Challenges of the MMX Rover mission to Phobos

The Martian Moons eXploration (MMX) mission by the Japan Aerospace Exploration Agency, JAXA, aims at the Martian Moons Phobos and Deimos. It will return samples from Phobos back to Earth and deliver a small (about 25 kg) Rover to the surface. The Rover will be released from the mother spacecraft from below 100m high. After an uncontrolled descent and landing on Phobos, the Rover will uprighten itself. This is followed by the deployment and pointing of its Solar Array for the Rover to become independent from an energy point of view. This is all to happen autonomously, as the ground loop duration (Rover > MMX spacecraft > Earth > MMX spacecraft > Rover) is too long for the Rover to survive on battery power alone. Over its 100-day mission on Phobos, the Rover aims to demonstrate locomotion in a milli-g environment, to provide valuable insights of what Phobos is like and how its surface behaves to the MMX spacecraft before its own landing to perform the sampling and to experimentautonomous navigations algorithms. We will report on the particular challenges of designing, building and operating a rover on Phobos. MMX will be launched in September 2024, with the Rover delivery to Phobos planned for 2026-2027. The Rover is a contribution by the Centre National d'Etudes Spatiales (CNES) and the German Aerospace Center (DLR)

Design Of The MMX Rover Attitude Control System For Autonomous Power Supply

The Martian Moons eXploration (MMX) mission led by the Japan Aerospace Exploration Agency (JAXA) aims at studying Phobos and Deimos. It includes a small rover that will explore Phobos, carried out jointly by the French Space Agency (CNES) and the German Aerospace Center (DLR). With its fixed solar array, the rover does not receive enough energy in nominal driving orientation to recharge its battery. Therefore, an attitude control system manages the rover orientation, using the locomotion system and a sun sensor. The specifics of the control loop such as movements limitations or tranquilization periods are due to the dynamic interactions with the regolith. This paper presents the attitude control system (SKA) architecture, through the various challenges encountered: limited design flexibility with major changes during the development, small knowledge of Phobos' expected soil, very tight schedule to meet the JAXA delivery date. The design drivers were to create the simplest and most robust system to orient the rover in order to maximize the battery recharge, while ensuring the rover stability and addressing the above issues. A particular focus is made on the preliminary simulation results. Finally, the way forward is outlined with the SKA development and validation steps

Roving on Phobos: Challenges of the MMX Rover for Space Robotics

This paper presents a small rover for exploration mission dedicated to the moons of Mars, Phobos and Deimos. This project is a collaboration between JAXA for the mother spacecraft, and a cooperative contribution of CNES and DLR to provide a rover payload. This rover will be different in many aspects compared to the existing ones. It will have to drive in a very low gravity with only little power given by the solar arrays. It will also need autonomy in order to achieve a consequent distance during a short mission of 100 days. Apart of the technology demonstration driven mission aspects, the first objective after landing for the rover is to secure the mother spacecraft landing through a characterization of the soil (regolith). Hence, in the nominal rover definition, several payloads are foreseen in order to contribute to the mission of the main spacecraft: to determine the origin of Martian moons

A rover for the JAXA MMX Mission to Phobos

The Martian Moons eXploration (MMX) is a mission by the Japan Aerospace Exploration Agency, JAXA,to the Martian moons Phobos and Deimos. It will primarily investigate the origin of this moon by bringing samples back from Phobos to Earth and deliver a small (about 25 kg) Rover to the surface. The Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German Aerospace Center (DLR). Its currently considered scientific payload consists of a thermal mapper (miniRAD), a Raman spectrometer (RAX) a stereo pair of cameras looking forward (NavCAM)and two cameras looking at the interface wheel-surface (WheelCAM) and consequent Phobos’ regolith mechanical properties.The cameras will serve for both, technological and scientific needs. The MMX rover will be delivered from an altitude of <100 m and start uprighting and deploying wheels and a solar generator after having come to rest on the surface. It is planned to operate for three months on Phobos and provide unprecedented science while moving for a few meters to hundreds of meters. MMX will be launched in September 2024 and inserted into Mars orbit in 2025, the Rover delivery and operations are planned for 2026-2027