Japan has launched its Martian Moons eXploration probe, known as MMX, on a long journey to bring back pieces of Mars' moon Phobos. An H3 rocket lifted off from Tanegashima on October 20, 2026, Japan time, which was October 19 in UTC, and the spacecraft separated from the upper stage about 71 minutes later, as planned. The probe is due to reach Mars in August 2027 and begin orbiting Phobos in September 2027. It will then deploy a rover and collect at least 10 grams of surface material from two sites using coring and pneumatic samplers, before returning the samples to Earth in 2031. NASA, ESA, France's CNES and Germany's DLR are all contributing instruments and expertise to the mission.

The launch is only the first step, and sample collection is not expected before December 2028. If everything goes to plan, MMX would be the first sample return from the Martian system, ahead of China's Tianwen-3, which is planned for around 2028. The samples could help scientists answer a big question, which is whether Mars' moons are captured asteroids or were formed from debris after a giant impact, and they could also shed light on how the solar system formed. The launch also matters for the H3 rocket itself, because this is its first interplanetary mission, coming after the rocket's failure last December. A long, risky road still lies ahead, but for now Japan has cleared the first big hurdle in a race to bring home material from another world.