Japan is set to launch the Martian Moons eXploration (MMX) mission in 2026, with the primary objective of reaching Phobos, one of Mars’ moons, to collect soil samples and return them to Earth. If successful, this will mark the first landing of a spacecraft on Phobos, potentially providing insights into its origin and paving the way for future human missions to Mars.
MMX is notable as the first international space mission led by the Japan Aerospace Exploration Agency (JAXA), with contributions from NASA (United States), CNES (France), DLR (Germany), and the European Space Agency (ESA). The mission aims to clarify the origins of Mars’ moons, Phobos and Deimos, which remain uncertain. Two primary theories exist: either these moons are remnants of Mars that broke off due to a collision with another celestial body billions of years ago, or they are asteroids captured by Mars’ gravity from the outer solar system.
To investigate these theories, MMX will gather samples from Phobos’ surface and conduct remote sensing observations. Scientists hope this will enhance understanding of Mars, its moons, and the Martian atmosphere.
Mission Details
The spacecraft is currently at the Tanegashima Space Center in Japan, where preparations for the launch are underway. If all goes according to plan, the launch is scheduled for late 2026, likely in November or December. The launch window to Mars opens approximately every 26 months due to the differing orbital speeds of Earth and Mars, which affects their relative positions.
Following the launch, the spacecraft will travel to Mars for about a year, with MMX expected to enter the planet’s orbit in 2027 and commence studies of Phobos. The spacecraft will create 3D maps of the moon’s surface, analyze soil composition, search for safe landing sites, and investigate dust and particles surrounding Mars.
Equipped with high-resolution cameras, the spacecraft will capture detailed images of Phobos’ surface. Some of the mission’s technology has been provided by NASA and CNES.
The most challenging aspect of the mission will be landing on Phobos, which has a very weak gravitational pull. As a result, the spacecraft risks bouncing off the surface if it lands too forcefully.
For sample collection, MMX will employ two systems: one will drill into the surface, while the other will utilize gas to lift dust and small particles into a container.
A small rover, developed by Germany and France, will also be deployed on Phobos to traverse its surface for at least 100 days.
According to the mission timeline, MMX will land on Phobos in 2029 to collect samples. The spacecraft is scheduled to leave Mars’ orbit in 2030 and return to Earth, with the sample capsule expected to arrive in 2031.
Yasuhiro Kawakatsu, the project manager, describes MMX as an ambitious plan. He stated,
“Phobos remains an unexplored territory for humanity. By delivering samples from Phobos, we hope to clarify the formation of Mars’ moons, the evolution of the Mars system, and the origins of water and organic materials found on terrestrial planets. We will also develop the necessary exploration technologies for future crewed missions.”
Context on Mars Research
Mars has long been a focal point for astrobiological research due to its similarities to early Earth. Investigations into the potential for life on Mars began in the 19th century and continue today. Early studies relied heavily on telescopic observations and hypotheses, while contemporary missions focus on examining water, organic compounds, soil composition, and atmospheric conditions.
The planet’s surface has remained largely unchanged for over 3.5 billion years, providing a unique opportunity to study conditions that may have fostered life. Currently, there is no evidence confirming the existence of life on Mars, either in the past or present, leaving the question open.
Modern research, particularly through NASA missions, aims to find traces of ancient microbial life, organic materials, and evidence of habitable environments that may have existed on the planet. MMX represents a new phase in Martian exploration, with a primary goal of returning samples to Earth. In addition to the Japanese mission, China is developing the Tianwen-3 mission, scheduled for launch in 2028, which aims to return at least 500 grams of Martian surface samples. NASA continues to operate the Perseverance rover, which is collecting rock samples in Jezero Crater, potentially contributing to an international program for returning Martian soil to Earth in the future.
Japan's MMX mission, set for a 2026 launch, aims to explore Mars' moon Phobos and return soil samples to Earth. This international collaboration seeks to enhance understanding of the origins of Martian moons and the planet itself.