Congratulations to NASA astronaut Scott Kelly, who has now been in space longer than any other US astronaut before him. Having most recently launched into orbit on 27 March this year, Kelly's record currently stands at 383 days. He still has some way to go to beat the all-time record though - that's the 879-day shift put in by long-serving Russian cosmonaut Gennady Padalka.

Kelly has been earning his space miles over five previous missions, stretching back to the STS-103 Discovery flight in 1999. His sixth and current trip into orbit is the ISS year-long mission, intended to help scientists better understand the long-term effects of living in space on the human body. If we do eventually make it to Mars, data from Kelly's mission is going to be an essential part of the preparations.

Mark your calendars for 29 October too, when Kelly will break another record for the most consecutive days in space - as well as the most days in total. At that point, the astronaut will have spent 216 days in a row outside of Earth's orbit. That's an impressive pair of records to break, even if Kelly has had to drink a serious amount of recycled urine in order to claim them.

Together with cosmonaut Mikhail Kornienko, Kelly is helping scientists on the ground better understand "how the human body adjusts to weightlessness, isolation, radiation and stress of long-duration spaceflight", says NASA. "Every additional day helps us better understand how long-duration spaceflight affects bodies and minds, which is critical to advancing NASA's journey to Mars."

Down on the ground, Kelly's twin brother Mark, himself a former astronaut, is helping with the study - by watching the differences in the way the pair age over the course of the year, the team at NASA should gain a greater understanding of exactly how space travel affects both mental and physical health.

"Records are meant to be broken," tweeted Kelly as he passed the milestone last week. "Look forward to one of my colleagues surpassing my 500+ days on our journey to Mars!"

By the time he sets foot on terra firma again, the astronaut will have amassed 522 in space - that's almost 1.5 years. 342 of those days will have come from the mission he's currently on.

Here are some of Scott Kelly's best moments from his year in space so far. Year in space mission launches:

Highlights of the mission so far:

Kelly and his colleagues talk to the cast of The Martian:

Happy 4th July from Scott Kelly:

Eating lettuce in space for the first time:

A fizzy blob of liquid on board the ISS: