This past weekend, the world observed the 50th anniversary of the Apollo 11 moon landing, the first time a human being ever set foot on the moon. Even fifty years later, we’re still in awe of what Neil Armstrong, Buzz Aldrin, Michael Collins, and hundreds of NASA employees accomplished. It’s easy to think of these space pioneers as mythical, larger-than-life figures. But they were very much human beings, just like you and me.

And do you know what’s a great way to humanize anybody, no matter how legendary? By learning about their bathroom habits. And so, today, in honor of the moon landing, we’re going to learn about an often overlooked but still essential part of the Apollo program: how the astronauts went to the bathroom.

Credit goes to author Mary Robinette Kowal, who has studied astronaut bathroom engineering in depth, particularly how it relates to gender. Recently, she published an essay in the New York Times titled “To Make It to the Moon, Women Have to Escape Earth’s Gender Bias.” Many uninformed internet commenters, (aka “internet commenters”) objected to the very idea that a woman could walk on the moon, arguing that biological differences make it impossible.

And so, to set the record straight, Kowal published an epic Twitter thread in which she broke down how NASA planned for astronauts to go to the bathroom, and what happened once these plans were put into action.

Let’s get to it!

Astronaut Alan Shepard was the first American to travel into space, via NASA’s first human spaceflight program, Project Mercury. Unfortunately for Mr. Shepard, Project Mercury did not have a plan for what to do in case nature called. Which nature did.

That detail probably didn’t make it into many history books.

Shepard’s accident forced NASA to come up with a plan, and they invented the Urine Collection and Transfer Assembly (UCTA), aka “the pee condom.”

Photo Credit: Youtube

Alas, even the best and the brightest are not immune to insecurity about the size of their “lunar module.”

Right now you’re probably thinking, “This information about peeing in space is great, but what about pooping in space?” Don’t worry! Kowal covered that, too.

And here’s a delightful photo demonstrating how to use the bag.

Photo Credit: NASA

What’s with the two fingers? Sorry in advance for being gross, but due to the lack of gravity in space, an astronaut’s poop does not simply fall out like it would on Earth. Manual intervention is necessary.

For the earliest space missions, pee condoms and adhesive poop bags were the solution to astronauts’ bathroom needs. However, the solution was far from perfect. Plenty could still go wrong, and it did. Like when the astronauts had to get the waste out of the space capsule.

Eliminating waste in space is difficult under ideal circumstances, but during the ill-fated Apollo 13 mission, it let to health problems for astronaut Fred Haise.

And then there was the Apollo 10 mission, which really should be renamed “the one with floating poop.” Here’s a real excerpt from the mission transcript, which is probably the best thing you will ever read:

Cernan: “Where did that come from?”

Stafford: “Get me a napkin quick. There’s a turd floating through the air.”

Young: “I didn’t do it. It ain’t one of mine.”

Cernan: “I don’t think it’s one of mine.”

Stafford: “Mine was a little more sticky than that. Throw that away.”

Young: “God Almighty” (laughter)

In 1978, NASA finally opened up the space program to female applicants, and an alternative to the pee condom was necessary.

Photo Credit: Flickr

The Maximum Absorbency Garment was so effective that the male astronauts switched over to it!

Astronaut bathroom technology has progressed since the 1960’s and 70’s, but it still isn’t foolproof. Kowal went on to detail the bathroom problems facing contemporary astronauts.

But wait! There’s more! What about other bodily functions? Kowal covered those, too. First up, the gassy ones.

Up next, menstruation.

Wow. Even literal rocket scientists are clueless when it comes to women’s health.

Finally, “morning wood.” Which, incredibly, does still happen in space despite the lack of a traditional day-night cycle!

So there you have it! Everything you ever wanted to know about astronaut pee and poop. If you enjoyed this article, you should buy Kowal’s book, The Fated Sky: A Lady Astronaut Novel here.

The next time you look up to the stars, maybe you’ll appreciate how much the astronauts had to go to through to achieve the impossible. Just be careful not to look too long, because you might get splashed in the face by falling astronaut pee.