Alexei Leonov performs the first spacewalk
A cosmonaut's suit balloons in vacuum and nearly traps him outside his own spacecraft
Quick facts
- Agency
- USSR
- Spacecraft
- Voskhod 2
- Spacewalk duration
- ~12 minutes
- Cosmonauts
- Alexei Leonov, Pavel Belyayev
What happened
On 18 March 1965, Soviet cosmonaut Alexei Leonov left the Voskhod 2 spacecraft to perform the first spacewalk in history, floating free for about 12 minutes while tethered to the capsule. The spacewalk went as planned until Leonov tried to return: his spacesuit had ballooned so severely in the vacuum of space that he could no longer fit through the airlock hatch. In a decision not part of the mission plan, he bled air out of his suit through a valve to shrink it enough to squeeze back inside, working alone with no way to consult ground control in real time about the fix. He and fellow cosmonaut Pavel Belyayev returned safely, though later in the mission a guidance failure forced them to land hundreds of kilometers off course in a forest, where they spent a night surrounded by wolves before rescue.
Why it matters
The spacewalk proved a human being could function and work outside a spacecraft, a prerequisite for any future lunar mission requiring exit from a capsule, but the near-disaster with the suit also exposed how little was actually understood about spacesuit behavior in vacuum, forcing redesigns before either country attempted the maneuver again.
How we know
The European Space Agency's own history of spacewalks documents the suit-ballooning incident and Leonov's improvised fix; the account matches details Leonov gave in later interviews after the Soviet Union eventually acknowledged the near-failure.
Sources
- European Space Agency. 50 years of spacewalks · Reputable sourceesa.int · The domain "esa.int" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Smithsonian National Air and Space Museum. The First U.S. and Soviet Spacewalks Had the Same Problem · Reputable sourceairandspace.si.edu · The domain "airandspace.si.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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