NASA wastewater system will turn human poop into plant food

University of North Dakota grad students will test the system that's destined for the moon.
a moon, poop emoji, plant emoji
The system would help astronauts sustain longer-term lunar habitats by filtering their own waste. Image: Popular Science composite, NASA

NASA’s ambitious plan to put humans on the moon may hinge on the bathroom habits of a handful of University of North Dakota grad students. In the name of science, those researchers will test the limits of a mobile wastewater treatment system designed to convert human waste into plant nutrients and other sustainable materials. The trial will serve as a stress test of sorts, measuring how well the Divergent Deployable Wastewater Treatment Facility holds up to regular use and heavy loads in an environment designed to mirror a lunar habitat. 

It’s not pretty work, but someone has to do it.

“The tests will help NASA evaluate real-world operation, crew training needs, system reliability, and how wastewater simulants compare with actual human metabolic waste in an analog mission environment,” Ali Alshami, University of North Dakota Chemical Engineering professor and test participant, said in a statement.

a gray trailer sits in a parking lot
The unassuming gray building could one day be an astronaut wastewater facility. Technicians prepared the Divergent Deployable Wastewater Treatment Facility for transport at NASA’s Kennedy Space Center in Florida on April 21, 2026. Image: NASA/Kim Shiflett  

Treated astronaut poop will feed lunar plants 

The mobile facility consists of three separate bioreactors, each tasked with handling a specific kind of waste. Feces, urine, and food waste are treated separately because each material contains different levels of salts, solids, carbon, nitrogen, and phosphorus. One reactor processes feces and food waste, converting it into nutrient-rich water that can feed plants. The other two handle urine and greywater from activities like showering and laundry, some of which can be filtered and recycled into  clean drinking water. From an astronauts’ perspective, the experience should feel pretty familiar to life onboard the International Space Station (ISS). They use the toilet as normal, and it automatically diverts waste at the source, routing each type to its corresponding bioreactor.

The whole process takes place in a mobile, 8.5-by-24-foot trailer. In addition to the bioreactors, the unit also houses a vertical garden maintained by the converted wastewater. The goal is to kill two birds with one stone: process waste efficiently and then use it to sustain lunar agriculture. Both are essential if astronauts want any shot at building longer-term habitats on the moon or even Mars. To that end, NASA has ambitions to start constructing a semi-permanent lunar structure or “moon base” by 2029.

Where no one has gone before 

Waste management in space has come a long way since the first moon missions. Back in the 1960s, NASA Apollo astronauts left behind 96 bags of human waste (filled with poop, urine, and vomit) on the lunar surface to save weight. Those bags are almost certainly still there. 

Thankfully, decades of research mean astronauts no longer have to relieve themselves into a bag, at least not most of the time. The most recent Artemis mission featured a fully functional space toilet, though it malfunctioned almost immediately after liftoff.

Recycling wastewater has also seen major improvements. NASA had a breakthrough in 2023 when its life support system aboard the ISS  managed to recover nearly 98 percent of all breath, sweater, and urine brought aboard by the crew. Future astronauts on prolonged spacewalks may also wear this Dune-inspired backpack that filters urine and sweat into drinking water in a single self-contained loop.

 
products on a page that says best of what's new 2025

2025 PopSci Best of What’s New