14, light flash phenomena, cosmic rays, Manned Spacecraft Center and Houston Texas.

What does Apollo 14 Crew Debriefing: Biomedical Sensor Failures say, in its own words?

"We ran completely out of these bite sized packages you know and to me that was the best the best thing we had." (source p. 2043).

Apollo 14 Crew Debriefing: Biomedical Sensor Failures

NASA-UAP-D026, Apollo 14 Debriefing, 1971

Brief

Key points

The recording is the Apollo 14 crew's post-mission debriefing, opening with a communications check and references to the prior night's printed debrief and the crew's technical tape debrief.p.23

Crew members debated their in-flight weight loss, with one saying he was three or four pounds overweight going in and doubting zero-G was the cause.p.1748

The crew reported the food's appeal tracked the flight plan's activity level, favoring cans and wet packs during busy periods over time-consuming rehydratable meals.p.1807

The crew ran completely out of the bite-sized sandwich packages, which one member called the best food they had.p.2043

A biomedical sensor harness produced erratic, full-scale-unreadable data after the crew was cinched into the couch pre-launch, then returned to normal over Australia without intervention.p.2233

The crew fixed a failing sensor on the second flight day by pulling it off, cleaning it, refilling it with electrolyte, and reattaching it, rather than swapping the whole harness as ground control assumed.p.2518

All three crew reported broken sleep, never a solid long sleep period, attributed to wanting pressure against the body, suit wear, and the lunar module tilt.p.2779

One crew member described low-back pain from using feet and legs to stabilize in zero-G, which eased after the second day once the crew began deliberate exercise and relaxation.p.3005

Verbatim

We ran completely out of these bite sized packages you know and to me that was the best the best thing we had.

p.2043

There we had data, and we went back to the MSOB from the firing room to catch that pass, and there you were, it was beautiful, just as if nothing had ever happened.

p.2276

But in my case, I felt very strongly that I was on reserves, that physically I was going downhill.

p.2888

But sleeping to me was a very insecure experience.

p.2910

It was really a pleasant experience to be in zero-g during the daytime, I thought.

p.2936

Most interesting

The debriefing's headline topic, per NASA's release, is the 'light flash phenomena': high-energy cosmic rays passing through the eye and striking the retina, perceived by crew as streaks or flashes.

A biomedical sensor went full-scale unreadable after the crew was cinched into the launch couch, then corrected itself over Australia with no crew action, which the crew and ground later attributed to a loosened sensor edge.

Ground control assumed the crew had swapped out an entire biomedical harness in flight; the crew had only cleaned and refilled a single sensor with electrolyte.

All three crew members independently woke the first morning with low-back pain resembling the ache of an 11-hour night, despite having slept far less.

The debriefing continues in NASA-UAP-D027, which contains some overlapping audio content.