Although the HUT and other components were designed to fit a wide range of standard body sizes, some women astronauts were so petite in height and frame that even the size small was too large. A few of them worked on a task team to explore the feasibility of an extra-small size, but technical and financial hurdles impeded consideration. Women taller than sixty-four inches with a larger frame had better luck wearing a small or medium suit. Even when the size worked, the suits generally didn’t fit women as well as men. In particular, the torso did not fit women’s shoulders and curves or the suit’s waist was below the women’s waists, affecting their ability to bend. Even with sizing adjustments, the suit’s knees and elbow parts didn’t always align well with their bodies. Some women wearing a suit in underwater training drifted around in the interior volume with too much empty space around their torso and legs. They would fall back in the suit, pulling their arms in and their hands out of the gloves, or they would sink down in the suit, compromising their view through the helmet. The extra air inside shifted like a big bubble as women moved and interfered with their position in the suit. That loose fit allowed the body to move around in the suit and thereby alter the center of mass, which made it difficult to maintain neutral buoyancy and also difficult to do a task properly. They had limited ability to reach the controls on the chest pack if the HUT held their arms out too much like a “T,” or they strained against the hard frame jutting into their shoulders and underarms as they tried to reach a task. Men and women alike often emerged from underwater training with bruises from working against the inflated suit and the drag of surrounding water, but movement in the suit was much easier in space. Kathy Sullivan and several other women wore a medium torso comfortably enough for their EVA training and orbital EVA. Kathy Thornton found that the small size suited her well; she felt as if she could have worn a ski vest inside the medium suit. Cady Coleman naturally fit into a small suit but was advised to use a medium because another problem was looming.

  During the 1990s one of the biggest responsibilities of the Astronaut Office was to determine how many EVAs would be required for space station construction and to ensure that enough astronauts were trained and ready for the job. They predicted the need for more than two hundred ISS assembly EVAs increasing in frequency to a “wall of EVA” by 2003 that would plateau at that peak for years. More astronauts needed to be trained and ready for that workload. At the same time, the cost of the space station kept increasing, and pressure mounted to trim costs wherever possible. As a result, some large components of the ISS were sacrificed—a dormitory-like habitation module, for example—as well as some scientific equipment and other features. That pressure extended even to the number of spacesuits supplied and maintained for use on the shuttle and ISS. Instead of developing a new and improved EVA suit for the space station years, NASA decided to enhance the baseline shuttle EMU suit, maintaining the same design but upgrading some of its systems.[99]

  For the ISS era, the small and extra-large HUTs were to be discontinued for economy’s sake. The reasoning behind this 1994 decision was not fully transparent, and some of the women astronauts were concerned that it was an attempt to edge them out of EVA. They suspected that an “EVA mafia” of larger men might be trying to hoard EVA assignments for themselves and supporting elimination of the small HUT to reduce their competition, or worse, were convinced that women couldn’t do the job and didn’t belong in EVA. It soon became evident that some of the men who wore the extra-large torso couldn’t fit in the size large. When the decision was finalized, the small size was discontinued but the extra-large was kept to accommodate the greater number of astronauts needing that size. Some women think that abandoning the small torso on the basis of cost, even though not explicitly on the basis of gender, actually was a gendered decision for its disparate effect on women, limiting their opportunities and flaunting inequity. Up to one third of the twenty-four women astronauts then active were affected by that decision.[100] It has not been reported whether any smaller men were similarly affected.

  Coleman was warned that this change was coming and that if she really wanted an EVA assignment she should wear the medium size torso and make it work. Thornton offered to help her.[101] For underwater training she had to stuff the suit full of foam padding to keep her position in the too-large volume, and even so she emerged from training sessions as battered and bruised as everyone else. Once she was faulted for poor performance when in fact the suit fit had not been adjusted properly for her; she thought it was almost a reflex to fault the woman than to consider other causes for the problem. When the suit fit was adjusted, her performance soared. She never complained, but after she flew her mission she used her new credibility to explain to the suit techs how much harder it was to work in a poorly fitted suit and how they could better help astronauts solve that problem. Mary Ellen Weber also wore a medium suit stuffed with padding although a small suit fit her better. Although it was inconvenient to do, and generally unnecessary for men, use of padding reflected the women’s resourcefulness and problem-solving ability. Both Coleman and Weber were assigned for unlikely contingency EVA duty, but neither had to do one in space.

  A complicating factor in the torso size and fit problem was that NASA tried to improve the HUT design during the 1990s after shoulder joint reliability issues arose. This introduced a new set of fit problems. The original torso was called the “pivoted” HUT, because the shoulder joint was hinged. Astronauts found it to be comfortable, flexible, with good reach across the front, but failure of the shoulder joint had endangered an astronaut—an unacceptable safety issue. In 1997, an enhanced HUT having a different shoulder joint design, the “planar” HUT, was introduced, and it soon replaced the pivoted HUT in EVA suits used on the ISS. This design changed the geometry but decreased the range of motion at the shoulder and made the suit harder to don and doff, but it solved the reliability problem of the pivoted HUT. Kathy Thornton had worn a small pivoted HUT on her three spacewalks but later tried a medium planar HUT and found it far too large. Some men who had worn a size large pivoted torso could not wear a large planar torso and had to move up into an extra-large size to accommodate their broader shoulders and longer arms. A few other men went in the opposite direction, downsizing from extra-large pivoted to large planar torso to get the best fit. Astronaut Jerry Ross, one of the most experienced spacewalkers and a former chief of the EVA branch in the Astronaut Office, noted that the extra-large planar HUT worn by many of the “musclemen” was absolutely critical to completion of the ISS.[102]

  For the last few years of the 1990s, astronauts could choose between the two HUT versions until the first fully enhanced EMU was used on an ISS assembly mission in 1998. The last time the baseline suit with pivoted HUT was used in space was in 2002. Thereafter, every spacewalker had to wear a suit with the new torso. Women were not the only ones affected by torso size and design issues. A number of men reported shoulder and rotator cuff injuries, some requiring surgery, caused by repetitive motion, limited range of motion, and other factors while wearing the planar HUT during their frequent underwater training sessions. The injuries did not occur in space. Based on this history, a 2003 study found the extra-large planar HUT unacceptable for long-term use in training because of its greater risk of injury due to restricted arm movement in its fit.[103]

  Discontinuing the small torso affected women disproportionately, and several cited it as having a significant effect on their careers. It didn’t help their morale when in 1997 NASA named spacewalkers for ISS assembly flights—a cadre of fourteen men, including two rookies who had not flown at all and a Canadian astronaut.[104] A spacewalking male astronaut later told a reporter, “Our spacesuits only come in medium, large, and extra-large. Anybody who is on the smaller side…will not be able to have a chance to go outside,” as if that privilege were the natural order of things, not a deliberate decision.[105] In the early 2000s, Nancy Currie and then Wendy Lawrence led an effort to develop a redesigned small torso, but funding was denied and the effort ended.

  The reason these suit size issues mattered so much was that EVA was often a step toward greater stature and leadership within the astronaut corps. Qualification (or not) for EVA could profoundly affect an astronaut’s career opportunities. Small women who might have been effective spacewalkers but could not work safely in the medium torso suit were effectively barred from EVA, which barred them from a long-duration stay on the ISS. During the 1990s, the Astronaut Office decided that given the small number of an ISS crew, in the event of an emergency and for workload management, everyone had to be qualified to do everything, including EVA. So, if a woman couldn’t qualify for EVA because no suit fit her properly for safety and work efficiency, she also couldn’t be assigned to a long-duration ISS expedition. She might be able to visit the ISS on a shuttle mission, but she would never be an ISS resident. Justifying the decisions to discontinue or redesign the small size torso as a cost-cutting measure signaled to some of the women that smaller astronauts were not valued enough to warrant the expense.

  One instance pushed the suit fit issue out into the public. In 2019, astronaut Anne McClain wore a medium torso suit for her first EVA at the ISS, and it fit perfectly. She had also trained in a large torso and planned to wear a large suit on her second EVA while her intended partner Christina Koch wore the medium suit. (Just these two suits were configured and available for use during their ISS expedition.) However, McClain bowed out of that EVA upon realizing that the large suit did not fit her properly in space and would affect her ability to work safely. Suits fit differently and are stiffer in space than on the ground; they aren’t as “broken in” as the training suits. Also, the body changes in length and girth in space, another reason for suits fitting differently. McClain stepped back in favor of her first partner astronaut, a man who wore the large suit, and he did the EVA with Koch instead. To McClain and the crew, this was a logical solution to a problem. McClain wore the medium suit on her second EVA, when she was again paired with a man wearing the large one.[106] Having been alerted to an imminent, historic all-woman EVA, the news media made much of the missed opportunity and framed the lack of enough suits to fit women as sexism. Although this interpretation missed the details of the situation, reporters did flag the problem that women astronauts had long recognized.[107]

  Weightlessness offsets to a great extent the male advantages of size and strength.[108] There are instances when a smaller-size astronaut can do a task as well as or more easily than a larger one. Mary Cleave, a very small woman, was able to reach through tight spaces and fit behind a wall of storage lockers in the shuttle crew cabin to do repair tasks that stymied her larger crewmates. Some ISS assembly tasks could be done by a smaller astronaut—fine motor work in installing or relocating components, for example, or running cables and making electrical connections. Other tasks may have logically required a larger astronaut with longer reach, such as mating massive modules or boom-like truss segments or working at the outer limits of a robotic arm’s length. Because some tasks require inordinate upper body strength, both men and women do rigorous weight training to build up their stamina using those muscles, but sometimes men may have a natural biomechanical advantage. Astronauts also work on hand and forearm exercises to prepare for the exhaustion of repetitive hand tasks, like tool use.

  In reality, anyone doing EVA must be able to perform all the tasks if things don’t go as planned. In addition, everyone must be able to rescue his or her EVA partner in an emergency and quickly bring the partner back to safety. Cady Coleman included in her memoir such an urgent rescue scenario.[109] No one would argue that a woman should be sent on EVA simply because she is a woman; EVA is too important and hazardous to send anyone but the best-trained, most capable person for all that the job entails. However, some of the women eager to be involved in ISS assembly, if not long-duration stays, perceived that the idea of tall, broad-shouldered, long-armed musclemen as spacewalkers was so ingrained in EVA planners’ thinking that their own potential as smaller human beings was simply not seen or considered. They felt invisible as candidates for EVA assignments.

  There were two solutions to that problem: design an EVA suit that any astronaut can wear comfortably and safely, or select more larger-framed women into the astronaut corps. The latter option seems facetious, but about half of the women selected since 2000 have performed EVAs without needing a small suit. The redesign option, called for and studied since 1998, is achievable with commitment despite the expense. Resolving the suit size and fit problem will indicate that women are fully and equally valued as participants in extravehicular activity, and that cost is no longer an excuse for not providing them equally enabling spacesuit technology as men receive. As NASA moves into the Artemis era, it has committed to have a next-generation spacesuit available to fit everyone and enable everyone who qualifies to move and work productively in EVA. That suit has not yet been unveiled, but several companies are working hard on designs to meet the requirement. It is expected to have a much-improved shoulder design and improved mobility for all. NASA has also committed that the next landing on the Moon will include a woman, which implies that qualified women (and smaller men) will have equal standing for future EVAs in a suit that fits them well.

  Over time, the number of women on a crew increased from one to two, then three, but never a full crew. In 2007 it happened by coincidence that two NASA women were simultaneously in command of both a shuttle mission (Pamela Melroy) and an ISS expedition (Peggy Whitson). It also happened that four women were aboard the ISS at once in 2010. And in 2019 it finally happened naturally that two women, Anne McClain and Christina Koch, were scheduled to do an EVA together for the first time. McClain chose to bow out because the spacesuit she had planned to wear didn’t fit properly. Instead, Koch and Jessica Meir became the first pair of women to do a spacewalk about seven months later and then did two more. In 2023, Jasmin Moghbeli and Laurel O’Hara also did a spacewalk together. These spacewalks were not arranged to be historic; given the composition of the astronaut corps, it was inevitable that two women eventually would work outside together. That happened without contrivance, no differently than two men had always been paired, on the basis of their competence. Now that the precedent has been established, two women simultaneously in EVA is just another day at work.

  The eighteen US women spacewalkers to date have performed a variety of EVA tasks, typically working with a man as their partner. EVAs in the 1980s focused primarily on satellite servicing tasks. Kathy Sullivan’s main EVA task was to demonstrate a technique for transferring fluids through valves from one container to another, a function that would be useful for refueling satellites in orbit. In the 1990s, EVA tasks often focused on demonstrating techniques for space station assembly and maintenance. Kathy Thornton’s first EVA tested different methods of assembling a structure in the payload bay of the shuttle. Her second and third spacewalks occurred during the first Hubble Space Telescope servicing mission, where she and her EVA partner removed a large instrument and installed a new optics system to correct the telescope’s faulty vision. They also replaced two large solar arrays. Three years later, Linda Godwin and her EVA partner were the first Americans to do an EVA at the Russian space station Mir during a shuttle docking mission; they installed canisters of environmental effects experiments on the Mir exterior and tested new tethers and foot restraints for future use on Mir and the ISS. From 1999 on, all NASA EVAs except those on Hubble servicing missions were carried out on shuttle missions to the ISS or by resident ISS crewmembers. ISS EVAs involved installing large and small components, linking modules together, working with electrical cables and fluid lines, replacing or repositioning items, doing inspections, cleaning and lubricating equipment, making repairs, and other tasks. As of 2024, fifteen more NASA women had logged their EVA hours on the ISS.[110]

  Of the eighteen American women to date who have done EVAs, Peggy Whitson has completed a total of ten, all at the ISS, and Sunita Williams closely follows with nine EVAs to date. Besides the US women spacewalkers, only five other women astronauts have participated in EVA. Svetlana Savitskaya of the Soviet Union did a spacewalk in July 1984 ahead of Kathy Sullivan’s EVA in October, thus claiming the title of first woman spacewalker. No other Soviet or Russian woman has done an EVA since. Almost four decades later, taikonaut Wang Yaping did an EVA at China’s Tiangong space station in late 2021 as the first Chinese woman spacewalker. Liu Yang followed with an EVA in 2022. Samantha Cristoforetti of Italy and the European Space Agency did an EVA at the ISS during her time as an Expedition 67/68 crewmember in 2022, the first woman spacewalker from one of the ISS partner nations. American commercial astronaut Sara Gillis did a stand-up EVA in the open hatch of a SpaceX vehicle on the private Polaris Dawn mission in 2024, but she did not fully exit the spacecraft.