MMX (Martian Moons eXploration)
MMX — Martian Moons eXploration, JAXA's mission to return the first sample from the Mars system. On 20 August 2026 JAXA set its launch for 20 October 2026 (JST) aboard H3 Launch Vehicle Flight No.10, with a reserved window to 7 November. 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. Planned launch dates can still shift.
Key facts
Mission & specifications
Mission
- Operator
- JAXA
- Planned launch
- October 20, 2026
- Status
- Planned
Trajectory
- Current speed
- 33.3 km/s
- Computed from the cached state vector
- Distance from the Sun
- 0.995 AU
- Computed from the cached position
- Distance from Earth
- 4,374,099 km
- Computed from cached positions
- Distance from Venus
- 0.282 AU
- Computed from cached positions
Specifications
- Launch mass
- 4,480 kg · Includes 3,030 kg of propellant (fuel)
- JAXA, paper to the MEXT space committee, 26 August 2026
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.
- 2026MMX's planned launch on an H3 rocketLaunch
MMX is scheduled to launch from Tanegashima toward the Mars system on a Phobos sample-return mission.
Expected to enter orbit near Phobos and begin surveying the moon and deploying the IDEFIX rover.
- Planned Phobos landing & samplingMilestone
The spacecraft is expected to descend to Phobos and collect at least ~10 g of surface material.
- 2030Planned departure from MarsMilestone
The spacecraft is expected to leave the Mars system and start the cruise home.
- 2031Planned Earth sample returnMilestone
The sample capsule is expected to return to the Australian desert — the first sample from the Mars system.
Images
Images from open archives · credit shown per image