For the 1st time in the history of the International Space Station, an astronaut experienced a health issue that required NASA to end a mission early.

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.

"Fundamentally, we're in space to learn. It's why NASA prepares for the unexpected  — so we are ready to respond decisively and safely."

An ailing astronaut is back on Earth. The crew of four returned Thursday, ending their space station mission more than a month early in NASA's first medical evacuation.

NASA Administrator Jared Isaacman said all four Crew-11 astronauts are 'in good spirits' after they landed early Thursday near California.

In an unprecedented move, NASA is bringing an astronaut crew home early from the International Space Station because one astronaut has an undisclosed medical condition.

The SpaceX Crew-11 Dragon spacecraft splashed down this morning as four astronauts completed an unprecedented medical evacuation of the International Space Station (ISS).

NASA's SpaceX Crew-11 mission is ending early to bring back a member with a medical issue. Astronauts who spend a long time in space may have brain changes, 'baby feet' and more.

The members of Crew-11 — two American, one Russian and one Japanese — splashed down after one became ill, prompting an early return.

A SpaceX ship recovered the spacecraft from the ocean and at around 1:30 a.m. and welcomed aboard NASA astronauts Zena Cardman and Mike Fincke, plus Kimiya Yui of the Japan Aerospace Exploration Agency and Oleg Platonov of Roscosmos, the Russian space agency.