In 1983, when Sally Ride was preparing to become the first American woman in space, National Aeronautics and Space Administration (Nasa) engineers posed an odd question: Would 100 tampons be enough for her seven-day mission?
Her reply: “That would be more than sufficient.”
This awkward exchange has since become a symbol of how unprepared space programmes were for the reality of women’s health in orbit. For decades, the male-dominated world of space exploration largely ignored the biological needs of half the population. But now, with more women heading to the stars, the question of how astronauts manage their periods in space has gone from taboo to tech.
The early challenges of menstruation in space missions
For years, space travel was considered a male domain. When the first astronauts went to space in the 1960s, the systems and suits were built exclusively with them in mind. The mere idea of a woman menstruating in space wasn’t even on the checklist.
In 1963, Soviet cosmonaut Valentina Tereshkova became the first woman in space. While a milestone, there’s little public documentation on how—or if—her menstrual cycle was addressed.
In 1964, a paper published in the American Journal of Obstetrics and Gynecology described women as “temperamental psychophysiologic humans” unsuited for piloting spacecraft. The authors cited studies claiming menstruating women were more accident-prone and even suggested they might be responsible for unexplained air crashes. Some scientists speculated that menstrual blood could flow backward in zero gravity—a myth later debunked by Nasa medical experts.
By the time Sally Ride made her historic flight in 1983, Nasa had to face reality: if women were going to space, they’d have periods there too. Unfortunately, the male engineers’ understanding of menstruation was limited, to say the least.
What happens to menstruation and periods in zero gravity?
When it comes to periods in space, one might imagine a ghastly nebula of levitating blood. Scientists had similar worries. But gravity doesn’t control your period. It turns out that while spaceflight affects many bodily systems, the female menstrual cycle remains largely unchanged.
“It can happen normally in space, and if women choose to do that, they can,” says Dr Varsha Jain, gynaecologist and researcher at King’s College London.
Astronaut Rhea Seddon, in a 2010 interview, recalled that female astronauts urged Nasa to treat menstruation as a “non-problem until [it becomes] a problem.” Since no one knew what to expect, they suggested just sending women up—and bringing them back if anything went wrong.
“I’m not sure who had the first period in space,” Seddon said, “but they came back and said, ‘Period in space, just like period on the ground. Don’t worry about it.’”
The challenge isn’t the menstruation itself—it’s managing hygiene and waste in a cramped, pressurised cabin with limited water and privacy.
Some waste-disposal facilities on the International Space Station can now handle human blood, but they weren’t originally designed to do so. Another challenge is calculating the added weight, storage, and waste management for items like tampons and sanitary products.
Why most astronauts suppress periods with hormonal birth control
Today, most female astronauts choose to suppress their periods entirely during missions. This is done safely through continuous hormonal birth control—either with pills or long-acting methods such as IUDs or injections.
Nasa medical teams now work with astronauts ahead of missions to determine the best approach based on individual needs. Some prefer to keep menstruating naturally, and that option is supported too.
Nasa physician and astronaut Serena Auñón-Chancellor has spoken openly about these choices. “It’s a choice,” she said. “Some women choose to menstruate, some don’t. Either way, we train for it.”
Still, long missions—such as a three-year journey to Mars—present new challenges. According to Dr Jain, astronauts on such missions would need about 1,100 pills, adding cost, packaging, weight and waste. That makes long-acting reversible contraceptives (LARCs), such as implants or hormonal IUDs, a more convenient solution.
Inclusive space design: Meeting female astronaut health needs
Menstruation is just one part of the larger push to make space travel inclusive. From designing space suits to fit more body types to conducting biomedical research on hormonal differences, space agencies are beginning to acknowledge the diversity of human needs.
More than 100 women have flown to space since Valentina Tereshkova, but the systems still lag behind. Future missions to the Moon, Mars and beyond will require safe, comfortable and sustainable menstrual care in microgravity. Nasa, the European Space Agency and private companies are now developing improved hygiene systems, reusable products and real-time body monitoring tools.
And it’s clear: the more women involved in designing space missions, the more thoughtfully inclusive those systems become.
Why menstruation in space is a symbol of design equity
Managing menstruation in space may seem minor compared to interstellar navigation or building Moon bases. But it highlights a larger truth: The systems we build reflect the people we expect to use them.
For too long, spaceflight ignored women’s biology. Today, mission checklists include tampons, hormonal therapy and custom-fit suits—paving the way for a future where anyone can go to space as their full, human self.
And no, Nasa no longer packs 100 tampons for a seven-day trip. We’ve come a long way—and still have a long way to go.