Space Farts: Flatulence Knows No Boundaries

New forms of propulsion in space are usually welcomed by NASA, but the flatulence-power behind the crew of Apollo 16 was a very stinky and unwelcome one.

It’s hard to imagine the crews aboard any of NASA’s eleven Apollo Program missions (including the six that landed on the moon) doing anything but serious space business: staying alive in often uncharted waters being a prime example. The three men aboard Apollo 16 had another legitimate concern, however: chronic flatulence that was an unpleasantly odiferous unwanted passenger. It made its mark on the Apollo missions, but farting in space has always been there and continues to leave its smelly calling card even today.

Source: NASA

Space Farts

Apollo 16’s flatulence issues began with the mission immediately before them. The crew of the Apollo 15 mission in 1971 experienced some troubling medical conditions. At one point, astronaut Jim Irwin thought he was having a heart attack heart, but upon return to Earth it was determined that the crew was all suffering from heart arrhythmias caused by a potassium deficiency.

As a result, when Apollo 16 launched in 1972 the three-man crew had an ample supply of orange juice chock full of potassium. The problem with that is that potassium can make you gassy.

Source: NASA

So there they are, walking on the moon, with spacesuits full of fart.

Source: NASA

The recordings of the crew complaining of excess farting, both while walking on the moon and in the capsule, are legendary. Punctuated by gratuitous foul language, the conversations caught on tape leave no doubt that the astronauts of Apollo 16 were appalled by their own flatulence. Right up until Mission Control reminds them that their mikes are hot, and everything they say can be heard back on Earth.

Source: NASA

Yet even before the Apollo missions, NASA had been concerned about space farts, specifically how our rectal expulsions naturally contains hydrogen and methane. These flammable gases can be dangerous enough down here on Earth, but up there it’s downright scary.

Source: NASA

NASA goes to great lengths to try to prevent sending anything that is overly flammable up into space, because even a little blaze could be catastrophic. Yet the average human produces half a litre of fart each day, and there’s only one place for it to go. (Holding it in doesn’t work. It’ll just come out in their sleep.)

Source: NASA

In the days of the Gemini missions, they conducted a study to discover how to prevent farty astronauts from producing large amounts of flammable gas. The researchers examined two 6-man control groups for 42 days. One group was fed an unspecified diet of “space food” and the other was given bland earth meals.

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Breath and rectal gases were analyzed during the first and final weeks. The end result: the Gemini-style diet created way more flammable gas than the bland diet.


Zero gravity presents a number of issues for manned space flights, including astronauts passing gas.

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Consider this: when you fart on Earth, you have gravity helping you out. Where there is gravity, you have buoyant convection: hot air rises and there is a constant flow of air. This means it doesn’t take long for expelled gases to dissipate.


In the micro-gravity of space, this convection of air is negligent. Unless artificially circulated, air just tends to sit there. This is actually a very real hazard to sleeping astronauts — without fans constantly blowing the air around, a person could suffocate on the CO2 they exhale while asleep.

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Now imagine your rotten fart just hovering around you and not going away. That’s what life on a spaceship is really like.

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Clayton Anderson, a veteran of two missions aboard the ISS, has said that during his time aboard the station crew would point their rear upwards to pass gas. Rather than saying they had farted, ISS crew members would state they were simply “sending emails”.


Rocket Deafness

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But don’t think that farts are the only challenges faced by our stellar explorers. Hearing loss is a real issue, and even one mission into space can be enough to cause permanent damage. The damage happens mostly to high frequencies, including those used for hearing speech. Noise levels are the biggest culprit — the living quarters of the International Space Station can be as loud as 75 decibels — but atmospheric contaminants, higher intracranial pressure, and greater carbon dioxide levels can also play a role. In the early days of the space station, astronauts all wore earplugs to help with the problem, but acoustic padding on the walls and quieter fans are helping a little.




As you’re slowly going deaf, your bones are also atrophying away every day you spend in space. Without the constant pressure of gravity keeping your bones tough, they just start to fade away to the tune of 1 to 2% loss of bone density per month. The body doesn’t need all the minerals that are seeping away from your bones, so it gets rid of them. In your pee.


Which leads to the next problem…


Cosmic Kidney Stones

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It’s normal for about 1 in 10 people to develop a kidney stone during their lifetime on Earth. But with their bones disintegrating and the excess minerals concentrating in their kidneys on the way to being peed out, astronauts are particularly prone to growing kidney stones. They start as microscopic little collections of calcium, but can grow as big as a walnut. To make matters worse, the microgravity of space also decreases blood volume, and astronauts tend not to drink as much water, neither of which help in passing stones when they’re small enough to get rid of painlessly.


Galactic Radiation


And then there’s the radiation. Here on Earth, the atmosphere protects us from most of the radiation that’s streaming through space, and there is rather a lot of it. Most comes from our sun, but there’s galactic radiation reaching us from all over the cosmos.

Too much exposure can lead to radiation sickness or cancer, since it can play havoc with your DNA. And every week in space is like getting a whole-body CT scan. Not good.


You want to know what else this kind of exposure to galactic radiation can cause?



Source: NASA

Tests on rats show that a dose of radiation equal to a trip to Mars had a significant impact on their cognitive abilities. The sort of high energy particles an astronaut would experience during a 3-year trip made the rats react slower and become distracted, and triggered protein changes in their brains. These kinds of brain chemistry and behavioural changes are associated with Alzheimer’s, which poses a serious set of concerns for anyone thinking of heading off to the Red Planet.


Space Blindness

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If hearing loss, bone loss, cancer, excruciating pain while urinating, and dementia aren’t enough, astronauts can expect to lose some of their vision if they spend any amount of time in space.


The more time off planet, the more risk of vision loss. After two weeks, about one in three astronauts suffer some loss of vision; after a few months, two in three lose some of their eyesight.


What happens is that the back of the eyeball becomes flattened, creating farsightedness. They’re pretty sure this is due to the impact of microgravity on the body’s fluids, so artificial gravity could make this problem go away.


Stellar Muscle Loss

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It seems pretty clear that our bodies were made to live with gravity, since so much seems to go wrong when we’re floating around without it. Alongside bone loss and distorted eyeballs you can add muscle loss to the list of problems caused by microgravity. Since astronauts aren’t using their muscles nearly as much, they just go away. Exercise can help, but the deterioration will happen regardless. A long stint in space can result in a loss of 20 to 40 percent of muscle mass.