Four NASA astronauts rushed to hospital following 235 days in space and no one knows why

A crew of four NASA astronauts have been hospitalised after returning to Earth on SpaceX's Dragon capsule.

The Crew-8 astronauts reached the coast of Florida in the early morning hours of October 25 after spending nearly eight months on the ISS.

Initially, NASA revealed that one astronaut needed medical care after they landed. But it turned out that all of them ended up in the hospital.

One astronaut had to stay overnight but was reportedly in a 'stable condition'.

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

Three were released later, while one remains at the hospital 'under observation as a precautionary measure.'

Crew-8 astronauts finally reached the coast of Florida in the early hours of October 25 (SpaceX)

The crazy thing is no one knows the cause of this except for NASA.

The US space agency hasn't released any details about why the crew was hospitalised or which astronaut had to spend the night.

After long missions, astronauts can experience several health issues like bone and muscle loss, vision problems and kidney stones.

But without specific details being confirmed, it's uncertain whether the conditions of the ISS played a part. It’s also possible something could have gone wrong during the Crew Dragon's return trip to Earth.

Shortly after the incident, a NASA safety panel advised SpaceX to focus on crew safety as they get ready for future ISS missions.

During a meeting of the Aerospace Safety Advisory Panel on October 31, former astronaut and committee member Kent Rominger said NASA and SpaceX must “guard against letting the high pace of operations [cloud] their judgment."

The Crew 8 astronauts spent a whopping eight months in space (NASA)

He said the mishaps serve as a reminder to stay alert as SpaceX ramps up its missions.

"Both NASA and SpaceX need to maintain focus on safe Crew Dragon operations and not take any 'normal' operations for granted," Rominger said.

The Crew-8 mission launched to the ISS on March 3 and the crew was originally supposed to return in August.

But a series of delays pushed the return flight to early October, turning what was meant to be a 180-day stay into a 235-day one.

Rominger also pointed out several issues with SpaceX's Falcon 9 such as the July launch failure that grounded the rocket for about two weeks.

Then in August, Falcon 9 launches were halted when a booster tipped over during a landing and caused a huge blaze. The rocket was back to launching Starlink satellites just three days later.