Japan to launch historic round-trip mission to Mars moon
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The propulsion (left), exploration and return modules of the Martian Moons eXploration spacecraft.
PHOTO: AFP
- Japan will launch the MMX probe on Oct 20 to study Mars moon Phobos and collect at least 10g of sample for the first round trip to the Martian system.
- The mission with NASA, ESA, CNES, DLR and others will test whether Phobos and Deimos formed by a giant impact or by capture, and may explain how life-supporting materials reached rocky planets.
- MMX will orbit Phobos for up to three years, use the IDEFIX rover for safe landing checks, and return to Earth, while Japan faces hard work in Mars gravity and China plans a rival sample mission.
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TOKYO – Japanese scientists are readying a mission to a moon of Mars to retrieve samples that could help unlock the origins of the solar system and life on Earth, in what is aimed to be the first round trip to the Martian region.
The unmanned Martian Moons eXploration (MMX) probe, a collaboration with US and European space agencies as well as universities and tech companies, could also help lay the groundwork for eventual human exploration.
The flagship H3 rocket carrying the MMX is set to blast off from the Tanegashima Space Center on Oct 20 at 4.41am local time, according to the Japan Aerospace Exploration Agency (JAXA).
The spacecraft will arrive near Mars one year later, where it will orbit its moon Phobos for up to three years before landing and collecting at least 10g of material from the surface.
A rover dubbed IDEFIX – the French name for the comic hero Asterix’s dog – will first conduct surface observations aimed at ensuring a safe landing.
“The sampling (from) Phobos is of course the world’s first, but it means... this is the first round trip to the Martian system,” said MMX’s project manager Yasuhiro Kawakatsu.
JAXA said the mission will explore the possibility of using Phobos as a “natural space station” by establishing the requirements for a round trip to Mars – something “essential for crewed Mars exploration”.
It will also observe Mars’ moon Deimos before returning to Earth.
Impact or capture
JAXA hopes the mission will reveal how Mars and its two moons formed, a key piece of knowledge in working out how the solar system was born.
One theory for the origin of the Martian moons – the “giant impact” hypothesis – is that they formed after a celestial body collided with Mars.
The “capture” hypothesis, meanwhile, postulates that the moons are asteroids captured by Mars’ gravity.
Determining which is right will help reveal “how a habitable environment for life might have arisen on the terrestrial planets”, JAXA said, referring to the four rocky worlds closest to the Sun – Mercury, Venus, Earth and Mars.
“MMX will shed light on the transport mechanisms that delivered water, volatiles and organic compounds from the outer solar system to the inner rocky planet region – processes that may have played a key role in making these worlds habitable,” said Patrick Michel, a French astrophysicist working on IDEFIX.
“If Phobos and Deimos are indeed remnants of these early delivery systems, they may hold clues to the origins of life itself or, to be more correct, to the transport of the materials that were key to the emergence of life on rocky planets,” he said.
Deep in the ‘gravity well’
MMX is a collaboration with France’s National Centre for Space Studies, the German Aerospace Center, NASA, the European Space Agency, and about 20 universities and tech companies.
The development of the spacecraft’s landing legs was particularly difficult, as gravity on Phobos is extremely weak, JAXA scientists say.
Japan’s unmanned Smart Lander for Investigating Moon – the “Moon Sniper” – tipped over after touching down on Earth’s Moon in 2024, but still transmitted data and survived several two-week lunar nights.
Japan also has experience in bringing back samples from space, including JAXA’s unmanned Hayabusa2, which returned 5.4g of rock and dust collected from an asteroid several hundred million kilometres from Earth in 2020.
One of the differences between JAXA’s past asteroid probes and the MMX mission is that “we have to travel very close to Mars and return”, which means escaping the planet’s heavy gravity, Kawakatsu told reporters.
Phobos orbits about 6,000km above the Martian surface. “Going deep into what we call the ‘gravity well’ is difficult,” he added.
China’s mission
US and Chinese space agencies have been racing to be the first to return rock samples from Mars’ surface back to Earth.
NASA’s Perseverance rover, which has been roaming the Red Planet since 2021, has already collected samples.
The mission was cancelled by the administration of President Donald Trump following a vote by the US Congress in January.
China, meanwhile, has announced its Tianwen-3 spacecraft is scheduled for launch around 2028 and hopes to return Mars samples to Earth as early as 2031.
JAXA scientists say sand and rocks from Phobos may offer a wider variety of samples than those on the planet itself, especially if it was formed by a collision between a celestial body and Mars. AFP