The gas chromatograph is used to separate out individual gases from a complex mixture into molecular components. The resulting gas flow is analyzed in the mass spectrometer with a mass range of 2–535 Daltons.
The SAM also has three subsystems: the 'chemical separation and processing laboratory', for enrichment and derivatization of the organic molecules of the sample; the sample manipulation system for transporting powder delivered from the MSL drill to a SAM inlet and into one of 74 sample cups. The SMS then moves the sample to the SAM oven to release gases by heating to up to 1000 °C; and the pump subsystem to purge the separators and analysers. The at the University of Michigan built the main power supply, command and data handling unit, valve and heater controller, filament/bias controller, and high voltage module. The uncooled infrared detectors were developed and provided by the Polish company VIGO System.
Timeline
9 November 2012: A pinch of fine sand and dust became the first solid Martian sample deposited into the SAM. The sample came from the patch of windblown material called Rocknest, which had provided a sample previously for mineralogical analysis by CheMin instrument.
16 December 2014: NASA reported the Curiosity rover detected a "tenfold spike", likely localized, in the amount of methane in the Martian atmosphere. Sample measurements taken "a dozen times over 20 months" showed increases in late 2013 and early 2014, averaging "7 parts of methane per billion in the atmosphere." Before and after that, readings averaged around one-tenth that level. In addition, high levels of organic chemicals, particularly chlorobenzene, were detected in powder drilled from one of the rocks, named "Cumberland", analyzed by the Curiosity rover.
24 March 2015: NASA reported the first detection of nitrogen released after heating surface sediments on the planet Mars. The nitrogen in nitrate is in a "fixed" state, meaning that it is in an oxidized form that can be used by living organisms. The discovery supports the notion that ancient Mars may have been habitable for life.
4 April 2015: NASA reported studies, based on measurements by the Sample Analysis at Mars instrument on the Curiosity rover, of the Martian atmosphere using xenon and argon isotopes. Results provided support for a "vigorous" loss of atmosphere early in the history of Mars and were consistent with an atmospheric signature found in bits of atmosphere captured in some Martian meteorites found on Earth.
