American astronaut spent nearly 100 days longer in space than 'stranded' Sunita Williams and Butch Wilmore

NASA astronauts Sunita 'Suni' Williams and Barry 'Butch' Wilmore safely splashed down off the Florida coast last night, wrapping up an epic nine months in space.

After emerging from the SpaceX Dragon capsule from a 17-hour journey back to Earth, they smiled and waved as the recovery crew came to their aid.

It would be some time before the astronauts reunite with their families as they first need to undergo medical evaluations after spending an extended period in space - and will have a long road of recovery ahead.

The two left Earth in June 2024 for what was meant to be an eight-day mission to test Boeing’s Starliner capsule. But due to technical malfunctions that made the craft unsafe for return, they ended up staying aboard the International Space Station (ISS) for a whopping 286 days.

As lengthy as their mission was, it seemingly doesn’t come close to the record for the longest spaceflight by an American.

Frank Rubio holds the record for the longest spaceflight at 371 days. NASA/Bill Ingalls

Francisco 'Frank' Rubio, a NASA astronaut, flight surgeon, and U.S. Army colonel, holds the NASA record for the longest spaceflight at 371 days.

Rubio launched aboard a Soyuz capsule on 21 September, 2022, along with Russian cosmonauts Sergey Prokopyev and Dmitry Petelin.

They were originally scheduled to return to Earth six months later on 28 March, 2023. However, their spacecraft endured a radiator leak that was likely caused by space debris or a micrometeoroid impact. It was deemed unsafe for transport and so had to be returned to Earth and replaced by another uncrewed capsule, which the trio used to return home.

Once the trio finally touched down in rural Kazakhstan in September 2023, they were pulled out of their Soyuz capsule and carried away as they were unable to walk from the microgravity.

Record-wise, Dr. Frank Rubio's prolonged mission surpasses the nearly yearlong stints of astronauts Mark Vande Hei (355 days) and Scott Kelly (340 days).

"Frank's record-breaking time in space is not just a milestone; it’s a major contribution to our understanding of long-duration space missions," said NASA Administrator Bill Nelson. "He embodies the true pioneer spirit that will pave the way for future exploration to the Moon, Mars, and beyond."

Butch Wilmore and Suni Williams returned to Earth last night after spending nine months in space. Handout / Handout / Getty

Dr. Rubio admitted that it was difficult to be away from his family for so long, but during his time, he had to 'stay positive' and focus on the mission.

"You try to just focus on the job and on the mission and remain steady, because ultimately, every day, you have to show up and do the work," he said.

According to the US space agency, Dr. Rubio completed '5,963 orbits of the Earth' during his record-breaking mission. Among his many scientific experiments in space, one of his favourites was observing how a tomato plant grew in microgravity.

"I love working with that little plant and seeing it grow and develop," he said.