JAXA Martian Moons eXploration (MMX) Sample Return

JAXA's MMX mission, launching in November-December 2026, aims for the first-ever sample return from the Mars system, collecting at least 10 grams from Phobos. This 5-year round trip, the longest-duration sample return ever attempted, will resolve Phobos's origin—either a captured asteroid or Mars debris—with profound implications for understanding water delivery to the inner Solar System. The 4,000-kilogram spacecraft carries a sophisticated payload, including NASA's MEGANE spectrometer and a novel sampler derived from Hayabusa2's success. Its success would cement Japan as the world premier in robotic sample return, exceeding the scientific legacy of past missions by unlocking Phobos's secrets over a 5-year, 2031 return timeline.