A group of astronauts have returned to Earth in a Pacific Ocean splashdown, in the first-ever medical evacuation carried out by NASA. The decision cut the team's mission short by over a month, after they launched into space in August. The astronaut's identity or condition hasn't been disclosed, but NASA said it was not an emergency situation.

The crew undocked from the orbiting outpost at 5:20 p.m. ET Wednesday — about a month earlier than planned —and are scheduled to splash down on Earth early Thursday.

Four NASA astronauts splashed down off the coast of San Diego early Thursday after their mission was cut short due to medical issues, with their spacecraft seen streaking across the sky from San Francisco to Los Angeles.

Yui is part of Crew-11, which will depart the ISS ahead of schedule due to one of the astronauts experiencing a "medical concern," according to NASA. The departure will bring the joint NASA and SpaceX mission to an early end.