Sally Ride’s tampons might be the most-discussed tampons in the world. Before Ride became the first American woman in space, scientists pondered her tampons, weighed them, and NASA’s professional sniffer smelled them—better to take deodorized or non-deodorized?—to make sure they wouldn’t smell too strongly in a confined space capsule. Engineers considered exactly how many she might need for a week in space. (Is 100 the right number?, they famously asked her. No, Ride said. That is not the right number.)
The engineers were trying to be thoughtful, though; reportedly they packed the tampons with their strings connected so that they wouldn’t float away. I imagine Sally Ride’s tampons hovering like sausage links in the space shuttle, and wonder if the male astronauts ever came across them and, embarrassed, tried to float quickly away.
All this is to say that menstruation clearly made NASA squirm. Before women went into space, there were not only the sadly typical concerns that women would become weepy or unable to function during their periods, but also that the menstrual cycle might somehow break in space. Would the blood come out without gravity to pull it from the womb? Maybe it would all pool up in there, or even flow backward through the fallopian tubes into the abdomen—a frightening condition called retrograde menstruation.
In the end, someone just had to try it and see what happened. And what happened was … nothing much. The uterus is pretty good at expelling its lining sans gravity, it turns out (after all, lying down doesn’t seem to matter much). Dealing with space tampons is something of a nuisance, though, and space cramps aren’t probably any nicer than Earth cramps. So now scientists have raised a possibility for female astronauts that has only begun to occur to most women—maybe we don’t need to have periods at all.
We have the technology. A combined oral contraceptive, or the pill, used continuously (without taking a week off to induce menstrual flow) is currently the best and safest choice for astronauts who prefer not to menstruate during missions, says Varsha Jain, a gynecologist and visiting professor at King’s College London. She and her colleague Virginia Wotring, who as NASA’s chief pharmacologist was asked to suggest the best contraceptive, published a study of space menses Tuesday in the journal Microgravity. Contraceptive implants and IUDs are options, too, but the pill already has a good track record in space.
In fact, not only have female astronauts already tried out the continuous-pill method (to much less fanfare than Sally Ride’s space tampons), but more women on Earth are opting out of periods too. Polls suggest that about a third of women feel they need to have a monthly period because it seems “natural” and reassures them they’re not pregnant, Jain says, but the bleeding that occurs during the week off the pill isn’t necessary, or even particularly natural. Women who take the pill continuously don’t build up a uterine lining that needs to be shed. And having a flow doesn’t ensure you’re not pregnant.
“It’s completely safe to suppress the menstrual cycle,” Jain says. Of course, the pill does come with some risks—blood clots in the legs and lungs are a main concern. But Jain says that studies have found no difference in health risks for taking the pill continuously compared with taking it for three weeks at a time.
For long-term space travel, there are added benefits of skipping the flow. “The waste disposal systems onboard the U.S. side of the International Space Station that reclaim water from urine were not designed to handle menstrual blood,” Jain and Wotring write. A woman spending three years in space, say to go to Mars and back, would need about 1,100 pills, which adds some weight to a mission, but is less unwieldy than all those tampons.
As with many aspects of female physiology, there’s still much we don’t know. Could an IUD be shifted by the high Gs astronauts experience during launch? Would an implant under the skin catch on a spacesuit? There’s no reason to think so, but no one has tried it.
Maybe if we weren’t so squeamish about discussing the menstrual cycle, we’d learn more.