A study of purification of the ISS Russian segment atmosphere in case of a containment failure in the hardware containing a toxic component

A study has been conducted on purification of the atmosphere in the Russian Segment of the International Space Station (ISS) using the newly developed Russian AFOT-M assembly and FTD-A ammonia filter in case of a containment failure in the external heat exchanger connecting the inner and outer loops of the Thermal Control System (TCS) on the US Orbital Segment of the ISS. Since the pressure in the outer loop is significantly higher than in the inner loop, an entry of ammonia into the inner TCS loop will result in the loop containment failure with ammonia entering the US Orbital Segment atmosphere and, subsequently, into the ISS Russian Segment atmosphere. Experimental data was obtained on ammonia absorption by the Russian-made ammonia filter FTD-A. A procedure was developed for calculating the removal of ammonia from the ISS Russian Segment atmosphere and experimental data was processed resulting in time values for Soyuz and ISS Russian Segment atmosphere purification that confirmed the effectiveness of the scrubbing. A parallel filter operation method is recommended for scrubbing the module atmosphere in order to achieve efficient use of the absorbers.