Three Chinese astronauts are currently stranded in space after their spacecraft was used to return another group to Earth. The three astronauts are currently taking part in a six-month mission called Shenzhou-21 on board China's Tiangong space station. But their spacecraft was used on Friday to return the previous crew, taking part in the Shenzhou-20 mission, after their own capsule was damaged by suspected space debris , delaying their return by more than a week. China's Manned Space Agency (