# How much thrust could a fart or burp produce in space?

**URL:** <https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213>\
**Category:** Factual Questions\
**Created:** [May 4, 2015, 5:51am UTC](https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213 "2015-05-04T05:51:11Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![cjackson](https://avatars.discourse-cdn.com/v4/letter/c/a3d4f5/32.png) [@cjackson](https://boards.straightdope.com/u/cjackson)\
**Post date:** [May 4, 2015, 5:51am UTC](https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213/1 "2015-05-04T05:51:11Z")

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Let’s say you bare your ass for the cosmos and let one rip, how much thrust will your gas produce?

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**Author:** ![Bender\_Bending\_Rodriguez](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Bender\_Bending\_Rodriguez](https://boards.straightdope.com/u/Bender_Bending_Rodriguez)\
**Post date:** [May 4, 2015, 6:20am UTC](https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213/2 "2015-05-04T06:20:50Z")

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If you’re only baring your ass through some sort of porthole with the rest of your body comfortable in a pressurised suit/capsule, the pressure difference between your body wall and the vacuum of space might prolapse your entire viscera out of your anus. This might not be the way you intended to gain thrust, but a sufficiently powerful prolapse (literally “letting one rip”) might act like a reaction engine and provide a significant amount of thrust. 😃

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**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\
**Post date:** [May 4, 2015, 6:47am UTC](https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213/3 "2015-05-04T06:47:40Z")

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I’d wonder how much propulsion you’d get if you were inside the ISS and let one rip. I recall picking up from some of my readings (maybe from _A Man On The Moon_), the fuel cells in the Apollo service module, besides electrical power, produced water that had some extra H2 in it. Not enough to harm anyone drinking it, but enough to pass on through one’s system and exit. Though, that could have been from the food provided for the crews also. I believe I also read at some point there was a skirmish between the flight crews and the nutritionists who made the flight rations. It was resolved after some power higher up (maybe Slayton, maybe Chris Kraft) made the nutritionists live off the rations they made for 2 weeks. The flight crews won that one.

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**Author:** ![Bender\_Bending\_Rodriguez](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Bender\_Bending\_Rodriguez](https://boards.straightdope.com/u/Bender_Bending_Rodriguez)\
**Post date:** [May 4, 2015, 6:57am UTC](https://boards.straightdope.com/t/how-much-thrust-could-a-fart-or-burp-produce-in-space/719213/4 "2015-05-04T06:57:59Z")

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> [@Ranger\_Jeff](#):
>
> I’d wonder how much propulsion you’d get if you were inside the ISS and let one rip.

I found a similar (if not nearly identical) thread on the dope…

> **[Could an astronaut fart himself back to the space capsule?](https://boards.straightdope.com/sdmb/showthread.php?t=503796)**
>
> If there was some way spacesuits were designed to allow venting of flatulence directly into the vacuum of space without harming the astronaut could some well aimed farts propel him back to safety should said astronaut accidentally untether himself?

Farting is not much help apparently. Ejecting a liquid or throwing a solid with substantial mass might be a better option.