Exploration Toilet Integration Challenges on the International Space Station

On the International Space Station (ISS) there are currently two toilets. One is located in the Russian’s Service Module and the other is located in the U.S. segment’s Node 3. A new Exploration Toilet will be integrated next to the existing Node 3 Waste and Hygiene Compartment (WHC). The Toilet will be evaluated as a technology demonstration for a minimum of three years. In addition, it will support an increase in ISS crew size due to Commercial Crew flights to ISS.

The Toilet is designed to minimize mass and volume for Orion, the first Exploration vehicle. Currently ISS does not have a designated volume for an additional Toilet. Furthermore, operating the Toilet on ISS presents a different set of challenges as it must integrate into existing vehicle systems for urine processing. To integrate the Toilet on ISS, a suite of hardware was developed to provide mechanical, electrical, data, and fluid interfaces. This paper will provide an overview of the Toilet Integration Hardware design as well as the engineering challenges, crew interface provisions and vehicle integration complexities encountered during the concept and design phases.