If you google the question, you will find an abundance of sources discussing the alleged fact that the Apollo missions left bags of fecal matter on the moon. A conversation on reddit got me looking deeper. Someone claimed that the story of Apollo astronauts leaving bags of poop on the moon is an urban legend started by a misunderstanding.

At first glance, I was incredulous. There were lots of sources, even NASA employees and scientists, talking about the poop on the moon. However, I noticed that all of these sources were recent. None of them contemporary. When I started digging into what evidence was used for this claim, I found most people pointed to catalogs such as this, which reference emesis bags. However, emesis is vomit, and while it is conceivable these bags may have been used for defecation, that is not definitive. They were supposed to use fecal collection bags. More critically, an official source claims the emesis bags left were empty spares.

[As Russell mentions in the comments, these catalogs also have "defecation collection device" listed, but those may also be empty spares.]

We have had a related question here:

Did astronauts on the moon poop in front of each other?

In this question it is discussed that defecation on the moon may not have occurred. However, it lacks a definitive answer to this question.

Is there contemporary evidence for the claim that bags containing fecal matter were left on the moon? Or have any of the Apollo astronauts explicitly verified this claim since the Apollo program ended? If not, is it possible to indicate whether the claims are plausible or straight-up legend?

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    $\begingroup$ A former colleague of mine claimed to have had the job of collecting returned 'Apollo bags' at KSC and bringing them back to JSC for analysis. I assumed these were bags from the CM, but now I wish I had asked more questions. I wonder if I could contact that guy somehow.... $\endgroup$ Aug 6, 2019 at 17:58
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    $\begingroup$ The second page of the catalog you link says "Defecation collection device [4]" as part of the Apollo 11 material. The Apollo 12, 14, 16, and 17 lists also include them. $\endgroup$ Aug 6, 2019 at 18:01
  • $\begingroup$ @RussellBorogove Yes, but the question is, do we have proof it was used, or was it also a spare? $\endgroup$
    – called2voyage
    Aug 6, 2019 at 18:02
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    $\begingroup$ A16 transcript at 191:19:09. Post-docking, during preparation for LM jettison, CAPCOM Haise reminds the crew to transfer "the used fecal-urine bags". history.nasa.gov/afj/ap16fj/24_Day9_Pt1.html $\endgroup$ Aug 6, 2019 at 18:09
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    $\begingroup$ Let us continue this discussion in chat. $\endgroup$ Aug 6, 2019 at 18:25

4 Answers 4


If any of the 12 had a bowel movement and then obeyed procedures, then yes there is poop on the moon

My 30+ hour search of Apollo documentation did not reveal a direct answer either way. Perhaps the reason why NASA has never given a direct answer is because "leave poop on the moon" is not good public relations.

However, multiple sources indicate detailed planning and procedures to leave feces on the moon. There is a notable absence of planning, procedures, or records of transfer of feces from the lunar module to the command module.

Fecal management in the command module was very different from management in the lunar module

  • Feces in the CM was intended to be brought back to Earth. The production of feces does not change the total mass of the CM, so there is no flight penalty in retaining it. In fact, jettisoning feces would make it harder to track the total mass of the CM. Furthermore, the fecal matter can be studied for medical purposes if brought back to Earth. So the CM had a special compartment to store feces. It even had a special ventilation system, with a backup in case that failed (see NASA Tech Note D-6737, p. 10).

  • In contrast, there was a flight penalty for leaving the moon with feces. It was extra weight, which would need more fuel or allow for less moon rocks to take back. Nor did the LM have a ventilation system for the waste compartment, which saved even more weight.

There were two types of fecal devices

  • The Fecal Containment System (aka FCS) was an adult diaper. It was used when the astronauts were in their spacesuits (e.g., launch, moonwalks, and re-entry).

  • The Fecal Collection Assembly (aka FCA) was a kit. It comprised an outer bag, an inner bag which attached to the buttocks, a germicidal pouch, toilet tissue, and some wet-wipes. To complicate things, in the LM it was called the Defecation Collection Device (DCD), but it's the same thing. Various sources sometimes called the inner or outer bags of this kit a "fecal/emesis bag" or "F/E bag".

Did anyone poop while they were on the moon? I can't tell. There is a list of every fecal sample returned by Apollo. Some entries label which astronaut did it, but other entries are unlabeled. Worse, no sample is labeled for when or where it was taken. So this list tells us nothing about pooping on the moon.

The astronauts were not asked to record their bowel history, nor is it discussed in the mission reports.

Some have raised the point that astronauts avoided pooping. It was an unpleasant process, and many astronauts avoided it as much as they could. Also, they were given low-residue diets to reduce bowel movements. I recently saw an interview with an Apollo astronaut who said that he didn't go the entire trip, and when he got on the recovery aircraft carrier, he wanted to go poop instead of waste time shaking the admiral's hand. It's certainly plausible for the early (7-14) missions.

However, Apollo 15-17 spent several days on the lunar surface, and the astronauts were asked to eat more because of weight loss on prior missions. So I'm skeptical that all of the 12 astronauts avoided pooping while on the moon.

How did they collect the feces?

LM Operations Handbook vol 1, section describes the process:

To defecate , the astronaut removes the inner bag from the outer bag. After unfastening the PGA and removing undergarments, the wax tissue is peeled off the bag's inner surface and the bag is placed securely over the anal area. After defecating, the used toilet tissue is deposited in the used bag and the disinfectant package is pinched and broken inside the bag. The used bag is then closed, kneaded, and inserted in the outer bag. The wax paper is removed from the adhesive on the fecal/emesis bag, it is sealed, then placed in the waste disposal compartment.

Now, compare that wording to section of the same document, which describes disposing food waste:

A germicide tablet, attached to the outside of the food bag, is inserted into the bag after food consumption, to prevent fermentation and gas formation. The bag is rolled to its smallest size, banded, and placed in the waste disposal compart­ment.

So food wrappers -- which were definitely not brought back for study -- are placed in the same waste compartment as feces.

Disposing of feces was an official procedure that they were expected to follow: Defecation Disposal

1.  Remove defecation device from stowage.
2.  Insert inner bag into unit.
3.  Open germicide pouch & insert into inner F/E bag.
4.  Perform task.
5.  Seal inner bag.
6.  Place inner bag into outer F/E bag & seal outer bag.
7.  Knead contents.
8.  Stow bag.

Was the waste container jettisoned? Yes, according to Apollo 17 Lunar Surface Procedures, p. 245:

11. Jettisoned to Lunar Surface Prior to L/O
2 Hammocks
Sleep Restraint
**Waste Receptacle**
Helmet/EVA Int. Stow. 
2 LCGAdapters
1 LM ECS LiOH cartridge and Cannister

But couldn't the feces be taken out of the waste receptacle before jettison?

  • It's not on the checklists.
  • Where would you place it in the LM? There's no entry for it in the LM stowage documentation, other than the waste receptacle.

But couldn't it have been transferred to the CM?

There was a person back in mission control whose job was to track what items were in each spacecraft. They even used computers to help them with inventory. Every mission has a printout of this inventory. Each mission has hundreds of entries, no matter how small or mundane (like watch wristbands). There are six lists:

A. Command module at launch. Apollo 17 had 3 FCS (diapers) stowed, 1 FCS on crew, 48 FCA stowed.

B. Lunar module at launch. No fecal devices listed.

C. Items transferred from the CM to the LM, before descent to the moon. Apollo 17 had 2 diapers on crew.

D. Items in the LM at ascent from the moon. Apollo 17 had 2 diapers on crew and 12 DCD kits with the note "offload used item".

E. Items transferred from the LM to the CM. Apollo 17 had the 2 diapers worn by the crew which were "offloaded prior to separation". No other fecal devices are documented in the transfer to the CM.

F. CM at Earth re-entry. Apollo 17 lists 36 FCA.

Such a transfer to the CM was not documented.

Conclusion: Probably yes. It is likely at least one astronaut pooped while on the moon, and the official procedures were to leave it on the moon.

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    $\begingroup$ Fantastic answer! Thanks for the detailed analysis. It does seem likely now that there must exist somewhere at least one bag of poop on the moon. $\endgroup$
    – called2voyage
    Aug 7, 2019 at 23:31
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    $\begingroup$ "Perform task." 😝 This is a really good argument; I wonder where the disconnect is between the ops and procedures documents suggesting FCAs were left behind, and the post docking transfer checklists suggesting they were returned to the CSM. I don't think the mass penalty argument is compelling, though; the ascent stages had 280-420 lbs of ascent engine propellant remaining when jettisoned, so the margins weren't tight enough for a few pounds of poop to make a difference. $\endgroup$ Aug 8, 2019 at 14:40
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    $\begingroup$ The official itemised lists of objects left on the moon includes among other things, "Defecation Collection Device x4" for apollo 11, 12, 14, an individual DCD for Apollo 16. and 12 of them for apollo 17. Apparently Apollo 15 took their poop with them, or perhaps just held it in for the duration. Additionally "emesis bags" and "urine collection devices" are also items left on the moon with most missions. This is probably one of the weirdest things I've looked up :P $\endgroup$ Sep 29, 2020 at 10:34

I believe used fecal bags from the LM were normally supposed to be transferred back to the CSM and returned with the crew to Earth for analysis.

In the Apollo 15 flight journal, in the annotation after 174:14:00, we have this:

[As Apollo 15 disappears behind the Moon, Al switches on the Gamma-ray Spectrometer, X-ray Spectrometer and the Alpha Particle Spectrometer. The crew transfer all required items from the LM aided by a list in the Flight Plan that includes notes on where each item should be stored. The list includes film magazines, bagged rock and soil samples, core tubes including the very long deep core, food, used urine and fecal bags, and one of the OPS packages from the surface.]

That annotation was added after the fact, but in the Apollo 16 flight journal, at 191:19:09, while preparing to close out the LM for jettison, CAPCOM Haise gives the crew a checklist of items to transfer to the CSM:

191 19 09 Haise: Okay. Another little block you might write out to the left there, label it "Transfer Items." And, maybe you've already done some of these, but this will take care of some of the ones we missed having you do yesterday. And they're the PTK(?) [PPK], the Flight Kit, the purse with the unused food, and the used fecal-urine bags, and lastly the DSEA.

This doesn't speak directly to the earlier flights, but given that the used bags on the CSM were retained for analysis from day one, I think this would have been the procedure for all the moon landings. It also doesn't even prove fecal bags were used in the LM on Apollo 16; Haise almost certainly meant "if any were used, transfer them, and please don't tell me about it".

I can't swear Aldrin didn't toss a used diaper onto the moon, but I am strongly leaning towards "Myth: Busted" here.

Since the earlier flights involved shorter lunar stays, it's less likely that fecal bags were used at all; having to do one's business in the cramped LM cabin next to your crewmate would not have been pleasant. Lomotil and willpower can get you through two days pretty easily.

Table 2 in SP-368 Biomedical Results of Apollo appears to enumerate all the collected fecal samples from the Apollo missions, but unfortunately doesn't give timestamps or origin locations for them; it is also thus inconclusive.

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    $\begingroup$ I hope we get a more definitive answer than this, but at the very least we can say it is sounding unlikely. $\endgroup$
    – called2voyage
    Aug 6, 2019 at 18:26
  • $\begingroup$ "Urine-fecal bag" doesn't sound right at all. Urine collection and disposal was a very different process with different equipment than fecal collection. Also, a diaper that is worn but never soiled would be considered a "used" device. Urine devices that had been worn would also count as "used". $\endgroup$
    – DrSheldon
    Aug 7, 2019 at 2:25
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    $\begingroup$ @DrSheldon Yes, they're two separate things, about which I assume Fred Haise does not want to talk about in detail or at length. He means "fecal and/or urine bags and, really, I don't need to know." (The transcripts are full of "says X, means Y" annotations.) $\endgroup$ Aug 7, 2019 at 2:26

tl;dr: The only source found so far is an article that claims that Charlie Duke claims to have left urine on the Moon. No definitive report about fecal matter on the Moon, though.

In total, it's claimed by several sources (probably all copying one article) that 96 bags of poop, urine and puke were left on its surface. By my own count from NASA's list (see below), there were at least 32 body fluid bags left on the Moon. Whether any of the bags left on the Moon contained fecal matter is hard to say.

Using the poop bags wasn't a nice experience, as Micheal Collins wrote in Carrying the fire: after defecation you had to add a small bag with some chemicals and then knead the whole thing to kill of the bacteria (this was done to all poop bags, as far as I know, not only those left on the moon).

There's an article at Vox.com about this and what we could learn from collecting those bags. The article claims:

Apollo 16 astronaut Charlie Duke spent 71 hours on the moon in 1972. On a recent phone call, he confirmed that the crew left human waste behind.

“We did,” he says. “We left urine that was collected in a tank ... and I believe we had a couple of bowel movements — but I’m not sure — those were in a trash bag. We had a couple of bags of trash we kicked out on the lunar surface.”

In response to this article, Buzz Aldrin wrote on Twitter:

Well, I sure feel bad for whoever finds my bag 💩

But this is no definitive statement that his bags did contain fecal matter.

There is also the NASA Catalogue of Manmade Material on the Moon which, for Apollo 11, lists four Defecation Collection Devices. Looking at the review of spacecraft waste-management systems, it becomes apparent that this is official name for the poop bags. Since this list is very detailed, there probably exist reports for each mission listing these items. It does not list whether these were used or unused.

The SP-368 Biomedical Results of Apollo does list details of samples returned from the missions (there are… interesting tables in there) but doesn't say anything about matter left on the Moon.

Another interesting document is the Apollo Experience Report - Crew Provisions And Equipment Subsystem. It says:

Lunar module waste-management system. - To prevent contamination on the lunar surface, the LM waste-management system uses a pressure-operated urine-collection system.

(Emphasize mine.) This may be an indicator that the bags left on the Moon were (supposed to be) empty.

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    $\begingroup$ The article by Vox is not contemporary evidence. Since Buzz's comment is tongue in cheek, I'm not sure we can count that as him verifying it, but it's better than nothing. $\endgroup$
    – called2voyage
    Aug 7, 2019 at 10:24
  • $\begingroup$ @called2voyage: Yes, it's not a detailed statement. I did some more searching and found NASA's list of things left on the moon. Not the contemporary evidence, either, but of interest nonetheless. $\endgroup$
    – DarkDust
    Aug 7, 2019 at 11:52
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    $\begingroup$ @DarkDust That catalog of objects left is a good find, thanks for the link. $\endgroup$ Aug 7, 2019 at 12:51
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    $\begingroup$ Also, from Russell's answer you can see that on Apollo 11 it is unlikely any defecation happened on the LM at all. So Buzz's comment really may be just a joke, without any serious meaning behind it. $\endgroup$
    – called2voyage
    Aug 7, 2019 at 13:47
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    $\begingroup$ @DarkDust Thanks for adding the tldr! I think at this point it seems likely that if there is any fecal matter up there, it is a lot less than we were led to believe. $\endgroup$
    – called2voyage
    Aug 7, 2019 at 18:41

Contemporaneous evidence that defecation occurred on the Moon appears in the Apollo 17 Technical Crew Debriefing (Jan. 4, 1973 -- https://history.nasa.gov/alsj/a17/a17tecdbrf.html). Schmitt goes into detail about pooping on the Moon: "Before and after EVAs, in the LM, I ate very well. There were some things we avoided. In my case, after having corn chowder once, which stimulated a major bowel movement, not a loose one, I did not, thereafter, eat the corn chowder." Also: "I think the LM feces bags are superior to the CSM's in that they have a goodly quantity of tissues cut to size and are quite good. . . . Although we ended up having plenty of tissue, there was some concern initially whether we would. And I think had we had any greater problem in loose bowel movements we probably would have had an inadequate supply of tissues." In the second statement, "we" implies that both Schmitt and Cernan defecated while on the Moon.

Feces bags were used on the Moon. It is highly likely that they were left there.

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    $\begingroup$ This plus the accepted post makes it about as conclusive as it gets, I think! Thanks so much for contributing this first-hand account. $\endgroup$
    – called2voyage
    Jul 24, 2023 at 17:15

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