NASA's Matthew Dominick, Michael Barratt and Jeanette Epps, and Russia's Alexander Grebenkin were flown to the hospital for additional medical checks Friday after parachuting into the Gulf of Mexico off the Florida coast aboard a SpaceX capsule.
Three were released and returned to Houston. A NASA astronaut - who was not identified - was kept for observation for an unspecified medical issue. Citing patient privacy, the space agency declined to identify the astronaut or release details about their condition - other than to say the astronaut is in "good health" and would "resume normal post-flight reconditioning with other crew members."
It can take days or even weeks for astronauts to readjust to gravity after living in weightlessness for several months.
The astronauts should have been back two months ago. But their homecoming was stalled by problems with Boeing's new Starliner astronaut capsule, which came back empty in September because of safety concerns. Then Hurricane Milton interfered, followed by another two weeks of high wind and rough seas.
SpaceX launched the four - NASA's Matthew Dominick, Michael Barratt and Jeanette Epps, and Russia's Alexander Grebenkin - in March. Barratt, the only space veteran going into the mission, acknowledged the support teams back home that had "to replan, retool and kind of redo everything right along with us ... and helped us to roll with all those punches."
Their replacements are the two Starliner test pilots Butch Wilmore and Suni Williams, whose own mission went from eight days to eight months, and two astronauts launched by SpaceX four weeks ago. Those four will remain up there until February.
The space station is now back to its normal crew size of seven - four Americans and three Russians - after months of overflow.