End-To-END Performance of the Future MOMA Instrument Aboard the ExoMars Mission

Abstract:

Following the SAM experiment aboard the Curiosity rover, the Mars Organic Molecule Analyzer (MOMA) experiment aboard the 2018 ExoMars mission will be the continuation of the search for organic matter on the Mars surface. One advancement with the ExoMars mission is that the sample will be extracted as deep as 2 meters below the Martian surface to minimize effects of radiation and oxidation on organic materials. To analyze the wide range of organic composition (volatile and non-volatile compounds) of the Martian soil, MOMA is equipped with a dual ion source ion trap mass spectrometer utilizing UV laser desorption / ionization (LDI) and pyrolysis gas chromatography (pyr-GC). In order to analyze refractory organic compounds and chiral molecules during GC-ITMS analysis, samples may be submitted to a derivatization process, consisting of the reaction of the sample components with specific reactants (MTBSTFA [1], DMF-DMA [2] or TMAH [3]).

Previous experimental reports have focused on coupling campaigns between the breadboard versions of the GC, provided by the French team (LISA, LATMOS, CentraleSupelec), and the MS, provided by the US team (NASA-GSFC). This work focuses on the performance verification and optimization of the GC-ITMS experiment using the Engineering Test Unit (ETU) models which are representative of the form, fit and function of the flight instrument including a flight-like pyrolysis oven and tapping station providing by the German team (MPS). The results obtained demonstrate the current status of the end-to-end performance of the gas chromatography-mass spectrometry mode of operation.

References: [1] Buch, A. et al. (2009) J Chrom. A, 43, 143-151. [2] Freissinet et al. (2011) J Chrom A, 1306, 59-71. [3] Geffroy-Rodier, C. et al. (2009) JAAP, 85, 454-459.