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National Aeronautics and Space Administration

EVA23Water Intrusion

Supporting Evidence: The MIB determined through interview and transcript review that the Phased Elapsed Time between first mention of water in EV2’s helmet and the call to terminate the EVA was roughly 23 minutes. The fact that no one on the Flight Control Team (FCT) or the EVA Crew, immediately recognized the severity of the hazard and terminated the EVA is discussed in the sections below. ECFT-4 – Flight Control Team sent EV2 back to Airlock unaccompanied during EVA termination. (Contributing Factor 1)(Figure 3-68) Supporting Evidence: The MIB determined from interviews, audio recordings and transcript reviews that, when the decision to terminate the EVA was made, EV2 was sent back to the Airlock unaccompanied which contributed to the severity of the event. At that time, it was still daylight and EV2 was not yet reporting difficulties seeing due to the water accumulating in his helmet. In addition, EV2’s translation to the Airlock from his location near Node1 was fairly short. Conversely, EV1’s safety tether was routed such that his translation back to the Airlock needed to be via a different, less direct route than EV2’s. This Safety Tether arrangement was specifically planned to avoid EV1 and EV2 tangling tethers. EV1 commented during a post-flight public interview on NASA TV that, as EV2 started his translation toward the Airlock, he felt he should probably have gone with him. However, this would have necessitated him dropping his safety tether and tethering to EV2 resulting in his safety tether being left outside and several “clean up” steps being left undone. EV1 accompanying EV2 back to the Airlock would also have necessitated further discussions with the Flight Control Team ultimately delaying EV2 from getting there as expeditiously as possible, which was the intention.

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ISS EVA Suit Water Intrusion Mishap Investigation Report  

Report of the NASA Mishap Investigation Board examining the high visibility close call event of July 16, 2013 when ESA astronaut Luca Parmit...