Four astronauts have landed back on Earth from the International Space Station (ISS) after the decision was taken last week to end their mission early due to a medical problem.

Nasa’s SpaceX Crew-11 mission safely splashed down early Thursday morning in the Pacific Ocean off the coast of San Diego carrying US astronauts Zena Cardman and Mike Fincke, Japan Aerospace Exploration Agency (Jaxa) astronaut Kimiya Yui and Roscosmos cosmonaut Oleg Platonov. The team had already spent five months aboard the ISS and were originally not expected to return until next month.

It is the first time astronauts have been evacuated due to a health issue since the ISS was put into Earth’s orbit in 1998. Nasa has been careful not to give any clues about which of the four passengers had the medical issue, but a planned spacewalk with Fincke and Cardman was cancelled the day before the announcement that they would return early. Jaxa has also separately confirmed that Yui was in good health.

Nasa has said that...