TOKYO, Japan / AsiaWire.IO / – A spacecraft operated by the Japan Aerospace Exploration Agency has embarked on a journey to Mars with the goal of investigating its two diminutive moons and bringing back samples. The Martian Moons eXploration spacecraft, or MMX, was launched on an H3 rocket from the Tanegashima Space Center. The launch occurred just before dawn at 04:41 Japan time on Tuesday, October 20. This five-year expedition aims to land both a robotic spacecraft and a rover on Phobos.
Phobos, being the larger and closer moon of Mars, is the primary target for this mission. MMX is anticipated to be the first spacecraft to orbit Phobos and to collect samples from its surface. Additionally, it seeks to be the first mission to send material back to Earth from the Mars system. The effort is led by JAXA, in collaboration with 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 scientific question the mission aims to address concerns the origin of Mars’ moons. One hypothesis, the giant impact theory, suggests they formed after a massive collision with Mars. Another, 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 returned samples will help clarify their origins.
International partners contribute rover and scientific instruments
The small rover IDEFIX, provided by CNES and DLR, weighs less than 30 kg and will land on Phobos ahead of the main spacecraft. It is designed to study how the surface responds to mechanical action and to test wheeled movement. The US space agency NASA contributed a neutron and gamma-ray spectrometer called MEGANE. CNES also assisted in developing an infrared spectrometer and is providing expertise in flight dynamics. In total, the spacecraft carries seven scientific instruments.
Deep space communication equipment supplied by ESA includes a transponder and power amplifier, with support for the mission via the Estrack ground station network. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher for its excellent performance in sending the spacecraft on its way. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on a successful launch.
Sample return scheduled for 2031
Following its arrival at Mars approximately one year after launch, ESA expects MMX to reach Phobos by next summer. The spacecraft will orbit Phobos in a quasi-satellite orbit and survey potential landing sites before touching down to collect at least 10 grams of surface material. It features a coring sampler on a robotic arm capable of reaching below 2 cm into the regolith, as well as a pneumatic sampler that uses pressurised gas to push soil into a container.
After completing its surface operations on Phobos, MMX will conduct a flyby of Deimos, Mars’ smaller moon. It will then leave the Martian system for a roughly one-year journey back to Earth. The sample return capsule is scheduled to deliver its cargo in 2031, with recovery planned in Australia. The mission was approved in 2020 and was initially targeted for launch in 2024, but the schedule was later moved to 2026.