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, using an H3 rocket from the 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 aims to place a robotic probe and a rover on Phobos.
Phobos, the larger and nearer of Mars’ two moons, is the primary target. MMX is anticipated to be the first spacecraft to orbit Phobos and the first to collect samples from its surface. Additionally, it aims to be the inaugural mission to return material to Earth from the Mars system. JAXA is leading this effort, collaborating with NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The rocket’s flight proceeded as planned, and confirmation of spacecraft separation was subsequently received.
A key question the mission seeks to answer concerns the origins of Mars’ moons. One hypothesis, the giant impact theory, suggests they formed after a massive body collided with Mars. Alternatively, the capture hypothesis proposes they are asteroids from the outer Solar System that were gravitationally captured by Mars. JAXA states that remote-sensing data and detailed analysis of the returned samples will shed light on their true origins.
International Collaboration Provides Rover and Scientific Instruments
The small rover IDEFIX, supplied by CNES and DLR, weighs less than 30 kg. It will land on Phobos prior to the main spacecraft, designed to study the surface’s mechanical response while testing wheeled mobility. NASA contributed the MEGANE neutron and gamma-ray spectrometer, while CNES assisted in developing an infrared spectrometer and offers expertise in flight dynamics. The spacecraft carries a total of seven scientific instruments.
Deep space communication equipment, including a transponder and power amplifier, was supplied by ESA. The agency will also support the mission through its Estrack ground station network. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher, describing its performance as “fantastic” in sending the spacecraft on its trajectory. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the successful launch.
Sample Return Scheduled for 2031
Following launch, MMX is expected to arrive at Mars roughly one year later, with ESA estimating its arrival next summer. The spacecraft will orbit Phobos in a quasi-satellite orbit, conducting surveys of potential landing sites. It will then descend to the surface, collecting at least 10 grams of material. A robotic arm equipped with a coring sampler can access soil deeper than 2 cm, while a pneumatic system uses pressurized gas to push soil into a container.
After completing its surface work on Phobos, MMX will perform a flyby of Mars’ other moon, Deimos. Subsequently, it will depart the Mars system and spend about a year returning to Earth. The sample return capsule is planned to deliver its cargo in 2031, with recovery operations set to occur in Australia. The mission was approved in 2020 and was initially scheduled for launch in 2024, but the timeline was later adjusted to 2026.