Japan's MMX probe set for historic round trip to Mars moons

Japan's space agency is preparing to launch the Martian Moons eXploration (MMX) probe on a landmark round-trip mission to Mars's moon Phobos, aiming to collect samples that could reveal the origins of the Solar System. The H3 rocket is scheduled to blast off from Tanegashima Space Center on Tuesday

TOKYO: Japanese scientists are readying a mission to Mars's 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 unmanned Martian Moons eXploration (MMX) probe, a collaboration with United States 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 on Tuesday at 4.41am, according to the Japan Aerospace Exploration Agency (JAXA).

"Being able to be involved in such a grand mission is incredibly exciting," Makoto Arita, project manager of JAXA's H3 rocket team, told reporters two days before the launch. The spacecraft will arrive near Mars around August next year, where it will 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 - 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," MMX's project manager Yasuhiro Kawakatsu told AFP.

JAXA said the mission will 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". It will also observe the Red Planet's moon Deimos, although it will not land on it, before returning to Earth.

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's gravity.

Determining which theory is correct 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.

MMX is a collaboration with France's National Centre for Space Studies (CNES), the German Aerospace Center (DLR), NASA, the European Space Agency (ESA), 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 also has experience in bringing back samples from space, including JAXA's unmanned Hayabusa-2, which returned 5.4g of rock and dust collected from an asteroid several hundred million kilometres 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, MMX project manager Yasuhiro Kawakatsu told reporters. Phobos orbits about 6,000km above the Martian surface.

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's gravity.

Determining which theory is correct 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. The mission will 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".

MMX is a collaboration with France's National Centre for Space Studies (CNES), the German Aerospace Center (DLR), NASA, the European Space Agency (ESA), 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 has experience in bringing back samples from space, including JAXA's unmanned Hayabusa-2, which returned 5.4g of rock and dust collected from an asteroid several hundred million kilometres 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, MMX's project manager Yasuhiro Kawakatsu told reporters. Phobos orbits about 6,000km above the Martian surface.

US and Chinese space agencies have been racing to be the first to return rock samples from Mars's surface back to Earth. NASA's Perseverance rover, which has been roaming the Red Planet since 2021, has already collected samples, though the mission was effectively 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 - potentially before the MMX's return.