Controlling the Catastrophic Hazard of Introducing Ammonia into the Breathable Atmosphere of The International Space Station Elements

The potential for a catastrophic hazard occurring on the International Space Station United States on-orbit segment exists due to using a single barrier heat exchanger as the interface between external active thermal control systems and the internal active thermal control systems of the habitable elements and the incompatible maximum design pressures of the respective systems. Pressurized ammonium hydroxide may engulf crewmembers if proper controls are not designed into the integrated system. Engineering review and analyses were made to determine the failure mechanisms and recommend controls to mitigate the hazard and lower the risk to a program acceptable level.