Japanese space mission launches to Mars moons

The Japanese MMX (Martian Moons eXploration) mission was launched on October 20, 2026, from the Tanegashima Space Center in Japan aboard an H3 rocket. The mission aims to explore Phobos and Deimos, the two small moons orbiting Mars.

International collaboration on the mission

The MMX probe carries the French-German Idefix® rover, developed by CNES and the German space agency DLR, as well as MIRS, a near-infrared imaging spectrometer built by the Paris Observatory-PSL and CNES. CNES also contributes to the mission's flight dynamics and trajectory planning.

Mission objectives and timeline

The primary goal of MMX is to investigate the origins of Phobos and Deimos. It will study the Martian atmosphere and collect at least 10 grams of material from Phobos, which will be returned to Earth in 2031. The probe will spend three years around Mars before beginning its return journey.

Flight dynamics and trajectory planning

CNES has worked closely with JAXA since 2017 on the mission’s flight dynamics. This includes designing and validating the probe’s paths around Phobos, particularly low orbits, and determining its navigation and orbit. This collaboration builds on CNES’s experience with past missions like Rosetta/Philae and Hayabusa-2/MASCOT.

Scientific instruments and research teams

MIRS will analyze the mineral composition of Phobos and Deimos and search for water or organic matter. CNES leads the development of MIRS with support from the Paris Observatory-PSL and several CNRS laboratories. Over twenty scientists from nine French research institutions are involved in the project.

Idefix® rover’s role and capabilities

Idefix® is a lightweight rover designed to explore Phobos’s surface. It will study the terrain to aid in the MMX probe’s landing, demonstrate mobility in low-gravity conditions, and take high-resolution images. The rover’s operations will be managed by teams from CNES and DLR, with scientific coordination by the Observatory of the Côte d'Azur.