PTAL, ADAMM and SpectPro: novel tools to support ExoMars and Mars 2020 science operations

NASA/Mars 2020 [1] and ESA/ExoMars [2] missions are scheduled to be launched in 2020 and 2022 respectively. For the first time in history, the analytical payload of both exploration rovers will be equipped with Raman systems that will work in combination with complementary spectroscopic techniques such as LIBS and NIR. Prior to science operations, detailed laboratory investigations are necessary to constrain the potential scientific outcome of Raman spectrometers, as well as to facilitate the comprehension of the advantages provided by combined Raman/LIBS (e.g. the SuperCam analytical suite [3] onboard the Perseverance rover) and Raman/NIR (as is the case of ExoMars RLS [4] and MicrOmega coordinated studies) analysis.

In this framework, beside coordinating the development of Mars 2020/SuperCam Calibration Target (SCCT) and ExoMars/Raman Laser Spectrometer (RLS), the ERICA research group is developing novel tools that are meant to facilitate both science operation teams in the analysis and interpretation of the spectroscopic data soon gathered from Mars. As such, the three main tools under development are presented below:

• 1) Planetary Terrestrial Analogue Library (PTAL)

Funded by the European Research Council through the H2020-Compet-2015 programme (grant 687302), the Planetary terrestrial analogue library (PTAL) project will provide science operation teams (and, in a broader extent, the whole scientific community) with free access to an extended multi spectral database of terrestrial analogues materials that have been selected basing on their congruence to well-known Martian geological and environmental contexts [5]. Through the collaboration of the Universities of Valladolid (UVa, Spain), Oslo (UiO, Norway) and Paris-Sud (UPSud, France) the PTAL database will offer Raman, LIBS, NIR and XRD data collected from 1) natural geological samples collected from terrestrial analogues sites and 2) artificial samples replicating Martian protoliths composition and altered in the laboratory under controlled physical-chemical conditions.  Beside the use of conventional laboratory instruments, the mineralogical and geochemical composition of PTAL samples is characterized by means of spacecraft derived instrumentation, as is the case of the RLS ExoMars Simulator, MicrOmega and ChemCam spare models. Furthermore, the PTAL platform will provide the opportunity to request physical access to Martian analogue materials thus enabling future users to combine PTAL spectroscopic data with further laboratory analysis.

• 2) Analytical DAtabase of Martian Minerals (ADAMM)

Complementary to PTAL, the ADAMM database will include diffractometric (XRD) and spectroscopic (Raman, NIR, LIBS) data from a wide collection of pure mineral phases that have been detected on Mars by orbital and on-ground analytical systems, as well as from the laboratory study of Martian meteorites. Financed by the Ministry of Economy and Competitiveness (MINECO, grant ESP2017-87690-C3-1-R) the ADAMM database also includes additional phases that, according to the modern knowledge about the geological evolution of Mars, are most likely to be present at the (sub)surface of the red planet. As such, over 300 specimens are being analyzed using both commercial and spacecraft derived instrumentations. Besides the previously mentioned RLS ExoMars Simulator, mineral samples will be also analyzed by means of SimulCam, a remote Raman/LIBS system recently developed by the ERICA research group to reliably simulate SuperCam analytical outcomes. After comparing ADAMM database with the mineralogy detected from orbit at Jezero Crater and Oxia Planum (the landing site for Mars 2020 and ExoMars missions, respectively) a more detailed analysis of selected samples will be carried out. Thus, complementary analysis will be performed in the framework of the SIGUE-Mars consortium by using additional instruments (including the RLS spare model), and under Martian conditions (temperature and atmospheric pressure). In this way, a reliable estimation of the potential scientific outcome of the forthcoming rover missions to Mars will be provided.

• 3) IDAT/SpectPro

The Instrument Data Analysis Tool (IDAT)/SpectPro software was developed by the University of Valladolid to receive, decodify, calibrate and verify the telemetries generated by the RLS instrument on Mars [6]. IDAT/SpectPro is able to open and process data in PDS4 format, as required by the ExoMars mission. In this way, as soon as the data from the processors is available, IDAT/SpectPro will automatically process it to obtain science and engineering (housekeeping) calibrated data and even generate autolooks.

IDAT/SpectPro also provides access to an extended set of analytical tools for spectral analysis such as labelling, trimming, shifting, normalization, baseline correction, and features a general-purpose spectrum calculator to perform lineal combinations, product, division and derivative of spectra. An automated identification algorithm to classify Raman spectra is also under development. This algorithm is based on the comparison of peak positions and intensities, which has provided good results, even for the detection of all samples present in simple mixtures.

The mentioned analytical tools will be made available to PTAL and ADAMM users through a dedicated version of IDAT/SPectPro software, which will have a direct interface to access the two databases.

Acknowledgements:

This work is financed through the European Research Council in the H2020- COMPET-2015 programme (grant 687302) and the Ministry of Economy and Competitiveness (MINECO, grant ESP2017-87690-C3-1-R). The authors gratefully acknowledge the support of the SIGUE-Mars consortium (MINECO, grant RDE2018-102600-T).

 

References:

[1] Williford, K. H. et al. From Habitability to Life on Mars (Elsevier Inc., 2018). [2] Vago, J. L. et al. Astrobiology 17, 471–510 (2017). [3] Wiens, R. C., Maurice, S. & Perez, F. R.  Spectrosc. (Santa Monica) 32, 50–55 (2017). [4] Rull, F. et al. Astrobiology 17, 627–654 (2017). [5] Veneranda, M. et al. J. Raman Spectrosc. 50, 1–19 (2019). [6] Lopez-Reyes G. et al. European Planetary Science Congress 2018 12 1–2 (2018).