NASA Exploration Toilet Hardware Technical Challenges and Accomplishments

The Universal Waste Management System (UWMS), ISS operational nomenclature “Toilet” was initially installed on the International Space Station (ISS) in 2020 with final installation completed in 2021. Technical progress continues to be made with each on-orbit operation and will ultimately culminate with nominal US crew use of the hardware on ISS. During 2024, another attempt was made to perform the Artemis II Demonstration on ISS with a re-flight of the Dosing Assembly using original components. This paper discusses the issues encountered when the Dosing Assembly failed to dispense pretreat as well as a subsequent failure to start of the UWMS and the on-orbit troubleshooting resulting in the removal and return of the controller. A summary of ground troubleshooting of the controller (which is the Orion common controller used in the Orion vehicle for numerous systems) as well as planned repairs is discussed. An updated design of the commode seat and fecal bag for Artemis-2 UWMS was demonstrated on ISS and a summary of the hardware, results and selection of seat for use on Artemis-2 is included in the paper. Details of air flow of each option of the updated seat, original seat along with permutations for original UWMS Fecal Bag, Updated Fecal Bag and current WHC ACY Insert (Russian design Fecal Bag) are described as well as crew feedback on the evaluation. Implications for all work on Orion missions will be detailed.