Calibration and Performance of the Spacecraft Atmosphere Monitor, an Air Constituent Monitor for Human Spaceflight

The Spacecraft Atmosphere Monitor (S.A.M.) is a miniaturized gas chromatograph mass spectrometer (GC/MS) instrument for monitoring the cabin atmosphere for human spaceflight missions. The first Technology Demonstration Unit (TDU1) operated successfully aboard the International Space Station (ISS) from August 2019 to July 2021. The second unit, TDU2, will be delivered to ISS in 2023. While on-station, TDU2 will continuously monitor the major atmospheric constituents and, on command, perform analysis of the cabin atmosphere for trace organic volatiles. The S.A.M. TDU2 uses the same quadrupole ion trap mass spectrometer (QITMS) sensor as in TDU1, but includes a MEMS preconcentrator, gas chromatograph, and microvalve system. Its miniature, ruggedized form factor allows the S.A.M. to be aisle-deployed to monitor the cabin in different locations and during activities such as exercise and sleep.