ガガーリン宇宙飛行士訓練センター
On 24 February 1998, Kornienko was selected as a test cosmonaut candidate and, in 1999, following basic training at the Yuri Gagarin Cosmonaut Training Center, he was qualified as a test cosmonaut. Since 1999, he has trained in the International Space Station group. He served on the ISS Expedition 8 backup crew as a flight engineer.