MMX (Martian Moons eXploration)

MMX (Martian Moons eXploration)

Spacecraft· JAXAplanned

MMX — Martian Moons eXploration, JAXA's mission to return the first sample from the Mars system. Planned for launch in late 2026, it will study Phobos and Deimos and land on Phobos to collect surface material (Earth return ~2031), aiming to settle whether the Martian moons are captured asteroids or debris from a giant impact. It carries international instruments and the French–German IDEFIX rover.

Open in 3D viewSee MMX (Martian Moons eXploration) in the live, interactive 3D map

Key facts

Distance from Sun
1.5 AU
Status
Planned
Launched
2026

Mission & specifications

Mission

Operator
JAXA
Launched
October 31, 2026
Status
Planned

Trajectory

Distance from the Sun
1.5 AU
Distance from Earth
1.91 AU
Distance from Mars
120,068 km

Mission

MMX — Martian Moons eXploration — is JAXA's plan to answer a stubborn question: where did Mars get its two little moons? Phobos and Deimos might be asteroids captured by Mars, or rubble flung into orbit by a giant impact, and the two stories predict very different rocks. The only way to be sure is to bring a piece home. Planned for launch in late 2026 on Japan's H3 rocket, MMX will enter the Mars system around 2027, settle into a delicate orbit that shadows Phobos, and drop the small French–German rover IDEFIX to scout the surface before the mothership itself descends to grab at least ten grams of soil. It carries instruments from NASA, France, Germany and Europe, will also study Deimos and watch the Martian weather, and — if all goes to plan — return its capsule to the Australian desert in 2031, the first sample ever brought back from the Mars system.

  1. 2026Planned launch on an H3Launch

    MMX is scheduled to launch from Tanegashima toward the Mars system on a Phobos sample-return mission.

  2. 2027Planned Mars-system arrivalArrival

    Expected to enter orbit near Phobos and begin surveying the moon and deploying the IDEFIX rover.

  3. 2029Planned Phobos landing & samplingMilestone

    The spacecraft is expected to descend to Phobos and collect at least ~10 g of surface material.

  4. 2031Planned Earth sample returnMilestone

    The sample capsule is expected to return to the Australian desert — the first sample from the Mars system.

Images

JAXA's MMX spacecraft at Phobos (artist's concept — not a photograph)
NASA (public domain) · Wikimedia Commons

Images from open archives · credit shown per image