NASA has announced plans to return four astronauts from the International Space Station (ISS) earlier than initially scheduled due to a crew member’s health issue encountered in orbit.

According to a statement released by NASA late Friday, the undocking from the ISS is set to take place by 5 p.m. ET on Wednesday, weather permitting at the designated splashdown site off California’s coast.

This marks the first occasion in the 25-year history of the ISS that a mission has been interrupted due to a medical incident in space.

While NASA confirmed a medical issue arose earlier this week, specific details regarding the crew member’s condition or identity have not been disclosed, citing medical privacy regulations.

During a news conference on Thursday, agency officials reassured that the situation is stable, and the decision for early departure is a precautionary measure rather than an emergency evacuation.

NASA Administrator Jared Isaacman stated, “After consulting with Chief Medical Officer Dr. J.D. Polk and agency leaders, we concluded that it’s best for the astronauts to return Crew-11 ahead of schedule.”

The returning crew includes NASA astronauts Zena Cardman and Mike Finke, Japanese astronaut Kamiya Yui, and Russian cosmonaut Oleg Platonov. Crew-11 was initially slated to reach the ISS in early August and remain in the laboratory until late February.

The astronauts will return in the same SpaceX Dragon capsule that transported them to the ISS. If all goes as planned, undocking will occur Wednesday night, with an expected splashdown in the Pacific Ocean around 3:40 a.m. Thursday.

NASA and SpaceX will provide further updates on the precise landing time and location as it gets closer to the undocking.

Post Crew-11’s departure, NASA will maintain one astronaut aboard the ISS to oversee U.S. scientific experiments and operations. Flight engineer Chris Williams launched aboard a Russian Soyuz spacecraft on November 27th and will be joined by Russian cosmonauts Sergei Kud-Sverchkov and Sergei Mikayev.

The next crew is scheduled to launch to the ISS in mid-February, with NASA considering enhancements to this mission, known as Crew-12.