Japan prepares to launch MMX mission to Phobos
Japan is preparing to launch the Martian Moons Exploration (MMX) spacecraft on Tuesday, October 20, from the Tanegashima Space Center using an H3 heavy-lift rocket, according to the Japan Aerospace Exploration Agency (JAXA). The uncrewed mission aims to collect at least 10 grams of surface and subsurface soil from Phobos, one of Mars’s two moons, during a five-year journey designed to uncover the origins of the Martian satellites and return the samples to Earth by 2031.
JAXA Partners with International Agencies to Study Martian Moons
The MMX initiative is a collaborative international effort supported by JAXA alongside the French National Centre for Space Studies, the German Aerospace Center, NASA, and the European Space Agency.
Japanese Minister of Education, Culture, Sports, Science and Technology Yoshihiro Seki stated during a Tokyo press conference that the probe will help determine the origin of the Martian moons while advancing technologies for future crewed missions to Mars. JAXA project manager Yasuhiro Kawakatsu noted that the returned samples will provide crucial data on the moons’ composition and assess whether Phobos could serve as a base for future crewed expeditions to the Red Planet.
Resolving the Origins of Phobos and Deimos
One theory suggests the moons are debris remnants generated by a massive celestial impact on Mars, while another proposes they are captured asteroids formed elsewhere in the solar system.
Kiyoshi Kuramoto, the project’s principal researcher, stated that analyzing soil samples from Phobos will allow researchers to reach definitive conclusions about the moon’s origin. Phobos was chosen as the primary target because its proximity to Mars increases the likelihood that it retains material from the planet itself, with JAXA officials estimating that Martian material could account for roughly 0.1% of the collected samples. The mission will also include close flybys of Deimos to gather comparative data, though the spacecraft will not land on the second moon.
Technical Challenges of Low-Gravity Landing
The spacecraft will travel hundreds of millions of kilometers, entering the Martian region in August 2027 before spending three years studying Phobos and executing landing maneuvers.
To mitigate this, the exploration unit features four-legged landing gear equipped with shock-absorbing systems. Prior to the main landing, a joint French-German rover named Idefix will deploy around 2029 to survey the terrain for roughly 100 days. The MMX spacecraft will then execute two sampling attempts using distinct technologies: a NASA-developed pneumatic system using pressurized gas to lift surface dust into a container, and a Japanese tool designed to extract subsurface material from a depth of about two centimeters.
The collected material will be secured in a heat-resistant capsule designed to withstand atmospheric re-entry, scheduled to touch down in 2031 before transit to Japan for laboratory analysis.
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