First year-long stay on the ISS about to begin

MAKE yourself at home. Two astronauts are set to get extra comfy on the International Space Station when they launch on Friday for the ISS’s first ever year-long mission, double the length of the normal stay. The mission will help the US and Russia study the long-term effects of space flight, which is essential if humans are ever to fly to Mars.

NASA’s Scott Kelly will join Mikhail Kornienko and Gennady Padalka, from Russia’s space agency Roscosmos, on a Soyuz spacecraft due to launch on 28 March from Baikonur Cosmodrome in Kazakhstan. Kelly and Kornienko will spend a year on the station.

Serendipitously, Kelly has an identical twin brother, Mark, who is also an astronaut but will spend this year on the ground. NASA will compare data on the twins’ health to try to distinguish the effects of space flight from those of genetics.

Thanks to Einstein’s theory of relativity, which says a traveller in a fast-moving spacecraft ages less than someone on Earth, Scott Kelly will return about 10 milliseconds younger than Mark at the end of the year – although the difference is too small to measure.

Kelly and Kornienko won’t beat the record for the longest single space flight. That is held by Valeri Polyakov, who spent nearly 440 days on board the Mir space station in the 1990s. But researchers studying the astronauts will make use of modern techniques such as microbiome analysis that weren’t available during Polyakov’s flight.

This article appeared in print under the headline “Longest ISS stay begins”