Japan launched the uncrewed Martian Moons Exploration spacecraft at 4:41 a.m. local time on Tuesday, October 20, 2026, targeting a 10-gram sample return from the Martian moon Phobos. The 4,480-kilogram spacecraft lifted off aboard an H3 rocket from the Tanegashima Space Center in Kagoshima Prefecture, according to Kyodo News via AP, aiming to become the first national mission to bring back material from Mars’ orbital system.
H3 Rocket Provides Thrust for Successful Spacecraft Separation
The mission relies on the H3 rocket number 10, which features a two-engine configuration and four solid-fuel boosters. This setup provides the highest thrust capacity in the H3 family, a critical upgrade after the vehicle’s initial failure in 2023 when a second-stage engine failed to ignite. Infoquest reported that the spacecraft successfully separated from the rocket roughly one hour and 11 minutes after liftoff, entering its designated trajectory without incident.
Project managers confirmed that telemetry data showed the craft operating in a stable condition after separation.
IDEFIX Rover Will Explore Phobos in 2027
The spacecraft is scheduled to reach the Martian system in August 2027. Once it arrives, it will enter orbit around Phobos, the larger of Mars’ two irregularly shaped moons, which orbits roughly 6,000 kilometers above the Martian surface and spans 20 to 30 kilometers across.
A miniature rover named IDEFIX, developed jointly by France and Germany, will detach from the main spacecraft to explore the surface of Phobos directly. The mission will then observe Deimos, the smaller Martian moon, before firing its engines to leave Martian orbit in November 2030.
Samples Will Reveal How Martian Moons Formed
Scientists want to determine whether Phobos and Deimos formed from debris after a giant impact with Mars or if they are captured asteroids pulled into orbit by planetary gravity. Resolving this debate will help researchers understand how rocky planets develop environments capable of supporting life.
NASA Science Mission Directorate head Nicky Fox congratulated the Japan Aerospace Exploration Agency during a live broadcast, stating that the samples will lead to paradigm-shifting scientific discoveries about the Martian system as NASA prepares its own crewed missions to the red planet.
More on Phobos
Japan has launched a five-year uncrewed mission to collect samples from Phobos, one of the two moons of Mars, and return them to Earth by 2031.If successful, it would be the first to bring back samples from a Martian moon. pic.twitter.com/csWQuYbUHI
