Nasa astronaut works on the International Space Station during a spacewalk in 2006

A stroll above the stratosphere

If this photo from 200-plus miles above Earth makes you dizzy, imagine how it felt to be Alexei Leonov on 18 March, 1965. The Soviet cosmonaut achieved the first-ever extravehicular activity (EVA - but let’s just call it a spacewalk). He spent about 20 minutes outside the orbiting Voskhod 2 capsule. It was the ultimate risk: no one knew just what could happen to a human body in the vacuum of space. Near heatstroke, drenched with sweat and with his suit dangerously inflating, Leonov barely made it back inside the airlock.

Of course, the art of EVA has been refined since then, and that vertigo-inducing panorama is now the view from the office for those working on the International Space Station. The astronaut you see here isn't Leonov but Nasa's Robert Curbeam, replacing a faulty component. On this mission in 2006, Curbeam set a record with four EVAs in one spaceflight, spending over 24 hours outside the vehicle. Since the ISS's first spacewalk in 1998, more than 227 have been performed by a large cast of astronauts — including a milestone excursion in 2019, which employed the first all-female crew.