Ninth International Conference on Mars 2019 (LPI Contrib. No. 2089) 6376.pdf

RAMAN AND THE RLS INSTRUMENT FOR THE CHARACTERIZATION OF SOIL ON IN-SITU PLANETARY MISSIONS. G. Lopez-Reyes1, F. Rull1, M. Veneranda1, J. A. Manrique1, A. Sanz1, E. Lalla2 and J. Medina1, 1Unidad Asociada UVa-CSIC-Centro de Astrobiologia. C/ Francisco Valles 8, Valladolid (SPAIN) [email protected]. 2 Center for research in Earth and Space Science, York University, Can- ada.

In-situ exploration of Mars: The in-situ explora- instrument features a 532 nm continuous wavelength tion of Mars with rover-based missions will be contin- with a spot size on the sample of 50 microns and ued with the launch next year of two new rover mis- an irradiance level around 0.3 kW/cm2, and a spectral sions to the red planet: NASA and ESA resolution between 6 and 8 wavenumbers. ExoMars rovers. These rovers will be the best The flight model of the instrument has already been equipped ever for the detection of or organ- delivered for integration in the rover, but other repli- ic molecules on Mars. cates and models have been widely characterized and On one hand, Mars 2020 rover includes a very wide tested in multiple environments to demonstrate the ca- range of instruments, including two Raman spectrome- pability of the technique -and the instrument- of ful- ters: SuperCam, a remote Raman-LIBS instrument also filling the ExoMars mission objectives, but also paving featuring microimaging [1], and Sherloc, an ultraviolet the way for the use of this technique in the upcoming Raman spectrometer placed in the rover arm, especially missions to Mars or other planetary bodies such as Eu- suited for the analysis of organics [2]. On the other ropa, or to comets. hand, the ExoMars rover is equipped with a 2-meter Having a critical role in the development of the long drill to extract samples of Martian soil down to RLS, the Erica research group from UVa is involved in two meters -unexposed to ionizing or UV radiation- numerous research fronts converging towards two pri- potentially preserving organic materials. In addition, it mary aims: 1) optimize the scientific outcome that features a carrousel that will allow the instruments of could derive from the interpretation of RLS spectra, the Analytical Laboratory Drawer (MicrOmega IR im- and 2) evaluate to which extend RLS data can contrib- ager [3], the RLS Raman Spectrometer [4] and the ute in the fulfillment of the general objectives of the MOMA mass spectrometer [5]) to analyze the same ExoMars mission. sample in the same spots. To achieve these aims, terrestrial analogues of Mar- and the Martian sample- tian rocks and soils need to be studied through Raman return missions: During the next years, following the systems that ensure a spectral response and an opera- needed technology development, the logical path is to tional mode comparable to the RLS. For this, two RLS- evolve to Martian return missions. In a first step, be- representative analytical models have been developed fore technology readiness for human exploration, the by the Erica team to perform in-situ and laboratory realistic approach consists on multi-phase sample re- studies of terrestrial analogues and further Martian- turn missions. Indeed, Mars 2020 features a series of related samples. containers to store samples that might be considered of On one hand, the RAD1 (RAman Demonstrator) is high interest, for a potential future recollection mission. a field-portable prototype that has the same geomet- Of course, the proper characterization and identifi- rical concept and spectral characteristics of the RLS cation of the samples is of paramount importance to instrument, mostly built with COTS elements (with the ensure that the right samples are selected for collection. exception of the diffraction grating, which is identical In this sense, the Raman spectroscopy technique has to the RLS instrument one). RAD1 also make use of proved to be considered as an essential tool for the the same algorithms employed by RLS to automatically chemical and structural characterization of samples in calculate the optimal analytical parameters to be set planetary in-situ missions given its non-destructive during analysis [6]. In addition of being employed for nature, as well as the possibility of being used in micro the in-situ mineralogical screening of terrestrial ana- or macro analysis, while providing very useful and logue sites (important in the selection of the optimal accurate identification of the analyzed materials in with samples to be collected for further laboratory studies), a short operation time. RAD1 has been successfully used to emulate RLS pro- The RLS instrument: Developed by an interna- cedures during ExoMars mission simulations, as is the tional consortium led by the University of Valladolid case of the ExoFiT field campaigns recently carried out (UVa) and the National Institute of Aerospace Tech- in Almeria (Spain) and Atacama (Chile). nology (INTA), RLS will become the first Raman On the other hand, RLS ExoMars simulator is a la- spectrometer ever used for space exploration. This boratory prototype that, compared to RAD1, is coupled Ninth International Conference on Mars 2019 (LPI Contrib. No. 2089) 6376.pdf

to a vertical and horizontal positioner emulating the [5] Fred, G., et al., The Mars Organic Molecule Sample Preparation and Distribution System (SPDS) of Analyzer (MOMA) Instrument: Characterization of the ExoMars rover. The RLS ExoMars Simulator has Organic Material in Martian Sediments. , been used to demonstrate that the analytical routine 2017.17(6-7). chosen for the RLS (between 20 and 39 spot of analy- [6] Lopez-Reyes, G. and F. Rull Pérez, A method sis por sample) allows to obtain a full picture of the for the automated Raman spectra acquisition. Journal mineralogical heterogeneities of powdered samples [7]. of Raman Spectroscopy, 2017. 48(11): p. 1654-1664. Furthermore, it also helped corroborating that, depend- [7] Lopez-Reyes, G., et al., Analysis of the scien- ing on the mineralogical complexity of the sample, a tific capabilities of the ExoMars Spec- limited number of spectra can ensure a reliable semi- trometer instrument. European Journal of Mineralogy, quantification of the detected mineral phases [7]. 2013. 25(5) The intensive use of these models in the framework [8] Lopez-Reyes, G., et al., Multivariate analysis of of the development of the RLS instrument for the Ex- Raman spectra for the identification of sulfates: Impli- oMars mission has provided a huge amount of data and cations for ExoMars. American Mineralogist, 2014. results that have helped developing a series of analyti- 99(8-9) cal techniques including multivariate analysis [8] [9] Manrique, J.A., et al., Raman-Libs Combination and/or data fusion techniques [9]. The study of ana- And Datafusion Evaluation For Solar System Explora- logues has resulted in the development of databases tion. JRS, 2019. In review. such as the Planetary Terrestrial Analogue Library [10] Veneranda, M., et al., PTAL multi-spectral da- (PTAL) [10], and also with interesting results on the tabase of planetary terrestrial analogues: Raman data potential identification of wet-target craters based on overview, JRS, 2019. In press. Raman spectroscopy data [11]. [11] Veneranda, M., et al., ExoMars/Raman Laser The use of these techniques will help improve the Spectrometer (RLS) – state of the art analytical tool for scientific return from the Raman spectroscopy data the potential recognition of wet-target craters on from in-situ instruments on Mars. Mars. Astrobiology, 2018. In review. Conclusions: Raman Laser Spectroscopy is a key technique for the analysis of samples in planetary in- situ¬ missions. The use of this technique has been am- ply demonstrated in field and laboratory tests around the world and will be corroborated during the upcom- ing ExoMars and Mars2020 missions due to its non- destructive analytical capabilities, combined with a powerful chemical and structural identification of the analyzed materials. For all these reasons, this technique proves to be essential for any in-situ exploration mission, including the future Martian-sample return missions.

Acknowledgements: This work is funded by the Spanish MINECO grants ESP2014-56138-C3-2-R and ESP2017-87690-C3-1-R.

References: [1] Gasnault, O., et al. SuperCam Remote Micro- Imager on Mars 2020. in LPSC 2015. [2] Abbey, W.J., et al., Deep UV Raman spectros- copy for planetary exploration: The search for in situ organics. Icarus, 2017. 290: p. 201-214. [3] Bibring, J.P., et al., The MicrOmega Investiga- tion Onboard ExoMars. Astrobiology, 2017. 17(6-7). [4] Rull, F., et al., The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars. Astrobiology, 2017. 17.