Floating above Earth at over 17,000 mph, Alexei Leonov opened the hatch of his Voskhod 2 spacecraft and pushed himself into the vacuum of space, tethered only by a 5.35-meter cord. The extravehicular activity lasted just over 12 minutes but delivered a decisive propaganda victory to the Soviet Union in the space race, coming weeks before any American attempt at a similar feat.
Leonov's suit ballooned so severely in the vacuum that he could no longer fit back through the airlock hatch. In a decision he kept secret from mission control for years, he opened a valve to bleed off suit pressure, risking decompression sickness, just to squeeze back inside headfirst instead of feet-first as trained.
The mission nearly ended in catastrophe on reentry too: the automatic guidance system failed, forcing Leonov and Pavel Belyayev to manually orient and fire the retrorockets. They overshot their landing zone by nearly 400 kilometers, touching down in a snowbound Ural forest full of wolves, where they spent a cold night awaiting rescue.
Despite the chaos, the achievement was undeniable. Leonov became the first human being to exist, however briefly, outside a spacecraft while in orbit, proving that astronauts could function and perform tasks in the hostile vacuum of space — a prerequisite for any future moon landing.
Key people: Alexei Leonov, Pavel Belyayev