NASA astronaut Scott Kelly will retire from the space agency on April 1st — less than a month after he returned from nearly a year in space, NASA confirmed today. Kelly just spent 340 days aboard the International Space Station for NASA's One-Year Mission, an experiment to see how long-term spaceflight affects the human body. NASA says Kelly will continue to participate in follow-up tests for the mission and periodically contribute fluid samples for research, but he won't fly into space for NASA again.

Kelly has spent a total of 520 days in space

Kelly is leaving an impressive career behind at NASA. The former ISS commander flew a total of four times since joining the astronaut corps in 1996. That includes two Space Shuttle missions, as well as another six-month stay on the station. He has spent a total of 520 days in space — the longest cumulative time an American astronaut has been off of Earth. However, his record will soon be broken when NASA astronaut Jeff Williams launches to the ISS on March 18th; Williams will eventually accrue 534 days, according to NASA.

Kelly also became known for his prominent social media presence during his time on the ISS, posting more than 700 images of Earth taken from space. He also shared all the ways he filled his time in lower Earth orbit, such as playing water ping pong or dressing up in a gorilla suit. Kelly's ability to both entertain and inform the public were commended by NASA Administrator Charles Bolden in a statement today. "All of us in the NASA family — and indeed in the broader scientific community — are grateful that he was willing to sacrifice time with his loved ones, meals that don’t come in a bag, a cold beer, hot showers, cool autumn breezes, the sounds of birds chirping, the ability to lay his head on an actual pillow, and so much more of the pleasures of life during his year of research and experimentation the International Space Station," said Bolden.

Just because Kelly is retiring from NASA doesn't mean he's done with spaceflight though. Kelly told press after returning to Earth that he may consider flying to space with a private spaceflight company in the future. "Maybe in the next 20 years, you can buy a cheap ticket and go for a little visit," he said.