Japan launches mission to retrieve samples from Mars moon Phobos

MMX probe successfully lifts off, aiming to be first to return material from Martian moon and shed light on Solar System origins

By LineZotpaper

Published20 October 2026

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Japan's Martian Moons eXploration (MMX) mission launched successfully early Monday, setting course for Phobos in an attempt to become the first spacecraft to return samples from a Martian moon. The uncrewed probe, carried by an H3 rocket from Tanegashima Space Center, is expected to reach Mars in August 2027.

The Japan Aerospace Exploration Agency (JAXA) confirmed the MMX probe separated from its rocket about an hour after liftoff at 4:41 a.m. local time (1941 GMT Monday) and was "beginning its journey towards the Martian system." Flight controllers at the space center celebrated as the spacecraft entered space, with JAXA scientist Mari Aida expressing relief and joy. "I'd dreamt of this day, so I'm incredibly happy," she said. "Right now I feel really relieved."

The mission aims to collect at least 10 grams of material from the surface of Phobos, the larger of Mars' two moons, and bring it back to Earth. A French-German rover named IDEFIX, roughly the size of a microwave oven, will explore the surface and help ensure a safe landing. The probe will also study Mars' other moon, Deimos, during flybys before departing the Martian region in 2030.

Scientists hope the samples will help determine how Mars and its moons formed, testing theories that the moons are either the result of a giant collision or captured asteroids. Confirming either could explain how habitable environments emerged on the inner planets. NASA's Nicky Fox said in a message broadcast on the JAXA livestream that the mission will "bring forth paradigm-shifting science on the Mars system for generations to come, especially as NASA prepares to send the first humans to Mars."

The mission is a collaboration involving U.S. and European space agencies and private technology companies. It joins international efforts to return samples from the Martian system; NASA's Perseverance rover has collected samples on Mars itself but the planned return mission was canceled by the Trump administration after a congressional vote in January.

Analysis

Why This Matters

If successful, MMX would be the first mission to complete a round trip to the Martian region, returning physical samples from Phobos.
The samples could resolve fundamental questions about the formation of Mars and its moons, with implications for understanding how the inner Solar System became habitable.
The mission also tests technologies for future human exploration, including using Phobos as a potential staging point.

Background

Phobos and Deimos are small, irregularly shaped moons that orbit Mars. Their origins remain debated: one hypothesis says they formed from debris after a giant impact on Mars, another suggests they are captured asteroids. No spacecraft has ever returned samples from either moon. Japan's MMX follows earlier successful sample return missions from an asteroid (Hayabusa2) but faces the greater challenge of operating in the Martian gravity well.

Key Perspectives

JAXA: The agency sees MMX as a flagship mission that builds on its asteroid sample-return expertise and demonstrates Japan's capability for deep-space round trips. Scientists hope the data will be "paradigm-shifting." NASA: The U.S. space agency supports the mission as complementary to its own Mars exploration. Administrator Nicky Fox highlighted the link to eventual crewed missions to Mars. European partners: The German and French space agencies contributed the IDEFIX rover, gaining surface exploration data and technology demonstration without the cost of a full mission. Critics/Skeptics: There are no direct critiques reported in the source, but the broader competition with China and the canceled NASA sample-return mission raise questions about international coordination and the pace of Mars exploration.

What to Watch

August 2027: Expected arrival of MMX at Mars and beginning of orbital operations around Phobos.
The rover IDEFIX's performance on the surface, which will inform future landings.
Whether the Trump administration's cancellation of NASA's Mars sample-return creates pressure on Japan to deliver results first.

Sources

Japan probe sets course for Mars moon · DW English

Checked

12 claims in this story checked against 1 source: 10 supported.

Show each claim

SupportedJapan launched the MMX mission to retrieve samples from Phobos.DW English: “It will attempt to collect samples from Phobos, the larger of the planet's two moons”
SupportedThe mission aims to be the first to return material from a Martian moon to Earth.DW English: “in a race to become the first mission to return samples to Earth”
Partly supportedThe probe successfully lifted off early Monday.DW English: “The flagship H3 rocket carrying the MMX probe lifted off into a pitch-black sky from the Tanegashima Space Center at 4:41 a.m. local time (1941 GMT Monday)”
SupportedThe probe is expected to reach Mars in August 2027.DW English: “The uncrewed Martian Moons eXploration (MMX) mission is expected to reach Mars in August 2027.”
SupportedJAXA said the probe had separated from its rocket and was “beginning its journey towards the Martian system.”DW English: “An hour later, JAXA announced that the probe had successfully separated from the H3 rocket and was "beginning its journey towards the Martian system."”
SupportedMari Aida said, “I'd dreamt of this day, so I'm incredibly happy,” and “Right now I feel really relieved.”DW English: “"I'd dreamt of this day, so I'm incredibly happy," said JAXA scientist Mari Aida. "Right now I feel really relieved."”
SupportedMMX aims to collect at least 10 grams from Phobos and bring the material back to Earth.DW English: “it will spend about two hours collecting at least 10 grams of material from the moon's surface before launching back into space.”
SupportedA French-German IDEFIX rover, roughly microwave-oven-sized, will explore Phobos and help ensure a safe landing.DW English: “A French-German rover named IDEFIX ... will be the first vehicle to travel across Phobos to conduct surface observations and help ensure a safe landing for the Japanese probe. It is no bigger than a microwave oven.”
SupportedMMX will study Deimos during flybys before leaving the Martian region in 2030.DW English: “It will also study Mars' other natural moon, Deimos, during a series of flybys before leaving the Martian region in 2030.”
Partly supportedConfirming either origin theory could explain how habitable environments emerged on the inner planets.DW English: “Confirming either theory would help scientists determine "how a habitable environment for life might have arisen on the terrestrial planets,"”
SupportedNASA's Nicky Fox said the samples would “bring forth paradigm-shifting science on the Mars system for generations to come, especially as NASA prepares to send the first humans to Mars.”DW English: “"The samples from MMX will bring forth paradigm-shifting science on the Mars system for generations to come, especially as NASA prepares to send the first humans to Mars," Nicky Fox, administrator of NASA's Science Mission Directorate, said in a message broadcast on the JAXA live stream.”
SupportedNASA's Perseverance rover has collected samples on Mars, but the return mission was canceled by the Trump administration after a congressional vote in January.DW English: “NASA's Perseverance rover, which has been exploring the planet since 2021, has already collected samples. The return mission, however, was canceled by US President Donald Trump's administration after a congressional vote in January.”