International Space Station duo return to Earth after year in space

The “one-year crew” mission — which began on March 27 last year — was the longest by an astronaut aboard the ISS and seen as a chance to measure the effects of a prolonged period in space on the human body, as a prelude to a manned mission to Mars.

Russian cosmonauts Mikhail Kornienko, left, Sergey Volkov, and US astronaut Scott Kelly rest in chairs outside the Soyuz TMA-18M space capsule after landing in a remote area outside the town of DzhezkShow more

DZHEZKAZGAN, KAZAKHSTAN // US astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko returned to Earth on Wednesday after spending almost a year in space in a ground-breaking experiment foreshadowing a potential manned mission to Mars.

The 340-day mission saw Mr Kelly claim the record for the longest single stay in space by a US astronaut, while Mr Kornienko is now fifth on the list for lengthiest mission by a Russian cosmonaut.

“We have landing,” Russian mission control confirmed after the trio, which also included Russia’s Sergei Volkov, who was stationed at the ISS for more than five months, touched down south-east of the settlement of Dzhezkazgan in central Kazakhstan at around 4.30am GMT.

After returning from his lengthy stint in space Mr Kelly was clearly in high spirits as he was lowered to the ground by burly Russian rescue workers at the landing site.

“The air out here feels great. I’ve no idea why you guys are so bundled up,” Nasa TV reported him as saying as he sat upright in a chair on the steppe in temperatures just below zero degrees Celsius.

The “one-year crew” mission — which began on March 27 last year — was the longest by an astronaut aboard the ISS and seen as a chance to measure the effects of a prolonged period in space on the human body.

“Scott Kelly’s one-year mission aboard the International Space Station has helped to advance deep-space exploration and America’s journey to Mars,” said Nasa administrator Charles Bolden in a statement. “Scott has become the first American astronaut to spend a year in space, and in so doing, helped us take one giant leap toward putting boots on Mars.”

The pair were subjected to a battery of tests before and after their ascent towards the ISS and underwent more tests soon after landing.

Weightlessness reduces muscle mass and bone density and is believed to diminish eyesight by increasing cerebrospinal fluid around the optic nerve.

Mr Kelly, 52, was also part of an experiment comparing his development and changes in space with his identical twin brother — Mark — back on Earth.

He will travel by chartered flight to Houston for a Nasa medical examination.

In his year aboard the space station, Mr Kelly has been an avid internet poster, capturing stunning views on his Instagram page and tweeting regularly to nearly a million followers while travelling some 230 million kilometres.

One image Kelly tweeted captured the economic divide between North and South Korea as visible from space, with the South aglow with electric lights and the North cast in a blanket of darkness.

Another impressive shot was one of the Milky Way which Kelly described as “old, dusty, gassy and warped. But beautiful.”

“Space flight is the biggest team sport there is, and it’s incredibly important that we all work together to make what is seemingly impossible possible,” Mr Kelly said when handing over command of the ISS to fellow Nasa astronaut Tim Kopra on Monday.

The ISS trio leave behind Mr Kopra, Russian cosmonaut Yuri Malenchenko and the European Space Agency’s Tim Peake, who is a British astronaut.

The record for consecutive days spent in space by an American astronaut was previously held by Michael Lopez-Alegría, who spent 215 straight days in 2007.

The world record for longest single stay in space is held by Russian Valery Polyakov, who spent some 438 days on the Mir space station from 1994 to 1995.

*Agence France-Presse