The Collapsible Contingency Urinal (CCU) for Spacecraft

The routine, hygienic collection and processing of urine aboard spacecraft remains difficult. This fact is perhaps as attributable to the myriad requirements of spaceflight life support as it is to the acute challenges of multiphase fluid physics in microgravity. In this paper we present the specification, development, flight demonstration, and certification of a Collapsible Contingency Urinal (CCU) for use aboard spacecraft. The passive device exploits recent advances in microgravity capillary fluidics research, combining robust superhydrophobic and superhydrophilic substrates that mimic gravity, where, in effect, droplets ‘fall’ and bubbles ‘rise.’ According to crew commentary, the device successfully delivers a method for clean, ergonomic no-moving-parts urine collection for females, which is in turn successfully adapted for males. The encouraging results provide a practical solution for CCUs aboard spacecraft as well as identify a design path forward for the myriad passive fluids management tasks ahead for space exploration. Directions for future CCU production are highlighted in summary.