Astronaut Scott Kelly is hanging up his spacesuit

After clocking up 520 days in space

After spending a record-breaking consecutive run of 340 days on board the International Space Station, Scott Kelly has announced he'll be retiring from Nasa next month. He's definitely earned some downtime.

The purpose of Kelly's epic sojourn was to help the space agency learn more about the long-term effects of outer space living on our frail human bodies – if we're going to get to Mars one day that sort of knowledge is going to prove very useful indeed.

Together with his twin brother Mark, who stayed on Earth, Kelly will continue to be monitored and get regular check-ups after he's retired. However, as far as getting off the planet is concerned, the astronaut is calling it a day.

Space odyssey

"[Kelly's] passion for this work has helped give hundreds of thousands of people a better understanding of what Nasa does, thanks in part to the numerous photos and updates he shared from space," said Nasa's Brian Kelly as the retirement was announced.

Kelly has also spent more time in total in space than any other US astronaut: 520 days. However, he says he expects the records he's set to be surpassed in the near future.

"My career with the Navy and Nasa gave me an incredible chance to showcase public service, to which I am dedicated, and what we can accomplish on the big challenges of our day," said Kelly. "I am humbled and excited by new opportunities for me to support and share the amazing work Nasa is doing to help us travel farther into the solar system and work with the next generation of science and technology leaders."