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National Aeronautics and Space Administration

EVA23Water Intrusion

Based on interviews, there is a general perception among teams that the ISS Program applies pressure to maximize crew time, at the expense of other mission requirements. This has led lower level teams to make risk decisions for the Program, assuming that they won’t be allowed to use crew time to accomplish other tasks that may be deemed necessary.

This is a high level organizational weakness and is not meant to reflect adversely on any one organization.

Finding: •

Organizational influences led to an acceptance of risk by workers below the Program management level.

A.1.7

OP001 Ops Tempo/Workload

Ops Tempo/Workload is a factor when the pace of deployments, workload, additional duties, off-duty education, PME, or other workload-inducing condition of an individual or unit creates an unsafe situation. Evidence:

Post HVCC interview data from MOD EVA personnel, Discussion with EVA MIB Chair and MOD Manager.

Ops Tempo/Workload during EV 22 event was considered, and found contributory to the HVCC. •

Discovery and troubleshooting of the EVA 22 water leak (in which approximately ½ to 1 liter of water leaked into EV2’s helmet during repress) occurred around the time of a shift hand-over, a time during which it is not uncommon to have distractions (note that this is an additional Human Factor captured in PC106) that can skew one’s attention away from certain details. For example, if a hand-over conversation is going on between two controllers, the possibility exists to miss a critical piece of information being discussed on the comm loops (another Human Factor captured in PC102 Channelized Attention).

The team knew about the water in the helmet but they thought they had a reasonable explanation, and there is interview evidence to indicate that a high Ops Tempo encouraged the team to accept the established drink bag explanation.

During the interview process, there were expressions to the effect of having wished the team had slowed down, to consider things in more detail, while on the other hand they thought that if they had pursued other causes, that process of running the options to ground would have caused a significant slowdown to the process of preparing for EVA 23, a challenge even under normal circumstances.

Finding: •

Ground team had started a shift hand-over when the event occurred.

Due to Ops Tempo, preparations for EVA 23 became the main focus after EVA 22 was concluded.

A-6

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...

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