Scott Kelly will leave Earth on Saturday for a 12-month trip to the International Space Station with Russian cosmonaut Mikhail Kornienko . He will undergo tests to compare his health to that of his twin brother , retired astronaut Mark Kelly , to see the effects of space on the body . The two astronauts are scheduled to spend about six months in orbit and return home after spending more than three years living aboard the ISS. They said they 'll miss human touch but know the mission is for the greater good - and said they are already looking forward to the homecoming .
Scott Kelly will leave Earth on Saturday for a 12-month trip to the International Space Station with Russian cosmonaut Mikhail Kornienko . He will undergo tests to compare his health to that of his twin brother , retired astronaut Mark Kelly , to see the effects of space on the body . But he will be leaving behind his girlfriend of five years , 41-year-old Amiko Kauderer , who works in NASA 's public affairs department . They said they 'll miss human touch but know the mission is for the greater good - and said they are already looking forward to the homecoming .