Four astronauts evacuated from the International Space Station (ISS) have landed back on Earth, after their stay in space was cut short by a month due to a "serious" medical issue. The astronauts arrived on the ISS on 1 August expecting to complete a standard six and a half month stay.

The crew member of concern is doing fine,” NASA said after their return early Thursday, the first time in the space station’s 25-year history that a crew returned home early because of a medical concern.

Crew 11 is expected to splash down off the coast of Southern California at 3:41 a.m., closing out a 167-day stay in space.

With its departure ahead of Crew-12's arrival, Crew-11 leaves behind a skeleton crew of three aboard the ISS, including Kud-Sverchov and fellow cosmonaut Sergei Mikaev as well as NASA astronaut Chris Williams. Crew-12 is currently scheduled to launch no earlier than Feb. 15.

Cruz is chairman of the Senate Committee on Commerce, Science, and Transportation and has an outsized say in space policy. As a senator from Texas, he has a parochial interest in Johnson Space Center, where the International Space Station Program is led.

After more than five months in space, four astronauts on a mission known as Crew-11 are about to cut their mission short and return to Earth.

The International Space Station (ISS) is a closed ecosystem, and the biology inside it — including its microbial residents — don't necessarily behave the same way on our home planet.

The spacecraft descended on parachutes, splashing down in calm Pacific waters near San Diego at 3:41 a.m. Eastern time (12:41 a.m. Pacific time). The capsule was hoisted out of the sea onto the deck of a SpaceX recovery ship and its hatch opened after 4 a.m., with the first of the returning astronauts exiting the capsule just before 4:30 a.m.