TOKYO, Japan / AsiaWire.IO / – The Japan Aerospace Exploration Agency has initiated a mission to explore Mars’s two small moons and retrieve samples, sending the Martian Moons eXploration spacecraft, known as MMX, into space. The spacecraft was launched atop an H3 rocket from the Tanegashima Space Center. The launch occurred before dawn at 04:41 Japan time on Tuesday, October 20, marking the start of a five-year project to land a robotic probe and a rover on Phobos.
Phobos, the larger and nearer of Mars’s two moons, is the primary target of the mission. MMX is anticipated to become the first spacecraft to orbit Phobos and to collect samples from its surface. It also aims to be the first mission to return to Earth from the Mars system. JAXA leads this international effort, working alongside NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The launch proceeded as planned, and spacecraft separation was subsequently confirmed.
A key goal of the mission is to shed light on the origins of Mars’s moons, a question that has puzzled scientists for years. One hypothesis, the giant impact theory, proposes they formed after a collision between Mars and a large celestial body. Alternatively, the capture hypothesis suggests that they are asteroids from the outer Solar System that were gravitationally captured by Mars. JAXA states that remote sensing and detailed analysis of the samples returned will help determine their true origins.
International Collaboration Provides Rover and Scientific Instruments
The small rover IDEFIX, supplied by CNES and DLR and weighing less than 30 kg, will land on Phobos prior to the main spacecraft. Its purpose is to study how the surface responds to mechanical interactions and to test wheeled movement. NASA contributed the MEGANE neutron and gamma-ray spectrometer, while CNES helped develop an infrared spectrometer and provides expertise in flight dynamics. In total, the spacecraft carries seven scientific instruments.
ESA contributed deep space communication tools, 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 performing outstandingly in launching the spacecraft. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the successful launch.
Sample Return Scheduled for 2031
The MMX spacecraft is expected to arrive at Mars roughly one year after launch, with ESA indicating a possible arrival next summer. It will orbit Phobos in a quasi-satellite orbit, survey potential landing sites, and then land to collect at least 10 grams of surface material. Its coring sampler, mounted on a robotic arm, can access regolith deeper than 2 cm, while a pneumatic system uses pressurized gas to push soil into a collection container.
Following its activities on Phobos, MMX will perform a flyby of Mars’s smaller moon, Deimos. It will then depart from the Mars system for a return trip lasting about one year. 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 targeted for a 2024 launch, but schedule adjustments moved the launch window to 2026.