What stranded NASA astronauts are doing on the International Space Station as Elon Musk rescue is delayed

They thought they were almost home. But Barry 'Butch' Wilmore and Sunita 'Suni' Williams have been left stuck on board the International Space Station (ISS) for a little while longer.

Having headed to the ISS back in June 2024, they were only meant to stay on board the vessel for a week.

Fast forward nine whole months and the veteran astronauts remain looking down on planet Earth as they whiz around the planet in the US Orbital Segment of the ISS.

Living a life of zero gravity 400 kilometres from the world below's surface, it's been quite the ride for Williams and Wilmore. The time to come home nears, though. Just not quite yet.

Why has their return to Earth been delayed?

President Donald Trump and Elon Musk, who heads up SpaceX, said they were moving the pieces behind the scenes to bring both Wilmore, 62, and Williams, 59, back to Earth as soon as possible.

A date was finally put on the cards, with the joint NASA and SpaceX Crew-10 mission given a launch date of Wednesday (12 March) and a return to Earth date of Sunday.

But Wednesday came and went, and the Crew-10 mission remained grounded after being postponed by a hydraulic issue. The next launch window from Florida is Friday evening (14 March), with a potential return being Monday (17 March).

Sunita 'Suni' Williams and Barry 'Butch' Wilmore (NASA)

What have Williams and Wilmore been up to on the ISS?

They're astronauts so you won't be shocked to know they have been using their time to carry out work in line with their expertise.

This has included a number of experiments, with the ISS effectively a laboratory orbiting Earth. Hello science.

One major experiment the duo have been undertaking relates to an ultrasound machine on the ISS, using the technology to see how space affects the human body.

The ISS (NASA via Getty Images)

It's not all as interesting as that, mind. Some of their work has focused on general maintenance of the ISS, which is approaching its end of service lifespan.

At that point, Musk's SpaceX is set to crash-land it back into Earth's oceans.

But until then, Williams and Wilmore have been doing task such as taking inventory of food supplies on the ISS so NASA knows what there is and what needs bringing up on the next cargo mission. They've also been working on the toilet system, with Wilmore some what of a handyman repairing his local church back in the USA.

Before they went in to space (Joe Raedle/Getty Images)

Astronaut health worries

When they do finally come back to Earth, Williams and Wilmore will need some time to physically adjust after spending months without gravity on their bodies.

The duo have been taking part in daily exercise on the ISS to keep their muscles and skeletal systems robust, with a NASA spokesperson previously telling LADbible: "All NASA astronauts aboard the International Space Station undergo routine medical evaluations, have dedicated flight surgeons monitoring them, and are in good health."

However, exercise won't be enough to negate all impact as weakened bone density loss is common among astronauts, as well as muscle waste in arms and legs. Your heart isn't exempt from this, with it having to do much less work to pump blood due to no resistance in the form of gravity.

Alan Duffy, an astrophysicist at Swinburne University, said their eventual return is a 'research project in itself' to see just how they are impacted physically.