TOKYO, Japan / AsiaWire.IO / – The Japan Aerospace Exploration Agency (JAXA) launched the Martian Moons eXploration spacecraft, known as MMX, on an H3 rocket from the Tanegashima Space Center. Liftoff occurred before dawn at 04:41 Japan time on Tuesday, October 20, marking the start of a five-year mission to land a robotic craft and rover on Phobos.
Phobos, the larger and closer of Mars’ two moons, is the primary focus of MMX, which is anticipated to be the first spacecraft to orbit Phobos and retrieve surface samples. It also aims to be the first mission to bring material back to Earth from the Mars system. The project is led by JAXA, in partnership with NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The rocket launched successfully, and spacecraft separation was subsequently confirmed.
One of the main scientific goals is to explore the longstanding debate over the origins of Mars’ moons. The giant impact hypothesis suggests they formed after a collision with a large body, while the capture hypothesis proposes they are asteroids from the outer Solar System captured by Mars’ gravity. JAXA states that remote-sensing data and detailed analysis of the collected samples will help clarify their true origin.
International collaborations contribute rover and scientific tools
A small rover named IDEFIX, weighing less than 30 kg, was provided by CNES and DLR. It will land on Phobos prior to the main spacecraft and is designed to study how the surface reacts to mechanical interaction while testing wheeled mobility. NASA contributed the MEGANE neutron and gamma-ray spectrometer, and CNES also assisted in developing an infrared spectrometer. Additionally, CNES supplies expertise in flight dynamics. In total, the spacecraft carries seven scientific instruments.
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, stating it performed “fantastically” in sending the spacecraft on its journey. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the successful launch.
Sample retrieval and return scheduled for 2031
The spacecraft is expected to arrive at Mars approximately one year after launch, with ESA estimating an arrival next summer. MMX will orbit Phobos in a quasi-satellite trajectory, surveying potential landing sites before touching down. It will then collect at least 10 grams of surface material using a coring sampler capable of reaching depths over 2 cm and a pneumatic system that pushes soil into a container.
Following its surface operations, MMX will perform a flyby of Mars’ smaller moon, Deimos. Afterwards, it will depart Mars’ vicinity for a roughly one-year journey back to Earth. The sample return capsule is scheduled to deliver its cargo in 2031, with recovery efforts planned in Australia. The mission was approved in 2020, initially targeting a 2024 launch, but the schedule was shifted to 2026 before the latest timeline.