An astronaut who found himself stuck in space for almost a year after his country ceased to exist has revealed how it felt to finally return to Earth.Not many people know what it's like to have their entire country suddenly become non-existent, but cosmonaut Sergei Krikalev does.In 1991, Krikalev left Earth on a routine mission to the Mir space station, which was in orbit from 1986 to 2001.