Japan has launched a spacecraft to Mars to study its mysterious moons and, for the first time, bring soil samples from one of them back to Earth. The launch took place on Tuesday from the spaceport on Tanegashima Island, and an hour after the spacecraft separated from the rocket, specialists announced success.
The mission is led by the Japan Aerospace Exploration Agency (JAXA). The project is called MMX, from the English Martian Moons eXploration. Five space agencies from around the world are taking part. The mission costs $578 million, of which Japan is contributing $350 million, NASA $87 million, the French space agency about $68 million, the German agency roughly $56 million, and the European agency another $17 million.
The main target is Phobos, the larger and closer of Mars's two tiny moons. It is an irregular lump about 22 km across, shaped like a potato. Scientists hope to understand how Phobos and Deimos formed: they may have formed after Mars collided with a large celestial body, or they may be asteroids captured by gravity.
The 4.5-tonne spacecraft is due to reach Mars by the end of next summer. It will then enter an orbit synchronized with Phobos's orbit and release the French-German rover Idefix, named after the white terrier from the Asterix comics. About the size of a microwave oven, it will descend to the surface on its own, bounce for several minutes in very weak gravity and only then come to a stop.
The rover will be able to right itself if it lands upside down, but it will not cope if it gets stuck in soft soil or trapped between rocks, said Julien Baruch, a representative of the French space agency. Once the solar panels are deployed, it will no longer be able to right itself, so the rover will move extremely slowly, at 1 mm per second. For 100 days it will act as a "safety scout" so that Japanese operators can choose a flat spot for the main spacecraft to land.
The lander itself, a four-legged stationary vehicle, will spend only two hours on Phobos. During that time it is to drill and collect at least 10 grams of soil in a vacuum container, after which it will launch back. The spacecraft will then make a series of flybys of Deimos and in 2030 leave the vicinity of Mars to deliver the samples to the Australian desert in 2031.
So far no one has managed to obtain samples from either Mars or its moons. NASA has successfully landed nine spacecraft on Mars over 50 years, and China landed in 2021, but no one has reached Phobos and Deimos. Japan has an advantage: it has already returned samples from asteroids twice. Russia tried three times to send missions to Phobos, but all attempts failed.
Scientists hope to find traces of Martian material on Phobos; this would yield two results at once: it would help clarify the formation of planets and moons and possibly the origin of life. According to Markus Grebenstein, a representative of the German space agency, this is a "once-in-a-lifetime chance." China plans its own Mars sample return mission for 2028, also with delivery in 2031, so Japan and China could end up neck and neck in this race.