Development of a low power, high mass range mass spectrometer for Mars surface analysis

A compact, low power quadrupole ion trap mass spectrometer is being developed that will achieve a mass range of 2000 Da at low voltage (0–300 V0–p) using a lower frequency fundamental voltage and supplemental excitation to very low qexcitation parameter. The instrument is a prototype for a spacecraft hardware design referred to as the Mars Organic Mass Analyzer (MOMA) that is currently scheduled for flight to Mars in 2013 as part of the European Space Agency ExoMars mission. MOMA is one of two “life detection” instruments that are being sponsored by NASA. MOMA will accommodate both an atmospheric pressure laser desorption ionization source that will provide direct sampling of core samples for the detection of organics over a broad mass range and an electron ionization source coupled to a gas chromatograph for the detection of atmospheric gases and specific biomarkers (e.g., amino acids, nucleobases, etc.). The instrument reported herein is an early prototype used to demonstrate the basic design concepts for a low power instrument with high mass range, including the use of supplemental frequency scans to record mass spectra. In addition, mass spectra are obtained using CO2 (the major constituent of the Mars atmosphere) as the bath gas, and a novel internal electron ionization source has been developed in which the electron beam enters through the ring electrode.