How Astronauts Poop in Space and 6 Other Weird Things About Life on the ISS

Let's hope astronauts can aim.

There are workplace hazards in any laboratory, but the International Space Station offers more than a few unique challenges. Since 2000, the microgravity lab has hosted over 200 people in lower Earth orbit, creating one of the most important environments for scientific research. Yet, the human experience of being onboard the ISS is a study unto itself.

Astronauts who arrive on the ISS expect abnormalities in the body, from deteriorating muscle mass and bone density to elevated blood flow in the head and chest. ISS staff physically train on a daily basis to avoid and offset some of these health risks, but beyond body composition, life onboard the satellite means a lifestyle overhaul.

Expedition 50 crewmates (from left) Andrey Borisenko, Oleg Novitskiy and Peggy Whitson at mealtime in Unity module.


1. Beware Flattened Eyeballs

Not only do astronauts face deteriorating muscle mass, they tend to develop serious vision issues during their time on the ISS as well. While in orbit, fluid can push on astronauts’ eyeballs, flattening the eye shape and leading to extreme farsightedness. The ISS is stocked with adjustable eyeglasses of varying prescriptions for those whose eyesight devolves while in space.

2. Dust-Filled, Itchy Eyes Are Also a Thing

And if that’s not bad enough, the astronauts frequently have to deal with something in their rapidly flattening eyeballs. Because dust does not fall to the ground but floats around until eventually being filtered out, eye irritation is an ongoing problem for astronauts. Allergy symptoms and feeling “stuffy” is also common, not just from dust by from the shift of blood to the chest and head thanks to the lack of gravity.

3. Pooping Is… a Challenge

NASA’s Peggy Whitson knows a thing or two about pooping on the ISS, seeing as she has spent more time in space — 665 days! — than any other American. Whereas peeing is a relatively straightforward process that uses a funnel and a fan to suction out the urine, pooping is complicated.

According to Whitson, bowel movements need to be directed into a “small target” of a hole on top of a silver can in the $19,000 Russian-made toilet. The poop is then suctioned out through a fan and sealed in a bag that fills up over time. Whitson shared that when the poop bag is filling up and garbage day is still far in the distance, astronauts have had to throw on a pair of rubber gloves and pack the poop down.

4. Pee Becomes Drinkable

While there’s no LaCroix in space, all sorts of unique beverage flavors are available. Whitson also shared with Business Insider that after the astronauts’ urine is suctioned away, it gets stored in a yellow cone on top of the toilet. From there, up to 85 percent of it is recycled into drinkable water, which usually takes about eight days to process. When NASA’s Scott Kelly spent a year in space, he drank roughly 730 liters of his own sweat and urine.

5. Astronauts Can Get Stuck.

This has to be some type of architectural oversight. Astronauts need to push off structures in order to move around the space station, but NASA astronaut Terry Virts once told Reader’s Digest that it’s possible to get stuck in place without any structure to help the astronaut mobilize. Virts shared a memory of scientists getting stuck in the Node 3 module before equipment was mounted to its sides. The room was wider than an arm span, meaning astronauts who found themselves in the middle would be stuck there for 5 to 10 minutes until air currents helped them reach a wall.

6. Sunrises Are Almost Nonstop

It might be difficult to get a little shut-eye when the ISS witnesses 16 sunrises per day. The space station travels about 17,100 miles per hour and can thus complete a full orbit of Earth every 90 minutes. There are 16 sunsets per 24-hour Earth day as well, creating stunning views all day, every day.

With nonstop sunrises and sunsets, it’s clear there are some perks to working in Earth’s lower orbit, as well. So long as astronauts avoid the center of large rooms and have an impeccable aim for the poop chute, it’s not all bad.

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