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

But nobody could have guessed one stumbling block would be that his prosthetic leg might poison the air on board the International Space Station (ISS).

The leg is made from a mixture of carbon fibres, resin and high-density foam and so may give off toxic gas that could build up over time and prove dangerous to astronauts on board.

Experts at the ESA are testing the leg to make sure it complies with Nasa standards. In 2015, the crew of the ISS were forced to evacuate the US part of the satellite following a rise in ammonia levels.