TOKYO, Japan / AsiaWire.IO / – A spacecraft from Japan has embarked on a journey to Mars with the goal of studying its two small moons and collecting surface samples, as part of a mission led by the Japan Aerospace Exploration Agency. The Martian Moons eXploration spacecraft, also known as MMX, was launched from the Tanegashima Space Center atop an H3 rocket. The launch occurred just before dawn at 04:41 Japan time on Tuesday, October 20, marking the start of a five-year mission that aims to deliver a robotic lander and rover to Phobos.
Phobos, which is the larger and closer of Mars’ two moons, is the primary target of the mission, with expectations that MMX will become the first spacecraft to orbit Phobos and to retrieve samples from its surface. Additionally, it is set to be the first mission to send material back to Earth from the Mars system. The project is a collaborative effort led by JAXA, working together with NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The launch was successful as planned, and confirmation of spacecraft separation was subsequently received.
The central question driving the mission is the origin of Mars’ moons, with two main hypotheses under consideration. The giant impact theory suggests they formed after a large body collided with Mars, while the capture hypothesis proposes they are asteroids from the outer Solar System captured by Mars’ gravity. JAXA has indicated that remote sensing and detailed analysis of the samples returned will provide crucial insights into their formation history.
International partners contribute rover and scientific instruments
A small rover named IDEFIX, provided by CNES and DLR, weighing less than 30 kg, is designed to land on Phobos prior to the main spacecraft. It will study how the surface responds to mechanical interactions and test wheeled movement. In addition, NASA supplied a neutron and gamma-ray spectrometer called MEGANE. CNES also played a role in developing an infrared spectrometer and is providing expertise in flight dynamics. Overall, the spacecraft carries seven scientific instruments to support its mission objectives.
ESA contributed deep space communication hardware, including a transponder and power amplifier, and will support the mission through its Estrack network of ground stations. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher for its excellent performance in delivering the spacecraft. Meanwhile, ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on their successful launch.
Sample retrieval expected to occur in 2031
It is anticipated that MMX will arrive at Mars approximately one year after launch, with ESA estimating a summer arrival next year. The spacecraft will first observe Phobos from a quasi-satellite orbit and examine potential landing sites before descending to the surface to collect at least 10 grams of material. Its coring sampler, mounted on a robotic arm, can reach depths greater than 2 cm into the regolith, while a pneumatic sampler employs pressurized gas to push soil into a container.
Following its surface operations, MMX will fly by Mars’ smaller moon, Deimos, before embarking on a roughly one-year journey back to Earth. The sample return capsule is scheduled to bring the material home in 2031, with recovery efforts planned in Australia. The mission was approved in 2020, initially targeting a 2024 launch, but the schedule was later shifted to 2026.