Japanese spacecraft races to bring Mars moon samples to Earth

By the Editorial Team · Wednesday, October 21, 2026

Japan’s space agency, JAXA, launched the Mars Moons eXploration (MMX) spacecraft on a mission to land on the Martian moon Phobos, collect samples, and return them to Earth by 2031. This mission, involving international partners including NASA and ESA, is the first attempt to retrieve material from Mars’ moons and could provide critical insights into the moons’ origins and the evolution of the Martian system.

A Japanese spacecraft launched early Tuesday morning on a pioneering mission to explore the Martian moon Phobos and return samples to Earth, marking the first attempt to collect material from Mars’ moons. The Japan Aerospace Exploration Agency (JAXA) led the effort, launching the five-ton Mars Moons eXploration (MMX) probe atop a H3 rocket from Tanegashima Island in southwestern Japan. The spacecraft successfully separated from the rocket’s upper stage about an hour after liftoff, prompting applause and celebrations in the control room.

The mission, involving collaboration among five international space agencies—including NASA and the European Space Agency—aims to study Phobos’ origin and composition, which could shed light on the formation of Mars and provide broader clues about the evolution of moons and planets in the solar system. The mission has a projected cost of around $578 million, with JAXA contributing approximately $350 million and NASA providing about $87 million in support.

MMX is expected to reach Mars’ orbit by late summer 2027 after a roughly one-year journey. Phobos is a small, irregularly shaped satellite roughly 22 kilometers (14 miles) in diameter that orbits Mars at about 6,000 kilometers (3,700 miles) above its surface three times a day. Scientists are particularly interested in determining whether Phobos is a captured asteroid or formed from debris ejected by a massive ancient impact on Mars.

Once in orbit, the spacecraft will conduct months of remote observations to select a safe landing site. MMX will then deploy a French-German rover called Idefix—named after a character from the Asterix comics—which will independently land on Phobos and spend about 100 days scouting terrain for the subsequent landing of a four-legged stationary lander. The rover, roughly the size of a microwave oven, will move extremely slowly due to Phobos’ low gravity and its delicate solar panels. It is designed to self-right if it tips but could be immobilized if trapped in dust or rough terrain.

Following the rover’s reconnaissance, the lander is scheduled to collect at least 10 grams of surface material by late 2028 or 2029. After sample acquisition, MMX will begin its return journey, with an anticipated Earth reentry and sample recovery scheduled for 2031.

The mission is notable as no country has previously attempted a landing on either of Mars’ moons—Phobos and Deimos—nor successfully returned samples from Mars or its satellites. While NASA and China have successfully landed spacecraft on Mars itself, attempts to collect material from the moons have been elusive. Russia’s 2011 mission to Phobos failed to return samples.

The scientific community has expressed enthusiasm over MMX’s potential. NASA astrophysicist Tom Statler, involved in the mission, described the launch as eliciting “a lot of adrenaline and a lot of excitement.” European scientists highlighted MMX’s versatile scientific instruments, including spectrometers, lasers, dust detectors, and cameras, which will provide a comprehensive analysis of Phobos’ surface and environment.

Ultimately, MMX could help answer long-standing questions about the origins of Mars’ moons and inform future Mars exploration, including crewed missions. Its success may represent a major milestone in planetary science and international cooperation in space exploration.

This article was reported by synthesizing coverage from multiple independent news outlets to present a balanced, unbiased account. Read about our editorial standards. Spotted an error? Let us know.