How will Japan’s MMX mission bring back the first samples from a Martian moon, and when does it launch?

JAXA’s Martian Moons eXploration launches October 19 EDT on an H3 rocket, lands on Phobos, deploys the Idefix rover, collects more than 10 grams, and returns the first samples from a Martian moon to Earth in 2031.

Nobody has ever brought a piece of a Martian moon home. Japan is about to try. Short answer: JAXA’s Martian Moons eXploration (MMX) is scheduled to launch on October 19 EDT (October 20 in Japan) from Tanegashima on an H3 rocket.

It arrives at Mars in 2027, lands on the moon Phobos, collects more than 10 grams of material, and returns the samples to Earth in 2031. Phobos and Deimos are small, dark, and mysterious: scientists still argue whether they are rubble left over from a giant impact on Mars or asteroids captured long ago. A sample in a laboratory settles arguments that remote sensing cannot, because researchers can measure its chemistry and age directly.

The mission is also a rehearsal in precision — landing on a tiny, low-gravity moon, gathering material, and flying it home across the solar system.1. Launch and cruise. The H3 lifts off from Tanegashima, and the spacecraft cruises to Mars, arriving in 2027.2.

Survey both moons. MMX studies Phobos and Deimos up close and picks its landing site on Phobos.3. Land and rove.

The spacecraft touches down on Phobos and deploys the small Idefix rover to scout the surface.4. Collect the sample. More than 10 grams gathered — NASA contributes a pneumatic sampler, the MEGANE gamma-ray and neutron instrument, and Deep Space Network communications support.5.

Come home. The return capsule is due back on Earth in 2031 with the first Martian-moon samples ever collected.Pro tip: Sample returns are marathons, so judge the mission milestone by milestone — arrival, landing, collection — instead of waiting a decade for a single verdict.Ad’s take: A decade from launch to laboratory sounds long until you remember the prize: a piece of another world, answering a question telescopes cannot. Worth the wait.