Optimizing Cold Resistance: The Thermal Design of the MMX Rover IDEFIX's Locomotion Subsystem for the Martian Moon Phobos

Abstract

The Martian Moon eXploration (MMX) mission, led by the Japan Aerospace Exploration Agency (JAXA) is set to launch in 2026. Its objectives are to conduct the first sample-return of the moon Phobos and collect further scientific data by observing the moon Deimos. The main goal is to understand the origin of both Martian moons. Within this mission, the MMX rover IDEFIX, a collaborative development of the French Centre National d'Études Spatiales (CNES) and the German Aerospace Center (DLR), is designated to serve as a mobile scout and explore the surface of Phobos. It will perform on-site scientific measurements using various on-board instruments and contribute data for JAXA's sample collecting task. The locomotion subsystem (LSS) of the MMX rover, developed, built, and qualified by DLR's Robotics and Mechatronics Center (RMC), holds a pivotal role in achieving the rovers' objectives. To ensure the resilience of the LSS under demanding conditions, especially the harsh environment during the cruise phase and the extremely low temperatures of Phobos surface during the night, a comprehensive thermal design was developed. This paper offers an examination of DLR RMC's design for addressing the thermal demands of the LSS in various mission phases.