Astronauts to Leave Space Station After Medical Issue.

A four-person Crew-11 team will return to Earth early after an undisclosed medical issue; NASA said the affected astronaut is "absolutely stable."

A crew of four astronauts is scheduled to depart the International Space Station Wednesday in what NASA describes as its first medical evacuation. The agency announced the move after a health episode that prompted the postponement of a planned spacewalk on Jan. 7. NASA declined to identify the astronaut or disclose the nature of the medical issue, citing privacy. Agency officials, including chief health and medical officer James Polk, said the astronaut is "absolutely stable." Known details: - The Crew-11 team will undock at roughly 5 p.m. Eastern in a SpaceX Dragon capsule and is expected to splash down off the coast of California at about 3:40 a.m. Thursday. - NASA characterized the return as its first medical evacuation from the International Space Station. - The agency would not release the affected astronaut's name or describe the medical issue and said the astronaut is "absolutely stable." - Crew-11 launched in August for an approximately six-month mission and will end its stay about a month early. - After Crew-11 departs, two Russian cosmonauts and NASA astronaut Christopher Williams will remain on the station. Summary: The early return shortens Crew-11's mission by about a month and represents NASA's first recorded medical evacuation from the ISS. The four crew members are scheduled to undock Wednesday and splash down early Thursday, and NASA is working to accelerate the arrival of the next crew that had been slated to launch in February.