Improving the Polyethylene Terephtalate (PET) perfomances, for the RAX Verification Target for MMX mission
Authors: Moral Andoni G. , Mora Julio , Prieto-Ballesteros Olga , Fernández Sanpedro Mayte , López-Reyes Guillermo , Ercilla Oscar , Sanz Arranz J. Aurelio , Herrera Alejandro , Pérez Carlos , Rull Fernando , Böttger Ute , Cho Yuichiro , Schöder Susanne , Hübers Heinz-Wilhelm 
Published: September 2022

&lt;p&gt;&lt;strong&gt;Introducction&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;JAXA&amp;#8217;s MMX (Martian Moons eXploration) mission, to be launched in 2024, will study both Martian satellites, for several years, and will drop a small rover to Phobos, to explore its surface [1]. As part of this rover scientific payload, it will be placed a Raman spectrometer, the RAX Instrument (Raman Spectrometer for MMX). The RAX will be able to analyse the mineral composition of the Phobos regolithe surface with in-situ measurements, complementing the Japanese Sample Return mission, and helping to reveal the nature and distribution of materials on the Martian Moon&amp;#8217;s surface, and ultimately its origin and evolution [2].&lt;/p&gt;
&lt;p&gt;The RAX instrument [3] has been designed, manufactured, integrated and tested by an international consortium led by DLR (Germany), with significant contributions from JAXA &amp; University of Tokyo (Japan), and INTA-CAB-UVa (Spain). One of the Spanish contributions to RAX, will be the instrument Verification Target, a small piece of PET (polyethylene terephthalate) attached to MMX spacecraft, to be used before launch, and during cruise; for spectral instrument performances verification on-ground and just before the rover release to Phobos.&lt;/p&gt;
&lt;p&gt;&lt;img src=&quot;&quot; alt=&quot;&quot; /&gt;&lt;/p&gt;
&lt;p&gt;Figure 1. RAX Verification Target design proposed by INTA-CAB-UVa&lt;/p&gt;
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&lt;p&gt;&lt;strong&gt;Experimental&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Thanks to previous expertise of the UVa-INTA group with PET material, used on the Raman Laser Spectrometer (RLS) Calibration Target [4] for ESA&amp;#8217;s ExoMars mission; and SuperCam Calibration Target [5] for NASA Mars2020; a newly design-deuterated PET material, decreasing the PET fluorescence background, and adding new Raman bands with respect to ordinary PET [6] has been developed, manufactured, characterized and space-qualified for MMX-RAX mission by INTA-CAB-UVa; so it was proposed as candidate the RAX Verification Target.&lt;/p&gt;
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&lt;p&gt;&lt;img src=&quot;&quot; alt=&quot;&quot; /&gt;&lt;/p&gt;
&lt;p&gt;Figure 2. RAX Verification Target Flight batch for qualification/acceptance&lt;/p&gt;
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&lt;p&gt;&lt;strong&gt;Results and discussion &lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;During the session, a detailed description of different tests carried out for the space qualification of the deuterated material, will be shown. And how the final performances with respect to other commercial PETs have been improved; and so, how the final verification-calibration of the Raman instrument has been optimized.&lt;/p&gt;
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&lt;p&gt;&lt;strong&gt;Acknowledgements&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;INTA&amp;#8217;s internal I+D+I project IDMats; and MICINN grants PID2019-107442RB-C32 &amp; PID2019-107442RB-C31&lt;/p&gt;
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&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;[1] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Michel P. et al. (2022) Earth, Planets and Space 74, 2.&lt;/p&gt;
&lt;p&gt;[2] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Hagelschuer, T. et al. (2019) 70th Int. Astronautical Congress, 2019.&lt;/p&gt;
&lt;p&gt;[3] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Hagelschuer, T. et al. (2022) 73th Int. Astronautical Congress.&lt;/p&gt;
&lt;p&gt;[4] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; L&amp;#243;pez-Reyes, G. et al. (2020) Journal of Raman Spectroscopy, 1-13&lt;/p&gt;
&lt;p&gt;[5] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Manrique, J.A. et al. (2020) Space Sci Rev, 216:138&lt;/p&gt;
&lt;p&gt;[6] &amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Mora, J. et al (2020) Acta Astronaut. 167 (2020) 360&amp;#8211;373&lt;/p&gt;
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