Flashback Friday: Farts: an underappreciated threat to astronauts.

By Seriously Science | March 14, 2014 6:00 am

On Earth, farts are typically no big deal — smelly, harmless, and they quickly dissipate. But if you’re an astronaut, every fart is a ticking time bomb. The gases in farts are flammable, which can quickly become a problem in a tiny pressurized capsule in the middle of space where your fart gases have no where to go. In this “oldie but goodie” study from the late 1960s, scientists fed subjects a then-state-of-the-art space diet compared with a “bland formula.” They discovered that the space diet actually produced more gas than the control diet, and noted that “volumes would be larger at reduced spacecraft and suit pressures.” This explains why astronaut food doesn’t include freeze-dried beans…

Intestinal hydrogen and methane of men fed space diet.

“Intestinal bacteria form two gases, hydrogen (H2) and methane (CH4), that could constitute a fire hazard in a closed chamber. So H2 and CH4 pass from the anus but these gases are also transported by the blood to the lungs and removed to the atmosphere. Several factors affect gas formation: 1) amount and kind of fermentable substrate; 2) abundance, types, and location of microflora; and 3) psychic and somatic conditions that affect the gut. We evaluated the first factor by studying men fed different diets and have also recorded influences of uncontrollable factors. One group of 6 men ate Gemini-type diet (S) and another received a bland formula (F), for 42 days. Breath and rectal gases were analyzed during the first and final weeks. Flatus gases varied widely within dietary groups but much more gas was generated with diet S than with F. In the first 12-hour collection, subjects fed S passed 3 to 209 ml (ATAP) of rectal H2 (avg 52) and 24 to 156 ml (avg 69) from the lungs (assuming normal pulmonary ventilation). With F, these values were 0 to 3 ml (avg 1) and 6 to 36 ml (avg 20). Subjects were calmer during the second test. Gas production was lower with S than initially; F values were unchanged. Methane differed idiosyncratically, presumably due to differences in flora. Computed from 12-hour values, maximum potential daily H2 and CH4 are per man: for S, 730 ml and 382 ml; for F, 80 and 222 ml. Volumes would be larger at reduced spacecraft and suit pressures.”

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  • D Hari Varshan

    So what happens to fart inside space station?

    • JimmyD

      What do you think is powering the thrusters?

      • D Hari Varshan

        explain more clearly

  • Hollandec Marokanec


  • Ben IncaHutz

    How did the measure the farts? Did these guys have to walk around for hours with a tube up their butts? If so those guys were heros of the highest order.

    • Maggiemay

      A fan with a rotation counter.

      • http://blogs.discovermagazine.com Glenn Jones

        What kind of person would be a fan of flatulence

        • Maggiemay

          don be judgin

  • farticustheelder

    Sounds like a job for an activated charcoal butt plug.

    • Peter Shaw

      OMG, that is actually a really good idea, a small filtration unit that could have small cartridges that you can change. TY, i will put this idea forward

  • Ralphus

    Geezus! I guess this means that my ex-wife Peggy could never become an astornut. Her farts smelled so fowl they would wake me up in the middle of the night!

    • Jim Sprague

      and now we know why she’s your ex

      • FlyOffTheWall

        But not why her farts smelled like chickens.


    One poot away from disaster.

  • vonskippy

    Those volumes, over 12 hours, inside a much much larger volume called a space suit, with circulating atmosphere present ZERO risk. Who makes up this nonsense.

  • Pete Sampson

    If I had a twelve-year-old, I now know what his science fair project would be.

  • DodgeMiniVan

    Did they use a Fartometer to measure the potency of the farts?

  • Teto85

    At least they aren’t asteroids from Uranus.

  • StanSki

    Flatus – Greek God of expended humours.

  • John Compton

    Submarines have the same problem ….

  • eetom

    Can fart be utilized as a source of power to propel astronauts from place to place in the vacuum of space? This can be achieved by feeding astronauts with a lot of peas and beans, which are cheaper than rocket fuel.

  • Carlo Stagnaro

    Maybe to put a mini- catalytic converter like a suppository in the anus of each astronaut or cosmonaut.


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