Overview
- The Japan Aerospace Exploration Agency launched the Martian Moons eXploration (MMX) spacecraft and confirmed it separated onto a trans‑Mars trajectory after liftoff on Tuesday, Oct. 20, 2026.
- MMX is on a roughly 10‑month cruise to Mars with arrival targeted for August 2027, followed by mapping, deployment of the French‑German IDEFIX rover and one to two Phobos touchdowns planned for late 2028–2029 before a return to Earth in 2031.
- The spacecraft carries 13 instruments supplied by JAXA, NASA, ESA and European partners, including NASA’s MEGANE spectrometer and a Honeybee pneumatic sampler, and NASA will curate a reserved share of at least 15% of returned material.
- Engineers face major technical risks because Phobos’ gravity is extremely weak, requiring novel landing and coring methods, and the mission is also the H3 rocket’s first interplanetary flight after earlier program setbacks.
- Scientists hope samples of at least 10 grams will settle whether Phobos and Deimos are captured asteroids or impact debris and may contain a small fraction of Martian ejecta, a figure variously estimated at about 0.1% to 1%, which will shape interpretations once the material returns.