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National Aeronautics and Space Administration

EVA23Water Intrusion

Recommendation R-14: The ISS Program should commission an independent technical review of the EMU 6-year certification plan which should identify all deficiencies or weaknesses in the certification and re-establish the true life expectancy of the EMU, and then plan appropriate use and logistic strategies commensurate with the results of the review. O-8

Differences noted between EMU plant and field procedures indicate a lack of two-way feedback and procedure control.

Supporting Evidence: During the timeframe of the MIB investigation, it was found that the UTAS plant and field procedures differ on whether or not to open Test Port B during certain tests of the water separator loop. This was revealed during the PLSS 1017 flooding investigation that occurred in August 2013. In addition, it was discovered by the MIB during discussions that some amount of contamination is considered acceptable by the field technicians but no process is in place to verify that the contamination found is understood and a nominal condition. Given the changing water environment the EMU is subjected to, this behavior could allow new issues to remain undiscovered. Recommendation R-15: The EVA Office should ensure that all EMU procedures are consistent between all teams that perform operations with the EMU, and require that all contamination found during ground processing be evaluated by the Engineering and Quality teams. O-9

The pace and potential hazards associated with EVAs on ISS are similar to other activities that should receive similar scrutiny by the ISS Program.

Supporting Evidence: The majority of the activities performed while operating the ISS do not have immediate hazards associated with them. EVAs are different than most, however, in that they require extreme focus from the ground teams, have hazards associated with them that can quickly lead to injury or death, and require decisions to be made quickly and efficiently. This report has focused on issues related to performing EVAs, however, the MIB was asked to identify activities on board ISS that have similar characteristics to EVA (immediate hazards, the need for quick decision making, etc.) and determine which recommendations should be applied to these other activities. To determine other areas which share characteristics with EVAs, per the direction of the Appointing Official, the MIB interviewed several experienced ISS Flight Directors, and used the experience of the MIB members. Several areas were identified: •

Visiting Vehicle operations

On board emergency operations

Software transitions

Reaction to serious hardware system failures

Visiting Vehicles: Visiting vehicles subject the ISS to potential immediate hazards when they are operating in the vicinity of ISS. Failures of their systems could lead to a collision risk with ISS. They also present a unique challenge to the flight control team because the vehicles are operated independently by an external flight control team, with various levels of experience. A significant focus has been placed on commercial cargo operations to ISS. The Engineering and Flight Control teams have worked very closely with both commercial companies to verify the safe and efficient operations of those vehicles. The MIB does not have specific concerns with commercial cargo activities today, but care must be taken by the ISS

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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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