Redesign of the Extravehicular Mobility Unit Airlock Cooling Loop Recovery Assembly



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46th International Conference on Environmental Systems


During EVA (Extravehicular Activity) 23 aboard the ISS (International Space Station) on 07/16/2013 an episode of water in the EMU (Extravehicular Mobility Unit) helmet occurred, necessitating a termination of the EVA (Extravehicular Activity) shortly after it began. The root cause of the failure was determined to be ground-processing short-comings of the ALCLR (Airlock Cooling Loop Recovery) Ion Beds which led to various levels of contaminants being introduced into the Ion Beds before they left the ground. The Ion Beds were thereafter used to scrub the failed EMU cooling water loop on-orbit during routine scrubbing operations. The root cause investigation identified several areas for improvement of the ALCLR Assembly which have since been initiated. Enhanced washing techniques for the ALCLR Ion Bed have been developed and implemented. On-orbit cooling water conductivity and pH analysis capability to allow the astronauts to monitor proper operation of the ALCLR Ion Bed during scrubbing operation is being investigation. A simplified means to acquire on-orbit EMU cooling water samples have been designed. Finally, an inherently cleaner organic adsorbent to replace the current lignite-based activated carbon, and a non-separable replacement for the separable mixed ion exchange resin are undergoing evaluation. These efforts are undertaken to enhance the performance and reduce the risk associated with operations to ensure the long-term health of the EMU cooling water circuit.


United States
UTC Aerospace Systems
United Technologies Corporation Aerospace Systems
ICES402: Extravehicular Activity: PLSS Systems
Vienna, Austria
John Steele, UTC Aerospace Systems, USA
Theresa Elms, UTC Aerospace Systems, USA
Barbara Peyton, UTC Aerospace Systems, USA
Tony Rector, UTC Aerospace Systems, USA
Mallory Jennings, NASA Johnson Space Center, USA
The 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.


Spacesuit, Extravehicular Mobility Unit, Ion Bed