[b]Summary of Findings[/b]
The Mishap Investigation Board (MIB) sought to determine if there were ways to prevent this mishap from re-occurring, if there were ways to have minimized the risk to the crew once it occurred, and if there were ways it could have been prevented before it occurred.
The MIB determined that the causes for this mishap evolved from: [list][*]Inorganic materials causing blockage of the drum holes in the EMU water separator resulting in water spilling into the vent loop.
[*]The NASA team's lack of knowledge regarding this particular failure mode, which led to a delay in recognizing the severity of the event when it occurred.
[*]Misdiagnosis of this suit failure when it initially occurred on [the preceding] EVA 22.
[i]The MIB determined that the space suit actually suffered the same failure at the end of EVA 22, performed a week earlier, and this event was not properly investigated which could have prevented placing a crew member at risk a week later during EVA 23.[/i][/list]
[b]Summary of Causes[/b]
Three Proximate causes were identified contributing to the severity of the event: [list][*]The ISS Program conducted EVA 23 without recognizing the EMU failure which occurred on EVA 22.
[*]EMU 3011 Helmet had a large quantity of water during EVA 23.
[*]Flight Control Team/Crew did not terminate EVA 23 as soon as water was reported in the helmet.[/list] Ultimately these (1 and 3) were caused by five Root Causes: [list][*]Program emphasis was to maximize crew time on orbit for utilization.
[*]ISS Community perception was that drink bags leak.
[*]Flight Control Team's perception of the anomaly report process as being resource intensive made them reluctant to invoke it.
[*]No one applied knowledge of the physics of water behavior in zero-g to water coming from the PLSS vent loop.
[*]The occurrence of minor amounts of water in the helmet was normalized.[/list]