Japan to launch historic round-trip mission to Mars moon to retrieve samples

By the Editorial Team · Monday, October 19, 2026

Japan's JAXA is launching the MMX spacecraft to collect surface samples from Phobos, a moon of Mars, with a planned return to Earth by 2031. This mission will help resolve longstanding questions about the origins of Mars’ moons and test technologies essential for future crewed Mars exploration.

Japan is set to launch an unmanned spacecraft on a historic mission to retrieve samples from Phobos, one of Mars’ two moons, marking the first round-trip journey to the Martian system. The Japan Aerospace Exploration Agency (JAXA) announced that the Martian Moons eXploration (MMX) probe will lift off from the Tanegashima Space Center early Tuesday morning, with the launch scheduled for 4:41 a.m. local time (1941 GMT on Monday).

The MMX mission aims to arrive near Mars by August 2027, where it will orbit Phobos and collect at least 10 grams of surface material during a planned three-year operation. The mission will also conduct observations of Deimos, Mars’ smaller moon, although it will not land there. A small rover named IDEFIX, named after the dog from the Asterix comic series, will first explore the surface of Phobos to aid in securing a safe landing.

Scientists expect the samples to offer insights into the origins of Mars and its moons, a question that scientists have long debated. Two main theories persist: one suggests Phobos and Deimos formed after a massive impact on Mars, while the other proposes that they are captured asteroids. Understanding which scenario is correct could help clarify the formation of terrestrial planets and the conditions that made them potentially habitable.

The mission is a collaboration involving multiple space agencies, including France’s CNES, the German Aerospace Center (DLR), NASA, the European Space Agency (ESA), as well as contributions from about 20 universities and technology companies worldwide. The project also aims to explore the feasibility of using Phobos as a “natural space station” for future crewed missions to Mars, which would be a crucial milestone in human space exploration.

JAXA scientists highlighted the technical challenges posed by the moon’s extremely low gravity, which made the development of the spacecraft’s landing legs particularly complex. The MMX mission builds on Japan’s prior experience with sample-return missions, notably the successful Hayabusa-2 asteroid mission that brought back material to Earth in 2020.

The scientific community anticipates that studying Phobos could improve the understanding of how water, organic compounds, and other volatiles were transported from the outer to the inner Solar System, factors that may have been vital to the development of life on Earth and potentially other rocky planets.

MMX represents a significant step not only in planetary science but also in testing technologies required for traveling deeper into the Solar System’s gravity well—specifically, launching from the Martian moon’s orbit and returning safely to Earth. The mission is slated to return its precious samples to Earth around 2031.

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