The year is 1985. The unmanned Soviet space station Salyut 7, which is in low Earth orbit, suddenly stops responding to commands from the Control Center. If the space station - the pride of Soviet space engineering - falls from the sky, not only will it damage the image of the country, it will also be a disaster bringing untold casualties. To investigate the failure and prevent the catastrophe, people must be sent to the station. Yet no one in history has ever attempted to dock an uncontrolled vehicle in space. To this day, this mission is considered to be the most technically challenging in the history of space exploration.