If an emergency arises aboard China's Tiangong space station in the next few days, its three astronaut residents could be in trouble.
That trio — members of the Shenzhou 21 mission — arrived at Tiangong on Oct. 31 for a six-month stay. But their planned ride home is already gone. On Thursday night (Nov. 13), the Shenzhou 21 spacecraft carried three different astronauts away from the station — members of the Shenzhou 20 mission, whose own vehicle was deemed unfit to carry people back to Earth after being damaged by a space-debris strike.
