'Stranded' NASA astronauts set to return from nine month space mission - but what health issues could they face?
15 March 2025, 14:07 | Updated: 15 March 2025, 14:38
A rocket has finally launched in a bid to bring two 'stranded' NASA astronauts back to earth after nine months in space - but how has the mission affected their health?
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Butch Wilmore and Suni Williams embarked on what was scheduled to be an eight day mission, however technical problems saw their stay extended to nine months.
As test pilots for Boeing's new Starliner capsule, the pair expected to be gone just a week or so when they launched from Cape Canaveral on June 5.
Now, after spending an extended period of time with no gravity, no sunlight and high levels of radiation, the conditions can cause a variety of hazardous side effects.
This comes as a SpaceX Falcon 9 rocket successfully lifted off from Florida on Friday following a string of delays, with the two astronauts set to finally return to earth from the International Space Station (ISS).
The duo are now set to be replaced by a team of four astronauts carried to space on the SpaceX rocket, with the team set to arrive late on Saturday evening.
Radiation
Astronauts Williams and Wilmore have been exposed to high-energy radiation in space.
On Earth, the atmosphere and our planet's magnetic field shield us from the sun's radiation, but in space exposure is much more severe.
This can lead to increased cancer risk, DNA damage, cardiovascular issues, immune system issues, and neurodegenerative effects.
Luckily, the ISS is still in the Earth's magnetosphere, the space around the planet that still has a magnetic field, providing some protection from radiation.
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Gravity
Microgravity, or very weak gravity, effects human bodies as the force helps to regulate bodily functions.
Astronauts are known to lose bone density - meaning your bones get more brittle and weaker.
For every month spent in space, astronauts' bones become 1% less dense if precautions aren't taken, says NASA.
Microgravity can cause muscle atrophy, the wasting or thinning of muscles too.
Boldly fluids can also shift upward in these conditions, causing facial swelling and intracranial pressure affecting vision.
This pressure leads to headaches too.
A study published last year found the 22 out of 24 astronauts who were in space for more than 26 weeks experienced frequent headaches.
Psychological impact
Living in cramped conditions with limited social interaction can cause psychological side effects.
Astronauts can experience stress, sleep and mood disorders, sleep disturbance and even cognitive performance declines, Afshin Beheshti, director of the Centre for Space Biomedicine at the University of Pittsburgh told Sky News.
Studies suggest that the longer astronauts spend in space, the longer it takes them to recover when returning to earth.
NASA astronaut Frank Rubio told Time Magazine: "The first two or three months after your return is really focused on [recovery], just kind of reincorporating yourself into Earth, your family, and then also rehabilitating your body.
"You adapt incredibly quickly to being in space, but then unfortunately, the readaptation process back to earth can sometimes be a little bit longer and more difficult.
"And that's just, I think, because the forces of gravity and the forces at play here on Earth tend to have a stronger effect on your body."
As test pilots for Boeing's new Starliner capsule, Mr Wilmore and Ms Williams expected to be gone just a week or so when they launched from Cape Canaveral on June 5.
A series of helium leaks and thruster failures marred their trip to the space station, setting off months of investigation by Nasa and Boeing on how best to proceed.
Eventually ruling it unsafe, Nasa ordered Starliner to fly back empty last September and moved the astronauts to a SpaceX flight due back in February.
To save a few weeks, SpaceX switched to a used capsule, moving up Mr Wilmore and Ms Williams' homecoming to mid-March.
