From childhood, Epps had been an excellent student, especially in science and math, and she was surrounded by encouraging family, teachers, and other adults who mentored her. She credits her graduate school advisors for opening doors for her into the engineering profession and a couple of astronauts for guiding her into the corps. Always grateful for the encouragement she received along her journey, Epps is committed to “paying it forward” by encouraging young people to pursue STEM interests.

  After Epps completed initial astronaut training and technical assignments, in 2017 she was assigned to the crew of ISS Expedition 56/57 and a Soyuz roundtrip. She completed two years of training in Russia and elsewhere for the mission and was just weeks away from launch in 2018 when NASA inexplicably announced a crew change and substituted her backup, Serena Auñón-Chancellor, in her position.[46] Epps would have been the first African American to serve on a resident ISS crew, a first later accomplished by Victor Glover and Jessica Watkins. Epps seemed as ready as possible for her first spaceflight, having completed not only mission-specific training for Soyuz and ISS but also the NEEMO-18 underwater mission as an aquanaut. Epps said that she had no medical, training, or family problems to warrant removal from the Soyuz-ISS mission and claimed that she herself did not know the reason and could not speculate.[47] That decision remains a mystery, since neither NASA nor Epps has revealed what happened, despite a flurry of speculative comments posted on the internet in the aftermath. Epps returned to Houston to resume duties in the Astronaut Office, working on the Orion project and serving as an ISS CAPCOM. In 2019, she completed a European Space Agency CAVES expedition, an otherworldly analog to a lunar or planetary mission, doing scientific research with a team and finite resources in the isolated environment of remote caves.

  A year later, NASA assigned Epps to the first operational mission of Boeing’s new Starliner spacecraft to the ISS, then anticipated to fly in 2021. She trained for that mission, but the flight tests and the first mission were delayed by technical issues. She also began cross-training on the SpaceX Crew Dragon spacecraft. In mid-2023, NASA assigned her to the SpaceX Crew-8 crew rotation mission for ISS Expedition 70/71, and in 2024 she launched and completed this mission after waiting almost fifteen years to reach space. At that time, she set a record as the African American who had spent the most time in space: 235 days.

  Jeanette Epps suited up for SpaceX mission to the ISS, 2024. NASA

  Epps recalls being in high school and the profound impression of seeing Mae Jemison celebrated on the cover of Jet magazine as the first African American woman astronaut. “It made me think…‘If she can do this then maybe I can do this as well.’ ” [48] That inspiration and the consistent encouragement she received along her journey toward space has made Epps passionate about being a mentor and role model: “Giving something back is huge for me. How can I not do that?”

  Flights: 1 on International Space Station via SpaceX • 54th US woman astronaut in space • 92nd woman worldwide • Time in space: 235 days, 3 hours (5,643 hours)

  Kathleen Hallisey Rubins

  A microbiologist whose interests range from disease-causing bacteria and viruses in humans to signs of microbial life in ancient rocks and lava, Kate Rubins holds degrees in molecular biology and cancer biology and has done virology fieldwork in Africa to study pox viruses, Ebola, and Lassa fever.[49] Before coming to NASA, Rubins gained government grants to establish her own lab of fourteen researchers at the Whitehead Institute for Biomedical Research at MIT. Since joining NASA, she has completed the European Space Agency’s Pangaea geological training course, an analog for lunar and planetary surface exploration that is conducted in otherworldly terrains in Germany, Italy, and Spain.[50]

  Rubins has completed two International Space Station missions, a four-month stay in 2016 on Expedition 48/49 and a six-month stay in 2020–21 on Expedition 63/64. Her biomedical research expertise and interest in genomics is a natural fit for many of the thousands of investigations conducted on the space station. On her first mission, she became the first person to sequence DNA in space, and she also cultured beating heart cells in a far-reaching study of changes in the heart in microgravity. Rubins is also a veteran spacewalker, having performed two maintenance and installation EVAs on each mission, and she has operated the space station robotic arm to capture arriving automated resupply spacecraft. After returning from the ISS, Rubins became chief of the EVA and robotics branch of the Astronaut Office, and she is involved in the development of new space suits for missions to the Moon.

  Sequencing DNA in space has practical relevance as well as basic research value, especially on long, remote missions. It could enable astronauts to diagnose an illness or identify microbes in their environment. Spacecraft are routinely sanitized but are not sterile, and the human body is populated with myriad bacteria; despite precautions, it is possible that microbes presenting a health threat could proliferate. About that potential, Rubins says, “There are some interesting places to take a look at the microbiome of the space station.”[51]

  Rubins has a long association with the US Army Research Institute of Infectious Diseases and the Centers for Disease Control and Prevention. In 2021, after completing her second spaceflight during the COVID-19 pandemic, she decided to join the US Army Reserve to continue pursuing her interests in public health. She “really wanted to give back” for the opportunities she has had and also sharpen her leadership and operational skills.[52] Major Rubins serves with the 75th Innovation Command in Houston.

  Flights: 2 on International Space Station via Soyuz • 44th US woman astronaut in space • 60th woman worldwide • Time in space: 300 days, 1 hour (7,201 hours) • EVA time: 26 hours, 46 minutes

  The Class of 2013

  NASA’s next recruitment was announced in 2011, the year of the last space shuttle missions.[53] This announcement clearly indicated that the next class of astronauts would be preparing for long-duration International Space Station missions and future deep space exploration missions beyond low Earth orbit, including a possible mission to an asteroid. NASA was surprised by the extraordinary response—more than 6,300 online applications, the second-highest number yet—through its first use of the USAJobs website. Longtime manager of the Astronaut Selection office Duane Ross attributed the high number to a major recruitment effort on social media and the internet to counteract public perception that NASA went out of business when the shuttles were retired.[54] Better communications extended NASA’s outreach to spread the message that exciting exploration programs lay ahead and being an astronaut was still a promising career.

  From that large applicant pool, NASA culled the smallest selection since 1978—eight candidates introduced as the Class of 2013. For the first and only time to date, the class included an equal number of men and women, a fact noted with approval but more coincidental than intentional. Parity was not a policy, and subsequent classes again included more men than women. In introducing this group, NASA Administrator Charles Bolden raved that “these new space explorers asked to join NASA because they know we’re doing big, bold things here—developing missions to go farther into space than ever before.”[55] The women in this class were Christina Hammock (later Koch), Nicole Mann, Anne McClain, and Jessica Meir.

  Christina M. Hammock Koch

  Christina Koch can’t remember a time when she didn’t want to be an astronaut.[56] She prepared well for this career: attending space camp five times, graduating from a math and science high school, receiving an astronaut scholarship to study engineering and physics, attending NASA Academy for collaborative research training, and in 2002 taking her first postgraduate job at NASA’s Goddard Space Flight Center. She earned bachelor’s and master’s degrees in electrical engineering and another bachelor’s degree in physics.

  During the ten years between completing her studies and applying to become an astronaut, Hammock, as she was then known, alternated between engineering work and scientific research in two-year intervals, augmenting her experience in various kinds of exploration. She said that she had always set her sights on working with NASA, “but I didn’t want to get there by checking the usual boxes, like learning to fly and scuba dive. I was passionate about science and the next frontier.”[57] As an electrical engineer at NASA’s Laboratory for High Energy Astrophysics and the Johns Hopkins University Applied Physics Laboratory, she developed instruments for space science and remote sensing. After each of these jobs, she did scientific and engineering fieldwork in remote environments, including a full year in Antarctica with the US Antarctic Program, seasonal stays in Greenland, and more fieldwork in Antarctica. When she returned from those expeditions in 2012, she went to work for the National Oceanic and Atmospheric Administration (NOAA) at research bases in Alaska and American Samoa. Hammock arrived at NASA in 2013 already well experienced as an explorer living and working in isolated, harsh environments.

  (left to right) Jessica Meir and Christina Koch in ISS Quest airlock, preparing power tools and spacesuits for their EVA, 2019. NASA

  After six years of training, Koch went to the International Space Station via Soyuz as a crewmember on Expedition 59/60 in 2019. Classmate Anne McClain was already on board to greet her. While there, her stay was extended into 2020 on Expedition 61 as an opportunity to collect more data on the physiological effects of longer duration spaceflight. Koch set a new record for the longest single spaceflight by a woman—328 days, just five weeks shy of a full year. No woman has yet spent a complete year in space, and only one American man thus far has done so.[58] While on the ISS, Koch conducted microgravity research in protein crystals, biomedical studies, 3D printing of biological tissues, and a variety of other disciplines. She accomplished six spacewalks, including the first EVA by a pair of women with partner Jessica Meir.[59] The women paired again on two additional spacewalks.

  Speaking from the space station on Women’s Equality Day in 2019, Koch noted, “I have truly been inspired by the struggle and triumphs of so many women that dare to break new ground in all aspects of society, and those who have pushed the boundaries of human imagination. And now I am both privileged and challenged to have the opportunity to be a part of that story…. I say to the record-breakers, ‘Thank you.’ ”[60]

  After her flight, Koch returned to serve as a branch chief in the Astronaut Office and rotated into the JSC Director’s Office as a technical assistant. In 2023 Koch was named to the four-person crew of the Artemis II mission, now planned to launch in 2026 as a lunar flyby rehearsal for a subsequent landing mission. Until then, she is in training for the complex mission.

  Flights: 1 on International Space Station via Soyuz • 47th US woman astronaut in space • 64th woman worldwide • Time in space: 328 days, 14 hours (7,786 hours) • EVA time: 42 hours, 15 minutes

  Nicole Aunapu Mann

  Nicole Mann is the first Native American woman in space, registered with the Wailaki of the Round Valley Indian Tribes in Northern California, where she was born and grew up. Her original surname, Aunapu, reflects her Estonian heritage as well.

  A distinguished graduate of the US Naval Academy, where she was a star and captain of the women’s soccer team and earned a slew of scholar-athlete and All-American honors, Mann was commissioned into the Marine Corps in 1999.[61] Upon earning a master’s degree in mechanical engineering, she completed basic training and flight training, picking up her call sign “Duke” and earning her wings of gold as a naval aviator in 2003. She was assigned to pilot the F/A-18 Hornet fighter/attack jet in the aircraft carrier fleet and was deployed twice. Mann flew almost fifty combat missions before reporting to the Naval Test Pilot School, which she completed as an honor graduate. She was an F/A-18 Hornet and Super Hornet test pilot and project officer when selected to train as an astronaut. Since joining NASA, Mann has advanced in rank from major to colonel.

  Before her first spaceflight, Mann served as the T-38 safety and training officer and led the astronaut corps’ developmental work on NASA’s Orion spacecraft, Space Launch System heavy-lift booster, and exploration ground systems for missions to the Moon. Mann then commanded SpaceX Crew-5 for ISS Expedition 68 from late 2022 into early 2023. During their five-month stay, the crew participated in hundreds of experiments and technology demonstrations. Mann completed two spacewalks doing maintenance on the solar arrays and other tasks, and she operated the robotic arm for two other EVAs. Upon returning, Mann was assigned to the test flight crew for Boeing’s Starliner spacecraft, still in development for roundtrip crew transportation for International Space Station expeditions.

  Mann didn’t contemplate becoming an astronaut until she considered her career path after combat duty. She missed engineering. Her decision to become a test pilot, and an opportune tour of NASA, put her on a course that never seemed possible in her youth. She understands that she is now an example and inspiration, especially for Native American young people, whom she encourages to dream big. “I hope that young women can connect with me and my journey and maybe see a little bit of themselves in me,” she says. “Maybe that will give them the inspiration and the courage that they need to follow their dreams.”[62]

  Flights: 1 on International Space Station via SpaceX • 51st US woman astronaut in space • 79th woman worldwide • Time in space: 157 days, 10 hours (3,778 hours) • EVA time: 14 hours, 2 minutes

  Anne Charlotte McClain

  Anne McClain is the first female graduate of the US Military Academy at West Point to enter the astronaut corps. Commissioned as an Army officer in 2002, she earned her wings as a pilot in the OH-58D Kiowa Warrior scout/attack helicopter, claimed the call sign “Annimal,” and flew 216 combat missions. She later became qualified in other rotary, fixed-wing, and multiengine aircraft and graduated from the Navy Test Pilot School. Colonel McClain is a Master Army Aviator, experimental test pilot, instructor pilot, and experienced leader in command at the platoon, company, battalion, troop, and detachment levels. She came to NASA after more than a decade of military service.

  McClain earned undergraduate and master’s degrees in mechanical/aeronautical and aerospace engineering. She holds two additional master’s degrees in international relations and strategic studies. She attended the Army War College and completed the Command and General Staff College. During some of her postgraduate years, she also played rugby on the USA Women’s National Team and captained a USA Women’s Rugby All-Stars team, and she played rugby in England while studying there as a Marshall Scholar. McClain applied to NASA in 2009 and was not accepted, but she reapplied after graduating as a test pilot in 2013 and was selected.[63] In the astronaut corps, McClain has been a branch chief and a CAPCOM, EVA, and robotics instructor.

  McClain flew roundtrip on a Soyuz spacecraft as a crewmember for ISS Expedition 58/59 (late 2018 to mid-2019), where she was a flight engineer, researcher, and spacewalker. She completed an EVA and was scheduled to do one with crewmate Christina Koch, the first time for a pair of women spacewalkers. However, McClain recommended that she not participate in that EVA because the large suit she would have worn did not fit her as well as a medium size.[64] She and Koch both needed to wear a medium size suit and only one was ready; assembling and checking out another would put the crew off schedule. For safety and schedule reasons, she thought it wiser to change places with her male EVA partner, who normally wore the large suit, for the spacewalk with Koch. All agreed, and McClain later did a second EVA in the medium suit. This instance highlighted a spacesuit size and fit issue that also had affected other women astronauts’ ability to do EVAs.

  Speaking to students at her hometown alma mater, McClain said that she wanted to be an astronaut since she was three years old. That is all she ever wanted to be, and she told her mom that her reason to go to school was to learn to be an astronaut. “I didn’t have any special gifts or talents or advantages or disadvantages,” she said, but “where you end up is a series of decisions you make, one after another. It’s not a giant leap; it’s making little decisions each day” to push yourself toward your goal, because “Our dreams don’t live in our comfort zones.” She suggested some affirmations that helped her along the journey from school to space: “I am brave” and “I can do hard things.”[65] McClain’s next assignment was to command the SpaceX Crew-10 mission in 2025.

  Flights: 1 on International Space Station via Soyuz • 46th US woman astronaut in space • 62nd woman worldwide • Time in space: 203 days, 15 hours (4,887 hours) • EVA time: 13 hours, 8 minutes

  Jessica Ulrika Meir

  Jessica Meir drew a picture of an astronaut standing on the Moon when she was five years old to show her class what she wanted to be when she grew up. At age thirteen, she attended a space camp at Purdue University. As a high school senior, she wrote in her yearbook that she intended to do a spacewalk. Her friends called her “space girl.”[66]

  Meir took a path less traveled to become an astronaut; instead of studying physics or engineering, she chose to follow her passion, biology, with graduate degrees in space studies and marine biology.[67] She pursued interests in marine mammals and birds in extreme environments, focusing on the physiology of oxygen deprivation in animals that dive below the ice in Antarctica and a species of geese that fly above the Himalayas. Between her master’s and doctoral studies, Meir worked at the Johnson Space Center supporting human physiology research on the shuttle and space station, which led to research flights on NASA’s KC-135 parabola-flying aircraft and the undersea NEEMO-4 (2002) mission as an aquanaut. She also participated in Smithsonian diving expeditions to the Antarctic and Belize. When selected as an astronaut candidate, Meir was an assistant professor at the Harvard Medical School and Massachusetts General Hospital.