Japan’s MMX Mission Launches to Retrieve First Samples from Mars’ Moon Phobos

Key points

• JAXA launched the MMX spacecraft on an H3 rocket from Tanegashima Space Center, targeting a five-year mission to Phobos.
• The mission will arrive at Mars in August 2027, orbit Phobos for three years, and land to collect at least 10 grams of surface and subsurface samples.
• Samples will be returned to Earth in 2031, with NASA curating approximately 15% of the material at its Johnson Space Center.
• The mission aims to determine if Phobos and Deimos are captured asteroids or debris from a giant impact on Mars, and may contain traces of Martian dust.
• The spacecraft includes a French-German rover (Idefix) and sampling devices from NASA and JAXA, with international support from ESA and others.

Background

This mission follows decades of failed attempts to land on Phobos, including a 2011 Russian mission. It is part of a broader trend in planetary exploration, with China’s Tianwen-3 mission also targeting Mars sample return by 2031. The MMX mission builds on previous Mars missions but is the first to focus on the moons, which have remained largely unexplored since the 1960s.

How outlets are covering it

The Guardian emphasizes the mission’s potential to inform future manned Mars missions and highlights the international collaboration, including NASA’s sampling device and ESA’s communication support. NASA Science focuses on the scientific significance of the samples, noting that they could resolve the origin of the moons and provide insights into the early solar system. NHK reports on the technical details, such as the four-legged landing gear and the cost of 55.3 billion yen, while New Scientist highlights the debate over the moons’ origins and the possibility of finding Martian material in the samples. All sources agree on the mission’s timeline and goals but differ in emphasis: The Guardian and NASA focus on the broader implications for human exploration, while NHK and New Scientist focus on the technical and scientific aspects.

Why it matters

The MMX mission could resolve a century-old debate about the origin of Mars’ moons and provide insights into the early solar system. The samples may contain traces of Martian material, offering clues about the planet’s history and the potential for past microbial life. The mission also tests technologies for future manned Mars missions, such as low-gravity landing and sampling techniques.

What to watch

The MMX spacecraft will arrive at Mars in August 2027, begin orbiting Phobos, and land to collect samples in late 2028 or early 2029. The samples will be returned to Earth in 2031, with NASA curating a portion of the material. The mission will also observe Deimos and test the Idefix rover on Phobos’ surface.