2023-06-152023-06-152023-07-16ICES-2023-43https://hdl.handle.net/2346/94494Melissa Borrego, NASA Johnson Space Center(JSC), USAMary Walker, NASA Johnson Space Center(JSC), USAYvette Carmona, KBR Wyle Services, LLC, USAAlexandra Eifert, KBR Wyle Services, LLC, USAAlisa Marshall, KBR Wyle Services, LLC, USAICES304: Physio-Chemical Life Support- Waste Management Systems- Technology and Process DevelopmentThe 52nd International Conference on Environmental Systems was held in Calgary, Canada, on 16 July 2023 through 20 July 2023.Human waste collection in space is a unique and necessary function that all crewmembers must perform. The variability in how each crewmember uses the toilet to urinate and defecate introduces complexities and challenges with regards to overall hardware design. Because of this variability, it is important to consider crew inputs in all aspects of a toilet design especially with regards to crew interfaces that could impact overall waste collection. Access to crew feedback is essential to the design process and should be considered early and often through the various design phases. In 2020, NASA started a project for the Human Landing System (HLS) program to develop a Government Furnished Equipment (GFE) toilet option. The project is known as the Lavatory On-Orbit (LOO). During the early development of the LOO, the project team conducted several crew evaluations to collect and summarize valuable crew feedback on system design, function, and overall usability to influence the next design iteration. Because every person could use the system differently in space, it was extremely important to collect and analyze the data in a very methodical manner to appropriately influence the design based on the evaluation results. Establishing a standard process ensures consistent data collection from one evaluation to another, helps to maintain privacy for each test subject’s inputs and removes any potential bias from test subject to test subject. To date, the team has completed four crew evaluations on prototypes for the different LOO hardware. This paper will summarize the methodology used to conduct the evaluations as well as how data was collected and analyzed. The paper will also provide details on each of the evaluations and how the design was updated based on the results.application/pdfengToiletCrew InterfacesHuman-in-the-Loop (HITL)Waste CollectionDesign IterationCrew FeedbackPresentations