WASHINGTON >> A NASA astronaut was flown to a hospital with an unspecified medical issue on Friday shortly after returning to Earth from a nearly eight-month mission on the International Space Station, the U.S. space agency said.

The astronaut, who NASA did not name for privacy reasons, had splashed down off Florida’s coast at 3:29 a.m. ET (0729 GMT) on Friday (9:29 p.m. on Thursday Hawaii time) aboard SpaceX’s Crew Dragon capsule with three other crew members — two NASA astronauts and a Russian cosmonaut.

The crew included U.S. astronauts Matthew Dominick, Michael Barratt, and Jeanette Epps, and Russian cosmonaut Alexander Grebenkin. Their 235 days in space made it longer than the usual six-month ISS mission duration and marked the longest stay in orbit for SpaceX’s reusable Crew Dragon spacecraft.

NASA initially said the entire crew was transported to the medical center for additional evaluation and out of an abundance of caution, but did not specify whether all or a portion of the crew had been experiencing issues.

NASA later said it was one of its astronauts who experienced a medical issue and that the crew had been flown to a hospital in Pensacola, Florida, near the splashdown site. The three other crew members have since left the hospital and returned to Houston, the space agency said.

“The one astronaut who remains at Ascension is in stable condition under observation as a precautionary measure,” NASA said in a statement, referring to Ascension Sacred Heart Pensacola hospital. The agency said it will not share the nature of the astronaut’s condition.

Russia’s space agency, Roscosmos, posted on the social messaging platform Telegram a photo of Grebenkin standing upright and smiling, with a caption reading: “After a space mission and splashdown, cosmonaut Alexander Grebenkin feels great!”

The crew’s return from the football field-sized science lab 250 miles up in orbit had been delayed for weeks because of two hurricanes that swept through the U.S. southeast near Crew Dragon’s expected splashdown zones.

SpaceX maintains a fleet of reusable spacecraft and has flown to the ISS 44 times. The Elon Musk-owned company remains the only U.S. option for NASA astronaut trips to and from the ISS. Boeing’s Starliner, intended as a second U.S. ride, has been hobbled by years of development issues.

Crew Dragon safely undocked from the ISS on Wednesday afternoon and reentered Earth’s atmosphere early Friday morning, deploying parachutes before plunking into the Gulf of Mexico.

At a post-splashdown news briefing, a NASA official said “the crew is doing great” and made no mention of any issues with the astronauts. He noted two hitches with Crew Dragon’s parachute deployment.

Richard Jones, deputy manager of NASA’s Commercial Crew Program, said Crew Dragon’s initial set of braking parachutes suffered some “debris strikes” and that one of four parachutes in a subsequent set took longer than expected to unfurl.

Neither event affected crew safety, Jones said, calling the splashdown weather “ideal” for the crew’s recovery.

The crew’s reusable Crew Dragon spacecraft was on its fifth flight, logging 702 days in orbit since its first mission, SpaceX’s vice president of flight reliability, William Gerstenmaier, a former senior NASA official, told reporters during the news conference.