A BRIEF HISTORY OF AN EXPERIENCE OUT OF THIS WORLD: EXTRAVEHICULAR ACTIVITY

Remember EVA? Not EVA the robot mate from Wall-e but the real extravehicular activity which accounts for the acronym?. Some news raised this week around the first female “couple” outside, then just as a quick recap for all, E.V.A. is any activity done by an astronaut or cosmonaut outside a spacecraft beyond the Earth’s atmosphere. The term most commonly is related to a spacewalk made outside a craft orbiting Earth (such as the ISS). The first man on doing this on March 18, 1965 was Alexei Leonov, exiting the capsule during the Voskhod 2 mission for 12 minutes and 9 seconds. The term also applied to lunar surface exploration commonly known as “moon walking”, (not Michael Jackson) performed by six pairs of US astronauts during 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 US first space station.

A “Stand-up” EVA (SEVA) is when an astronaut does not fully leave a spacecraft, but is completely reliant on the spacesuit for environmental support. Its name derives from the astronaut “standing up” in the open hatch, usually to record or assist a spacewalking astronaut.

EVAs may be either tethered (the astronaut is connected to the spacecraft; oxygen and electrical power can be supplied through an umbilical cable; no propulsion is needed to return to the spacecraft), or untethered. Untethered spacewalks were only performed on three missions in 1984 using the Manned Maneuvering Unit (MMU), and on a flight test in 1994 of the Simplified Aid For EVA Rescue (SAFER), a safety device worn on tethered U.S. EVAs.

The Soviet Union/Russia, the United States, and China have conducted also EVAs.

The very first EVA was performed on March 18, 1965, by Soviet cosmonaut Alexei Leonov, who spent also 13 minutes at the Voskhod-2 spacecraft. Carrying a white metal backpack containing 45 minutes worth of breathing and pressurization oxygen, Leonov had no means to control his motion other than pulling on his 15.35 m (50.4 ft) tether. After the flight, he claimed this was easy, but his space suit ballooned from its internal pressure against the vacuum of space, stiffening so much that he could not activate the shutter on his chest-mounted camera.

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Alexei Leonov, circa 1965. Photo Credit: Science Photo Library

The first US spacewalk was performed on June 3, 1965, by Ed White from the second manned Gemini endeavor, the Gemini IV during 21 minutes. White was tethered to the spacecraft, and his oxygen was supplied through a 7.6 meter umbilical cord, 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.

Outside the Gemini IV spacecraft, astronaut Ed White floats in the microgravity of space.
Outside the Gemini IV spacecraft, astronaut Ed White floats in the microgravity of space.
Photo Credit: © NASA/Jim McDivitt)

Between Alexei Leonov and Ed White, there was a lot of people making EVAs such as those at the Apollo missions or on the Soviet missions, but more importantly is to quote about the recent developments.

This month, Christina Koch and Jessica Meir floated feet-first out of the International Space Station’s (ISS), tasked to replace a failed power control unit as the first “coupled” female spacewalk: Awesome!

The spacewalk, took place seven months of planning after the original planned date for an all-female outing, which had to be scrapped because the ISS had only one medium-sized spacesuit on board. The agency sent up a second medium spacesuit in October.

It was Meir’s first spacewalk and Koch’s fourth, according to NASA. Both are on their first spaceflight after they were selected as astronaut candidates in 2013, as part of a class that was 50 percent women.

Astronaut Stephanie Wilson, who has completed three spaceflights, guided the pair from Mission Control. The three commentators narrating the endeavor for NASA were also all female.

According to their own words: “For us, this is really just us doing our jobs,” she said. “We were the crew that was tasked with this assignment. At the same time, we do recognize that it is a historic achievement, and we do of course want to give credit to all of those that came before us,” Said Meir, who added she hoped the pair could be an inspiration to everybody, not only women but for all manking. Awesoooome!!!!

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Author: Jesus Padilla

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