Read | How do periods work in space?

by Grey Fraser

Header image: Sian H. Proctor, left, and Hayley Arceneaux, right, during the Inspiration4 space mission, CC BY-NC-ND 2.0, credit: Crew of Inspiration


From your computer

Who for

Families and adults

Bodily functions in space. They grasp at a part of our psyche fascinated with the grotty and the gross. Whether you’re puzzling the logistics of urinating in microgravity, picturing yourself jetting backwards with the force of your own sneeze, or pondering what happens when people menstruate aboard the International Space Station; the gloopy ins and outs of our bodies operating in space raise a slew of questions. 

So how do astronauts deal with menstruation? Is it dangerous to have a period in space? And what barriers have female astronauts faced because of their body’s natural cycle?

Let’s hurtle back in time to the 1960s, when people first began to answer these questions.


Valentina Tereshkova before her mission, Credit: Roscosmos

Who was the first woman in space?

The first human in space was a Russian man named Yuri Gagarin. He completed his mission in April 1961. A mere month after, he was followed by the first American to make it into space - Alan Shepard.

The Russians assembled an all-female space squad in 1962. In June 1963, Valentina Tereshkova became the first woman to venture into space.

After orbiting the Earth 48 times, Tereshkova returned to earth unconscious. She suffered a bad bruise from her helmet and had gotten sick from her space food rations. Following this, Sergey Korolev, a Soviet engineer critical to the mission, declared that he wouldn’t be putting any more women into space. The Russians had reaped enormous propaganda benefits from Tereshkova. They saw no reason to pursue further female flights. The female space squad was later disbanded. 

The Russians may have beaten the Americans when it came to putting women into space. Yet, they didn’t exactly win a gold star for galactic gender equality.

Humanity had set its future sights to the stars. But it was having trouble leaving its prejudice in the past.

Were periods the problem with sending women to space?

In America, NASA were reluctant to send a female astronaut to follow in Valentina Tereshkova’s footsteps.

In 1962, John Glenn, the first American to be sent into orbit, argued against women being able to do the same, stating “The fact that women are not in this field is a fact of our social order.”.

As if social barriers weren't enough, scientists went ahead and proposed biological ones too.  In 1964, a paper was released in the American Journal of Obstetrics and Gynecology.  It described women as ‘temperamental psychophysiologic humans’ unsuited for piloting a spacecraft. The authors referenced studies 'proving' menstruating women were more accident prone. They even suggested menstruating women were to blame for some unexplained air crashes. 

The minds bright enough to launch men out into space were not quite so brilliant at helping quash the sexism rife in 1960s America. In the eyes of NASA, periods mentally incapacitated women. They couldn't be trusted to operate spacecraft.

It would be 20 years after the first Russian woman went to space when the Americans finally sent Sally Ride - the first female astronaut.

Sally Ride, America's first woman astronaut communicates with ground controllers from the flight deck, credit: NARA

How many tampons does an astronaut need?

By the time of Sally Ride’s mission in 1983, NASA had moved from a state of outright misogyny, into general tomfoolery. An observer is lead to question whether their engineers had ever lived with a woman.

How many tampons might she have needed for her first spaceflight? NASA first proposed to Ride that they send her with 100 for the one-week expedition.

Some maths, in case you’re unsure of how many tampons someone might use during a single period:

The total amount of blood lost during one period is usually about 60 millilitres. Heavier periods may be about 80ml. A regular absorbency tampon holds around 6ml of menstrual blood. Using these numbers, we could assume that one period may use around 10 to 14 tampons. Of course, every body is different and the actual number may be around 20. Ride informed NASA’s engineers that they could cut down to 50% of their proposed number without a problem.

Proof That NASA Doesn’t Know Anything About Women, credit: Marcia Belsky

Is menstruating in space dangerous?

When it comes to periods in space, you might be picturing some kind of bloody horror show; a ghastly nebula of levitating menstrual blood. Scientists had similar macabre worries. Before the first women went into space, they asked questions like: ‘would blood end up flowing upwards in the fallopian tubes (retrograde menstruation)?’. Weird - they didn't voice similar worries surrounding testicles.

Menstrual blood flow went against scientists' predictions. It isn’t affected by the weightlessness experienced by the body in space. Unlike the cardiovascular system, which gets lazy, the menstrual cycle does its job. Blood does not float off to places where it shouldn’t be floating. The human body is smart - it knows menstrual blood is a waste product it needs to be rid of.

Astronaut Rhea Seddon talked about the 80s and its unknowns in a 2010 interview. She said female astronauts asked NASA to consider periods in space a ‘non problem until [they become] a problem’. Because no one knew what would happen, women proposed they should just be sent into space. Like anyone, they could always be brought home again if they got sick.

Seddon stated ‘I’m not sure who had the first period in space, but they came back and said, “Period in space, just like period on the ground. Don’t worry about it.”’

Rhea Seddon, first female surgeon in space, credit: NASA

Is it easier to not have a period in space?

So, periods in space do not make you unwell. But they can be inconvenient. 

The International Space Station has a urine processing assembly (UPA). This reclaims water from astronauts’ urine. It doesn’t handle blood very well and astronauts must be careful not to contaminate it. The UPA, cramps and periods generally being a bit messy, mean many astronauts now choose to not menstruate on missions. 

By taking birth control in the form of a hormonal pill, people who menstruate can induce amenorrhea (say: uh-men-o-REE-uh). This is the absence of menstruation, and a neat little trick for those who find it helpful. Medical studies show that brief periods of induced amenorrhea pose no significant dangers to health.  

What is the future of menstruation in space?

People who menstruate have had to battle against sexist barriers whilst pushing forwards towards the stars. 

NASA reached a milestone on October 18th 2019.  Two Americans - Christina Koch and Jessica Meir - became the first to take part in an all-female spacewalk. Venturing out of the ISS, they were tasked with replacing a power controller. And this was not a planned walk. Just something that happened because there are increasing numbers of female astronauts.

On the 3rd April 2023, Christina Koch was announced as one of four astronauts on the Artemis II mission.  Artemis II will fly around the moon before returning to Earth.  Its sister-mission, Artemis III, plans to put the first people on the moon since 1972.

The crew of NASA’s Artemis II mission (left to right): Christina Hammock Koch, Reid Wiseman (seated), Victor Glover, and Jeremy Hansen, credit: NASA

Hopefully, in the not so far off future, we will see a woman walk on the moon. And maybe, we will see new solutions to space menstruation - after all, does anyone really want to lug 1,100 birth control pills to mars?

Curious about how people live in space?  Watch our video ‘Can you eat real food in space’ to see what astronauts have to think about when they make their lunch.

You might like...