The previous longest US record was set by Mike Fincke’s with 382 cumulative days.
Kelly will break another record on 29 October when he will have spent 216 consecutive days in space, overtaking astronaut Michael Lopez-Alegria’s record for the single-longest spaceflight by an American.
But the absolute record for most time in space is held by Russian cosmonaut Valeri Vladimirovich Polyakov. He stayed aboard the Mir space station for more than 14 months (437 days 18 hours) during one trip in 1994-95. His combined space experience is more than 22 months.
Another record falls on 2 November 2015, which marks 15 years of continuous human presence on the International Space Station.
Bill Condie is a science journalist based in Adelaide, Australia.
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