In May this year, a serious leak of ammonium coolant caused an emergency on the International Space Station. There was only one way to fix the problem: go out into the vacuum on a spacewalk. In July ESA astronaut Luca Parmitano had to end a sortie into space after just an hour and a half of work as water leaked into his helmet. In both cases, the astronauts and ground control handled the situation with astonishing cool considering the high-stakes environment they were working in.

In training, like in a real spacewalk, astronauts always have to keep an eye on their own and their crewmate's safety. It's tough. Learning to work in the void can be exhausting. But the training takes them closer to that most extraordinary dream: the chance to walk in space. Euronews looks at the history of spacewalks and the intensive training behind them.