Japan prepares historic mission to bring back samples from Phobos

Japan is set to launch a spacecraft on a mission to collect samples from Phobos, one of Mars’ two moons, in what would be the first sample-return mission from the Martian sphere. The Japan Aerospace Exploration Agency, or JAXA, says the Martian Moons eXploration mission is designed to land on Phobos, gather at least 10 grams of soil, and bring the material back to Earth.

The project matters because the samples could help scientists determine whether Phobos formed from debris around Mars or was captured by the planet’s gravity. Researchers also hope the mission will provide clues about the early Martian system and whether a Martian moon could one day serve as a staging point for human exploration.

JAXA has described MMX as a world-first mission. The agency says the spacecraft will study both Phobos and Deimos, the two small moons of Mars, before attempting to land on Phobos and collect material from the surface. The mission has been in development for years and is part of Japan’s broader deep-space exploration program.

What the mission is designed to do

According to JAXA, MMX is scheduled to launch in fiscal year 2026 and follow a roughly five-year journey to the Martian system and back. After arrival, the spacecraft will observe the moons from orbit, release a small rover and conduct close-range investigations before moving to the sampling phase. JAXA says the spacecraft will use two sampling methods to gather material from Phobos.

The current mission plan calls for the spacecraft to return to Earth in 2031. JAXA says the sample return capsule will then deliver the material for curation and scientific analysis. The agency has also said the mission is intended to build on technology developed for previous sample-return work, including Japan’s Hayabusa2 asteroid mission.

The project has attracted international participation, including contributions from NASA, the European Space Agency and research institutions in Europe and Japan. JAXA has said the findings could deepen understanding of how rocky worlds formed and how materials move through the inner solar system, adding another chapter to Japan’s long record of planetary exploration.