page_title: Extravehicular activity
section_title: Project Gemini
hierarchical_section_title: Extravehicular activity / Development history / Project Gemini
caption_attribution_description: English: On June 3, 1965 Edward H. White II became the first American to step outside his spacecraft and let go, effectively setting himself adrift in the zero gravity of space. For 23 minutes White floated and maneuvered himself around the Gemini spacecraft while logging 6500 miles during his orbital stroll. White was attached to the spacecraft by a 25 foot umbilical line and a 23-ft. tether line, both wrapped in gold tape to form one cord. In his right hand White carries a Hand Held Self Maneuvering Unit (HHSMU) which is used to move about the weightless environment of space. The visor of his helmet is gold plated to protect him from the unfiltered rays of the sun.
context_page_description: Extravehicular activity is any activity done by an astronaut or cosmonaut outside a spacecraft beyond the Earth's appreciable atmosphere. The term most commonly applies to a spacewalk made outside a craft orbiting Earth. On March 18, 1965, Alexei Leonov became the first human to perform a spacewalk, exiting the capsule during the Voskhod 2 mission for 12 minutes and 9 seconds. The term also applied to lunar surface exploration performed by six pairs of American astronauts in the Apollo program from 1969 to 1972. On July 21, 1969, Neil Armstrong became the first human to perform a moonwalk, outside his lunar lander on Apollo 11 for 2 hours and 31 minutes. On the last three Moon missions astronauts also performed deep-space EVAs on the return to Earth, to retrieve film canisters from the outside of the spacecraft. Astronauts Pete Conrad, Joseph Kerwin, and Paul Weitz also used EVA in 1973 to repair launch damage to Skylab, the United States' first space station.
  A "Stand-up" EVA is when an astronaut does not fully leave a spacecraft, but is completely reliant on the spacesuit for environmental support.
context_section_description: The first American spacewalk was performed on June 3, 1965, by Ed White from the second crewed Gemini flight, Gemini IV, for 21 minutes. White was tethered to the spacecraft, and his oxygen was supplied through a 25-foot (7.6 m) umbilical, which also carried communications and biomedical instrumentation. He was the first to control his motion in space with a Hand-Held Maneuvering Unit, which worked well but only carried enough propellant for 20 seconds. White found his tether useful for limiting his distance from the spacecraft but difficult to use for moving around, contrary to Leonov's claim. However, a defect in the capsule's hatch latching mechanism caused difficulties opening and closing the hatch, which delayed the start of the EVA and put White and his crewmate at risk of not getting back to Earth alive.
  No EVAs were planned on the next three Gemini flights. The next EVA was planned to be made by David Scott on Gemini VIII, but that mission had to be aborted due to a critical spacecraft malfunction before the EVA could be conducted. Astronauts on the next three Gemini flights (Eugene Cernan, Michael Collins, and Richard Gordon), performed several EVAs, but none was able to successfully work for long periods outside the spacecraft without tiring and overheating. Cernan attempted but failed to test an Air Force Astronaut Maneuvering Unit which included a self-contained oxygen system.
  On November 13, 1966, Edwin "Buzz" Aldrin became the first to successfully work in space without tiring during Gemini XII, the last Gemini mission. Aldrin worked outside the spacecraft for 2 hours and 6 minutes, in addition to two stand-up EVAs in the spacecraft hatch for an additional 3 hours and 24 minutes. Aldrin's interest in scuba diving inspired the use of underwater EVA training to simulate weightlessness, which has been used ever since to allow astronauts to practice techniques of avoiding wasted muscle energy.
caption: Ed White performs the first American spacewalk during Gemini IV
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