Japan begins an ambitious journey to Mars’ moons
TOKYO, Japan — Japan has successfully launched a spacecraft towards Mars’ moon Phobos, opening a new chapter in planetary exploration. The mission, known as Martian Moons eXploration, or MMX, lifted off aboard the H3 rocket from the Tanegashima Space Center in southwestern Japan on 20 October 2026.
Editorial Insight
Key Highlights
Important points readers should notice.
Successful launch: Japan launched its MMX spacecraft aboard an H3 rocket on 20 October 2026.
Historic objective: The mission aims to become the first to return samples from a moon of Mars.
Sample collection: JAXA plans to retrieve at least 10 grams of material from Phobos.
International collaboration: NASA, CNES, Germany’s aerospace centre and ESA are contributing to the mission.
Return planned for 2031: Scientists hope the samples will clarify how Mars’ moons formed and improve understanding of the solar system.
The Japan Aerospace Exploration Agency confirmed the mission’s planned launch, and subsequent reporting from Japan said the rocket placed the spacecraft into its intended orbit. The launch also marked the H3 rocket’s first interplanetary mission.
What makes the MMX mission historic?
Phobos is an irregularly shaped moon that orbits relatively close to Mars. Despite decades of robotic exploration of the Red Planet, no mission has yet returned a sample from either of its moons.
Editorial Analysis
Why This Matters
Understanding planetary origins: Samples could help scientists determine how Phobos and Deimos formed. Exploring the early solar system: Material from Phobos may preserve clues about ancient planetary processes. Advancing space technology: The mission tests navigation, landing, sampling and sample-return techniques. International scientific cooperation: Multiple space agencies are contributing expertise and equipment. Future Mars exploration: Findings could inform future robotic missions and longer-term human exploration plans.
The MMX spacecraft is expected to reach the Martian system in 2027. It will study Phobos before attempting surface operations, with a small French-German rover called Idefix designed to examine the terrain and help assess potential landing locations.
JAXA aims to collect at least 10 grams of material from Phobos during planned sampling operations. If the mission proceeds as intended, a return capsule will bring the samples back to Earth in 2031.
Scientists seek clues to the origins of Mars’ moons
One of the mission’s main scientific goals is to determine how Phobos and Deimos formed. One theory suggests that the moons are asteroids captured by Mars’ gravity. Another proposes that they formed from debris after a major collision involving Mars.
Analysing Phobos’ surface material could help scientists distinguish between these explanations. Researchers also hope to learn more about the evolution of the Martian system and the processes that shaped the early solar system.
The mission is a collaboration led by JAXA, with contributions from NASA, the French space agency CNES, the German Aerospace Center and the European Space Agency.
A challenging mission with major scientific ambitions
Landing on Phobos will be difficult because its gravity is extremely weak and its surface contains uneven, rocky terrain. The spacecraft and rover must operate carefully to avoid problems during landing and sampling.
The mission also carries broader technological goals. Developing the ability to navigate around Mars, operate near its moons and return samples to Earth could improve preparations for future deep-space exploration.
The spacecraft’s success will ultimately depend on reaching Mars, completing its scientific operations, collecting useful material and safely returning the sample capsule to Earth.
