The way we practise spacewalk is in water. Water gives us the neutral buoyancy that we need. So we sink training modules into swimming pools and then practise the spacewalking on them. We wear very specific equipment, a pressurized spacesuit – very difficult to move in actually – it's hard to bend the fingers, it's hard to bend your arms – and it really gives you quite a difficult workout.
British astronaut Tim Peake says water gives us buoyancy, which is the ability to float. Floating in space is similar to floating in water, so astronauts practise their spacewalk in swimming pools.