Description: To LIVE in space, NASA’s Advanced Habitation Systems is developing capabilities under Life Support and Logistics capability areas that enable future missions. The life support priorities include >98% water recovery. There currently is no fecal water contaminant or recovery available on ISS. Feces is ~75% water by mass and, due to biological activity, generate noxious gases that must be contained, adsorbed, or become an air contaminant burden. For exploration missions, there is an opportunity to capture this water and recycle it back to the crew to limit resupply requirements while stabilizing the feces for safe disposal [Fecal Resource Recovery (STARPort ID 365)]. The proposed project addresses the main technological gaps associated with human solid waste drying for space applications (including International Space Station (ISS), Moon, Mars, and beyond). We propose developing a functional, hybrid, portable ultrasonic solid waste dryer that uses piezoelectric transducers to extract water from fecal matter inside a membrane bag. The prototype will investigate the piezo performance, water capture, and user interaction. The proposed system will be a stand-alone system that leverages the Universal Waste Management System (UWMS)’ air, odor, and water handling system with minor (almost negligible) modifications. The system is also compatible with the existing or future firm or flexible fecal canisters. Ultrasonic Technology Solutions (UTS) has successfully completed the proof-of-concept (SBIR I), improved piezo performances for water removal (SBIR II), and initial microgravity testing. In Phase IIe, UTS will design the integrated system around its core drying technology and measure its performance and the relevant metrics (described in the next sections) under microgravity conditions. Currently, the ultrasonic drying for solid human waste applications is at TRL Level 5, and by the end of the proposed phase IIe project, it is expected to reach TRL 6.

Benefits: Water Recovery: In the short term, ISS could play as a test bed for technology maturation. In the longer term, it could be an enabler technology for long-duration missions, Mars Rover, human habitat on the moon, and Mars application. Clothing Laundry Applications: Our technology can help accelerate technological improvements in space washing and drying applications. Useful byproduct: The byproduct of ultrasonic feces drying can open many new opportunities for processes that can use solid biomass as their feedstock in space.

During the ARPA Innovation summit, the GTI Energy team learned about our NASA project and showed their keen interest in the technology. Based on our technical discussion, they are in the process of scaling green fuel and biofuel production. Converting municipal waste into biofuel is cost prohibitive due to the enormous energy requirement for drying municipal waste.