Four astronauts returned safely to Earth early on Thursday after an undisclosed serious medical condition affecting one of them forced an end to their International Space Station mission a few weeks early. Their SpaceX capsule splashed down in the Pacific off California, capping a 10-hour-plus descent from the space station and fiery re-entry through Earth's atmosphere. It was the first time that NASA has cut short the rotation of an ISS crew due to a health emergency. #SpaceX​ #NASA​ #Crew11​ #ISS