2023-06-212023-06-212023-07-16ICES-2023-402https://hdl.handle.net/2346/94772Mark Weislogel, IRPI LLC, USAOleg Krishcko, IRPI LLC, USALogan Torres, IRPI LLC, USAColin Campbell, NASA Johnson Space Center(JSC), USAPaul Dum, NASA Johnson Space Center(JSC), USAJohn Graf, NASA Johnson Space Center(JSC), USATessa Rundle, NASA Johnson Space Center(JSC), USAICES408: ISS US EVA-80 Water Helmet Incident InvestigationThe 52nd International Conference on Environmental Systems was held in Calgary, Canada, on 16 July 2023 through 20 July 2023.Following a second crew report of excess water inexplicably accumulating in the helmet during EVA-80 on March 23, 2022, NASA initiated an aggressive effort to identify, mitigate, and/or eliminate all sources of the potentially life-threatening water. Our narration highlights demonstrations of microgravity flow expectations using terrestrial scale models, mitigations to dangerous water migration within the helmet, low-g two-phase flow separations for the flow entering the helmet, and an investigation of the nature of liquid carry-over from the EMU condensing heat exchanger source. Fast-to-flight demonstrations of each aspect of the work are carried out during hands-on crew interaction with flight scale hardware on ISS during the 2022-2023 timeframe. The results of the tests are described with a focus on the rarely observed, and thus rarely studied, large length scale air-driven wall-bound droplet and rivulet two-phase flows in microgravity. The success of the mitigations and directions for continued work is discussed in summary.application/pdfengEVA Helmet LeakWater in HelmetMitigationsMicrogravity fluid mechanicsCapillary FluidicsCarry-overISS demonstrationspassive phase separationsPresentations