Mark Owen is pleased to welcome Michel Tognini, former head of the European Astronaut Centre of the European Space Agency. Tognini sees a spacewalk as a paradox of human spaceflight: from the ground, it can look almost effortless, but outside the space station, even the simplest movement takes place within an exceptionally unforgiving environment. Sophie Adenot’s EVA demands constant attention to her suit, her tether, her tools, her route around a structure roughly the size of a football pitch, and the dramatic temperature changes between sunlight and darkness. For Tognini, the essential discipline of a spacewalk is simple to describe but extremely challenging to master.