MMX

MMX, the Martian Moons eXploration mission, is the first mission planned to collect a sample from Phobos, one of the two moons of Mars, and bring it back to Earth.^[1] It is led by the Japan Aerospace Exploration Agency (JAXA), in collaboration with NASA, the French space agency CNES, the German Aerospace Center DLR and ESA.^[1]

Why Phobos

Phobos and Deimos remain mysterious: they may be asteroids captured by Mars, or remnants of debris thrown into orbit by a giant impact on Mars.^[1] Only a few flybys have studied them, and samples are needed to settle how they formed.^[1]

The mission

MMX launched on an H3 rocket from the Tanegashima Space Center at 04:41 Japan time on 20 October 2026.^[2] It is expected to enter orbit around Mars in August 2027 and to orbit Phobos from September 2027, the first spacecraft to do so.^[1]

After studying Phobos and Deimos from a distance, MMX is to release the 25 kg Idefix rover onto Phobos in early 2029.^[1] Phobos's gravity is so weak that the rover will weigh the equivalent of only 15 grams there.^[1] In 2030 the main spacecraft is to land on Phobos to collect samples, and a return module is to bring at least 10 g of Phobos material back to Earth in 2031.^[1]

MMX carries 11 science instruments, seven on the main spacecraft and four on the rover.^[1] It is also to be the first mission to return to Earth after visiting the Mars system.^[1]