Four astronauts evacuated from the International Space Station (ISS) have landed back on Earth, after their stay in space was cut short by a month due to a “serious” medical issue.
The astronauts arrived at the ISS on 1 August expecting to complete a typical six and a half month stay.
But last week, a scheduled spacewalk was called off at the last minute. Hours later, Nasa revealed that a crew member had fallen ill.
This is the first time that astronauts have been evacuated due to a health issue since the station was placed in Earth orbit in 1998.
BBC science correspondent Pallab Ghosh explains how Nasa handles medical emergencies in space.