After a year in space, NASA astronaut Scott Kelly returned to Earth a changed man.
For one, he emerged from the Soyuz landing capsule Tuesday around 1.5 inches taller than he was before the mission. (In microgravity, the spine decompresses and extends.) And, at first, he felt great, Kelly said at a NASA press conference on Friday.
But then, gravity started tugging on his body.
"I'm surprised how I do feel different physically than I did the last time," Kelly told reporters, comparing this latest re-entry to his previous six-month mission in 2010.
His description of the experience since landing sounds like an epically bad hangover. Every muscle hurts. His skin even hurts. And he just can't perform at his best. (Though he made no mention of a headache.)
Initially, this time, coming out of the capsule, I felt better than last time. But at some point those two lines have crossed. My level of muscle soreness and fatigue is a lot higher than it was last time. It makes me think there a linear function to it [meaning the more time you spend in space, the worse you will feel when you return.] Also, my skin, because it hasn't touched anything for so long ... it's very, very sensitive. It's like a burning feeling wherever I sit or lie or walk.
Later in the press conference, Kelly explained he tried to shoot some hoops after returning to the ground. "I didn't get any of them in the net," he said. "Not like I'm a good basketball player generally."
NASA sent Kelly on the year-long mission to study whether a year in space would take a greater toll on his body than the typical six-month mission. They won't actually know for a while: It will take at least a year for Kelly's data to be analyzed, NASA scientists said.
But anecdotally, the man himself says it was tougher both physically and psychologically. With six months, he said, "you can see the end." With the year trip, he said, it felt like he lived on the space station forever.
"The hardest part is being isolated in a physical sense from the people on the ground that are important to you," Kelly said during a previous press conference aboard the space station. "There's a loss of connection with folks on the ground that you care for and love and you want to spend time with, which is a challenge."
NASA will have to address these concerns during a Mars mission, where a round trip journey would last a year or more.
And while Kelly did say he grew an inch and a half in space, (possibly giving him a height advantage over his twin Mark for the first time in his life) he knows that benefit will disappear quickly.
"Gravity pushes you back down to size," he says.