NASA and SpaceX are targeting no earlier than 5:05 p.m. EST, Wednesday, Jan. 14, for the undocking of the agency’s SpaceX Crew-11 mission.

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 Crew Dragon spacecraft, with two Nasa astronauts, a Japanese crewmember, and a Russian cosmonaut aboard, undocked from the station at around 3:30 am IST. It is now heading for a splashdown in the Pacific Ocean off California's coast at 2:11 pm.

On Thursday, a pair of astronauts will venture outside the space station to prepare for the future installation of roll-out solar arrays that will help power its deorbit in 2030.