2023-06-212023-06-212023-07-16ICES-2023-435https://hdl.handle.net/2346/94788Ben Gardner, Collins Aerospace, USAStephen Denson, Collins Aerospace, USAMark Huffman, Collins Aerospace, USATyler Zimmerman, Collins Aerospace, USAICES404: International Space Station ECLS: SystemsThe 52nd International Conference on Environmental Systems was held in Calgary, Canada, on 16 July 2023 through 20 July 2023.This is the latest installment in our series of presentations describing the performance of the Major Constituent Analyzer (MCA) onboard the International Space Station (ISS). The MCA is a mass spectrometer-based system for monitoring six major atmospheric constituents and is an integral part of the Environmental Control and Life Support System (ECLSS). The MCA has accumulated an extensive history of performance data that can be used to drive improved design and performance requirements for both the MCA proper and for future atmosphere monitoring systems. This paper discusses the latest performance of the MCA on orbit during 2018 through 2022 years, with particular attention to ion source filament current and lifetime, response drift, and sensitivity drift. Expected component lifetimes, impact to logistics and ISS support, and implications for future missions going forward will be discussed.application/pdfengMass SpectrometerECLSSMCAAtmosphereMass SpectrometryPresentations