Ed White performed the first American spacewalk during NASA’s Gemini 4 mission in June 1965.
White opened Gemini 4’s hatch on 3 June 1965 and floated outside the spacecraft for about 20 minutes. He used a hand-held maneuvering gun powered by compressed oxygen to move around, while remaining connected to the spacecraft by an umbilical line.
The achievement followed Soviet cosmonaut Alexei Leonov’s first spacewalk during Voskhod 2 earlier in 1965. White’s activity demonstrated that astronauts could work outside a spacecraft, an ability essential for later lunar missions, satellite repairs, and space-station construction.
White was not the mission commander; James McDivitt commanded Gemini 4. White later died with Virgil Grissom and Roger Chaffee in the Apollo 1 cabin fire during a ground test in January 1967.