The NASA International Space Station (ISS) crew that includes a sick astronaut splashed down in the Pacific Ocean early on Thursday morning. On Jan. 8, NASA said it was ending the current the ISS mission out of abundance of caution because of a medical situation involving one of the astronauts on board.

The medical evacuation from the space station is underway, with four astronauts in their spaceship heading back to Earth so one of them can receive medical treatment.

The spacecraft carried two American astronauts – Mike Fincke, 58, and Zena Cardman, 38 – as well as Russian cosmonaut Oleg Platonov, 39, and Japanese astronaut Kimiya Yui, 55.