The MMX Rover: Performing in-situ Surface Investigations on Phobos Patrick Michel ( [email protected] ) CNRS Délégation Côte d'Azur https://orcid.org/0000-0002-0884-1993 Stephan Ulamec DLR: Deutsches Zentrum fur Luft- und Raumfahrt Ute Boettger DLR Matthias Grott DLR Berlin: Deutsches Zentrum fur Luft- und Raumfahrt DLR Standort Berlin Naomi Murdoch ISAE-SUPAERO Pierre Vernazza LAM: Laboratoire d'Astrophysique de Marseille Cecily Sunday ISAE-SUPAERO Yun Zhang UCA: Universite Cote d'Azur Rudy Valette CEMEF: Centre de mise en forme des materiaux Romain Castellani CEMEF: Centre de mise en forme des materiaux Jens Biele DLR: Deutsches Zentrum fur Luft- und Raumfahrt Simon Tardivel French Space Agency: CNES Olivier Groussin LAM: Laboratoire d'Astrophysique de Marseille Laurent Jorda LAM: Laboratoire d'Astrophysique de Marseille Joerg Knollenberg DLR: Deutsches Zentrum fur Luft- und Raumfahrt Jan Thimo Grundmann DLR: Deutsches Zentrum fur Luft- und Raumfahrt Denis Arrat French Space Agency: CNES Gabriel Pont French Space Agency: CNES Stéphane Mary French Space Agency: CNES Markus Grebenstein DLR: Deutsches Zentrum fur Luft- und Raumfahrt Hirdy Miyamoto University of Tokyo: Tokyo Daigaku Tomoki Nakamura Tohoku University Graduate School of Science Faculty of Science: Tohoku Daigaku Daigakuin Rigaku Kenkyuka Rigakubu Koji Wada Chiba Institute of Technology: Chiba Kogyo Daigaku Kent Yoshikawa JAXA Kiyoshi Kuramoto Hokkaido University: Hokkaido Daigaku Full paper Keywords: Camera, Numerical Modeling, Phobos, Radiometer, Raman Spectrometer, Regolith, Regolith Dynamics,101 Thermal Inertia, Rover102 Posted Date: January 15th, 2021 DOI: https://doi.org/10.21203/rs.3.rs-139920/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License 1 2 3 4 5 1 The MMX rover: performing in-situ surface investigations on 6 7 8 2 Phobos 9 10 11 ∗ 12 3 Patrick Michel , Universit´eCˆote d’Azur, Observatoire de la Cˆote d’Azur, CNRS, Laboratoire Lagrange, 13 14 4 Nice, 06304, France, [email protected] 15 16 5 17 18 6 Stephan Ulamec, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), Linder H¨ohe, Cologne, 51147, 19 20 7 Germany, [email protected] 21 22 8 23 24 9 Ute Boettger, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), Institute of Optical Sensor Sys- 25 26 27 10 tems, 12489 Berlin, Rutherfordstr. 2, Germany, [email protected] 28 29 11 30 31 12 Matthias Grott, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), Institut f¨ur Planetenforschungn 32 33 13 Rutherfordstrasse 2, 12489 Berlin, Germany, [email protected] 34 35 14 36 37 15 Naomi Murdoch, ISAE-SUPAERO, Universit´ede Toulouse, DEOS/Space Systems for Planetary Appli- 38 39 16 cations, 10 avenue Edouard Belin, BP 54032, 31055 Toulouse Cedex 4, France, Naomi.MURDOCH@isae- 40 41 17 supaero.fr 42 43 18 44 45 46 19 Pierre Vernazza, Aix Marseille Universit´e, CNRS, CNES, Laboratoire d’Astrophysique de Marseille, Mar- 47 48 20 seille, France, [email protected] 49 50 21 51 52 22 Cecily Sunday, Universit´ede Toulouse, DEOS/Space Systems for Planetary Applications, 10 avenue 53 54 23 Edouard Belin, BP 54032, 31055 Toulouse Cedex 4, France, [email protected] 55 56 24 57 58 25 Yun Zhang, Universit´eCˆote d’Azur, Observatoire de la Cˆote d’Azur, CNRS, Laboratoire Lagrange, Nice, 59 60 26 06304, France, [email protected] 61 62 63 64 1 65 27 1 2 28 Rudy Valette, Mines ParisTech, PSL Research University, CEMEF, Centre for Material Forming, CNRS 3 4 29 UMR 7635, CS 10207 rue Claude Daunesse, 06904 Sophia Antipolis Cedex, France, rudy.valette@mines- 5 6 30 paristech.fr 7 8 9 31 10 11 32 Romain Castellani, Mines ParisTech, PSL Research University, CEMEF, Centre for Material Form- 12 13 33 ing, CNRS UMR 7635, CS 10207 rue Claude Daunesse, 06904 Sophia Antipolis Cedex, France, 14 15 34 [email protected] 16 17 35 18 19 36 Jens Biele, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), Linder H¨ohe, Cologne, 51147, Ger- 20 21 37 many, [email protected] 22 23 38 24 25 39 Simon Tardivel, CNES, BPI 2532, Laplace 116B, 18 avenue Edouard´ Belin, 31401 Toulouse Cedex 9, 26 27 28 40 France, [email protected] 29 30 41 31 32 42 Olivier Groussin, Aix Marseille Universit´e, CNRS, CNES, Laboratoire d’Astrophysique de Marseille, 33 34 43 Marseille, France, [email protected] 35 36 44 37 38 45 Laurent Jorda, Aix Marseille Universit´e, CNRS, CNES, Laboratoire d’Astrophysique de Marseille, Mar- 39 40 46 seille, France, [email protected] 41 42 47 43 44 48 Joerg Knollenberg, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), Institut f¨ur Planeten- 45 46 47 49 forschungn Rutherfordstrasse 2, 12489 Berlin, Germany, [email protected] 48 49 50 50 51 51 Jan Thimo Grundmann, Deutsches Zentrum f¨ur Luft- und Raumfahrt e. V. (DLR), Institute of Space 52 53 52 Systemsn Robert-Hooke-Strasse 7, D-28359 Bremen, Germany, [email protected] 54 55 53 56 57 54 Denis Arrat, CNES, BPI 2532, Laplace 116B, 18 avenue Edouard´ Belin, 31401 Toulouse Cedex 9, France, 58 59 55 [email protected] 60 61 56 62 63 64 2 65 57 Gabriel Pont, CNES, BPI 2532, Laplace 116B, 18 avenue Edouard´ Belin, 31401 Toulouse Cedex 9, France, 1 2 58 [email protected] 3 4 59 5 6 60 Stephane Mary, Directorate for Orbital Systems / Science Project Department, 18 avenue Edouard Belin, 7 8 9 61 31401 Toulouse Cedex 9, France, [email protected] 10 11 62 12 13 63 Markus Grubestein, Deutsches Zentrum f¨ur Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, 14 15 64 Germany, [email protected] 16 17 65 18 19 66 Hirdy Miyamoto, Department of Systems Innovation, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 20 21 67 Tokyo 113-8656, Japan, [email protected] 22 23 68 24 25 69 Tomoki Nakamura, Laboratory for Early Solar System Evolution, Department of Earth Science, Graduate 26 27 28 70 School of Science, Tohoku University, Aoba, Sendai, Miyagi 980-8578, Japan, [email protected] 29 30 71 31 32 72 Koji Wada, Planetary Exploration Research Center (PERC), Chiba Institute of Technology (Chitech), 33 34 73 Tsudanuma 2-17-1, Narashino, Chiba 275-0016, Japan, [email protected] 35 36 74 37 38 75 Kent Yoshikawa, Research and Development Directorate, Japan Aerospace Exploration Agency, Sagami- 39 40 76 hara 252-5210, Japan, [email protected] 41 42 77 43 44 78 Kiyoshi Kuramoto, Faculty of Science, Hokkaido University Kita-10 Nishi-8, Kita-ku, Sapporo 060-0810, 45 46 47 79 JAPAN, [email protected] 48 49 80 50 51 81 Joint first authors: P. Michel and S. Ulamec contributed equally to this work 52 53 82 54 ∗ 55 83 Corresponding author: [email protected] 56 57 58 59 60 61 62 84 Preprint submitted to Earth, Planets and Space on January 1, 2021 63 64 3 65 85 Abstract 1 2 86 The Japanese MMX sample return mission to Phobos by JAXA will carry a Rover developed by CNES 3 4 87 and DLR that will be deployed on Phobos to perform in-situ analysis of the Martian moon’s surface 5 6 88 properties. Past images of the surface of Phobos show that it is covered by a layer of regolith. However, 7 8 9 89 the mechanical and compositional properties of this regolith are poorly constrained. In particular 10 11 90 nothing is known regarding the particle sizes, their chemical composition, the packing density of the 12 13 91 regolith as well as other frictional parameters and surface dynamics from current remote images. 14 15 92 Understanding the properties and dynamics of the regolith in the low-gravity environment of Phobos is 16 17 93 important to trace back its history and surface evolution. Moreover, this information is also important 18 19 94 to support the interpretation of data obtained by instruments onboard the main spacecraft and to 20 21 95 minimize the risks involved in the sampling by the spacecraft. The instruments onboard the Rover are 22 23 96 an infrared radiometer (miniRad), a Raman spectrometer (RAX), two cameras looking forwards for 24 25 97 navigation and science purposes (NavCams), and two cameras observing the flow of regolith around the 26 27 28 98 rover wheels (WheelCams). The Rover will be deployed before the sampling of Phobos’ surface by MMX 29 30 99 spacecraft and will be the first rover driving on a Martian moon and in a low-gravity environment. 31 32 33 100 Keywords 34 35 101 Camera, Numerical Modeling, Phobos, Radiometer, Raman Spectrometer, Regolith, Regolith Dynamics, 36 37 102 Thermal Inertia, Rover 38 39 40 41 42 43 44 45 103 Introduction 46 47 104 The MMX Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German 48 49 105 Aerospace Center (DLR) to the Martian Moons eXploration (MMX) mission by the Japan Aerospace 50 51 106 Agency, JAXA, to the Martian moons Phobos and Deimos (Kuramoto et al. 2017; Kawakatsu et al. 52 53 54 107 2019). It will be delivered to the surface of Phobos to perform in-situ science but also to serve as a 55 56 108 scout, preparing the landing of the main spacecraft. The Rover is planned to be released from the mother 57 58 109 spacecraft at an altitude of less than 100 m (the current baseline foresees 45 m), ballistically descend 59 60 110 to the surface of Phobos and come to rest in an arbitrary attitude after several bounces.