It's really hard to walk when you come back to Earth from space
No one said it was easy to adjust to life on Earth after living in space.
From your lack of spatial awareness to missing that bird's eye view from the International Space Station, astronauts come back home to solid ground and experience all kinds of symptoms as a result of long stays in space.
And according to a newly released video from NASA astronaut Drew Feustel, one of those symptoms is being unable to walk a straight line with your eyes closed.
Feustel posted the video to Twitter after some of his colleagues came home from the space station on Thursday.
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Feustel spent close to 200 days floating in the weightlessness of the space station, so it's understandable that he might have a little trouble walking heel to toe once back on Earth.
"On October 5th this is what I looked like walking heel-toe eyes closed after 197 days on @Space_Station during the Field Test experiment...I hope the newly returned crew feels a lot better," Feustel said in the tweet.
Astronauts exercise for about two hours every day when in space to keep up muscle mass and bone density while in microgravity, but that doesn't mean that it's automatically simple to walk upright in Earth's gravity.
Once back on Earth, astronauts and cosmonauts have to go through a series of physical and medical tests to see how their bodies withstood living in space.
That kind of data is incredibly important for NASA as the agency gears up to send humans on longer and longer missions out into the solar system.
If we want to send humans to Mars one day, scientists need to understand exactly how the human body reacts to long-duration spaceflight from weightlessness to radiation exposure.
Long missions to the space station -- like astronaut Scott Kelly's year spent aboard the orbiting laboratory -- will be key to understanding exactly what medical issues may crop up during trips to far-flung places in deep space.
Miriam Kramer worked as a staff writer for Space.com for about 2.5 years before joining Mashable to cover all things outer space. She took a ride in weightlessness on a zero-gravity flight and watched rockets launch to space from places around the United States. Miriam received her Master's degree in science, health and environmental reporting from New York University in 2012, and she originally hails from Knoxville, Tennessee. Follow Miriam on Twitter at @mirikramer.
