TOKYO, Japan / AsiaWire.IO / – A spacecraft from Japan has embarked on a journey to Mars with the goal of investigating its two small moons and retrieving samples. The Japan Aerospace Exploration Agency launched the Martian Moons eXploration spacecraft, known as MMX, aboard an H3 rocket from Tanegashima Space Center. The launch occurred just before dawn at 04:41 Japan time on Tuesday, October 20. Over the next five years, the mission plans to land both a robotic spacecraft and a rover on Phobos.
Phobos, the larger and closer moon of Mars, is the primary target. MMX aims to become the first spacecraft to orbit Phobos and to collect samples from its surface. It also seeks to be the first mission to return material to Earth from the Mars system. JAXA leads this international effort, collaborating with NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The rocket launched successfully as planned, and spacecraft separation was confirmed afterward.
The main goal of the mission is to resolve a long-standing debate about the origins of Mars’s moons. One hypothesis, the giant impact theory, suggests they formed after a large body collided with Mars. The alternative, the capture hypothesis, proposes they are asteroids from the outer Solar System captured by Mars’s gravity. JAXA states that remote sensing and detailed analysis of the samples returned will help determine their true origins.
International partners contribute rover and scientific tools
CNES and DLR supplied a small rover named IDEFIX, weighing less than 30 kg. This rover will land on Phobos ahead of the main spacecraft, testing how the surface reacts to mechanical interaction and wheeled movement. NASA contributed a neutron and gamma-ray spectrometer called MEGANE. Additionally, CNES helped develop an infrared spectrometer and offers expertise in flight dynamics. The spacecraft carries a total of seven scientific instruments.
ESA provided essential deep space communication hardware, including a transponder and power amplifier. It will also support the mission through its Estrack ground station network. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher, saying it performed superbly in sending the spacecraft on its trajectory. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the successful launch.
Sample collection scheduled for 2031 return to Earth
MMX is expected to arrive at Mars approximately one year after launch, with ESA estimating arrival next summer. The spacecraft will observe Phobos from a quasi-satellite orbit and assess potential landing sites. It will then land on the moon, collecting at least 10 grams of surface material. A robotic arm equipped with a coring sampler can reach depths greater than 2 cm into the regolith, while a pneumatic system uses pressurized gas to push soil into a container.
Following its surface work on Phobos, MMX will perform a flyby of Mars’s smaller moon, Deimos. Afterwards, it will depart the Mars system and return to Earth after about a year-long voyage. The sample return capsule is planned to deliver its cargo in 2031, with recovery operations set to take place in Australia. The mission was approved for development in 2020 and was initially scheduled for launch in 2024 before the timeline shifted to 2026.