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🚀 Science › MMX: Japan's mission to Phobos
MMX: Japan's mission to Phobos
By The Trends Incoming team
JAXA launched the Martian Moons eXploration (MMX) spacecraft on an H3 rocket on Oct 20, 2026. It reaches Mars orbit in 2027, lands on Phobos, collects samples and returns them to Earth in 2031. Timeline, the rover and why it matters.
What's trending in MMX: Japan's mission to Phobos
Japan launches MMX to a moon of Mars
JAXA's MMX lifted off on an H3 rocket on Oct 20 and is healthy after its first critical operations. It reaches Mars orbit in August 2027, drops a French-German rover on Phobos, grabs samples and brings them home in July 2031. A world first.
The quick version
Japan is going to a moon of Mars. JAXA launched the Martian Moons eXploration (MMX) spacecraft on H3 rocket Flight No. 10 from Tanegashima at 4:41 a.m. JST on October 20, 2026. The spacecraft separated about 71 minutes later, and on October 21 JAXA confirmed it is healthy with its solar panels out. The plan: orbit Mars from 2027, land on Phobos, scoop up rock and sand, and bring it home in 2031. No one has ever returned samples from a Mars moon.
| Launch | Oct 20, 2026, 4:41:03 a.m. JST, Tanegashima Space Center |
|---|---|
| Rocket | H3 Flight No. 10, the most powerful two-engine, four-booster version |
| Spacecraft | 4,480 kg, about 5.3 m tall, three modules: propulsion, exploration, return |
| Arrives at Mars | August 2027 |
| Rover | IDEFIX, built by French (CNES) and German (DLR) teams, lands on Phobos first |
| Sample landings | Two attempts by the spacecraft itself |
| Leaves Mars | November 2030 |
| Samples home | July 2031, capsule recovered in Australia |
| Partners | NASA, CNES, DLR and ESA |
| Cost | About 55.3 billion yen (about $350 million), per Kyodo |
Why Phobos?
Scientists still argue over where Mars's two little moons came from. One idea says a giant impact blasted material off Mars, which then clumped into moons. The other says they are asteroids that Mars captured. Real samples from Phobos should settle it, and could tell us how water and other building blocks for life were delivered to the inner solar system.
What happens next
JAXA is now running functional checks on the instruments before the cruise to Mars. Expect quiet months, then big news in August 2027 when MMX arrives, and again when IDEFIX touches down. You can follow along on JAXA's mission site and social accounts.
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Quick answers
When did MMX launch?
October 20, 2026, at 4:41 a.m. Japan time, on H3 Flight No. 10 from Tanegashima Space Center.
What is the MMX mission?
Martian Moons eXploration, a JAXA mission to study Mars's moons Phobos and Deimos and bring samples from Phobos back to Earth.
When will MMX return samples to Earth?
The capsule is due back in July 2031, with recovery planned in Australia.
When does MMX reach Mars?
It is scheduled to enter orbit around Mars in August 2027.
Is NASA part of MMX?
Yes. NASA, the French and German space agencies (CNES and DLR) and ESA all take part. The IDEFIX rover was built by French and German teams.