Paragon’s STOOLE Tech Seeks to Recycle Space Poo

by Douglas Messier
Managing Editor

Astronauts working on the moon or on long-duration space missions to Mars could use water recycled from their own excrement using technology being developed by Paragon Space Development Corp.

The Tucson-based company is developing Separation Technology of On-Orbit Liquid and Excrement (STOOLE), a system that aims to recover 75 percent of fecal matter that is water.

NASA recently selected STOOLE for a Small Business Innovation Research (SBIR) phase II award worth up to $750,000. The space agency previously funded the project under a smaller phase I award.

The funding will allow Paragon to further develop the technology, which will eventually be tested on the International Space Station (ISS).

“After further SBIR development and relevant test completions on the ISS, STOOLE would be a viable subsystem of the Waste Management System on Gateway, Human Lunar Landers, [and] Habitats,” according to the project description.

The project summary follows.

Separation Technology of On-Orbit Liquid and Excrement (STOOLE)
Subtopic: Spacecraft Solid Waste Management

Paragon Space Development Corporation
Tucson, AZ

Principal Investigator
Brittany Zimmerman

Estimated Technology Readiness Level (TRL) :
Begin: 4
End: 5

Technical Abstract

Future exploration and planetary missions will generate large quantities of fecal matter which contain 75% water by mass which is currently not recovered onboard the ISS. The matter is not biologically stabilized and requires disposal within impermeable containers.

Quantified, this represents as much as 680 kg for a 1,000-day long-duration human exploration mission. STOOLE allows the recovery of this water in concert with the traditional ECLSS and the high-level of feces dehydration will limit ongoing biological risks.

STOOLE also improves the overall logistics of long-duration and planetary exploration by eliminating the disposable Universal Waste Management System (UWMS) canisters and bags and replacing them with a reusable canister and potentially up-cycleable expanded PTFE bags that can be fused into useful end products or allow the solid waste to be likewise upcycled as filler and reinforcement of 3D printed objects.

On a long duration mission or stay, this upcycling allows the waste to be used to create useful products to outfit habitation modules, and/or repurpose storage areas that used to contain the food and other consumables that led to the waste.

Potential NASA Applications

Future exploration and planetary missions will generate large quantities of fecal matter which contain 75% water by mass. NASA desires to recover water from solid wastes to enable greater water recovery and reduced logistical burden for these missions.

STOOLE offers a significant improvement in water recovery over current SOA.  After further SBIR development and relevant test completions on the ISS, STOOLE would be a viable subsystem of the Waste Management System on Gateway, Human Lunar Landers, Habitats.

Potential Non-NASA Applications

Paragon is on several of the prime’s programs providing the ECLSS system so there is a direct path to commercialization including Dynetics’ Human Lunar Lander. We are also a team member of Northrop Grumman and SNC. We are on Boeing’s Next Step BAA ECLSS team. Other targets SpaceX, Blue Origin, and Bigelow Aerospace. 

Duration: 24 months