During their mission, Alexey Leonov, then only 30 years old, ventured outside of Voskhod-2 spacecraft and stepped into the void, becoming the first person to walk [or rather float] in space. Leonov spent 12 minutes and 9 seconds floating in space attached to his ship by a cable.
A peculiar albeit potentially dangerous scenario happened when Leonov was getting back into the spacecraft — his space suit became bloated and prevented Leonov from returning to Voskhod-2. To reenter the gateway of the spaceship, the cosmonaut had to release pressure from his suit and climb into the hatch of Voskhod-2 head first, as opposed to feet first, as it was described in a Soviet space manual.
Leonov's spacewalk was an extraordinary achievement at a time when people were just beginning to understand space travel. The brave Soviet cosmonaut paved the way for future space discoveries and development — since Leonov's first spacewalk over two hundred cosmonauts have carried out extra-vehicular activities (EVAs) in space.