Today is back-to-Earth day for International Space Station's Expedition 46 crew – Scott Kelly of NASA, above, and flight engineers Mikhail Kornienko and Sergey Volkov of Roscosmos.
Their Soyuz TMA-18M spacecraft is due to touch down southeast of Dzhezkazgan, Kazakhstan at 10:25 a.m. local time (4:25 a.m. UTC; 11:25 p.m. 1 March, EST )
Kelly handed over command of the orbiting complex to NASA astronaut Tim Kopra in a ceremony last week. When the Soyuz undocks, Expedition 47 formally will begin.
Kelly and Kornienko set a record for their 340-day mission in space during which time they orbited the Earth 5,440 times, travelling a distance of 231,498,542 kilometres at 28,160 km/h. Kelly is the first American to spend a year in space, although the all-time record was set by Russian Valeri Polyakov who spent 437 days in orbit.
"I've been up here for a really long time, and sometimes, when I think about it, I feel like I've lived my whole life up here," Kelly said in a recent media interview.
The mission included genetic studies that gathered important data on the effects of very long durations in space on the crew. What, arguably, is more valuable though is that Kelly has an identical twin, his brother Mark – also an astronaut – is acting as a control.
With Mark remaining on Earth, doctors will be able to compare the two men’s bodies after a year.
Scott Kelly's stunning photos from a year in space