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Japan's MMX is headed to a moon of Mars: what it is and why it's trending
By The Trends Incoming team · Published 2026-10-21
Space fans, this one's a keeper. Japan just launched a spacecraft that plans to land on Phobos, the bigger of Mars's two moons, grab a handful of it and fly it back to Earth. Nobody has ever done that.
What it is
It's called MMX, short for Martian Moons eXploration. JAXA launched it on an H3 rocket from Tanegashima at 4:41 a.m. Japan time on October 20, 2026, and on October 21 confirmed the spacecraft is healthy, with its solar panels deployed and steering locked in. It weighs about 4,480 kg and stands about 5.3 meters tall, with three modules for getting there, exploring and coming home.
| Launch | Oct 20, 2026 |
|---|---|
| Mars orbit | August 2027 |
| Rover on Phobos | IDEFIX, from French and German teams |
| Leaves Mars | November 2030 |
| Samples home | July 2031, landing in Australia |
Why it's trending
Three reasons. It's a world first: a sample return from a Mars moon. It's a comeback story, since the launch slipped from 2024 after the H3 rocket's first flight failed in 2023. And it could answer a decades-old puzzle about whether Phobos and Deimos were knocked off Mars in a giant impact or are captured asteroids. JAXA has done this kind of thing before with its Hayabusa asteroid missions, so expectations are high. Our MMX guide has the full timeline and FAQ.
Where to follow it
JAXA's mission site and press releases are the official source. On social, follow #MMX and #JAXA for updates and pretty spacecraft pictures. The next big moment is the arrival at Mars in August 2027. Want more launches and big moves? See what's trending in science, and read about the Boeing 737 MAX 10's long-awaited approval.
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.
Follow it
The trend card
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.
Sources
By The Trends Incoming team · Fact-checked 2026-10-21. Dates change, so double-check with the official source.