A Russian Soyuz rocket lifted from the Baikonur Cosmodrome in Kazakhstan on Friday, carrying a US-Russian crew to the International Space Station (ISS). The crew comprised NASA astronaut Scott Kelly, 51, and cosmonauts Mikhail Kornienko, 54, and Gennady Padalka, 56.

Kelly and Kornienko will spend a year on the orbiting space laboratory, which is double the time astronauts spend at the ISS.

Padalka will return to earth in September and his stay will increase his total number of days being spent at the ISS to 878. The current flight is the fifth for Padalka.

Kelly and Kornienk will remain on board until next March. The crew arrived at the ISS on Friday night following a launch from Kazakhstan. "It's like coming to my old home", said Scott Kelly, who spent five months at the space station in 2010-2011.

The White House congratulated the crew for achieving the feat. President Barack Obama's science adviser, John Holdren, said best of luck to Kelly, Kornienko and the rest of the crew. He also highlighted the importance of the year-long mission as a key to prepare for manned Mars mission in the mid-2030s. Holdren said in a phone hookup that the astronauts at the ISS are heroes and humanity is relying on them to start living in other worlds.

Scientists want to determine the effects on human body by long stays in space. This will certainly help them start planning multi-year missions to Mars.