WASHINGTON -- A NASA astronaut who returned to Earth on the Crew-8 mission is hospitalized in stable condition after experiencing an unspecified medical issue after splashdown.

In an Oct. 25 statement, NASA said the unidentified astronaut "experienced a medical issue" after the Crew Dragon splashdown in the early morning hours off the coast of Pensacola, Florida. The astronaut "is in stable condition under observation as a precautionary measure" at Ascension Sacred Heart Pensacola hospital.

All four Crew-8 crewmembers were transported to the hospital for additional medical checks after undergoing routine post-flight medical examinations on the SpaceX recovery ship. "During routine medical assessments on the recovery ship, the additional evaluation of the crew members was requested out of an abundance of caution," NASA stated.

The agency did not identify the astronaut who is hospitalized or details about their medical issue, citing medical privacy. The other three members of the crew have been discharged from the hospital and returned to the Johnson Space Center in Houston.

Crew-8 returned NASA astronauts Matthew Dominick, Michael Barratt and Jeanette Epps along with Roscosmos cosmonaut Alexander Grebenkin. All four appeared to be in good condition when exiting the Crew Dragon spacecraft a little more than half an hour after splashing down, smiling and waving on the NASA broadcast.

"Right now, the crew is doing great," Richard Jones, deputy manager of NASA's Commercial Crew Program said during a media teleconference about 90 minutes after splashdown. "They are going to spend a little bit of time on the recovery vessel going through their medical checks and they'll soon be on their way back to Houston after all of those are done."

The fact that NASA decided to have all four undergo additional medical checks at the hospital would appear to rule out an isolated medical issue and instead raises the possibility of some kind of incident during or after their return. However, NASA officials said at the briefing there were no issues with the spacecraft during its reentry and splashdown, giving no indication of anything out of the ordinary taking place.

"We're grateful to Ascension Sacred Heart for its support during this time, and we are proud of our team for its quick action to ensure the safety of our crew members," NASA stated.