Science operations of IDEFIX, the MMX Phobos rover

Abstract IDEFIX, a rover to be delivered to the martian moon Phobos, is part of the Martian Moons eXploration (MMX) mission by the Japan Aerospace Exploration Agency, JAXA. MMX will explore both moons of Mars remotely but will also land on Phobos and collect samples from its surface and return them back to Earth. The IDEFIX rover will be released from the main spacecraft during its landing rehearsal at an altitude of about 40 m. It will fall to the surface, probably bounce several times and upright itself after having come to rest by applying an autonomous sequence of the deployment of its locomotion system. This sequence is followed by deployment of the solar generator and recharging of the batteries. After commissioning, on-Phobos operations are planned for at least 100 (Earth-) days. Sequences of science operations (instrument measurements), driving, battery charging and communications with Earth (via the main spacecraft) will alternate in a way to maximize scientific return and fulfill technical demonstration goals. IDEFIX accommodates a payload of four scientific instruments: a Raman spectrometer (RAX), a stereo pair of cameras looking forwards (NavCams; also used for navigation), a radiometer (miniRAD), and two cameras looking at the wheel-surface interface (WheelCams). MMX will be launched in autumn 2026, the Rover delivery to Phobos is currently planned for late 2028, before the first touch down of the spacecraft and sample collection. The Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German Aerospace Center (DLR) with additional contributions from INTA (Spain) and JAXA (Japan).