Doctor reveals how long it could take ‘stranded’ NASA astronauts to walk again

While Sunita Williams and Butch Wilmore’s space mission is finished, the experience is far from over as the pair have a lengthy recovery period ahead of them.

The astronauts landed earlier this week, finally returning home after more than nine months in space.

They now have to work through an extensive rehabilitation process designed to reacclimatise their bodies after spending the best part of a year living in the International Space Station.

Before they embarked on the mission, they will have ensured their bodies were in peak physical condition to reduce the impacts of space travel, and continued with workouts while out there to maintain these levels as best as possible.

However, Dr Vinay Gupta, a pulmonologist and Air Force veteran, told the Daily Mail: “The reality is, they're effectively getting a fraction of the sort of exercise that we all take for granted just by walking in [Earth's] gravity."

Butch Wilmore being stretchered away from the capsule (Keegan Barber/NASA via Getty Images)

Ahead of Williams and Wilmore landing, Gupta said they would not be able to walk on their own when they return due to living in low gravity.

Gupta added that they could need up to six weeks of rehabilitation to regain their strength, which will include guided exercise and a nutritional plan and began the very same day they got back to Earth.

Indeed, the duo now have to undergo NASA’s official 45-day rehabilitation programme, which consists of three phases.

This begins with a focus on walking, flexibility and muscle strengthening, before things move on to phase two, which adds proprioceptive exercises – aimed at strengthening the body and improving the mind's perception of its movement and position - and cardio reconditioning.

The pair have a lengthy rehab process ahead of them (NASA/Keegan Barber/Handout/Anadolu via Getty Images)

Finally, phase three – the longest – focuses on returning astronauts to their optimal level of physical performance via functional development training.

This process is crucial for astronauts returning home, as while they may exercise for at least two hours a day while on the ISS, this isn’t enough to fully counter the effects their bodies experience.

Dr John Jaquish, a biomedical engineer, told the Daily Mail how astronauts who spend long periods of time in low gravity 'lose musculature, they lose bone density'.

“The human body needs the Earth's gravitational pull, and in an absence of that, a lot of things are not functioning correctly,” he added.