The ExoMars Rover Instrument Suite
MOMA - Mars Organics Molecule Analyser
MOMA is the largest instrument in the ExoMars Rover, and the one directly targeting biomarkers. MOMA will answer questions related to the potential origin, evolution and distribution of life on Mars. These studies will be carried out through two main activities:
In addition to studying the samples collected by the drill, MOMA will also analyse gases in the Martian atmosphere.
MOMA has two complementary operational modes: Gas Chromatograph-Mass Spectrometry (MOMA GC-MS) and Laser Desorption-Mass Spectrometry (MOMA LD-MS).
The GC-MS mode will be used to identify and analyse volatile molecules found in Martian soil samples. The powdered sample material provided by the Rover's drill will be used to fill one of twenty one-time-use, small ovens. At high temperature, all volatile materials will evaporate and will be extracted to be routed to the gas chromatograph, where they will be separated and identified. Some ovens are filled with a chemical product, the derivatisation agent, used to transform the chemical compound into another similar compound, in order to make the samples suitable for chiral analysis. This type of analysis is an indicator of the biological versus abiotic origin of organic molecules. The separate volatile molecules will be ionised and then will be analysed individually with the mass spectrometer.
In the LD-MS mode, the powdered sample material is carefully positioned under a high-power laser head, which is then pulsed to liberate ions. The ions are guided into the mass spectrometer where they are analysed. This mode is used to study less volatile molecules and heat-resistant materials.
MOMA is a complex instrument with a number of components and modules, all of which have to work together – on the remote outpost of Mars - in a robust and reliable manner. At the end of 2009 a test campaign for the MOMA instrument was carried out at the Max Planck Institute for Solar System Research (MPS) to monitor how individual elements of MOMA – represented by instrument breadboards – perform when coupled together. The first test campaign coupled a gas chromatograph breadboard (GC) with ovens and the tapping station. Tests have also been performed at the Johns Hopkins University School of Medicine (JHU SoM) by coupling the GC with the MS which gave promising results. In addition, a field campaign using oven, tapping station and GC was performed at Svalbard (Norway) in August 2010. All three test campaigns were successful.
The next steps include the improvement of the breadboards and the performance of tests on the complete system, coupling all elements of the MOMA instrument.