Unsurprisingly, the pre-mission project descriptions and post-mission summary reports used the language of the era: Tektite was an effort to study “highly trained men” and the “biomedical responses of men,” an “opportunity for men” to conduct meaningful scientific research on “man’s first long-term scientific mission into the sea,” and to observe “man” under stress in confined and isolated environments. There is no mention of women except in reference to their single mission and to note that there were no discernible differences in performance.

  The women proved their competence and equaled the male teams in research productivity. Earle has said that they were not consciously competing with the men but were trying to take maximum advantage of this unique opportunity to do their research.[77] They impressed all observers with their ready accommodation to isolation and confinement, camaraderie, and productivity. They logged more hours in the water than the other groups. They experienced no physical or psychological problems; one even had a normal menstrual period during the expedition. Earle logged a record eighty-six hours—more than anyone—working outside the habitat, accomplishing in two weeks the amount of research it would have taken her in two months of surface dives.[78]

  When the women emerged from twenty hours in the decompression chamber at the end of their two-week underwater stay, they were greeted with long-stem red roses, a welcome back pineapple, a large piña colada with five straws, and a spate of glowing publicity.[79] Their public appearances included a luncheon at the White House hosted by First Lady Pat Nixon, a parade and award presentation in Chicago, and other accolades as reported in national news articles. Team leader Earle accepted a request to address Congress on the Tektite project and was named Time’s Woman of the Year for her leading role in this pioneering underwater venture.[80] The entire crew was relieved when the unexpected, almost overwhelming attention abated, and they could return to their usual work.

  In 2020, during the COVID pandemic, the four women still alive and many other luminaries appeared in an online conference, Tektite2020: Women of Sea and Space, to mark the fiftieth anniversary of their historic undersea mission. In her remarks, Sylvia Earle noted that “sea-space connections were so clear back in the ’70s.”[81] The parallels between hydrospace and aerospace expeditions include living in a container surrounded by a hazardous environment and depending on life support systems and one another. Whether in sea or space, explorers are far away and alone. They are reliant on technology and responsible for staying mentally and physically fit, adapting to isolation and confinement, and doing good work. The Tektite missions demonstrated how astronauts and aquanauts are fellow explorers of outer and inner space. President Richard Nixon recognized this when he congratulated the crew of the record-breaking Tektite I mission, proclaiming that “the aquanauts join the astronauts as space pioneers.”[82] Astronauts participating in this conference also paid tribute to Tektite’s importance in anticipating long-duration space missions.

  The all-woman Tektite II mission could have opened NASA’s eyes to the potential of women as astronauts if word of it had spread beyond the human behavior and habitability research teams that participated. Instead there is little mention of Tektite II in NASA publications or archives, and little indication that NASA leadership was paying attention. In 1969 and 1970 the Tektite program merited just one line in the annual Aeronautics and Space Report to the President, where progress on Skylab was reported in detail. The primary NASA book on Skylab mentions Tektite in only one sentence and one photo caption. The Department of the Interior and the US Navy released significant reports about their involvement, but not NASA. However, buried in a conference paper presented by the NASA and Interior Department managers of the Tektite II program was this prediction about upcoming manned space flight: crews will increase in number and variety, missions will be longer, and “women will be in space.”[83] Separately, in an interview for Smithsonian magazine, the NASA program director for Tektite predicted that “the day is not far off when women will be included as passenger-scientists in mixed spacecraft crews.”[84]

  Nevertheless, it is fair to consider the Tektite II all-woman mission a precursor to NASA’s eventual acceptance of women as astronauts. Earle’s team showed they could do the job without causing problems. The women themselves believed that their mission was a great step toward acceptance of women as scientists and especially as members of research expeditions, from which they had often been excluded. They keenly saw their experience as breaking down career barriers for women in science and exploration.[85] The idea of women in space was catching on, as evidenced by a long feature article in the New York Times during the lead-up to the 1973 Skylab missions: “Will man ever live in space? (If so, woman will live there too).”[86]

  If this crew’s performance didn’t persuade NASA to admit women into the astronaut corps or to select a woman for the 1973–1974 Skylab missions, it did demonstrate that women could live and work in an extreme and isolated environment as effectively as men. As an analog to a space mission, the all-woman undersea mission was as productive and uneventful as anyone could hope. Astronaut Scott Carpenter, a veteran of the Navy’s underwater Sealab program, was sent to observe Tektite from the control center during the women’s on-site training mission, and he went diving with Earle to see some of their equipment.[87] NASA’s attitude toward women in space seemed to be softening as it accepted and evaluated the all-women crew no differently from the male crews. Before their mission, NASA arranged for engineer Peggy Lucas to test equipment in the underwater facility at the Marshall Space Flight Center in Huntsville, Alabama. This opportunity made her the first woman allowed to work in the Neutral Buoyancy Simulator used for astronaut training.[88]

  After all the planned missions were completed, NASA’s Marshall Space Flight Center hosted a two-day symposium, “Tektite II: Men Undersea.”[89] This event in 1971 brought together many of the participants from various agencies to assess the underwater facility and research program in sessions organized around topics in engineering, operations, and human behavior. The prelude to the program explicitly recognized that the Tektite II missions were analogous to manned spaceflight and the habitat was analogous to a manned spacecraft. On a panel that included NASA astronauts and aquanaut-engineers, Peggy Lucas and Renate True spoke about the effects of isolation and confinement on the job to be done. As the only two women among twenty-five men scheduled to speak, they surely were noticeable. Their appearance beside astronauts and other renowned researchers visibly elevated them as peers and signaled that their role was as relevant and acceptable as anyone else’s.

  The Tektite legacy affected the course of marine research and also spaceflight, demonstrating how productively scientists could live and work while isolated in an extreme environment. It led to new generations of undersea habitats, and lessons learned from Tektite informed NASA’s Skylab space station. Skylab lessons then influenced Spacelab and International Space Station design and operations. Thirty years later, NASA again began to use another underwater habitat, Aquarius Reef in the Florida Keys, to prepare astronauts for International Space Station missions. Most important, Tektite erased doubts and modeled how women could have the same kinds of productive roles in spaceflight as men; the all-woman mission produced no physical or behavioral evidence for exclusion. This mission may have helped to advance NASA’s position on training women as astronauts, given the similarities between underwater and in-space operations. That idea dawned on someone, because Sylvia Earle and Peggy Lucas both received inquiries from NASA inviting them to consider becoming astronauts.[90] Had they been less devoted to the sea, these aquanauts might have been America’s first women astronauts.

  Practicing for Science Missions

  In December 1974, four women researchers participated in a five-day simulation as the crew of a space laboratory mission. All were employed at NASA’s Marshall Space Flight Center, where the simulation occurred. It isn’t clear whether they volunteered or were assigned to this session in a series of concept verification tests (CVT), but they were eager for the experience and would have welcomed being on an actual mission. Their job was to conduct eleven materials science experiments in a space-like laboratory environment while acting under mission-like communications and operations protocols.[91]

  They were the only women to participate in the series of ten tests, each one focusing on a different set of science experiments, whether biomedical, physics, atmospheric, or astronomy. Three of the four, all in their thirties, were materials science specialists from the Materials and Processes Laboratory and were responsible for conducting the experiments: astronautical engineer Carolyn S. Griner, metallurgist Mary Helen Johnston, and physicist Ann F. Whitaker. Engineer Doris Chandler joined them as crew chief to handle their communications and schedule their daily workload. They worked in a general-purpose laboratory module, a big horizontal cannister, for eight hours a day, returned home for the night, and resumed the “mission” the next morning. Although they were not confined overnight in a crew quarters area as part of the simulation, in the spirit of a real mission they wore identical coveralls while on duty.

  Women participants in a simulated space laboratory mission on November 13, 1974: (left to right) Mary Helen Johnston, Ann Whitaker, Doris Chandler, Carolyn Griner. NASA

  The purpose of this series of tests was to evaluate whether the kinds of experiments normally conducted in labs on Earth could be performed effectively in a space laboratory equipped to accommodate any discipline. NASA and the European Space Agency were developing such a laboratory, Spacelab, to be installed in the payload bay of the shuttle and connected to the crew cabin by a tunnel, so scientist-astronauts could move freely back and forth in the pressurized environment. Spacelab and the shuttle would provide power, water, air, vacuum, controlled temperature and humidity, communications, and computer and data services to permit 24/7 scientific research for up to two weeks. Spacelab would turn the shuttle into an intermittent space station. In these early years before the first Spacelab mission flew in 1983, the concept verification tests would help scientists and instrument developers understand how their equipment should be designed to fit into and operate within Spacelab.

  NASA was also trying to verify what the roles of scientist-astronauts should be in the coming space shuttle era. To that point, only four scientists had served on mission crews: Harrison Schmitt on Apollo 17, and Joseph Kerwin, Owen Garriott, and Edward Gibson, each on one of the three Skylab missions. How adept might scientist-astronauts be in conducting other scientists’ research? Should the astronauts be generalists or specialists? For this test (CVT-4), the women were not only materials science specialists but had also developed the experiments being tested, and they were among the few women holding such technical positions at the Marshall Center. The mission was simulated again the next year with a generalist crew of men who were not experts in materials science but received intensive hands-on training with the experiment hardware in advance of their test (CVT-4A).

  Griner, Johnston, and Whitaker coauthored the report of these two successful tests with a full description of the laboratory, the materials science experiments, how well the experiment hardware and the lab interfaced, and the effects on delicate experiments of vibrations caused by the crew’s movements in the lab. The crew noted that thoroughly understanding the equipment and the experiments allowed them to refine procedures and explore results during the mission. In fact, they reported that at least two experiments would have failed entirely without the crew’s intimate knowledge of the hardware and science. The major difference between the two tests was that the second one required much more communication between the crew and a specialist “on the ground” nearby, which pointed to the need for more training and simulation for generalists.[92]

  In interviews before the simulated Spacelab mission, these women expressed confidence that “a woman could do any job a man could do on a space flight” and that there were “plenty of qualified women available for scientific-type missions.”[93] They also admitted their interest in going on a space mission themselves. During the next two years, Griner, Johnston, and Whitaker took steps to prepare for spaceflight. They received neutral buoyancy training (simulated weightlessness) in the deep-water tank used for astronaut training at Marshall and gained zero-gravity weightlessness experience on parabolic flights on NASA’s KC-135 aircraft. They took flying lessons, and they may also have received familiarization training in Apollo spacesuits.[94]

  Soon Griner and Johnston applied to become astronauts, and Whitaker was a finalist for a payload specialist position as a guest crewmember on the first Spacelab mission, STS-9 in 1983. Whitaker’s selection for a possible Spacelab flight was announced before NASA announced any women astronaut candidates; it was reported that she “could become the first American woman in space.”[95] Although none of the Marshall women were selected for the astronaut corps, all stayed involved with the early Spacelab missions. Johnston was named an alternate payload specialist for the Spacelab-3 mission of 1985; she trained with that crew and was on duty in the payload control center during the mission. She left NASA after Spacelab-3 to become a university professor and inventor with twelve patents. Whitaker’s experiments flew on several shuttle missions, and Griner held technical management roles for science payloads. Griner eventually became deputy director and acting director of the Marshall Space Flight Center, the first woman to reach that level. Meanwhile, Whitaker earned a PhD and rose through the ranks to head the MSFC Science Directorate.

  Like the Tektite story, the Spacelab simulation shows that NASA was on the way to bringing women into spaceflight in the years before it actually happened. In the mid-1970s NASA was wrestling with equal opportunity and affirmative action planning with a view toward admitting women into the astronaut corps. Management at the Marshall Center clearly was preparing its group of outstanding women scientists to qualify as astronaut candidates; otherwise, they would have had no access to the neutral buoyancy simulator, aircraft, or pressure suits. The Spacelab simulation is little more than a footnote in NASA history, but it is a significant story.

  Occasionally photos of this group of women pop up during Women’s History Month, with greater appreciation now than then. They were on the leading edge of women assuming prominent positions in the space agency. They proved their abilities as scientists and their readiness to become astronauts in the coming space shuttle era precisely when NASA was nearing the decision to recruit women for spaceflight. Their experience made it evident that the sex of a scientist or engineer was immaterial to the conduct of science, and women could do the kind of scientific experiments planned for Spacelab.[96] It was disappointing that they were not selected to fly, despite their timely demonstration of readiness.

  Another Spacelab mission simulation occurred in 1977 at the Johnson Space Center, this one focused on developing life sciences missions.[97] Called Spacelab Mission Development Test III, it was a collaboration of JSC and NASA’s Ames Research Center, the home of much of the agency’s life sciences research focused on humans and animals. Like the materials science lab simulation, this one aimed to assess the feasibility of different types of experiments and equipment that could be supported in Spacelab.

  One of NASA’s longest-tenured African American scientists, Patricia S. Cowings at Ames, was selected to train and act as a mission specialist for this weeklong simulation and for all the preliminary planning and development activity. She had established a specialty in psychophysiology and focused much of her research on biofeedback—self-regulating techniques to avoid space sickness, control heart rate and blood pressure, and manage other bodily responses in microgravity and returning to Earth. Her research aimed to help astronauts adjust better to space and back.

  Cowings claims to be the first woman scientist trained to be an astronaut.[98] Her role in the simulated mission was immersion in the science—operating and evaluating the experiments, procedures, equipment, and provisions of the lab to guide development of the same for life sciences research in Spacelab on the shuttle. Her work later extended to life sciences research on the space station. Her key role in this effort, like that of the Marshall women materials scientists, indicated that NASA was beginning to see women as potential astronauts. In fact, this simulation occurred in the same year as the initial recruitment of space shuttle astronauts and NASA’s explicit effort to find highly qualified women and people of color to apply.

  Simulating Weightlessness in Bed

  Between the occasions when the Tektite and Marshall women scientists were demonstrating their suitability for spaceflight, NASA tested a group of women for physiological fitness. In 1973, twelve nurses participated in a study of the female body’s adaptation to simulated weightlessness. Prolonged bed rest is an analog for the reduced use of muscles in space, where it is possible to “float” weightless without using one’s legs to move about. Male astronauts showed evidence of general weakening without the normal stress on muscles, bones, and the heart, but there was no data yet from females.

  The biomedical research team at NASA’s Ames Research Center in California conducted a five-week experiment with twelve Air Force nurses selected for their medical and flight training.[99] During the first two weeks, all were evaluated physically and medically. In the second two weeks, eight of the women were confined to bed rest and were not allowed to get up or use their muscles except to raise themselves up on one elbow to eat. The other four women served as controls, confined to the same facility but able to move around as they wished. The last week was a recovery period. All were subjected to the same battery of tests before, during, and after the bed rest period.