A ‘Dune’-Inspired Space Suit To Turn Astronaut Pee Into Water

RACHEL BOUTON: On the International Space Station, resources are precious. That includes every single drop of water, which is why astronauts drink their own filtered and recycled pee. That might sound a little undignified. But things get worse when astronauts go out for a spacewalk. If nature comes calling, their only option is a super strength diaper.

Inspired by the stillsuits that recycle water in Frank Herbert’s Dune series, researchers have designed a system that turns astronauts pee into nice, clean drinking water while they’re suited up. The researchers reported on their prototype in the journal Frontiers in Space Technology.

Joining me today is Sofia Etlin, a researcher at Weill Cornell Medicine in New York. Sofia, welcome to Science Friday.

SOFIA ETLIN: Hi, Rachel. Thank you.

RACHEL BOUTON: So tell me, has astronaut pee always been top of mind for you, a burning research question?

SOFIA ETLIN: I don’t know for who it’s been. But I would say that Frank Herbert has been thought of mind for perhaps too long. And the dream of making a stillsuit or of turning science fiction into reality has been part of my life since I started getting into reading science fiction.

And when I was in high school, and then after I took a gap year, I spent all that time developing the stillsuit. I knew that there would be some form of utility to it, but I wasn’t sure how or where it would fit in. And I’m also a big space nerd.

And I knew of Dr. Christopher Mason, who has done incredible work when it comes to astronaut well-being. And I cold emailed him out of the blue. And he gets back to me and he says, did you know that it’s 2022 and astronauts wear diapers? And so it was this beautiful moment of putting everything together where this thing that I’d been wanting to build for such a long time, could actually truly benefit someone.

RACHEL BOUTON: Yeah. Wow, what an awesome backstory. So how does the system actually work?

SOFIA ETLIN: It’s a three-part system. We have the part that collects the urine from the astronaut’s body and then the part that filters it. And then the part where all that now filtered urine is collected. And so originally in the ’70s when only men were allowed to be astronauts, we had condom catheters as the primary mechanism of urine collection. And then when women were suddenly allowed to go to space, they sort of haphazardly stumbled onto the solution of an oversized diaper. But that was never the original intention for waste management within spacesuits.

We developed an external catheter cup with a male and a female version that could then collect that urine in a noninvasive manner and then pass it through a membrane filtration system. And the reason that we decided to do a membrane system is because it’s forward and reverse osmosis. So the forward osmosis part of it is purely by osmotic pressure, no power required, which is lovely for us. And that’s where we get our urine brine.

RACHEL BOUTON: So what’s urine brine? [LAUGHS]

SOFIA ETLIN: Imagine if you have a cup of urine and you leave it out in the sun for a very long time and all the water is gone. Urine brine is all the things in your urine that make it stink, basically–

RACHEL BOUTON: Got it.

SOFIA ETLIN: –returning to our membranes. So we have this forward osmosis system where just by osmotic pressure, the water travels via this membrane into this salt solution. And then from that salt solution, we then do need battery power to pass it through another membrane to get rid of that salt, at which point that filtered water then returns to an in-suit drinking bag.

Currently, astronauts do have an in-suit drinking bag. It contains less than a liter of water to drink for spacewalks that can last up to 12 hours. And it has been a source of complaint for astronauts over and over and over again. So we’ve redesigned it so it can hold more water given the, I suppose, bladder conditions of each astronaut. So that we’re tackling two birds with one stone here, and boom, we fix both with. Thank god, for Frank Herbert.

RACHEL BOUTON: You are clearly a sci-fi nerd, as am I, and as are many of our listeners, I think. So how does it feel to have created something inspired by Dune and to have it formally published and out there in the world?

SOFIA ETLIN: It sort of is what science fiction is for, to inspire and to create. And while space exploration and settling might be far off, be able to build towards that direction and reunderstand understand what it means to be an astronaut, reunderstand what it means to be a person who is allowed to go to space, I think is something that I really wanted to get at, because we’re not sending the healthiest people in the world to space anymore.

It’s not the 100 pages of regulation where if you’ve ever had a broken pinky, you can’t go to the ISS. Now you have real people with real problems. And we have to start taking that into account if we ever want to make this in any way, shape, or form equitable, whether it be in 10 or 20 or 30 years.

RACHEL BOUTON: Yeah, no, that’s a really awesome goal and one that I’m sure Frank Herbert would approve of. Sofia, thanks so much for joining me. This has been great.

SOFIA ETLIN: Thank you so much, Rachel.

RACHEL BOUTON: Sofia Etlin is a researcher at Weill Cornell Medicine in New York.

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