S Kelly and M Kornienko have started their year-long trip out is space. US astronaut Scott K and Russian cosmonaut Mikhail K left today on a 12-month tour of duty on the International Space Station.

Scientists will study the effects on the human body of living in micro-gravity for an extended period of time. It may be the longest continuous stay anyone has had aboard the orbiting platform.

NASA To Study A Twin In Space And His Brother On Earth http://n.pr/1Btgvou

Astronauts blast off for 1-year trip to space station http://fw.to/CP5aw9R

BBC News - Kelly and Kornienko begin year-long space trip http://www.bbc.com/news/science-environment-32089169

Yearlong International Space Station crew launches successfully http://upi.com/4227093