TOKYO, Japan / AsiaWire.IO / – Japan has initiated a spacecraft journey aimed at investigating the enigmatic moons of Mars and retrieving samples to bring back to Earth. The Japan Aerospace Exploration Agency launched the Martian Moons eXploration (MMX) probe into space on an H3 rocket from Tanegashima Space Center. The launch occurred before dawn on Tuesday, October 20, at 04:41 local time. This five-year mission is a collaborative effort involving five space agencies.
The mission plans include landing a robotic prospector and rover on Phobos, the larger and closer of Mars’ two small moons. If all goes as planned, it will mark the first time a spacecraft orbits Phobos, collects surface samples, and returns to Earth from the Mars system. JAXA leads this effort, with partners including NASA, France’s CNES, Germany’s DLR, and the European Space Agency. Confirmation of spacecraft separation from the rocket was received after launch.
Scientists aim to clarify the origins of Phobos and Deimos. The giant impact hypothesis suggests the moons formed after a large body struck Mars, whereas the capture hypothesis proposes they are asteroids from the outer Solar System pulled into orbit by Mars’ gravity. Data from orbit and returned surface material are expected to help determine which theory is correct.
Global Partners Provide Rover and Scientific Instruments
The French and German space agencies contributed IDEFIX, a rover weighing less than 30 kg, which will land on Phobos prior to the main spacecraft. Its objectives include testing surface behavior under mechanical interaction and demonstrating wheeled mobility. NASA supplied the MEGANE instrument, a neutron and gamma-ray spectrometer. The spacecraft also carries seven science instruments, including an infrared spectrometer developed jointly with CNES.
Europe’s support extends to communications, with ESA providing a transponder and power amplifier for deep space links. The ESA Estrack ground station network will facilitate command transmission and data reception. ESA Director of Science Carole Mundell congratulated JAXA and the MMX team on the launch. Elliot Sefton-Nash, the project scientist for MMX at ESA, praised the H3 launcher’s performance in propelling the spacecraft.
Sample Return Scheduled for 2031 in Australia
Following its launch, the spacecraft is expected to reach Mars vicinity roughly one year later. It will observe Phobos from a quasi-satellite orbit and assess potential landing sites before descent. Using two tools, MMX will gather at least 10 grams of material: a coring sampler on a robotic arm will target regolith deeper than 2 cm, and a pneumatic sampler will use pressurized gas to push soil into a container.
During a flyby, MMX will also perform observations of Deimos, Mars’ smaller moon. Afterwards, the spacecraft will leave the Mars system for a return journey estimated to take about one year. The capsule containing the samples is planned to return to Earth in 2031, with recovery operations scheduled in Australia. JAXA announced the mission in 2015, and development started in 2020, initially targeting a 2024 launch, which was later rescheduled to 2026.