British astronaut’s prosthetic leg could poison ISS crew

John McFall is helping with tests to see if disabled astronauts can go into space – ESA/NOVESPACE

When former Paralympian John McFall was chosen to become the European Space Agency’s (ESA) first disabled astronaut last November, he knew there would be testing times ahead.

But no one could have guessed that his prosthetic leg could poison the air on board the International Space Station (ISS).

The leg is made from a combination of carbon fibres, resin and high density foam and therefore could give off toxic gas that could build up over time and be dangerous to astronauts on board.

ESA has experts testing the leg to ensure it meets NASA standards. In 2015, the ISS crew had to evacuate the US portion of the satellite after a rise in ammonia levels.

“It’s things you don’t have to think about,” Mr McFall told The Telegraph. “The socket is carbon fiber and it’s like high density foam on the inside. The carbon fiber socket is filled with resin. The foam is made with polymers.

“Those materials will continue to release gases to one degree or another and in an environment like the ISS where the air is constantly being recycled, any significant amount of gases produced by a material will be amplified over time due to on them. you are not filtered out.”

It is one of several revelations that Mr McFall helped ESA to find as part of the feasibility project to find out if it is possible to send disabled astronauts into space.

There are nearly 100 requirements that astronauts must pass to be able to fly, including moving safely around the ISS and SpaceX Crew Dragon module, being able to perform emergency procedures and experiments, fitting into a suit space and maintain good health in orbit.

Ensuring that Mr McFall's prosthetic leg is intact and continues to fit properly in microgravity is challenging.Ensuring that Mr McFall's prosthetic leg is intact and continues to fit properly in microgravity is challenging.

Ensuring that Mr McFall’s prosthetic leg is intact and continues to fit properly in microgravity is challenging – Tony Jolliffe/BBC

Although the team initially thought that wearing a prosthesis in space might not be necessary, tests have shown that it is likely to be vital for maintaining fitness, balance and rapid evacuation in an emergency.

But making sure it’s safe and continues to fit properly in microgravity is challenging. Astronauts’ bodies change in space due to microgravity, meaning Mr. McFall’s legs may shrink or expand, and his prosthetics no longer fit.

To find out what would happen in space, he is experimenting in Cologne on tilt tables where he is hit at an angle with his head lower than his feet, to imitate the effect of a fluid rising up the body in microgravity.

“Most of the evidence suggests that fluid moves up to your midsection up to your trunk, and you actually lose some fluid volume in your lower limbs,” he said.

“But we have to prove because it is easier to manage a reduction in the volume of the stump by padding it a little with additional material, but to increase the volume of stumps you would have to make a socket that gets bigger.

“The most common question I get is ‘do you need legs in space?’ and for swimming around, maybe not necessary, but it is useful to stabilize yourself so that you can free your hands for experiments.

“But we found that I would have to wear a prosthesis in orbit to do the exercise countermeasures to maintain bone density and muscle mass.”

Mr McFall, 43, who was born in Surrey and grew up in Somerset, had his right leg amputated when he was 19 after a motorbike accident. But after taking up running again, he became a professional athlete, winning bronze at the 2008 Beijing Paralympics in the 100 meter T42 event.

Mr McFall (left) represented Great Britain at the 2008 Paralympics in Beijing, winning bronze in the 100 meters T42 eventMr McFall (left) represented Great Britain at the 2008 Paralympics in Beijing, winning bronze in the 100 meters T42 event

Mr McFall (left) represented Great Britain at the 2008 Paralympics in Beijing, winning bronze in the T42 100 meters event – Andrew Wong/Getty Images

He also re-elected as a doctor, working in the NHS for several years, and recently completed his final exams specializing as an orthopedic surgeon.

The astronaut feasibility study ends in 2025, when GSE will present a case to European ministers, who will decide whether to fund a mission.

“It’s at that point that they will make a decision about whether they want to support a flight for me or someone with a similar disability. I hope so,” he said.

“There are no red flags or show flags at any level so far. I think a long-duration mission to the space station is a great opportunity for us to learn about a person with a physical disability living and working in space.

“Astronauts don’t have much choice when or where they fly but I would love to go to the Moon.”

The married father of three recently moved his family to Germany to support his training. In fact, the only obstacle to their space flight may be something more mundane. He wants to be a doctor.

“I think the change of direction was tough from a psychological point of view, rather than the actual astronaut training,” he said.

“I miss the day-to-day operating hand. I’m a very practical person and this phase of the feasibility study is a little less hands on.”

Leave a Reply

Your email address will not be published. Required fields are marked *