One small step for periods in space, one giant leap for research in long-term space missions

Before NASA spaceman sallying forth sit’s historical set in motion aboard the space shuttle in 1983 as the first American woman in space, she was asked a question: Would 100 tampons be the right number for her week-long mission?

“No,” she said. “That would not be the right number.”

But if we’re going to venture further into space than we ever have before — and on longer missions — it’s something we can’t afford to ignore.

For those not in the know, someone who menstruates typically does so once a month, with their period lasting, on average, anywhere from four to seven days.

There are different types of ways to manage menstruation. People can use tampons, menstrual pads or menstrual cups. There are also intrauterine devices (IUD), which are inserted, with hormonal versions that can stop monthly menstruation.

But how do you manage it in space? A new study published in the Nature journal NPJ Women's Health is looking at giving astronauts who menstruate a new option.

Getting your period in space provides some challenges. Most astronauts who menstruate choose to use hormonal methods to stop their periods altogether, however some choose pads or tampons.

But now, researchers have completed key testing for another potential option for astronauts who menstruate: menstrual cups.

“We want to give different options to women because right now, astronauts are, let's say, induced to take menstrual suppression,” said Catarina Miranda, science communicator and co-author of the new study. “And since we already have solutions here on Earth that are sustainable and that we can use, why not try that in space conditions and adapt what we have here on Earth to space and to these long missions?"  

Menstrual cups are reusable, flexible bell-shaped devices that are inserted vaginally to collect blood. 

This could be a viable option for astronauts who don’t want to suppress their periods.

The mission, called AstroCup, launched two cups on a suborbital, uncrewed flight (meaning it didn't orbit Earth), measuring the temperature, acceleration and humidity. They then tested the integrity of the cups using water and glycerol, a liquid that mimics the viscosity of blood. The test was successful, with the integrity of the cups remaining intact.

In early 2026, the Artemis II crew — with Canadian Space Agency astronaut Jeremy Hansen and NASA astronauts Victor Glover, Christina Koch and Reid Weisman — is scheduled to blast off and head for a trip around the moon. This is considered the first step to return humans to the moon, with the goal of Mars in sight.

Going to Mars will be a years-long mission. And that would require a lot of supplies, which is costly to launch: every kilogram matters.

"This is just a situation where people didn't know this could be a problem, because nobody thought about it," said Ligia Coelho, co-author of the study who is an astrobiologist. "So we decided to continue to do the these experiments and then it opened a new field that we kind of created."

Canada's Jeremy Hansen on getting ready for the moon

Instead of packing up pads and tampons to last years, the menstrual cup may be a better option, according to the researchers, as it's lightweight and reusable. Another consideration is that the pills used to suppress periods would likely expire during the mission.

But cups aren't the only new option, Coelho said.

"Now we are being contacted by all these other people that are interested maybe in sending other kinds of menstrual devices. We are partnered with a menstrual cup company that are is very eager also to help us continue doing these these experiments."

The main goal for the authors of the study is to provide options to astronauts.

"I don't think a lot of people realize that within the next couple of years, few years, we'll be going back to the moon. And within the next decade, Mars is on the table as well," said study co-author Adam Langeveld.

And in order to have successful missions, there's the need to hire the most skilled people, he said.

"You don't want to be limited by by having a barrier of entry to a certain group of people. So that that's kind of my motivation for for joining this … to make make sure that these missions are as successful as possible. And one of the ways to do that is through providing accessibility for for everybody."

Shawna Pandya is Canada's first named commercial female astronaut who will be flying onboard Virgin Galactic's new Delta class of spacecraft with the International Institute for Astronautical Sciences (IIAS) as early as 2026. She's also a physician with a special interest in women's health, who has also done a lot of women's health research in space and human space life.

That includes research on parabolic flights (a flight that simulates low gravity) on IUDs that could also be used in space.

"[The IIAS] were the first in the world to demonstrate the feasibility of IUD insertion and removal in microgravity in parabolic flight," she said. "It was … to address some of the concerns of menstrual health management and menstrual suppression for long duration space flight."

(No, they didn't do it on actual people; they used a model of the uterus.)

Pandya is excited to see more research being done on human presence in space, even beyond menstruation options.

"I'm the chief of space medicine at the Advanced Space Life Research Institute. And literally we are looking at the roadmap and the considerations around human sexuality and reproduction in space flight," she said.

That includes sex.

"Now, in the era of commercial human space flight, when you know, you can't really dictate what people do, especially when we're hearing about proposals about space hotels," she said. "We all know what people do in hotels."

As for the Cornell researchers, they say the next step is to test the cup in space to see how it fares with radiation and more, as well as finding ways to sterilize the cups.

But they're excited about the prospects that will now become available to astronauts who menstruate.

"These options are not rocket science," Coelho said. "There's really no excuse not to put them on the table."

Senior Science Reporter

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