Japan Mars moons mission targets Phobos sample return

Japan is preparing an unmanned mission to Mars' moons that aims to collect material from Phobos and return it to Earth around 2031.

The Martian Moons eXploration mission, known as MMX, is set to launch from Tanegashima Space Center in the coming months. The spacecraft is expected to remain in Mars' orbit for about three years and attempt a landing on Phobos, where it will collect at least 10 grams of surface material.

The mission will also use the IDEFIX rover for surface observations on Phobos and observe Deimos, Mars' other moon, without landing. A return capsule is planned to land in Australia around 2031.

The Japan Aerospace Exploration Agency says the mission could help explain how Mars and its moons formed. It is examining whether the moons were created after an impact with Mars or whether they are asteroids captured by Martian gravity.

Patrick Michel, a French astrophysicist working on IDEFIX, said the mission could shed light on how water, volatile materials and organic compounds moved from the outer Solar System to rocky inner planets.

JAXA also says the mission will test technology needed for a round trip to Mars and could support future crewed exploration, including the possible use of Phobos as a natural space station.

MMX is being developed with partners including France's CNES, the German Aerospace Center, NASA, the European Space Agency, universities and technology companies. Akinari Uehara, a Mitsubishi Electric engineer, said designing the spacecraft's landing legs was difficult because gravity on Phobos is extremely low.

Other Mars sample efforts are also underway or planned. NASA's Perseverance rover has collected samples on Mars, but AFP reports that the return mission has effectively been cancelled by President Donald Trump's administration after a US Congress vote in January. China has announced that its Tianwen-3 spacecraft is scheduled for launch around 2028 and could return Mars samples to Earth around 2031, potentially earlier than MMX.