Mars Organic Molecule Analyzer (MOMA) on the 2028 Rosalind Franklin Rover Mission: Status and Plans

Introduction:  The Mars Organic Molecule Analyzer (MOMA) investigation is part of the scientific payload of the European Space Agency (ESA) Rosalind Franklin rover mission (RFM, a.k.a. ExoMars) that has been replanned for launch in late 2028, following its earlier suspension. RFM now features a partnership with NASA which provides a launch vehicle, descent engine systems, and radioisotope power supplies in addition to major elements of MOMA. The rover will arrive at Oxia Planum on Mars in 2030 carried by a new ESA-led entry, descent, and landing module (EDLM).

MOMA (Fig. 1) is a dual-source (laser desorption, LD, and gas chromatography, GC) mass spectrometer (MS) that will analyze the organic chemical composition of collected samples in support of the ExoMars/RFM objective to seek the signs of life in the near subsurface (up to two meters depth) of Mars [1]. The dual-source design allows MOMA to provide broadly sensitive detection of organics over a range of molecular weights and volatilities, as well as probe structural patterns of molecules such as enantiomeric ratios or chain length biases in aliphatic species [2].

The deeper drill samples will enable MOMA to examine the organic composition of materials that may have been well protected from degradation by cosmic radiation over geologic timescales.

Flight Hardware Status and Plans: The MOMA flight instrument was delivered to rover assembly, integration, and test (AIT) at Thales Alenia Space – Italy (TAS-I) in 2018. All MOMA functional checkouts since that time have completed nominally and are planned to continue regularly until launch. Items not originally qualified for the much extended “shelf life” or the longer cruise phase have been reviewed and determined to be stable. The team has decided to replace two MOMA elements that since delivery have been found to present risks to achieving the required operational life of at least 218 sols on the martian surface. These are the Power High Voltage module in the MS electronics (produced in the U.S.) and the Gas Chromatograph (produced in France). Refurbished and new elements will be integrated to complete the flight model in 2025. MOMA along with its neighboring instruments in the rover’s Analytical Laboratory Drawer (ALD) – namely the MicrOmega [3] and Raman Laser Spectrometer (RLS) [4] instruments, will subsequently undergo final integrated tests under Mars temperature and pressure conditions to “re-qualify” the ALD payload for flight.

A novel and powerful aspect of the RFM science operation is the co-registration of the overlapping analysis fields-of-view of all three ALD instruments on the delivered sample in the rover’s Refillable Container sample tray (Fig. 2). This collaborative science mode will enable correlation of composition determined by the three techniques (IR reflectance spectroscopy, Raman spectroscopy, and laser desorption mass spectrometry) on the crushed sample. The co-registration will be re-verified in these tests.

Testbed Model: The MOMA Testbed (TB) combines the highest fidelity copy of the flight model, comprising flight spare subsystems, with supporting apparatus to enable operations precisely simulating the RFM environmental and rover conditions in a laboratory Mars thermal vacuum chamber (Fig. 3). The TB is a dual-role facility serving both as an engineering reference for verification and validation of flight procedures and for diagnosing flight performance (including any anomalies or off-nominal situations), and as a science reference with direct traceability to the sensitivity, background, and other characteristics of the FM, with the potential to carry out selected sample studies for scientific interpretation of MOMA data. However, to maintain flight equivalence (including minimal contamination) through the nominal surface mission, such studies using complex analogs on the TB are expected to be rare; rather these will be carried out elsewhere using MOMA lab bench instrumentation.

Engineering Test Unit: A variety of sample studies are conducted in team laboratories, including use of an Engineering Test Unit (ETU) that serves as a “user-friendly” high-fidelity MOMA performance reference (lacking the stringent access restrictions of the TB). The ETU, along with analog instrumentation across the team, permits analyses of analog samples with flight-like protocols, such as:

• Derivatization GCMS to characterize instrument, sample matrix, and environmental factors in organic detection and amino acid chiral separation;
• LDMS and LDMS/MS to refine protocols [5] to maximize both sensitivity to heterogeneous, possibly surficial, organics and identify chemical structures;
• Participation in ExoMars collaborative analysis campaigns, such as with mission analog samples reflecting aspects of possible compositions at Oxia Planum, including phyllosilicate, Fe-oxide, and sulfate mineralogies [6,7], alongside other investigations such as MicrOmega and RLS.

The ETU will additionally serve as a testing, triage, and optimization bench for modified or new protocols and software scripts, prior to their certification on the TB for use on the flight instrument. As such the ETU, in addition to the TB, is expected to perform an operational role within the distributed MOMA team supporting tactical and strategic surface mission activities from remote locations in continual collaboration with the RFM Rover Operations Control Center (ROCC) at the Aerospace Logistics Technology Engineering Center (ALTEC) in Turin, Italy.

Science Operations Preparation: The MOMA team continues to prepare for RFM operations across the spectrum of planning and training for telemetry management, science analysis, and decision-making processes (e.g., flow chart development, science scenario simulation) and role definition. It is considered of prime importance for optimal rover science activities and data analysis to reflect the latest knowledge and hypotheses under development in the Mars science community. Communication and collaboration with diverse groups and ongoing missions is thus envisioned to play an increasingly important role in MOMA science preparations through this decade.

[1] Vago J., Westall F. et al. (2017) Astrobiology, 17, 471-510. [2] Goesmann F. et al. (2017) Astrobiology, 17, 655-685. [3] Bibring J.-P. et al. (2017) The MicrOmega Investigation Onboard ExoMars. Astrobiology, 17, 621-626. [4] Rull F. et al. (2017) Astrobiology, 17,627-654. [5] Siljeström S. et al. (2021) Astrobiology, 21, 1515-1525. [6] Quantin-Nataf C. et al. (2021) Astrobiology, 21, 345-366. [7] Fawdon P., Orgel C. et al. (2024) J. Maps, 20(1), doi: 10.1080/17445647.2024.2302361.