Four astronauts are hours away from strapping into a spacecraft and departing the International Space Station about a month early after one of them experienced a health issue. The impending departure would mark the first time in the station's 25-year history that a crew on the orbital outpost has cut a mission short in order to be medically evacuated.

The members of NASA's Crew-11 mission are coming home about a month early because one of the crew has a health condition worrisome enough that the space agency decided the person needed to get thoroug...