NASA's oldest astronaut who spent 220 days in space reveals the ‘significant challenge’ after returning to Earth

NASA's oldest astronaut, who spent 220 days in space, has spoken about one of the most difficult parts of returning to Earth.

When astronauts return back to their home planet, it would make sense that they'd be feeling a little worse for wear, what with the fact they've been living up in space and all of the lifestyle changes that can bring.

And while every person is different and every astronaut experiences varying levels of side effects after returning to Earth, 70-year-old Don Pettit has been pretty frank about how his recent trip affected him.

Don, along with two cosmonaut team members, returned on a Russian Soyuz spacecraft last month after seven months on the International Space Station (ISS).

They touched down in Kazakhstan and images show Don being carried to the medical tent.

Don Pettit (middle) set off in September last year to spend seven months onboard the ISS (Bill Ingalls/NASA via Getty Images)

After the photos of the American NASA astronaut returning circulated online, many people were concerned over his appearance.

"I didn't look too good because I didn't feel too good," Pettit told reporters earlier this week. "I was right in the middle of emptying the contents of my stomach onto the steppes of Kazakhstan."

If you're wondering why you didn't see any photos of Don looking like he was about to throw up, there's a simple explanation for that.

"They're polite, and they don't have a camera shoved in your face when you're in the middle of doing that," he later added.

"They cut away to give you a little bit of privacy when you're not feeling too good. Because, after all, nobody wants to be on camera when you're doing that."

The astronauts recently returned from their seven-month mission (Bill Ingalls/NASA via Getty Images)

Don went on to explain that he's always struggled with returning back to Earth, explaining that it's just 'his physiology'.

"Some people can roll off a [space] shuttle flight, and they're ready to go out and have pizza and dance," he said.

"Someone like me, coming back to Earth has always been a significant challenge. And even with a 16-day shuttle mission, that felt about like being gone for six months on space station.

"And that's just my physiology."

Don was carried to the medical tent upon his return to Earth (Bill Ingalls/NASA via Getty Images)

Don - who is NASA's oldest astronaut - is recovering now and is currently undergoing rehab for the next few weeks.

While he might not feel his best returning to Earth, Don certainly feels good while he's up there, explaining that all the aches and pains melt away.

“It makes me feel like I’m 30 years old again," said Don.

"All that kind of stuff heals up because you’re sleeping, you're just floating and your body, all these little aches and pains and everything heal up."