Astronaut Scott Kelly and cosmonaut Mikhail Kornienko returned to Earth after spending almost a year in space, landing in barren Kazakhstan.

International Space Station (ISS) crew member Scott Kelly of the U.S. shows a victory sign after landing near the town of Dzhezkazgan, Kazakhstan, on Wednesday, March 2, 2016.

International Space Station (ISS) crew member Scott Kelly of the U.S. shows a victory sign after landing near the town of Dzhezkazgan, Kazakhstan, on Wednesday, March 2, 2016. Image by (Krill Kudryavtsev/Pool photo via AP)

Their Soyuz capsule parachuted onto the central Asian steppes and ended a science-rich mission at the International Space Station that began last March and was deemed a stepping stone to Mars.

International Space Station (ISS) crew member Scott Kelly of the U.S. reacts after landing near the town of Dzhezkazgan, Kazakhstan, on Wednesday, March 2, 2016.

International Space Station (ISS) crew member Scott Kelly of the U.S. reacts after landing near the town of Dzhezkazgan, Kazakhstan, on Wednesday, March 2, 2016. Image by (Krill Kudryavtsev/Pool photo via AP)

It was a triumphant homecoming for the American and Russian after 340 days in space.

Mr Kelly pumped his fist as he emerged from the capsule, then gave a thumbs up. He smiled and chatted with his doctors and others, as photographers crushed around him in the freezing cold.

A search and rescue team works at the site of landing of the Soyuz TMA-18M space capsule carrying the International Space Station (ISS) crew of U.S. astronaut Scott Kelly and Russian cosmonauts Mikhail Kornienko and Sergey Volkov outside the town of Dzhezkazgan, Kazakhstan.

A search and rescue team works at the site of landing of the Soyuz TMA-18M space capsule carrying the International Space Station (ISS) crew of U.S. astronaut Scott Kelly and Russian cosmonauts Mikhail Kornienko and Sergey Volkov outside the town of Dzhezkazgan, Kazakhstan. Image by (Krill Kudryavtsev/Pool Photo via AP)

He said: “The air feels great out here. I have no idea why you guys are all bundled up.”

Mr Kelly, 52, and Mr Kornienko, 55, travelled in total 144 million miles through space, circled the world 5,440 times and experienced 10,880 orbital sunrises and sunsets during the longest single spaceflight by an American.

International Space Station (ISS) crew member Mikhail Kornienko of Russia is seen inside the Soyuz-TMA-18M space capsule after landing near the town of Dzhezkazgan, Kazakhstan, Wednesday, March 2, 2016.

International Space Station (ISS) crew member Mikhail Kornienko of Russia is seen inside the Soyuz-TMA-18M space capsule after landing near the town of Dzhezkazgan, Kazakhstan, Wednesday, March 2, 2016. Image by (Krill Kudryavtsev/Pool Photo via AP)

Piloting the Soyuz capsule home was the much fresher and decade younger cosmonaut Sergey Volkov, whose space station stint lasted the typical six months.

(Press Association)

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