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National Aeronautics and Space Administration

A.2.3

EVA23Water Intrusion

PC102 Channelized Attention

Channelized Attention is a factor when the individual is focusing all conscious attention on a limited number of environmental cues to the exclusion of others of a subjectively equal or higher or more immediate priority, leading to an unsafe situation. It may be described as a tight focus of attention that leads to the exclusion of comprehensive situational information. Evidence:

RB interview, EVA 23 S/G and CAPCOM loops

Channelized Attention was investigated and found contributory to the HVCC. • •

The team primarily focused on EV2’s DIDB as the possible source of water in his helmet. Other suggestions included accumulation of sweat and leakage from the LCVG, but both were ruled out fairly quickly. Although the CO2 detector is not a moisture detector, its failure is commonly associated with moisture in the vent loop. The attention given to the CO2 detector early on was because it initially indicated rapidly increasing levels of CO2. When it was noted that EV2’s metabolic rate was not unusually high, part of the team wondered if a used METOX canister was accidentally inserted into the EMU. This was only a brief supposition, because a few minutes later, the CO2 sensor failed completely. It should be noted that the way the CO2 sensor failed (off-scale high voltage) was indicative of excess moisture, which had never previously caused a serious hazard. The sudden sensor failure led some of the team to believe that it failed due to a nominal accumulation of water, or moisture in the vent loop. Since nominal water carryover only results in a limited/manageable amount of water in the helmet, the significance of the CO2 sensor failure was quickly disregarded, despite the fact that this type of failure almost always occurred near the end of a long EVA. Channelization may have prevented the team from continuing to ask questions to come up with a different answer or ask new and more specific questions that would have pointed to something other than the drink bag.

Finding: •

No one on the team recognized the relationship between the early failure of the CO2 sensor and an abnormally large amount of water in the vent loop because they channelized on the drink bag as the source and missed the potential cues from the early CO2 sensor failure.

A-12

ISS EVA Suit Water Intrusion Mishap Investigation Report  
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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