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National Aeronautics and Space Administration

EVA23Water Intrusion

section details the human factors issues that contributed to the specific events that created a lifethreatening situation as EV2 returned to the Airlock.

A.3.1

PE203 Visibility Restrictions

Visibility Restrictions are a factor when the lighting system, windshield / windscreen / canopy design, or other obstructions prevent necessary visibility and create an unsafe situation. This includes glare or reflections on the canopy / windscreen / windshield. Visibility restrictions due to weather or environmental conditions are captured under PE101 or PE102. Visibility Restrictions was investigated and found contributory to the HVCC. Evidence:

Transcripts from Audio Logs, Post EVA 23 Crew Debrief, Expedition 35/36 Post Flight Debrief, Post HVCC interview data from MOD EVA, CORE, SA and CB/Astronaut Office personnel

Shortly before the call to terminate, EV1 looked through the face shield of EV2’s helmet and noticed a large amount of water pooling around his eyes, ears, and nose, as well as blobs of water on the face shield.

During portions of the EVA, EV2’s vision was degraded due to both face shield obscurations and water in his eyes. EV2 was disoriented during his translation to the airlock and his visibility conditions due to water in the helmet created an unsafe situation.

While visibility restrictions alone did not lead to the HVCC, they impacted safety, making them a contributing factor.

Finding: •

EV2’s vision was impaired by water in his helmet.

EV2 was unable to remove the water from his eyes and his face shield.

A-17

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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