A Nasa astronaut who just returned from the International Space Station has been hospitalized for an unspecified medical condition but remains stable, according to the US space agency.

The four-member Crew-8 mission splashed down off the coast of Florida early on Friday after nearly eight months aboard the orbital laboratory.

On its way back to Earth, the SpaceX Dragon executed a normal re-entry and splashdown, and recovery of the crew and spacecraft was without incident, Nasa said in a blog post.

But during routine medical assessments on the recovery ship, an “additional evaluation of the crew members was requested out of an abundance of caution”, it added, without elaborating.

The Nasa astronauts Matthew Dominick, Michael Barratt and Jeanette Epps, and the Roscosmos cosmonaut Alexander Grebenkin were all flown to Ascension Sacred Heart Pensacola.

Three were subsequently released, while one of the Nasa astronauts remains at the hospital “under observation as a precautionary measure”.

Nasa said it would not disclose specific medical information to protect the crew member’s privacy but would provide updates as available.