The Portable Monitor for Measuring Combustion Products Aboard the International Space Station

The Toxicology Laboratory at Johnson Space Center (JSC) had provided the combustion products analyzer (CPA) since the early 1990s to monitor the spacecraft atmosphere in real time if a thermodegradation event occurred aboard the Shuttle. However, as the operation of the International Space Station (ISS) grew near, an improved CPA was sought that would include a carbon monoxide sensor that did not have a cross-sensitivity to hydrogen. The Compound Specific Analyzer-Combustion Products (CSA-CP) was developed for use on the International Space Station (ISS). The CSA-CP measures three hazardous gases, carbon monoxide, hydrogen cyanide, and hydrogen chloride, as well as oxygen. The levels of these compounds in the atmosphere following a thermodegradation event serve as markers to determine air quality.

The first permanent ISS crew performed the CSA-CP checkout operations and collected baseline data shortly after arrival aboard the ISS in December 2000. The CSA-CP is currently deployed in the Service Module, Zvezda. This paper summarizes the reasons and process for transitioning from the CPA to the CSA-CP. Furthermore, the CSA-CP's performance characteristics are presented, and the early CSA-CP flight data obtained aboard the Shuttle and ISS are discussed.