Three weeks have now passed since a trio of Extravehicular Activities (EVAs) took place outside the International Space Station (ISS) to prepare the orbital outpost for a significant period of expansion and hardware relocation in 2015. Astronauts Barry “Butch” Wilmore and Terry Virts spent more than 19 cumulative hours in the vacuum of space, laying cables and utilities, installing the Common Communications for Visiting Vehicles (C2V2) infrastructure, lubricating the 57.7-foot-long (17.6-meter) Canadarm2 robotic arm, and configuring a pair of Common Berthing Mechanisms (CBMs) on the station’s Tranquility node. Coming at the dawn of the 50th year since Soviet cosmonaut Alexei Leonov performed humanity’s first spacewalk, these excursions continue a long history of astronauts and cosmonauts working outside their pressurized craft to construct and maintain a succession of space stations.
Following the completion of the final piloted voyage to the Moon—recounted in Thursday’s AmericaSpace article—the United States’ next steps into space were the launch of the Skylab orbital station and its planned occupancy by three long-duration crews throughout 1973 and into the spring of 1974. Original plans for EVAs outside Skylab were relatively minimum in number, and the first crew was expected to spend 28 days aboard the station and astronauts Charles “Pete” Conrad and Joe Kerwin were tasked to perform a single 2.5-hour spacewalk to retrieve photographic film cassettes from the large Apollo Telescope Mount (ATM). All of those plans were cast into disarray, shortly after Skylab’s 14 May 1973 launch, when a mishap resulted in the micrometeoroid shield being torn away, along with one of two power-generating solar arrays, and jamming the other with debris, thus virtually crippling the station before its mission had even begun.
Spacewalking took center-stage of the plan to save Skylab. Three possible repair options were developed: placing a sunshade across the exposed hull, erected by means of a long pole, or deploying a sunshade from the hatch of the Apollo command module, whilst station-keeping, or the extension of a sunshade through Skylab’s scientific airlock. The third option was ranked least suitable, and teams from NASA’s Johnson Space Center (JSC) in Houston, Texas, and Marshall Space Flight Center (MSFC) in Huntsville, Ala., set to work on the others. Underwater evaluations of the sunshades were performed by Kerwin and the mission’s backup commander, Rusty Schweickart, in the Neutral Buoyancy Simulator (NBS) at MSFC. “We had to answer certain very basic questions,” Schweickart recalled in a March 2000 oral history for NASA. “Could we get physically around to where we had to be? Could we see certain things? These were questions which you couldn’t answer just looking at drawings. We had to get into the water, get on the real vehicle and see whether certain things could be done.”
The remarkable effort to develop the sunshade has been described in another AmericaSpace history article, and the urgent need for the first crew to arrive added further tension. “Just get me up there, goddamn it!” was Conrad’s typically to-the-point remark. On 25 May, he, Kerwin, and fellow astronaut Paul Weitz were launched into orbit and after a successful rendezvous with Skylab they set to work. Unlike the Apollo lunar surface suits, the Skylab ensembles lacked a backpack and instead featured an Astronaut Life Support Assembly (ALSA)—a kind of “belly-pack,” supported by a leg-mounted emergency oxygen bottle—which provided water, oxygen, and electrical power.
The first EVA kicked off with the opening of the command module’s hatch. With Kerwin hanging onto his ankles to provide stability, Weitz reached out and set to work assembling a pair of modified tree loppers and a kind of “shepherd’s crook” to free Skylab’s jammed solar array. (Under the original flight plan, Weitz had not been scheduled for an EVA during the mission.) Kerwin passed him three sections to assemble a pole, with the loppers at the end, whilst Conrad kept the spacecraft steady, just 24 inches (60 cm) from the station, his view blocked by the open hatch. However, as he worked, Weitz found that his actions were actually moving the command module toward Skylab. “It made for some dicey times,” Weitz later told the NASA oral historian. The torrent of four-letter words from the entire crew prompted the Capcom, at one stage, to advise them to modify their language, as they were on an “open-mike.” The main problem was that a strip of metal had become wrapped across the solar array system during the separation of the micrometeoroid shield and none of Weitz’ efforts to cut the strip had any effect. The EVA ended after 35 minutes.
Although the crew was able to board Skylab and deploy the sunshade, the need to unfurl the jammed solar array proved critical, and a second spacewalk was scheduled for 7 June. Practiced in the NBS by Rusty Schweickart, the 3.5-hour EVA saw Conrad and Kerwin successfully complete this task and restore electrical power to the station. It was a watershed moment in the history of U.S. EVAs. “Before that, there was still the legacy of problems with EVA during Gemini,” recalled Schweickart. “Apollo, of course, made a big difference, but that was sort of running around on the [lunar] surface in gravity again. So, here was EVA of a massive scale in weightlessness that we never anticipated; [we] did it with flying colors, everything worked just fine, never had a problem and saved the mission.” A third and final EVA on 19 June saw Conrad and Kerwin retrieve photographic films from the ATM.
The second Skylab crew of astronauts Al Bean, Owen Garriott, and Jack Lousma was assigned to perform three EVAs: the first to load the ATM with film and install a twin-pole sunshade to provide protection, followed by two others to retrieve and reload ATM film. They were also launched into orbit with a six-pack of replacement gyrodynes for redundancy. Unfortunately, circumstances conspired against the crew in the form of space sickness, which delayed the first spacewalk until 6 August 1973. Garriott and Lousma took longer in space than they had in the NBS, and they returned inside Skylab after six hours and 31 minutes. Excluding the Moonwalks of the final three Apollo missions, this established a new world record for the longest EVA at that time.
“The spacewalks are just absolutely the high point,” Lousma explained to the NASA oral historian, years later. “It really is the most memorable part of being in orbit; just an unusual experience, in that when you go outside, it’s different than being inside. When you’re inside, you look through the window and you see part of world.” Outside, in the ethereal void, the Earth was an enormous “sphere,” just beyond the helmet visor. Lousma was dazzled by the glare of the unfiltered sunlight and was astonished that, for the very first time, he really felt the sensation of speed and motion over Earth. At the same time, however, unlike the related sensations associated with speed in an aircraft, there was no vibration and absolutely no sound. “It’s like gliding along on this magic carpet,” he said, “going into the sunset and sunrise every hour and a half … doing that for six hours.” On one occasion, perched on the end of the ATM, installing a film cassette, Lousma remembered moving into orbital night, somewhere over Siberia, he guessed, and being thrown headlong into blackness. Through his visor, he could hardly see his own gloved hands and had the profound realisation that “it’s just me, God, the spacecraft and my buddies and that’s it!”
Two weeks later, on 24 August, Garriott and Lousma were outside for the second EVA of the mission to install the six-pack of gyrodynes. In his diary—preserved in the book Homesteading Space: The Skylab Story, by David Hitt, Joe Kerwin, and Garriott—Al Bean noted that it was a tough decision determining which tasks would be completed by which crewman. As the physically strongest, Lousma would do the gyrodyne installation (“If anyone can twist those connectors that had never been designed to be loosened in flight,” Bean wrote, “Jack was the man”) and the EVA ran like clockwork for 4.5 hours. During the occasional quiet spell, Garriott managed to glance at the panorama “beneath” him and beheld the snow-capped Andes Mountains, stretching toward Peru, and strained to see further toward Tierra del Fuego.
The third and final EVA occurred on 22 September, shortly before the crew’s return to Earth. This time, Bean—making his first “spacewalk,” having previously performed two Moonwalks on Apollo 12—and Garriott spent almost three hours retrieving ATM film. Bean’s decision that he should be part of the EVA was down to a feeling that Lousma would probably fly again and perform another spacewalk, whereas Garriott probably would not. (As circumstances transpired, none of them ventured outside the pressurized confines of their craft again in their astronaut careers.) In establishing both spacewalks and Moonwalks under his belt, Bean became one of only four humans to have done so. From his lofty position, high above the roof of the world, he was exultant. At one point, he kicked himself out of his foot restraints on the ATM and spun himself into a handstand. Years later, he convinced himself that he had set a new world record handstand for both height and speed.
With the return to Earth of Bean, Garriott, and Lousma, the final Skylab crew—comprising astronauts Gerry Carr, Ed Gibson, and Bill Pogue—were tasked with performing as many as five EVAs during their mission. These were expected to begin a week after their mid-November 1973 launch with the loading of ATM film, then be followed by the installation of external experiments, observing Comet Kohoutek, and retrieving film.
The first EVA, lasting 6.5 hours, was performed on 22 November, Thanksgiving Day, and saw Pogue and Gibson successfully load the ATM and checking and repairing an inoperable antenna. Their pressurized suits, Pogue remembered, were hard to work with, particularly in view of the reality that the astronauts’ spines lengthened slightly after a few days in weightlessness. “Our space suits had been very carefully custom-fitted … so when we got up in space and our bodies increased in length, it was not only difficult to get into them, but you got back after working six or seven hours outside [and] you’d have cable burns on your shoulders because, from crotch to shoulder, you’d grown two inches and that put a lot of pressure on the shoulders.”
The second spacewalk—and the only one ever to have taken place on the traditional date of Christ’s birth—occurred on 25 December and saw Carr and Pogue photographing Comet Kohoutek. Pogue carefully set up his camera, mounting it onto a strut and positioning it such that one of Skylab’s ATM arrays barely blocked the Sun. He could not physically see the comet, but Mission Control had earlier sent him a diagram on the teleprinter. “The instructions were clear and it was a fairly easy job,” he recalled. “I turned on the camera and I was finished.” For Carr, who was making his first career EVA, the biggest surprise was that he did not need to urinate throughout the seven hours that he was outside the space station. “I was amazed when I got back in, because I expected that I’d have to go to the bathroom something fierce,” he told the NASA oral historian, years later. “Apparently, I’d gotten rid of a lot of fluids in the form of sweat through my pores. When I got back in, I was really sweaty, but I really didn’t have to urinate.”
This was Pogue’s final EVA and he made the most of it. “I crawled all over the accessible parts of Skylab,” he recalled. “It reminded me of when I was a kid, doing a mud-crawl in a four-feet-deep stock tank used for watering cows and horses.” Returning inside Skylab after seven hours and three minutes, they had eclipsed the previous crew and established a new empirical single-EVA record. Four days later, on 29 December, Carr and Gibson spent 3.5 hours outside, acquiring yet more Kohoutek photography, and also embarked on a final spacewalk on 3 February 1974 to retrieve ATM film. The crew returned to Earth a few days later, closing the book on the Skylab era and marking the last EVA by U.S. astronauts until the dawn of the shuttle era.
However, the absence of U.S. spacewalkers from the scene throughout the remainder of the 1970s also made way for three Soviet EVAs from the Salyut 6 space station. Not since the excursion of Alexei Yeliseyev and Yevgeni Khrunov in January 1969 had cosmonauts departed their craft in orbit, but this changed in December 1977 when Yuri Romanenko and Georgi Grechko spent 88 minutes inspecting Salyut 6’s docking mechanism for damage. During this activity, a particularly hairy event transpired. “It is claimed,” wrote Soviet space historian Phillip Clark, “that Romanenko fancied a taste of spacewalking experience and slowly left the transfer compartment.” This story gained an ominous note when related in the Western press, partly due to Grechko’s misunderstood joke that his partner was on the verge of being “lost” in space. Romanenko’s electrical and communications umbilicals would have kept him from drifting away from Salyut, but according to David Portree and Robert Treviño in Walking to Olympus, Romanenko “was very angry about the story,” since it implied that he had acted irresponsibly.
Several months later, in July 1978, cosmonauts Vladimir Kovalyonok and Aleksandr Ivanchenkov spent two hours outside Salyut 6, retrieving external experiments. Portree and Treviño noted that during one period of orbital darkness, the spacewalkers were treated to a brilliant meteor, burning up “beneath” them in the upper atmosphere, and that the pair photographed areas of the Black Sea, Kazakhstan, and China, then watched as Australia and its Great Barrier Reef passed beneath them. The final Salyut 6 EVA took place in August 1978 and saw cosmonauts Vladimir Lyakhov and Valeri Ryumin perform a contingency excursion to cut free a troublesome antenna.
By the end of the 1970s, a decade and a half had elapsed since humanity first pushed open the hatch and ventured from a spacecraft and into the harsh radiation and vacuum environment beyond. During that span, nine Soviet cosmonauts and 29 U.S. astronauts had spent periods of between 12 minutes and more than seven hours in the most hostile conditions ever encountered, testing maneuverability, building, repairing and installing hardware, and walking on the surface of the Moon. Their ages had ranged from just 30 years, in the case of Alexei Leonov, to 47 years, in the case of Al Shepard. With the 1980s and beyond, the envelope would be pushed yet further with the shuttle era, the Salyut 7 and Mir orbital outposts, and today’s International Space Station (ISS).
The fourth part of this series will appear tomorrow.