Astronaut Scott Kelly talks about acid pee, sleep and fears in space

Ask this astronaut anything: Kelly reveals what life is like aboard the International Space Station in an interview on Reddit.

Astronaut Scott Kelly is currently spending a full year aboard the International Space Station to help NASA understand how the human body reacts to long periods in microgravity.


We've seen NASA astronaut Scott Kelly send spooky Halloween messages from the International Space Station, talk about poop and show us what last weekend's blizzard looked like from space.

Recently, Kelly passed Day 300 of his 365 days living in space. In a candid Ask Me Anything interview on Reddit, he answered questions from those of us on Earth who wanted to know anything and everything about what his life is like on the ISS. Here are some highlights.

On why Kelly always folds his arms:

"Your arms don't hang by your side in space like they do on Earth because there is no gravity. It feels awkward to have them floating in front of me. It is just more comfortable to have them folded. I don't even have them floating in my sleep, I put them in my sleeping bag."

On what happens to your feet in space:

"The calluses on your feet in space will eventually fall off. So, the bottoms of your feet become very soft like newborn baby feet. But the top of my feet develop rough alligator skin because I use the top of my feet to get around here on space station when using foot rails."

On what it's like to sleep in zero gravity:

"Sleeping is harder here in space than on a bed because the sleep position here is the same position throughout the day. You don't ever get that sense of gratifying relaxation here that you do on Earth after a long day at work....there are humming noises on station that affect my sleep, so I wear earplugs to bed."

On the largest misconception about space travel:

"I think a lot of people think that because we give the appearance that this is easy that it is easy. I don't think people have an appreciation for the work that it takes to pull these missions off, like humans living on the space station continuously for 15 years. It is a huge army of hard-working people to make it happen."

On the creepiest thing he's encountered while on the job:

"Generally it has to do with the toilet. Recently, I had to clean up a gallon-sized ball of urine mixed with acid. The acid is added to the urine so the urine doesn't damage the machinery that moves it through the system. It keeps it from clogging up the system."

Scott Kelly with hydrophobic paddles.

Video screenshot by Amanda Kooser/CNET

On whether a rogue spaceship could sneak up and secretly dock on the space station:

"Maybe an alien spaceship with a cloaking device. But not your normal spaceship, no. Unless it had a cloaking device, which doesn't exist, the US Air Force would see it coming."

On what it feels like to have nothing but a suit between him and space during a space walk:

"It is a little bit surreal to know that you are in your own little spaceship and a few inches from you is instant death."

Advice for aspiring astronauts:

"You need to choose a field to work in that is qualifying first. Some kind of engineering, math, science, medicine, military pilot, etc. Then, you need to do well at whatever you are doing. Also, try to develop other skills beyond your work."

On fear and loneliness in space:

"I don't feel alone or afraid. I was up here for six weeks as the only American on the US side of the space station and I was fine. I have been afraid when the ground has called and privatized the audio, generally meaning something bad has happened. So I have been a little afraid.

"As for lonely, we have pretty good ways to stay connected with people in your life. I certainly miss my loved ones, but I never feel lonely. And connecting to people back on Earth on social media like this helps too!"

Space fans can keep track of Kelly and his activities at ISS on Twitter here.

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