The first space walks significantly threatened the lives of the walkers. But hey, it was all a part of the learning experience of early spaceflight. They had to walk before they could walk…er…well, you know what we mean.

The primary problem involved the extra complexities in the environmental control and life support systems (ECLSS) of the earliest Russian and American suits.

In short, the suits rather lacked the “environmental control” part. So any exertion caused you to heat rapidly and dehydrate. And there was the reason why the early astronauts were over-exerting themselves.

Spacewalks, The First

Bravery incarnate: Alexey Leonov. (Ria Novosti/Science Photo Library)

The very first guy to stroll in space was the most-excellent Alexey Leonov, strolling outside his Voskhod 2 spacecraft on March 18, 1965. Russians were and still are gutsy about EVAs (more about that in a bit). Leonov just left the spacecraft that day without any propulsive equipment. He had just his suit, a chest-mounted camera, and his large, titanium-plated Siberian-born balls, fortified with months of weightlessness training.

Leonov’s big problem involved his suit. Its pressurization caused the suit to balloon out, making the use of his camera virtually impossible and getting back in his spacecraft very difficult (he pulled on his umbilical to move around). After accidentally wedging himself head-first in his airlock, overheated and tired, Leonov lathered on some extra ball polish and partially depressurized his suit to get back inside. Did we mention that Leonov was a lone cosmonaut on this walk? His crewmate, Pavel Belyayev, was on the other side of their airlock and, because it was an airlock, unable to help.

The second problem, encountered by two of the American walkers was the simple concept that there’s no freakin’ gravity for your human limbs to do much of anything.

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Ed White on Gemini 4, making it look easy. It wasn’t. (NASA)

The first American to do this, the awesome, late great Ed White on Gemini 4, got the easy track. He only floated around, like Leonov, but carried a small nitrogen-powered thruster gun. He was having so much fun that the flight director had to yell at White and his partner, Jim McDivitt, to get White back inside.

Things weren’t so nice in walks #2, 3 and 4. On Gemini 9, Gene Cernan’s objectives on his walk were to test out the Astronaut Maneuvering Unit, an improved jet-pack. But his Gemini lacked sufficient any real hand or footholds. Cernan quickly began to overheat, and his suit couldn’t do much other than to make matters worse by causing the interior of his visor to fog. Mission commander Tom Stafford soon called it off and guided a very tired Cernan back inside.

Mike Collins, travelling with John Young on Gemini 10, was slightly more successful in his three EVAs. After the first EVA, just standing up inside the spacecraft, Collins struggled a bit on the second EVA to retrieve some environmental exposure samples from one of two Agenas they met (one was future Apollo 11 comrade Neil Armstrong’s Agena from Gemini 8).

Then the American space comedy team of Pete Conrad and Dick Gordon on Gemini 11 gave EVA a try. Gordon managed to connect a tether from the Agena to their Gemini for a passive stabilization experiment but also was stressed out by the exertion of moving about.

The EVA struggle finally became real to NASA. With Buzz Aldrin and others, the idea of training in an underwater tank was invented. Aldrin and others developed specialized handholds, footholds and tools that understood that no gravity meant that you, and not the tool would spin without restraints. Aldrin’s trip with Jim Lovell on the last Gemini mission mastered the basics of EVA, and these lessons were incorporated into later missions.

Spacewalks, The Sequels

The next big thing for the Americans in EVA technology was testing out the suit that couldn’t use a tether: the Apollo lunar space suits. Connected to their Portable Life Support System (PLSS), these suit passed its final test on Apollo 9.

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Red Rover, Red Rover, EVA on over. (NASA)

In earth orbit, the great Red Rover, Rusty Schweickart, stood on the porch of the Lunar Module Spider in the new suit. The suit’s improved mobility and specialized cooling system passed their tests and paved the way for the moonwalking teams.

The Command Module Pilots got some EVA love in the later Apollo extended (“J”) missions. One side of the Service Module was converted into a science bay for these flights.

On the way home from Apollo 15, 16 and 17, CMPs Al Worden, Ken Mattingly and Ron Evans became the first and only men to make a spacewalk in cislunar space to retrieve experiments and film from their equipment bays.

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Ron Evans never gets enough love, so he gets to hog the whole page, here in his Apollo 17 translunar EVA. (NASA)

The walks were comparably easy for them with handholds added to the exterior of the Service Module and the suit’s improved mobility. The CMP space suits were simplified from their lunar counterparts.

Spacewalks, The Reboot

Spacewalks were certainly a must in the build-it, deploy-it era of the Space Shuttle. First, with new astronauts of more varying sizes and genders, the Extravehicular Mobility Unit was a suit in two parts.

The hard upper torso (HUT) was literally an inflexible fiberglass shell built in three sizes, then various layers and equipment and arms and helmet collar added. To complete it, the lower torso assembly fit around your bottom and legs, attaching to the HUT with single ring near your waist. No more boots: These were incorporated into the lower torso. The general design allowed almost all in the astronaut corps to use the suits and made entry and exit a little easier.

NASA’s Kool-Aid drinking about the safety and routine purported by the Shuttle meant, however, that the new EMU wasn’t standard equipment for regular wear by their astronauts. Until 1986, all crews flew up to space and home in just their blue jumpsuits.

Still yearning for astronauts to fly free, NASA dusted off their old Gemini jet-pack plans and developed the Manned Maneuvering Unit, a fully self-sufficient unit that allowed an astronaut to fly about the Orbiter with ease. First used on STS-41-B in 1984, these rather-badass jet-packs could hold station automatically to allow an astronaut to use their hands for other things.

The MMU’s mission history is brief. After helping to retrieve three wayward satellites, the aftermath of the Challenger disaster retired the MMU as too risky, limiting future satellite work to using the Orbiter’s remote manipulator arm and tethered walks.

All later Shuttle crews also returned to a specialized pressure suit for all launches and landings, which were not intended for EVAs but for increasing the safety of the crew in the case of a launch or landing abort, allowing them enough life support (with parachute) to bail out of a wayward Orbiter in a few cases. These rescue suits weren’t of use in the loss of Columbia in 2003: The crew was far too high and flying far too fast. Re-entry and deceleration forces would pulverize and incinerate the disintegrating Orbiter and occupants, suits or no.

These post-accident adjustments didn’t thwart later astronauts from shining their made-in-the-USA brass balls in deploying and then refurbishing (twice) the Hubble Space Telescope, preparing them for some grand space walks in the latter years of the Shuttle era.

The Perfection of EVA and More Russian Brass Shining

But the pinnacle of EVA technology came (and continues) with the construction and maintenance of the International Space Station. With 159 space walks, 32 of them from the Shuttle itself, and over 1,000 hours outside, astronauts and cosmonauts grew the station from 1998 to its current configuration.

Being a station, parts come and go and maintenance is needed. EVAs from the ISS use a special airlock and often last up to 8 hours with the greatly improved ECLSS of the American suits.

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Chris Cassady and Tom Marshburn during an ISS EVA in 2013. The SAFERs are located at the base of their life-support backpacks, the thruster exits clearly visible. (NASA)

One special addition was added to the American space suits since 1994. Derived from the MMU jet-pack is a mini-pack, added to the base of the EMU backpack, is the SAFER, or Simplified Aid for EVA Rescue.

Developed by former astronaut Joe Kerwin and others as part of the original space station concept for “Space Station Freedom” (with budget cuts that later nicknamed that project as “Space Station Fred”) the SAFER takes into account that accidents might happen. While astronauts would be always tethered to the station or the Shuttle, there’s a remote chance they can become untethered. While an Orbiter could maneuver to get the astronaut back if the spacecraft were free-flying, an astronaut that gets loose while on an ISS EVA would have no such option as it would take time to make an emergency undocking with either Soyuz or Orbiter to reach the astronaut.

With the end of the Shuttle flights and the schedule of very busy ISS Expedition crews, the SAFER’s justification is more important to astronaut safety.

Back to Russian EVAs. Notice that I didn’t say “cosmonaut safety.” In the spirit of “hold-my-vodka-glass-I-got-this” Alexey Leonov, the Russian spacesuit has no counterpart to SAFER. At least, not yet. They have been thinking about how to adapt SAFER units to those suits.

So, for now, if a cosmonaut becomes untethered in their Orlan-M suit during an EVA, they’ll going to get some time off from work and enjoy the view until one of their comrades takes a Soyuz out to pick them up.