Strategy for Monitoring Trace Contaminants on International Space Station

The complexity of the atmosphere aboard the International Space Station (ISS) will require a multifaceted monitoring strategy for both nominal and emergency conditions to protect the health and safety of the crew. Samples to be collected for air-quality assessment will include both archival sampling for ground analysis and on-board automatic analyses. Archival samples will be analyzed after return by standard gas chromatography/mass spectrometry; a separate formaldehyde analysis will be conducted as well. On-orbit analyses are planned for specific combustion products and for specific volatile organic compounds of toxicological significance. The air-lock will be monitored after EVAs to ensure that no propellants are introduced into the cabin atmosphere. Additional remote samples can be collected in sample bags from other ISS elements and brought to the Volatile Organic Analyzer (VOA) for analysis. Samples also will be collected during contingency events, e.g., fire or spill, to confirm that the atmospheric clean-up procedures have been effective. JSC toxicologists will assess all downlinked results to ensure that crew health and safety is not compromised.