Three NASA astronauts and one Russian cosmonaut were unexpectedly transferred to a medical facility in Florida, rather than returning to their home base in Houston after their splashdown early Friday morning aboard a SpaceX Crew Dragon capsule.

One of those astronauts remained in the hospital Friday afternoon with a “medical issue,” while the three others flew to NASA’s Johnson Space Center in Houston after a health evaluation at Ascension Sacred Heart Pensacola, a hospital near the crew’s splashdown site in the Gulf of Mexico. NASA did not provide any further details about the crew member who remained at the medical facility.

“To protect the crew member’s medical privacy, specific details on the individual’s condition or identity will not be shared,” according to a Friday afternoon statement from NASA news chief Cheryl Warner.

“The one astronaut who remains at Ascension is in stable condition under observation as a precautionary measure,” the statement said.

The four-person crew, which spent nearly eight months aboard the International Space Station before landing in the Gulf of Mexico at 3:29 a.m. ET Friday, had a “safe splashdown and recovery,” NASA said Friday morning.

However, all four astronauts “were taken to a local medical facility for additional evaluation,” according to an update from Warner shared at 8 a.m. ET. The measure was taken for the entire crew “out of an abundance of caution,” according to NASA.

The four crewmates — including NASA astronauts Matthew Dominick, Michael Barratt and Jeanette Epps and Alexander Grebenkin of the Russian space agency Roscosmos — make up the staff of Crew-8, a routine mission to the International Space Station that Space X carried out on behalf of NASA.

All four astronauts were seen smiling and waving as they exited their Crew Dragon capsule and boarded a recovery ship during a live stream of their splashdown overnight. (CNN)…[+]

Photo: The SpaceX Crew-8 astronauts are seen inside the SpaceX Dragon Endeavour spacecraft onboard the SpaceX recovery ship MEGAN shortly after having landed Friday in the Gulf of Mexico off Pensacola, Florida. (Getty Images)