Japan is preparing a major planetary exploration mission that aims to bring material from one of Mars’s moons back to Earth. The Martian Moons eXploration (MMX) mission, led by the Japan Aerospace Exploration Agency (JAXA), is scheduled for launch on October 19, with the ambitious goal of collecting samples from Phobos, the larger of Mars’s two natural satellites.

The mission seeks to achieve a milestone in space exploration by returning samples from a Martian moon for detailed scientific examination on Earth. Researchers hope that studying this material will provide new evidence about the origins of Phobos and the early evolution of the Martian system.

The European Space Agency (ESA) is contributing deep-space communication technology and ground-station support to help maintain contact with the spacecraft during its journey. Such international cooperation is essential for missions travelling far beyond Earth, where reliable communications are needed to transmit commands, receive scientific information and monitor spacecraft operations.

Why Phobos Is a Scientific Priority

Phobos is an unusual moon that orbits relatively close to Mars. Despite decades of planetary observations, important questions remain about how it formed. One possibility is that it is a captured asteroid; another suggests that it originated from material associated with a major impact involving Mars.

Examining samples directly could help scientists investigate these competing explanations. Laboratory analysis on Earth can reveal details about a sample’s mineral composition, chemical properties and geological history that may be difficult to determine through remote observations alone.

The findings could also improve scientific understanding of the relationship between Mars and its moons, offering clues about the processes that shaped the inner Solar System billions of years ago.

International Partnership Supports the Mission

The MMX programme involves JAXA alongside NASA, France’s CNES, Germany’s DLR and ESA. Each partner contributes expertise and technology to support different aspects of the mission.

ESA’s contribution includes deep-space communication equipment, such as a transponder and power amplifier, as well as support from its Estrack ground-station network. These systems will help mission controllers send instructions to the spacecraft and receive operational data across the vast distance between Earth and Mars.

The mission is scheduled to launch aboard Japan’s H3 rocket from the Tanegashima Space Center. After travelling for approximately a year, the spacecraft is expected to reach Mars in 2027 and begin detailed investigations of its moons.

From Phobos to Earth: The Mission Ahead

MMX plans to study Phobos and Deimos before deploying a small rover to examine the surface of Phobos. The main spacecraft is expected to collect samples in 2030, with the return capsule scheduled to deliver the material to Earth in 2031.

Scientists anticipate that the returned samples will help resolve questions about the formation of Mars’s moons and the evolution of the Martian environment. The mission will also test technologies needed for future round-trip exploration of the Martian system.

If successful, MMX will establish a new milestone in planetary science by bringing material from Phobos to terrestrial laboratories, where researchers can examine it using advanced instruments unavailable on a spacecraft.