Japanese scientists are readying a mission to Mars’ moons to retrieve samples that could help unlock the origins of the solar system and life on Earth, in what aims to be the first round trip to the Martian region.
The uncrewed Martian Moons eXploration (MMX) probe, a collaboration with US and European space agencies, as well as numerous 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 tomorrow at 4:41am, the Japan Aerospace Exploration Agency (JAXA) said.
Martian Moons eXploration project manager Yasuhiro Kawakatsu speaks to reporters in front of a spacecraft at the Tanegashima Space Center in Minamitane, Japan, on Aug. 13.
Photo: AFP
“Being able to be involved in such a grand mission is incredibly exciting,” JAXA’s H3 rocket team project manager Makoto Arita told reporters yesterday.
The spacecraft would arrive near Mars in about August next year, where it would orbit one of its moons, Phobos, before landing and collecting at least 10g of material from the surface during three years of operating within the Martian sphere.
A rover dubbed Idefix — the French name for the comic hero Asterix’s dog — would 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,” MMX project manager Yasuhiro Kawakatsu said.
The mission would also 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,” JAXA said.
It would also observe the Red Planet’s moon Deimos, although it would not land on it, before returning to Earth.
JAXA hopes the mission would 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.
Meanwhile, the “capture” hypothesis postulates that the moons are asteroids captured by Mars’ gravity.
Determining which theory is correct would 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.
MMX is a collaboration with NASA, the European Space Agency, France’s National Center for Space Studies, the German Aerospace Center, 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 said.
Japan’s uncrewed 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 uncrewed Hayabusa-2, which returned 5.4g of rock and dust collected from an asteroid several hundred million kilometers from Earth in 2020.
On the upcoming mission “we have to travel very close to Mars and return,” which means escaping the planet’s heavy gravity, Kawakatsu said.
Phobos orbits about 6,000km above the Martian surface.
“Going deep into what we call the ‘gravity well’ is difficult,” Kawakatsu said.
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.
However, the mission was effectively canceled by US President Donald Trump’s administration following a vote by the US Congress in January.
Meanwhile, China has announced its Tianwen-3 spacecraft is scheduled for launch in about 2028 and hopes to return Mars samples to Earth as early as 2031 — potentially before MMX.
Sand and rocks from Phobos might 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, JAXA scientists said.