Humanity in Space Series: The science of spacewalks
By Death Wish Coffee — / Death Wish Coffee Blog
The history and science of NASA spacewalks
By Angela Garrity, Guest blogger
Continuing with Part 2 of the Humanity in Space series, the Incredible Jeff glides us through The Science of Spacewalks in this episode of Fueled By Death Cast.
As of October 2019, there have been 410 spacewalks performed from spacecraft, space stations, and the surface of the moon — 14 of those spacewalks have been Moonwalks.
Extra-Vehicular Activity (EVA) was a term coined by NASA in the 1960s when they had their sights set on landing on the Moon and having astronauts working outside of a spacecraft.
The history of spacecraft actually starts with the Russians in 1965. The space race between Russia and America was at a fever pitch in the mid-1960s, with Russia beating the Americans to sending the first man and woman into space.
America was working hard to have the first astronaut perform the first spacewalk in history — but Russia wanted to be first again.
After a failed test mission in newly designed rocket equipped with an inflatable airlock, the Russians pushed ahead and launched the Voskhod 2 spacecraft on March 18, 1965. Commander Pavel Belyayev and pilot Alexei Leonov, both first-time Cosmonauts, reached orbit and deployed the airlock. Alexi put on the EVA backpack that contained 45 minutes of oxygen, connected the tethered umbilical cord to his spacesuit and exited the airlock – becoming the first person to perform a spacewalk.
After 12 minutes in space, Alexi re-entered the spacecraft and the official report from TASS, the Russian news agency, was “outside the ship and after returning, Leonov feels well.”
After the Cold War ended, the actual report was released. It was releveled that Alexi actually encountered some life-threatening problems on that first spacewalk.
His Berkut spacesuit ballooned more than they anticipated, and he was unable to bend his arms to snap the shutter of his chest-mounted camera. He also entered the airlock headfirst, and he got stuck, having to then depressurize his suit, risking getting the bends.
His core temperature also rose 3.2 degrees and he suffered heatstroke. Alexi recalled he was “up to his knees in sweat and sloshed in his suit.”
The first American spacewalk was performed by astronaut Ed White, a few months later, on June 3, 1965.
Part of the Gemini IV mission, the second manned flight of the Gemini Program, Ed White walked in space for 29 minutes tethered to the spacecraft via an umbilical cord that supplied his oxygen. White also was the first to test and use the HHMU, (handheld maneuvering unit) to help him control his motion in space. It only contained 20 seconds of propellant.
While outside the spacecraft, White exclaimed, “I feel like a million dollars!” But when he had come back into Gemini, he said it was the “saddest moment in his life.”
Spacewalks have an incredible early history rooted in determination. Those early astronauts with the ability to just go out there and get it done.
With the early space stations, and now the international space station, spacewalks have become a much more regulated and trained-for event.
It wasn’t until NASA was preparing for Gemini 12 that they introduced underwater training for astronauts. This would become the staple of spacewalk training that astronauts still use today.
Edwin “Buzz” Aldrin trained for 2-hour intervals underwater for his EVA on Gemini 12. On November 11, 1966, it launched into space — Buzz’s first spaceflight and Commander Jim Lovell's second.
Buzz performed three spacewalks, two of which are considered SEVAs or standup EVAs, where he was in a full spacesuit but was standing half in the hatch and half hanging out of the spaceship to perform tasks such as installing the handrail along the side.
His third spacewalk was fully out of the spacecraft and he broke all of the records by staying in space and working on the spacecraft for 5 hours and 20 minutes. This mission was the last of the Gemini missions and helped achieve all the goals Gemini set out to do and ushered in the new space exploration space program, Apollo.
In 1969, the Russian space program chalked up another first — the docking of a two-man spacecraft and a spacewalk between the crafts. Soyuz 4 was sent up in January of 1969 with Commander Vladimir Shatalov.
Soyuz 5 launched directly after with Commander Boris Volynov and engineers Aleksei Yeliseyev and Yevgeny Khrunov. Cosmonauts Yeliseyev and Khrunov performed the EVA from Soyuz 5 to 4, joining Shatalov for re-entry and leaving Volynov to pilot Soyuz 5 back to Earth solo.
In July 1969, the most famous spacewalk ever was made on the Moon by astronauts Neil Armstrong and Buzz Aldrin. With all the historical significance of this event, it is forgotten just how small the actual spacewalk was. The solid ground, lunar surface EVA lasted only 2-and-a-half-hours out of the 21 total hours the crew was landed on the Moon. This moonwalk not only proved that the next generation of spacewalks, but also the importance of the newer spacesuits, that protected the astronauts on the lunar surface.
Many spacewalks later in 1984, a pair of firsts helped to further what could actually be accomplished by astronauts in space.
On February 7, 1984, astronaut Bruce McCandless left the space shuttle Challenger with a brand new, 300-pound jetpack called the man maneuvering unit (MMU). McCandless became the first astronaut to perform an untethered spacewalk and drifted 320 feet away from the shuttle with the MMU — no tether, no umbilical cord, just held miles about the Earth by sheer physics. Science indeed.
In July of 1984, two Russian cosmonauts performed a spacewalk to repair the Salyut, a first-generation space station of its kind. They performed the repairs by welding and braising metal samples — the first time this had ever been attempted in the vacuum of space. Cosmonaut Svetlana Savitskaya also became the first woman to perform a spacewalk.
The first time three astronauts performed a spacewalk together happened in 1992, when NASA astronauts Richard Hieb, Pierre Thuot, and Thomas Akers captured a satellite to repair. The first flight of the space shuttle Endeavor delivered a crew to rendezvous with the intel stat 603 satellite, which needed to be equipped with a new motor to get it into geosynchronous orbit around Earth.
The first attempt to capture the satellite was planned for just Thuot and Hieb, but they couldn’t get it. After two failed attempts, the three-person, the unplanned spacewalk was performed, and a successful hand capture was achieved.
This mission also held the record for the longest spacewalk ever, at 8 hours and 29 minutes, until 2001 when the current longest spacewalk was recorded.
In the early days of the International Space Station (ISS), pieces were being added and moved around the station, which was a very delicate process. Astronauts Susan Helms and James Voss moved the multipurpose logistics module and were outside the station for 8 hours and 56 minutes.
The American Neutral Buoyancy Lab (NBL) is a facility that has been in use since 1995 to give astronauts EVA training. This replaced the Weightless Environment Training Facility (WETF) that was used by NASA since the early 1980s but wasn’t large enough to hold models of the space station or space shuttle for the astronauts to train on. The suits they wear underwater are downgraded from the space flight EVA suits and weighted down to give astronauts as near to neutral buoyancy or simulated microgravity. Astronauts perform the same tasks and use the same tools in the underwater simulations to perfect their movements and spend over 100 hours underwater.
Today, astronauts can train even longer and harder underwater, as part of the NASA Extreme Environment Missions Operations (NEEMO) program. Now, astronauts today are doing extensive training at the underwater facilities to learn precise procedures to be used in space, on the Moon and eventually on the surface of Mars.
Since 2006, the preparation for a spacewalk involves almost a day of lead up for the astronaut. Astronauts need to perform a camp out procedure in the Quest Airlock of the ISS. This allows them to acclimate to a room reduced nitrogen atmosphere and purge the nitrogen from their bloodstream, avoiding the bends.
Science and technology continue to aid astronauts on future spacewalk missions and the newest spacesuit designs have taken the first steps towards the next generation of space exploration.
One of the more recent spacewalks took place on October 18, 2019. NASA astronauts Christina Koch and Stephanie Meer performed the first all-woman spacewalk in history. They replaced and repaired batteries on the space station and performed other tasks, in their successful 7 hours and 17 minutes in space.
NASA will continue to perform spacewalks for repairs on the stations and also testing the newest spacesuits, as we look forward to returning to the Moon.
Here’s to infinity and beyond!
Tune into Fueled by Death Cast weekly to see more of this six-part series about the science of humans in space. Catch the episodes on the Death Wish Coffee YouTube channel.
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