Here's an anecdote I always assumed was apocryphal: Sally Ride was going to space, the first American woman to do so. Down on Earth, the NASA engineers in charge of equipment wondered about a possible scenario - what if Ride got her period while on the Challenger?

So they came to her with a question: Would 100 tampons be the right number to pack?

No, she told them. It would not be the right number.

If you're a menstruating woman you see the absurdity already, and if you're a man you can pause now to engage in some educational Googling. Either way, I recently called up Brian Odom, NASA's chief historian, expecting he'd tell me that I'd heard it wrong - that of course the top scientific minds of 1983 knew better than to send a hilariously large number of feminine hygiene products for a six-day mission.

"Ah, no," Odom said ruefully. "That actually did happen."

You could give NASA the benefit of the doubt. Maybe engineers were behaving cautiously because nobody knew what would happen to a uterus in zero gravity. But historians I talked to seemed to think that the answer was simpler: NASA just hadn't thought that much about women. The organization was operating with the most cutting-edge technology of the time but was stymied by rudimentary biology; they could do the math to put a man on the moon but couldn't do the math to put tampons on a rocket.

That was a long time ago. NASA is now several years into the Artemis spaceflight program, which plans to be the first series of missions since Apollo in the 1960s-1970s to land astronauts on the moon. The program has come with a promise: The moon astronauts will include an astronaut of color and a woman.

"America will demonstrate a new level of global space leadership," read the official Artemis plans. On the program's website, you can click through the bios of the nine women who have a shot at becoming the first: biologists, physicists, nuclear engineers, search-and-rescue firefighters who winter in Antarctica and other women who generally make you wonder what you're doing with your own life.

Any one of them would make America proud.

So how do you put a woman on the moon?

I've been asking myself that question recently, while getting excited by the Artemis program in that geeky way that space travel still feels exciting. Putting a man on the moon, as America first did 53 years ago, was a purely technological endeavor: If you build it, he will land.

But putting a woman on the moon is a question that is about more than science and technology. It's a question about culture and sociology, about who we are and who we want to be, and about Sally Ride's tampons and the men who didn't understand them.

"The first thing you need to do in order to put a woman on the moon is decide that it's worth putting a woman on the moon," Margaret Weitekamp, a space historian and curator of the National Air and Space Museum, told me in a recent conversation. "And that's a relatively recent historical phenomenon."

Back when "astronaut" was a concept but not yet a profession, NASA decided that space explorers should be drawn from a pool of military test pilots, who had already been through rigorous government testing and training. It seemed a reasonable requirement, but it eliminated half the population: Women could not be military test pilots, and thus they could not be astronauts. A physician named William Randolph Lovelace II, who would one day become NASA's director of space medicine, ran his own independent program to test the suitability of space travel for women. Using private funding, he selected 13 women and planned to assess them with the same grueling physical and psychological tests that the male Mercury astronauts had been through.

None of those women were allowed in NASA's official program. In a 1962 House hearing on gender discrimination in the space program, John Glenn told a panel of congressmen, "The fact that women are not in this field is a fact of our social order." The fact that they dared to ask to upend this social order was seen as an impediment to the speed of the program as a whole, which wanted to be beating Soviets, not blazing trails for gender equality.

Instead, the Soviets beat America. The first woman in space was a Russian named Valentina Tereshkova. She hadn't been a test pilot, either. When she was admitted to the Soviet Union's cosmonaut program, she was a textile worker and an amateur skydiver. The Soviets didn't care. "We cannot allow that the first woman in space will be American," wrote the director of the cosmonaut program in his diary. "This would be an insult to the patriotic feelings of Soviet women."

Shortly after Tereshkova returned to Earth, the writer Clare Booth Luce published an essay in Life magazine. Scathingly, she took American male officials to task for dragging their feet in putting a woman in space. "The U.S. could have been first to put a woman up in space merely by deciding to do so," she wrote. The cover line describing her essay was even blunter: "Soviet space girl makes U.S. men sound stupid."

But that is the nature of progress. It's not that women have become more deserving - they always had the right stuff. It's that their country has become more willing. More willing to see patriotism as the purview of Americans, not the purview of men, and more willing to acknowledge that John Glenn's "social order" was something as invented as space travel itself: a concept that can be constantly improved upon, frequently due for an upgrade.

In 2019, NASA was mocked when its first all-female spacewalk - which had been much publicized and anticipated - had to be canceled because there weren't enough correctly sized spacesuits to suit the female astronauts.

This won't happen again. The Artemis program is pioneering new modular spacesuits, with exchangeable arms and legs that can fit a broad variety of body shapes and sizes.

The program is also pioneering a new space toilet, one more usable for those who prefer sitting down when they pee. And NASA has partnered with German and Israeli space agencies to study the effects of radiation - which impacts every human leaving the Earth's atmosphere and has implications for long-term crewed missions - on women's bodies. Two anatomically correct "radiotherapy phantoms," named Helga and Zohar, are equipped to ride in the passenger seats of the Orion spacecraft.

You put a woman on the moon by thinking about what will make her successful on the moon. What will allow her to complete spacewalks and stay healthy?

While you're thinking about that, you get a lucky byproduct. Modular spacesuits won't just be helpful to women. They'll be helpful to astronauts of any gender who have longer or shorter arms or legs, who have any body type different from the test-pilot physique idealized by NASA's first astronauts.

You put a woman on the moon, and what you're really doing is saying that space is for all bodies. Exploration is for everyone. Figuring out how to put a woman on the moon is not just a symbolic mission, it's a way of finding out what other questions you weren't asking.

The moon - and I'm probably not supposed to say this - seems like a sucky place to visit. It has no weather. Temperatures fluctuate from 250 degrees to minus 200 degrees. We go there not because it's great but because it's the closest thing that's not Earth and, well, because we can.

The ultimate goal of the Artemis program, though, is not to repeat what we can do, but to figure out how to do what we can't do yet: support human life away from Earth on a long-term basis. The ultimate goal of the program is to prepare to go to Mars. It's a beginning, not an ending.

A woman on the moon is not only the culmination of decades of work and societal progress, but it is also a beginning and not an ending.

That's what the mission to put a woman on the moon is about. Not the moment that she steps onto the lunar surface, but America's gradual process of understanding why it was important to put her there. It took so long, that one small step, that leap for humankind.