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What Is It Like to Live on the International Space Station?

As a writer of educational articles with a Master of Science degree, I explore scientific research on fascinating subjects such as this.

Astronaut Karen Nyberg combing hair on the ISS.

Astronaut Karen Nyberg combing hair on the ISS.

Six Months Without Gravity

Would you be willing to live for six months without gravity, where your way of life is awkward and bothersome?

For this article, I've researched how astronauts live and work on the International Space Station to review living with weightlessness and its unique concerns.

Factors About the International Space Station

The astronauts on the ISS are scientists and engineers. Their mission is to conduct science experiments in space. They do research projects and investigate life without the conveniences of gravity or the conditions we take for granted on Earth. The work may lead to knowledge of colonizing the Moon and possibly Mars.

NASA placed the first module of the ISS in low Earth Orbit in 1998. That’s an average altitude of about 248 miles (or 400 kilometers) above the Earth. It circles the Earth every 90 minutes.1

The ISS consists of 14 pressurized modules that astronauts added one by one. These modules contain science labs and living quarters.

External trusses and solar arrays were brought to the ISS by Russian Proton and Soyuz rockets, American Space Shuttles, and Elon Musk's SpaceX aerospace suppliers. Eight solar arrays provide 75 to 90 kilowatts of electric power.

The cost to build and maintain the ISS has reached over $150 Billion, with the United States paying over half that cost.

How Does the ISS Stay in Orbit?

The ISS is continually falling back to Earth. However, it remains in orbit because of its speed, known as “orbital velocity.” This speed (close to 18,000 MPH) makes it perfectly balanced between the gravitational pull and its forward thrust around the planet.

Orbital velocity is what causes the Moon to stay in orbit around the Earth and the Earth to remain in orbit around the Sun.

How Many Astronauts Stay on the ISS?

There are sometimes up to ten crewmembers inhabiting the ISS at one time. Most countries refer to their crewmembers as astronauts. The Russians are known as cosmonauts.

It truly is an international expedition, as they are from the United States, Russia, Japan, Canada, and other European Partners.

How Long Do Astronauts Stay on the ISS?

Each astronaut has an expedition that lasts about six months to complete their mission, although three to ten crew members are on board at a time.

They stay on board only six months before returning to Earth because life in space takes a toll on the human body, as I’ll explain later in this article. However, astronaut Mark Vande Hei remained for almost a year. He returned to Earth in March 2022 after 355 days on the ISS.2

Extended living arrangements on the ISS helps to collect vital data about the impact on humans. That data is useful for anticipated long trips in space. A trip to Mars, for example, takes two years when the planets are arranged just right.

International Space Station

International Space Station

What Do Astronauts Need for Survival?

We take a lot for granted living on Earth with fresh air, running water, and healthy amenities. However, on the ISS, astronauts need to be concerned about the following issues that I'll discuss in the rest of this article, with video presentations by various astronauts.

  • Recyclable wastewater
  • Replenish breathable oxygen
  • Maintain a healthy heart
  • Privacy consideration
  • Personal hygiene without running water
  • Cooking and eating on the ISS
  • Keeping a clean environment
  • Handling trash and other waste

Recycling Wastewater on the ISS

Water is the most precious commodity, especially in a self-contained living environment where a new supply is impossible to attain. Therefore, all wastewater needs to be collected and recycled. That includes sweat and urine.

Perspiration is collected from sweaty clothes and removed from the air. An aesthetically appealing name has been made up for the water collected from perspiration: Humidity Concentrate.

About 85% of the water in urine is recovered by using distillation. Overall, about 94% of all the wastewater from the astronauts is recycled.

How Breathable Oxygen Is Created

Oxygen is replenished by separating it from the water through electrolysis. I used to do that as an experiment in high school science class. We learned that water is chemically made up of two hydrogen atoms and one oxygen atom. That’s why it has the chemical name H2O, which represents that configuration of molecules.

The process is done by inserting electrodes in the water with a DC current. The DC current splits the water molecules into their individual atoms. The negative electrode collects hydrogen gas, and the positive electrode collects oxygen.

Besides oxygen, other atmospheric components such as nitrogen, carbon dioxide, hydrogen, methane, and humidity, are monitored and controlled by a device called the Major Constituent Analyzer.

Personal Privacy and Sleeping Quarters

Each astronaut has his or her own personal quarters, known as a crew cabin. That is the only place where they have privacy, and they spend their alone time in there.

Each crew cabin contains a sleeping bag and personal effects. They are small, just big enough for one person.

They also have laptops to keep notes, write about their thoughts and feelings, and communicate with friends and family back home. WiFi is available on the ISS so that they can use email and chat with Skype or Zoom.

When they sleep, they usually use sleeping bags so they don't float around. The sleeping bags can be attached to a wall or upside down on the ceiling. Remember, there is no up or down in space, so they can sleep in any position in their cabin.

They generally sleep eight hours for a good night’s rest to be ready for another busy day.

Personal Hygiene in Space

Astronauts do need to get haircuts occasionally. Female astronauts tend to leave their hair long. The men get haircuts with a buzz cutter that has a vacuum machine attached to it to capture the hair as it’s cut off. Otherwise, the hair would float away since there is no gravity.

When brushing their teeth, they need to keep their lips closed. Otherwise, the saliva and toothpaste will float out. Not a pretty sight.

How Astronauts Wash Their Hair With No Running Water

The lack of gravity also rules out the ability to have running water. Water would just float around the space capsule. Therefore, they wash their hair with a no-rinse shampoo.

Watch how astronaut Karen Nyberg washes her hair aboard the ISS:

How Astronauts Cook and Eat on the ISS

The lack of running water makes eating very different from the way we do it on Earth.

Food is dehydrated or freeze-dried and stored in plastic packages. The astronauts squeeze water into the food packages before eating. They use hot water to make hot meals. Freeze-dried fruit can be eaten dry.

Social Activities Abord the ISS

Astronauts need some free time to relax, and they get weekends off. Social activities are crucial for getting along with other astronauts and involve watching movies, playing cards, and other games, and generally having a good time with one another. At times, individual crew members might relax alone, playing music or reading books.3

Exercising in Space Is Crucial for a Heathy Heart

Astronauts lose muscle tone while in space due to the lack of gravity on the body. The heart is also a muscle, and it will weaken to the point that it fails if one spends too much time without the resistance force of gravity.

The solution is to exercise against the resistance of elastic ropes. Think of it as running on a treadmill with oversized rubber bands holding you to the mill. The same is done with stressing every part of the body.

The astronauts have to exercise two and a half hours each day on the ISS. When they exercise with weight lifting, they have to keep track of how much weight and how many reps they did.

Now you're probably wondering that weights would be weightless in space. And you're right! Lifting weights is not done the same on the ISS. Astronauts do it by pulling or pushing against the resistance of springs or elastic bands.

Keeping Track of Health Records

Astronauts keep a record in the computer of what they eat so NASA can keep track of everything: How many calories, protein, how much salt they are getting, and so on.

Everything needs to be monitored and tracked with accuracy. The computers record their heart rate when they are working out. They even have to keep a record of when they use the toilets.

How Astronauts Use a Space Toilet With No Gravity

Both urinating and bowel movements need to be handled in a completely different manner in a weightless situation. You wouldn’t want that stuff floating away from you.

A vacuum system is built into the special toilets. Astronaut Samantha Cristoforetti shows you how space toilets work in this next video.

How Astronauts Keep the ISS Clean

It's essential to keep the living environment clean, especially in such as cramped space. Once a week, they go around with a vacuum, but they also need to clean everything with a wet wipe that kills germs.

They even use wet wipes to clean their eating utensils—their forks, spoons, and trays.

Concern With Orbital Debris (Space Junk)?

People don’t only pollute the land and oceans. They pollute space too.

This junk consists of over 100,000 pieces of discarded satellites and rockets, and that's increasing. Although roughly only 27,000 pieces are tracked by global Space Surveillance Network (SSN) sensors maintained by the Department of Defense.4

A primary concern of orbiting space debris is that it can be deadly if any of it strikes the ISS. A solution tested in labs is using two layers of shields around every part of the ISS. That is important for the crew's survival.

If small objects the size of a grain of sand were to strike, the outer shield slows it down and causes it to dissipate so that it’s too weak to penetrate the second shield.

Larger space junk is monitored by mission control. They are continually making changes to the path of the ISS to avoid these larger pieces. They do this from ground control so that the astronauts don’t even have to think about it.

Delivery of Essentials via the Cygnus Orbital Capsule

The Cygnus Orbital Delivery Capsule is a space vehicle that NASA uses to replenish needed items. It’s launched about every six weeks containing groceries, clothing, and new science experiments.5

Once the Cygnus Capsule is within 10 meters of the ISS, they use a robotic arm to capture and guide it to connect with the locking hatch. The astronauts can then open the hatch and enter the capsule to get all the new goodies.

Cygnus Orbital Delivery Capsule

Cygnus Orbital Delivery Capsule

How Trash Is Handled on the ISS

Waste accumulates among the astronauts just the same as our trash builds up in our homes. They deal with it the same way, filling garbage bags.

The bags also contain dirty laundry since they can't wash anything. They wear clothes much longer for that reason, but then they dispose of them with the rest of the trash.

They store those garbage bags in the Cygnus Orbital Capsule, which takes the trash with it when it leaves.

When Cygnus enters the Earth's atmosphere, it burns up, just as most meteorites do, and all the trash burns up with it.

The SpaceX Dragon Capsule6, which also delivers supplies to the ISS, has the added advantage of successfully returning 5,400 pounds of science equipment and other gear in March 2017.

Scientific Lab Experiments Aboard the ISS

Experiments are continually being carried out on tests such as how crops will grow and how animals are bread in weightlessness. These experiments are conducted in anticipation of journeys to other planets someday.

Ants are studied to see how they handle weightlessness. They get confused as they fall and just float around.

Varieties of vaccines are also tested to study how they develop in a weightless environment.

Temperature Control on the ISS

Equipment and experiments that need temperature control are kept cool by a cooling pump attached outside the ISS.

If that pump fails, mission control can try to repair it remotely. In some cases, that’s not possible, and a couple of astronauts need to do a spacewalk to go out and fix it.

Spacewalk to Fix the Cooling Pump

Astronauts need to wear a spacesuit that is a complete life support system to do a spacewalk. It includes the ability to hold waste if they need to relieve themselves.

While working outside the ISS, they have no sense of touch since they are in their spacesuits. They hold onto hand grips while they inch their way along to the cooling pump to replace it with a spare.

That cooling pump weighs 800 pounds but carrying it is easy since it's weightless in space. However, they have to be careful not to rub up on anything that might tear their spacesuit.

One thing they have no control over at all is the concern about micrometeoroids. These tiny particles can hit their spacesuit at any time, and there is no way to avoid the possibility.

Astronaut Michael Fincke Busy with a Spacewalk Repair Mission

Astronaut Michael Fincke Busy with a Spacewalk Repair Mission

A Summary of Daily Life on the ISS

To sum up, NASA Flight Engineer Catherine "Cady" Coleman discusses daily activities on the ISS and how she feels about being away from her family. In the following video, Cady summarizes everything I mentioned in this article.7

After two space shuttle missions with 159 days in space, Cady left the International Space Station on May 23, 2011, at the age of 50, and is now a retired astronaut.


  1. National Geographic Channel - Living on the ISS
  2. Anna Wichmann. (March 30, 2022). “NASA Astronaut Returns to Earth After Record-Breaking Stay in Space” - Greek Reporter
  3. Sandra May. (Apr 28, 2021). “Free Time in Space” -
  4. Mark Garcia. (May 27, 2021). “Space Debris and Human Spacecraft” -
  5. Chris Gebhardt. (August 31, 2015). “Enhanced Cygnus to help Orbital ATK meet CRS contract by 2017”
  6. Dragon Sending Humans and Cargo Into Space” (Retrieved June 6, 2021)
  7. Video from CBS News Program "The Talk" on January 18, 2011

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2017 Glenn Stok


Glenn Stok (author) from Long Island, NY on May 30, 2020:

Today, May 30th, 2020, two NASA astronauts, Robert Behnken and Douglas Hurley, are on their way to the ISS after a successful SpaceX launch under the new Commercial Crew Program.

Glenn Stok (author) from Long Island, NY on March 25, 2017:

This morning on March 25th, 2017 American astronaut Shane Kimbrough and French astronaut Thomas Pesquet just completed the first of three scheduled space walks to prepare a second International Docking Adapter.

The new docking ports will be used for SpaceX and Boeing commercial spacecraft to dock with the International Space Station.

Glenn Stok (author) from Long Island, NY on March 25, 2017:

Sure thing Mary. Without gravity the muscles atrophy and the bones deteriorate if they don't diligently keep up with those exercises.

Mary Wickison from USA on March 24, 2017:

I loved this. A good cross section of videos about living and working on the ISS. Their keep fit routine is interesting and makes you realize just how important gravity is in relation to the pressure it puts on our bodies. Two hours of exercise just to maintain muscle and heart health.

Glenn Stok (author) from Long Island, NY on March 24, 2017:

Good question Dora. I wonder how much they value life when so much can go wrong, being that they are dependent on life-support all the time while in space.

Dora Weithers from The Caribbean on March 24, 2017:

What a different kind of life! I wanted to scream "gross" at some of the facts you mentioned, but would not on realizing the purpose for these seeming inconveniences. I bet that the astronauts respect and value life ('normal' or otherwise) much more than the average person.

Glenn Stok (author) from Long Island, NY on March 22, 2017:

Thanks for that informative comment Melody. Stephen Hawking may have a desire to take that trip, but he needs constant attention of health aides to bath him and perform normal hygiene, so I don't think it's feasible. As for trust – Yes indeed. It takes a lot of trust that the other people working on the mission do things right. In 1986, all seven crew members of NASA’s Space Shuttle Challenger were killed when its rocket booster exploded 73 seconds after takeoff. The failed O-ring was not designed for the cold weather conditions during that launch. Anyone could have called off the mission if they were alert to do so. Trust? Yes. Who do you trust?

Melody Collins from United States on March 22, 2017:

I have been following Elon Musk and his dream of taking us to Mars. Then I heard that Stephen Hawking may be taking a trip to space. I never gave what it might be like to live in space much thought until I realized the possibilities of space!

After reading your informative article. I learned from your informative article that ISS was placed in low orbit around the earth when I was a late teen. I wouldn't have learned about it in school.

It is amazing the amount of trust that astronauts must place in the technology they use!!

Glenn Stok (author) from Long Island, NY on March 22, 2017:

Yes Louise, With limited resources in space they have to recycle whatever possible. Imagine a trip to Mars that takes two years. Thats would required even more diligence.

Heidi Thorne from Chicago Area on March 22, 2017:

Thanks for the tip, Glenn! Will check it out.

Louise Powles from Norfolk, England on March 22, 2017:

Yes, I learned a lot too. I didn't realise they collected perspiration and sweat too.

Glenn Stok (author) from Long Island, NY on March 22, 2017:

Heidi, you may want to check out "Galactic Unite" – a collaboration between Virgin Galactic and future civilian astronauts.

Heidi Thorne from Chicago Area on March 22, 2017:

In spite of the inconveniences, I so would love a tour on the ISS! Saving my dollars for a possible Virgin Galactic trip. :)

Glenn Stok (author) from Long Island, NY on March 22, 2017:

Thanks for being the first to read and comment CJ, and thanks for sharing.

CJ Kelly from the PNW on March 22, 2017:

Great job, Glenn. Very interesting and I learned a lot. Sharing everywhere.