NASA Mishap Board Report on Serious Spacesuit Anomaly July 2013 ISS Space Station EVA EMU Suit Helmet Water Intrusion: Threatened Astronaut Luca Parmitano with Drowning

This is the NASA Mishap Investigation Board (MIB) report released to the public in February 2014 about the serious problem encountered with a spacesuit during a space station spacewalk in July 2013. Roughly 44 minutes into EVA 23, Luca Parmitano (EV2) reported water inside his helmet, on the back of his head. The EVA ground team and EVA crew members were unable to identify the source of the water. As EV2 continued to work, the amount of water in his helmet increased and eventually migrated from the back of his head onto his face. EVA 23 was terminated early and the crew safely ingressed the airlock. After the airlock was re-pressurized, the crew member's helmet was removed. The water quantity introduced into the helmet was estimated at about 1.5 liters. After the EVA was completed, it was learned that during his return to the airlock, Luca experienced intermittent loss of communication, his vision was impaired by water covering his eyes, and water had entered his nose making breathing more difficult.

The MIB determined that the causes for this mishap evolved from:

• Inorganic materials causing blockage of the drum holes in the EMU water separator resulting in water spilling into the vent loop.

• The NASA team's lack of knowledge regarding this particular failure mode, which led to a delay in recognizing the severity of the event when it occurred.

• Misdiagnosis of this suit failure when it initially occurred on EVA 22.

• The MIB determined that the space suit actually suffered the same failure at the end of EVA 22, performed a week earlier, and this event was not properly investigated which could have prevented placing a crew member at risk a week later during EVA 23

A related concern occurred during a post-EVA 23 suit dry-out procedure. A vacuum cleaner was used and unexpectedly suctioned O2 from the suit's secondary high pressure oxygen tank, causing a potentially hazardous mix of electricity and pure O2, which could have ignited flammable materials in and around the vacuum cleaner. Fortunately, no incident of this nature was detected.