TOKYO, Japan / AsiaWire.IO / – A Japanese spacecraft has been launched on a mission to explore Mars’s two small moons and retrieve samples. The Japan Aerospace Exploration Agency deployed the Martian Moons eXploration spacecraft, known as MMX, aboard an H3 rocket from the Tanegashima Space Center. The launch occurred before sunrise at 04:41 Japan time on Tuesday, October 20. The mission, which spans five years, plans to land a robotic probe and a rover on Phobos.
Phobos, the larger and nearer of Mars’s two moons, is the primary target. MMX is anticipated to become 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 to Earth from the Mars system. JAXA leads this effort in partnership with NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The rocket launch proceeded as planned, and spacecraft separation was subsequently confirmed.
This initiative seeks to resolve a long-standing debate about the origin of Mars’s moons. The giant impact hypothesis suggests they formed after a large object collided with Mars, while the capture hypothesis proposes they are asteroids from the outer Solar System that were captured by Mars’s gravity. JAXA states that remote sensing and detailed analysis of the returned samples will shed light on their true origins.
International collaborations provide rover and scientific tools
CNES and DLR contributed a compact rover called IDEFIX, which weighs less than 30 kg. This rover will land on Phobos ahead of the main spacecraft, aiming to study surface reactions to mechanical stimuli and test wheeled mobility. NASA supplied a neutron and gamma-ray spectrometer called MEGANE. CNES also assisted in developing an infrared spectrometer and offers expertise in flight dynamics. In total, the spacecraft is equipped with seven scientific instruments.
ESA contributed deep space communication hardware, including a transponder and power amplifier, and will support the mission through its Estrack ground station network. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher for performing exceptionally well in sending the spacecraft on its trajectory. Additionally, ESA Director of Science Carole Mundell congratulated JAXA and the MMX team for the successful launch.
Sample collection scheduled for 2031 return to Earth
Expected to arrive at Mars roughly one year after launch, ESA estimates the spacecraft will reach its destination next summer. It will observe Phobos from a quasi-satellite orbit and examine potential landing sites. Subsequently, it will land, collecting at least 10 grams of surface material. A robotic arm with a coring sampler can access regolith deeper than 2 cm, while a pneumatic system uses pressurized gas to push soil into a container.
Following its surface operations on Phobos, MMX will fly past Mars’s smaller moon, Deimos, before leaving the planet’s vicinity for a journey of about one year back to Earth. The return capsule is planned to deliver the samples in 2031, with recovery efforts taking place in Australia. The project was approved in 2020, initially scheduled for a 2024 launch, but the timeline was later adjusted to 2026.