TOKYO, Japan / AsiaWire.IO / – A spacecraft from Japan has been launched on a mission to investigate Mars’s two small moons and retrieve samples. The Japan Aerospace Exploration Agency sent the Martian Moons eXploration spacecraft, known as MMX, into space atop an H3 rocket from the Tanegashima Space Center. The launch occurred just before dawn at 04:41 Japan time on Tuesday, October 20. The five-year expedition aims to deploy a robotic lander and a rover on Phobos.
Phobos, the larger and nearer moon of Mars, is the primary target of the mission. MMX is anticipated to be the first spacecraft to orbit Phobos and to gather samples from its surface, aiming also to be the first mission to return material to Earth from the Mars system. JAXA is leading the project with partnerships involving NASA, the French space agency CNES, the German Aerospace Center DLR, and the European Space Agency. The launch was successful as planned, with spacecraft separation confirmed later.
A key goal of the mission is to resolve questions about the origins of Mars’s moons. One hypothesis, the giant impact theory, suggests they formed after a massive collision with Mars. Alternatively, the capture hypothesis proposes that they are asteroids from the outer Solar System captured by Mars’s gravity. JAXA states that remote sensing and detailed analysis of the returned samples will help determine their true origin.
International partners contribute rover and scientific instruments
The small rover IDEFIX, supplied by CNES and DLR, weighs less than 30 kg and will land on Phobos before the main spacecraft. Its purpose is to study surface responses to mechanical interaction and test wheeled mobility. NASA provided a neutron and gamma-ray spectrometer called MEGANE, while CNES helped develop an infrared spectrometer and provides flight dynamics expertise. The spacecraft is equipped with a total of seven scientific instruments.
ESA contributed deep space communication tools, 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 its excellent performance in sending the spacecraft on its trajectory. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the successful launch.
Sample return scheduled for 2031 after Mars mission
Expected to arrive at Mars roughly one year post-launch, ESA anticipates the spacecraft reaching the planet next summer. During its orbit, MMX will survey Phobos, identify potential landing sites, and eventually land to collect at least 10 grams of surface material. Its coring sampler can reach depths beyond 2 cm into the regolith, while a pneumatic system uses pressurized gas to push soil into a container.
Following its surface work on Phobos, MMX will fly past Mars’s smaller moon, Deimos, before heading back to Earth in about one year. The sample return capsule is planned to deliver its cargo in 2031, with recovery efforts set in Australia. Originally scheduled for a 2024 launch, the mission was approved in 2020 and later rescheduled to 2026.