Dragonfly Mass Spectrometer Investigation at Titan

International audienceDuring the 17 years it explored the Saturn system, the Cassini-Huygens mission revealed that Titan is an amazing world. With a diversity of surface environments (dunes, lakes, impact craters…), a richness of physical and chemical atmospheric processes that generate organic molecules, an interior ocean, and the potential for transient liquid water environments in its past, Titan is unique and among the best places in the solar system to search for evidence of prebiotic chemistry or possible life. To advance Titan's exploration with the objectives to investigate the prebiotic chemistry, habitability and potential presence of biosignatures on Saturn's moon, NASA's Dragonfly mission will send a rotorcraft relocatable lander that will explore the Shangri-La region, including the Selk impact crater to access previously melted water ice (Barnes et al., 2021). In order to address the science goals of the Dragonfly mission related to the characterization of the organic chemistry and the search for biologically relevant organic materials, the scientific payload includes the Dragonfly Mass Spectrometer (DraMS) dedicated to perform molecular analyses on various solid surface samples. These samples will be collected in different surface environments (dunes, ice…) explored by the rotorcraft lander, using the Drill for Acquisition of Complex Organics (DrACO) (Grubisic et al. 2021). Additionally, DraMS will also perform measurements of atmospheric noble gases to constrain the outgassing and the history of atmospheric methane. To achieve these analytical goals, DraMS is based on a linear ion trap mass spectrometer with a dual ion source allowing to perform analyses of solid samples with two different and complementary modes : - the Laser Desorption Mass Spectrometry (LDMS) for the broad compositional survey of surface materials including refractory organics. LDMS mode allows for structural disambiguation of surface molecules using ion isolation and tandem mass spectrometry (MS/MS) - Gas Chromatography Mass Spectrometry (GCMS) for the separation and identification of key prebiotic molecules and measurement of enantiomeric excesses (if present). For GCMS analyses, the samples delivered to DraMS ovens are heated for pyrolysis or derivatization-enhanced evolution. The gases thus produced are injected into one of two of chromatographic columns to proceed either to a general separation of a breadth of volatile and semi-volatile analytes, or to specifically separate enantiomers of chiral compounds. The DraMS design strongly inherits from the Sample Analysis at Mars (Mahaffy et al. 2012) and Mars Organic Molecule Analyzer (Goesmann et al. 2017), onboard the Curiosity and Rosalind Franklin martian rovers respectively. Design adaptations are required and currently in development to meet the technical, environmental, and scientific requirements of the Dragonfly mission at Titan's surface. The aim of this communication is to present the current status of the DraMS science investigation and instrument development, addressing the aforementioned areas of the instrument that have been advanced during Phase B and in preparation for the DraMS Preliminary Design Review (PDR). Acknowledgments: Dragonfly and DraMS development is currently supported by the NASA New Frontiers program. The GC module for DraMS is being developed in partnership with the French Centre National d'Études Spatiales (CNES). Barnes J. et al. (2021) Planet. Sci. J. 2, 130 Goesmann F. et. al. (2017) Astrobiology, 17, 655-685 Grubisic A. et al. (2021) Int. J. Mass Spec. 470, 116707 Mahaffy P. R. et al. (2012) Space Sci Rev, 170, 401-47