NASA gives crucial update on when astronauts trapped in space will return to Earth - and why any sooner could burn them to a crisp

NASA said it needs at least another week to determine how long its stranded astronauts will be stuck in space because of Boeing's faulty space craft.

In a crucial update, space agency officials repeated the line from last week that one of the most likely options is to attach them to a different mission that would bring them home in February 2025. 

NASA astronauts Sunita Williams and Barry Wilmore were only supposed to be up there for eight days when they launched on Boeing's Starliner in June, but an issue with the craft's thruster system means it's not safe to undock and bring them home.

NASA officials said that one of their biggest concerns is that Starliner burns up in Earth's atmosphere as it tries to re-enter - which would incinerate anyone on board.

The fate of stranded astronauts Sunita Williams (left) and Barry Wilmore (right) remains unclear as NASA and Boeing work towards a plan to get them home.

The fate of stranded astronauts Sunita Williams (left) and Barry Wilmore (right) remains unclear as NASA and Boeing work towards a plan to get them home.

'That's why we're looking so closely at the thruster jets and even thinking about how the larger thrusters work,' they said during a Wednesday press conference.

The February 2025 plan involves attaching the astronauts to a mission that involves Elon Musk's Space X Dragon ship.

It's scheduled to launch in September and return them to earth with that mission in that following February.

If they go the SpaceX route, it will come with additional risks to the astronauts' health.

Each additional day the astronauts spend in space exposes them to more radiation, which could cause them to develop cancer later in life.

The ISS has shielding to reduce the amount of space radiation that astronauts are exposed to. But they still endure about 365 times more radiation than we do here on Earth. 

Plus, the spacesuits that Williams and Wilmore traveled in on their way to the ISS would not be suitable on Crew Dragon, meaning that the astronauts would have to make the journey home unsuited, officials said. 

Without the protection that spacesuits provide, Williams and Wilmore could face additional dangers during the return flight.   

But there are risks associated with returning on Boeing's Starliner too, which faced numerous technical issues before, during and after it launched toward the ISS in June. 

NASA says there's a chance the Boeing's faulty Starliner could still return Williams and Wilmore to Earth, despite numerous technical issues with the spacecraft.

NASA says there's a chance the Boeing's faulty Starliner could still return Williams and Wilmore to Earth, despite numerous technical issues with the spacecraft. 

Williams and Wilmore were expecting to return to Earth in about a week. But thruster failures and helium leaks on Starliner prompted NASA and Boeing to keep the two astronauts in orbit for longer over fears a trip back on the spacecraft could end in disaster.

Despite these issues, Boeing is hopeful that their spacecraft could still return to Earth with Wilmore and Williams on board.

'We still believe in Starliner's capability and its flight rationale. If NASA decides to change the mission, we will take the actions necessary to configure Starliner for an uncrewed return,' A Boeing spokesperson previously told DailyMail.com in an emailed statement.

NASA, too, still has confidence in Starliner's capabilities.

Officials said that that the fact that the astronauts can spend weeks on board the International Space Station means that they have time to try to address the technical issues with the spacecraft. 

'We've had very honest discussions with each other, and I am not surprised the Boeing team are 100% behind their vehicle,' said Ken Bowersox, the associate administrator at Nasa’s Space Operations Mission Directorate.

'But I can also tell you that they want to work with us in a partnership. What the NASA team thinks is important, and when we get to a decision, we will work through it together,' he added. 

But an expert told the BBC that some NASA decisionmakers likely remain unconvinced.

Officials previously stated that they would make a decision about the return plan by mid-August, but have now pushed the decision deadline to the last week of the month.

But that there's 'no sharp cutoff.' 

NASA's chief astronaut, Joe Acaba, said that astronauts like Williams and Wilmore 'embark on missions fully aware of the various scenarios and outcomes that may become our realities.'

'This mission was a test flight... they knew this mission might not be perfect,' he said. 

At this time, Williams and Wilmore appear to be 'doing fine.'

'In my office right now I can watch them working on the ISS,' Abaca said, adding that they have fully integrated into the station's crew. 

'But we are human,' he said. 'And this is hard on crew members and their families, and we take that into account.'