NASA finally reveals shocking reason why astronauts have been stranded in space for 9 months

A NASA official has offered some background on why astronauts Sunita 'Suni' Williams and Barry 'Butch' Wilmore have had to stay in space for nine months after their original plan to return home fell through.

Wilmore and Williams had to settle in for the long haul on board the International Space Station last June, after what should have been an eight-day mission was scuppered when the Boeing spacecraft intended to bring them back was determined to be unsafe.

Now, the end is finally in sight for the two astronauts as SpaceX's Falcon 9 ship is set to arrive at the ISS and bring them home in a matter of days.

However, there have been some mixed reports on exactly why it's taken so long to get Wilmore and Williams back to solid ground.

On December 17, NASA said the return would have to take place in March so it could work with SpaceX to finish a new Dragon spacecraft for the mission.

Then, in an interview with Joe Rogan released on February 28, SpaceX CEO Elon Musk claimed his company could have brought the astronauts back 'way sooner', but the delay was a matter of 'politics'. Previously, former NASA administrator Bill Nelson claimed 'politics has not played any part in this decision'.

Wilmore and Williams set off on their mission in June 2024 (Joe Raedle/Getty Images)

Kenneth Bowersox, the associate administrator for NASA's Space Operations Mission Directorate, has now helped to clear things up as he offered a new explanation in a teleconference last Friday. It turns out, NASA simply couldn't afford the mission.

He explained: "The SpaceX folks helped us folks - helped us with a lot of options on how we would bring Sunny and Butch home on Dragon [a capsule] in a contingency.

"They've been so helpful this last year, coming up with those options. When it comes to adding on missions or bringing a capsule home early, those were always options."

However, despite having a number of options available to them, Bowersox said NASA 'ruled them out pretty quickly'.

The astronauts are set to return on a SpaceX ship (NASA)

Bowersox explained: "This was] just based on how much money we've got in our budget, and the importance of keeping crews on the International Space Station. They're an important part of maintaining the station."

NASA's Space Operations Mission Directorate added: "The best option was really the one that we're embarking upon now."

The space agency's comments also received backing from Bill Gerstenmaier, the vice president for SpaceX, who explained that delaying the return until March allowed for the astronauts to be used 'in a very productive manner' which allowed them to 'keep the science going'.