After traveling in space for 340 days, making 5,440 orbits around the Earth, witnessing 10,944 sunrises and sunsets (and doing one special Reddit AMA), NASA astronaut Scott Kelly returned home from his epic mission. The voyage was a momentous one—Kelly’s year aboard the International Space Station has given researchers all sorts of biomedical and psychological data to help them figure out how to keep astronauts healthy on long space voyages. This is a key component to achieving a future goal: putting American astronauts on Mars in the 2030s.

While it will take some time before we see published results from the research, a team of doctors and scientists behind the mission hosted a Reddit AMA to answer questions about all the science involved (along with many other things). The panel included Julie Robinson, NASA’s chief scientist for the International Space Station; John Charles, associate manager for International Science for NASA’s Human Research Program; Scott M. Smith, nutritional biochemistry laboratory manager for NASA’s Human Research Program; Dr. Shannan Moynihan, NASA Flight Surgeon; and Bruce Nieschwitz, a strength and conditioning coach.

Here’s what we learned.

When they landed, Scott Kelly and Russian cosmonaut Mikhail Kornienko had to be carried off the capsule as they didn’t yet have their “Earth legs.”

Kelly grew taller in space.

Kelly’s trip made him about two inches taller, according to a NASA spokesperson. But back on Earth, he has already shrunk back down to his normal height. (Hope he got to try his jump shot while it lasted.) The spine elongates in space. Some astronauts report back pain due to changes in their intervertebral discs.

And he’s younger than he would be had he stayed on Earth.

When they return to Earth, many astronauts want pizza.

On the ISS, everything they ate was tracked.

Awww.

The astronauts likely had vision issues.

They performed a lot of experiments.

They also drank recycled urine.

Here’s how they described it:

He asked what we're all thinking: How weird is it to drink recycled urine aboard @Space_Station? #sciencehttps://t.co/f73wtvCXdt — ISS Research (@ISS_Research) November 19, 2015

Scott Kelly had a space playlist.

Also on the list: Eminem’s “Lose Yourself” and Dixie Chicks’ “Wide Open Spaces.” Appropriate.

The astronauts grew their own vegetables.

Kelly was one of the first astronauts to harvest and eat lettuce grown in the space station’s VEGGIE facility.

Kelly’s trip allowed NASA to conduct the first ever Twins Study on the space station.

While Scott Kelly was in space, his twin brother Mark Kelly was on Earth. Their genetic makeup is close to identical, which allows researchers to make unique comparisons.

Learn more about the voyage in the original Reddit AMA.