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National Aeronautics and Space Administration

EVA23Water Intrusion

application. By not identifying failures to their root cause a greater risk is taken for a recurrence of the issue. A related issue was found in other documentation. As a case in point, no FIAR/PRACA or IRIS entry exists for the vacuum cleaner oxygen incident, with the rationale being that the hardware performed nominally. This waive off does not resolve that the failed validation process allowed a potentially hazardous close call. A part of this gap may be because the Agency has no guidance or training on expectations for root cause analysis for engineering investigations (NPRs 7123 and 7120 are silent). Current labor and time constraints tend to focus upon hardware specific fault trees to the detriment of logic flow based troubleshooting and seeking process based root causes. If the tendency to focus on symptoms continues, more fundamental issues will be missed. Ideally, root cause pursuit would be institutionalized in standard program and project practices and not left to rare mishap investigations. Recommendation R-30: The Agency, Centers, and Programs should improve requirements for root cause determination and subsequent training and provide the training for Engineering and Safety personnel to better ensure root cause determination of critical and reoccurring failures. O-17 The Flight Crew and all ground-based MCC and MER personnel involved in the event were properly certified for their positions by their respective organizations. Supporting Evidence: Training and certification records including certification requirements for all personnel were reviewed by the MIB. In this activity there was no determination as to the validity of the certification. This was merely an audit function to verify that all personnel working in positions requiring certification were properly certified according to the rules at that time. O-18 Integrated sims are intended to run their entire scheduled length, which causes the Flight Control Team to never experience the pressure of terminating an EVA early before a majority of the objectives are accomplished and may be providing negative training that all problems can be overcome in the course of an EVA and therefore delays the decision to terminate. Supporting Evidence: An integrated EVA simulation is a complex undertaking. Integrated sims are considered the most realistic training possible for the Flight Control Team and therefore are of the highest fidelity. The instructors work very hard to provide challenges to the Flight Control Team to fulfill training objectives for all the members of the Flight Control Team. For an EVA sim, three facilities are used: the MCC, the ISS simulator, and the Neutral Buoyancy Laboratory. As a result, integrated sims are also very expensive to conduct. In order to maximize the training benefit, it is important that the Flight Control Team remain unaware of the objectives of the simulation so as not to anticipate where the sim scenario is going. It is important that the scenarios are constructed so that there is a high probability that all of the training objectives will be met no matter what course the Flight Control Team takes along the way. In short, if the scenario is intended to cause the team to call for a terminate or an abort EVA, there is a risk that this will cause the sim to end early and therefore training objectives for other flight controllers may not be accomplished for that sim. Therefore it is rare, if ever, the case that a sim scenario will cause the EVA team to call for a terminate significantly prior to the scheduled end of a sim. Thus, the EVA team never gets the experience of making a call with significant consequence prior to flight i.e. they are inadvertently trained not to terminate an EVA early in an EVA because they are never asked to do that in training. They are much more comfortable late in an EVA when the consequences are lower both in terms of the potential impact to a sim and the impact to the real EVA when most tasks are accomplished. This can lead to the EVA team, when put into a real situation, of doubting when to end the EVA in real-time


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...