NASA Spacesuit Water Incursion Mishap Board Sounds All Too Familiar Themes

NASA released the report of an independent Mishap Investigation Board (MIB) yesterday that looked into the July 2013 incident when European astronaut Luca Parmitano’s spacesuit helmet filled with water during a spacewalk.  The board’s conclusions sounded familiar themes about schedule and other pressures creating an environment where people did not want to question assumptions or perceptions about matters that could literally make the difference between life and death.  Perhaps most troubling is a determination that this “mishap” could have been avoided if a previous incident a week earlier had been properly investigated.

The technical root cause of the spacesuit failure remains a mystery, but the MIB report listed five organizational root causes that evoke memories of other spaceflight failures that did not have such a happy ending.  In this case, Parmitano lived to tell the tale of feeling like “a goldfish in a fishbowl” as his helmet filled with water while outside the International Space Station (ISS).   NASA now knows that foreign contaminants blocked the spacesuit’s Fan Pump Separator disrupting the flow of water in the suit’s cooling system into the helmet, but is still trying to determine the source of that contamination.

On a spacewalk (officially called Extravehicular Activity or EVA) designated EVA 23 on July 16, 2013, Parmitano began feeling water at the back of his head 44 minutes into the planned 6.5 hour excursion.  The initial assumption was that his drink bag was leaking, but the amount of water steadily increased and the EVA was terminated 23 minutes later.  By the time he was able to return to the airlock, the water covered his eyes, ears and nose impairing his ability to see, communicate and breathe.

Identified as “EV2” in the report (his spacewalk companion, NASA astronaut Chris Cassidy, was EV1), Parmitano had a total of 1.5 liters of water in his helmet by the time it was removed by fellow ISS crewmembers inside the airlock.

“EV2’s calm demeanor in the face of his helmet filling with water possibly saved his life,” the MIB concluded.

The investigation determined that this was not the first time such a leak occurred.   In fact, the suit had leaked during the previous spacewalk, EVA 22, a week earlier, and the problem was “misdiagnosed” as a leaking drink bag.

“The MIB could not identify a clear reason why the EVA community has a perception that the EVA drink bags leaked.  When presented with the suggestion that the crew member’s drink bag leaked … no one in the EVA community ….challenged this determination and investigated further.  Had that conclusion been challenged, the issue would likely have been discovered prior to EVA 23 and the mishap would have been avoided.”

MIB chairman Chris Hansen briefed the media during a teleconference yesterday and said that the incident “evolved” from three causes:

• Inorganic materials causing blockage of the drum holes in the spacesuit’s water separator, causing water to spill 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; and
• Misdiagnosis of this suit failure when it occurred on EVA 22.

The report lists the following five root causes “at the organizational level”:

• Program emphasis was to maximize crew time on orbit for utilization;
• ISS Community perception was that drink bags leak;
• Flight Control Team’s perception of the anomaly report process as being resource intensive made them reluctant to invoke it;
• No one applied knowledge of the physics of water behavior in zero-g to water coming from the PLSS vent loop; and
• The occurrence of minor amounts of water in the helmet was normalized

The MIB made 49 recommendations categorized as Level 1, 2 or 3 in priority.  It said that all 16 Level 1 (highest priority) recommendations should be completed prior to allowing “planned” EVAs.

ISS Program Manager Mike Suffredini said during yesterday’s teleconference that all Level 1 and most Level 2 recommendations would be completed before planned EVAs resume, hopefully in the July/August time frame, and the remainder would be completed by the end of the year.

Planned EVAs are in contrast to “contingency” EVAs necessitated by circumstances.  Astronauts have already conducted two contingency EVAs to repair a malfunctioning ISS coolant loop.  Hansen said those two EVAs, in December 2013, were “planned with full cooperation between the ISS Program and the MIB.”

The MIB report and briefing slides and an audio recording of yesterday’s teleconference are available on NASA’s space station news website.