In situ science on Phobos by the Raman spectrometer RAX on board the MMX rover
Authors: Prieto-Ballesteros Olga , Böttger Ute , Cho Yuichiro , Huebers Heinz-Wilhelm , Rull Fernando , Schroeder Susanne , Belenguer Tomás , Benito Marina , Börner Anko , Buder Maximilian , Bunduki Yuri , Dietz Enrico , Hagelschuer Till , Kameda Shingo , Kopp Emanuel , Lopez-Reyes Guillermo , Moral Inza Andoni G. , Mori Shoki , Perez Canora Carlos , Pertenais Martin , Peter Gisbert , Rockstein Steve , Rodd-Routley Selene , Rodriguez Perez Pablo , Ryan Conor , Santamaria Pilar , Säuberlich Thomas , Schrandt Friedrich , Ulamec Stephan , Usui Tomohiro , Weber Iris , Westerdorff Karsten 
Published: September 2022

&lt;p&gt;&lt;strong&gt;Introduction. &lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Understanding the origin and evolution of Phobos and Deimos is the goal of the coming Martian Moons eXploration mission (MMX) led by JAXA [1, 2, 3]. This mission will be launched in 2024 to the Martian system and return samples from Phobos. Before sample return operations, a rover of 25 kg approximately will be delivered to the surface carrying four instruments: a Raman spectrometer (RAX), a radiometer (miniRad), a stereo pair of cameras looking forwards (NavCams), and two cameras looking at the wheel-surface interface, (WheelCams) [4].&lt;/p&gt;
&lt;p&gt;&amp;#160;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;The RAX instrument.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;The RAman spectrometer for MMX, RAX, has been developed together by DLR, INTA/UVA, and JAXA/UTo [5]. It consists of three elements: I) The RAX Laser Assembly (RLA), which was originally designed for the RLS instrument of the ExoMars mission, and includes a laser emitting at 532 nm; II) The RAX Spectrometer Module (RSM), comprising a sophisticated confocal optical assembly and a CMOS detector that covers a spectral range of up to 4000 cm&lt;sup&gt;-1&lt;/sup&gt; with a spectral resolution of&amp;#160; &amp;#820; 10 cm&lt;sup&gt;-1&lt;/sup&gt;; III) The Autofocus System (AFS) to measure with high precision at different positions onto the ground.&lt;/p&gt;
&lt;p&gt;RAX will in situ examine the minerals of the surface and their formation conditions at rover sampling spots. By analysing the vibrational modes of the substances, RAX will be capable to characterize the igneous phases, volatiles, organic species, and secondary alteration minerals at grain scale. RAX&amp;#8217;s targets may be correlated, on the one hand to the orbital data to better approach the spatial distribution and stratigraphic relationship between the Phobos&amp;#8217; blue and red material units, and on the other hand to the mineral and rock types observed on the Mars&amp;#8217; surface by other Raman spectrometers to link their genesis (or not) (e.g. RLS [6], or Supercam [7]). The identified mineral assemblages can be used to determine whether Phobos is a captured asteroid rich in carbon and water, or is a remnant body of a giant impact to Mars. In addition, the information may also support the sample return selection and provide context information of the materials once they are in terrestrial laboratories.&lt;/p&gt;
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&lt;p&gt;&lt;strong&gt;References.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;[1] T. Usui, et al., Space Sci. Rev. 216:49, 2020; [2] S. L. Murchie, D. T. Britt, C. M. Pieters., Space Science 102, 2014, 176&amp;#8211;182; [3] C.M. Pieters, S. L. Murchie, N. Thomas, and D. Britt, Planetary and Space Science 102, 2014, 144-151; [4] P. Michel, et al., Earth, Planets and Space 74: 2, 2022; [5] Y. Cho et al., Earth, Planets and Space 73:232, 2021; [6] F. Rull et al., Astrobiology 17 (6-7), 2017, 627&amp;#8211;654; [7] S. Maurice et al., Space Sci. Rev. 217, 2021.&lt;/p&gt;