TOKYO, Japan / AsiaWire.IO / – The launch of Japan’s Martian Moons eXploration spacecraft marks a significant step toward uncovering the origins of Mars’ two small moons and retrieving surface samples. The Japan Aerospace Exploration Agency sent the MMX spacecraft into space aboard an H3 rocket from the Tanegashima Space Center, with liftoff occurring before dawn at 04:41 Japan time on Tuesday, October 20. Over the course of five years, the mission aims to deploy a robotic lander and a rover on Phobos.
Phobos, the larger and closer moon of Mars, is at the center of this ambitious mission. MMX is anticipated to become the first spacecraft to orbit Phobos and to collect samples from its surface, as well as the first to return material to Earth from the Mars system. The project 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 confirmed afterward.
A primary goal of the mission is to resolve longstanding questions regarding the formation of Mars’ moons. One hypothesis, the giant impact theory, suggests they formed following a collision between Mars and a massive body. Alternatively, the capture hypothesis proposes they are asteroids from the outer Solar System that Mars gravitationally captured. JAXA states that remote-sensing observations and detailed analysis of the collected samples will help determine their true origins.
International partners contribute rover and scientific instruments
CNES and DLR supplied a compact rover named IDEFIX, weighing under 30 kg. This rover will land on Phobos before the main spacecraft, primarily to study how the surface responds to mechanical interactions and to test wheeled mobility. NASA contributed a neutron and gamma-ray spectrometer called MEGANE, while CNES assisted with developing an infrared spectrometer and provided expertise in flight dynamics. The spacecraft carries a total of seven scientific instruments.
Deep space communication hardware was supplied by ESA, including a transponder and power amplifier. ESA will also support the mission through its Estrack network of ground stations. ESA project scientist Elliot Sefton-Nash praised Japan’s H3 launcher for its excellent performance in sending the spacecraft on its journey. Carole Mundell, ESA Director of Science, congratulated JAXA and the MMX team on the successful launch.
Sample return scheduled for 2031 after Mars mission
Following its launch, MMX is expected to reach Mars approximately a year later, with ESA estimating arrival next summer. The spacecraft will orbit Phobos in a quasi-satellite orbit and survey potential landing sites. It will then land to collect at least 10 grams of surface material using a coring sampler on a robotic arm capable of reaching depths greater than 2 cm, and a pneumatic sampler that uses pressurized gas to push soil into a container.
Post-sampling, MMX will observe Mars’ smaller moon, Deimos, during a flyby. Subsequently, it will leave the Martian system and embark on a roughly one-year journey back to Earth. The return capsule is scheduled to deliver its samples in 2031, with recovery efforts planned in Australia. The mission was approved in 2020, originally targeting a 2024 launch, but the schedule was later moved to 2026.