Japan's Martian Moons eXploration spacecraft, known as MMX, launched aboard an H3 rocket from Tanegashima Space Center at 4:41 a.m. Japan time on October 20, 2026. JAXA said the spacecraft separated about 71 minutes later and entered its planned orbit in its launch report.
That completed the launch phase, not the mission. MMX is designed to study both of Mars' moons, Phobos and Deimos, land on Phobos, collect material and bring it back to Earth, according to JAXA's mission description. The target is a moon of Mars, not the planet's surface.
Why bring material back from Phobos?
Scientists have not settled how Phobos and Deimos formed. They may have come from material blasted into orbit by a large collision with Mars, or they may have been asteroids captured by Mars' gravity. NASA describes both possibilities in its mission science briefing.
MMX will examine the moons from space and attempt to return a Phobos sample for laboratory analysis. NASA says it is contributing an instrument that measures elements on Phobos' surface and a device designed to collect loose material. Those observations and samples could help test the origin theories, but they have yet to be obtained.
What happens next?
NASA's updated mission timetable projects a Mars arrival in 2027, sampling no earlier than 2028 and an Earth return in 2031. These are plans that depend on the spacecraft completing each stage. For now, JAXA has confirmed launch, separation and the planned orbit, not arrival or sample collection.
Phobos photographed by NASA's Mars Reconnaissance Orbiter in 2008. Contextual image; credit: NASA/JPL-Caltech/University of Arizona.
