Japan to launch first mission to retrieve Mars moon samples

The Japan Aerospace Exploration Agency said the flagship H3 rocket is scheduled to blast off from the Tanegashima Space Center at 4:41 am local time on Tuesday, carrying the unmanned Martian Moons eXploration probe toward the Red Planet. If successful, the spacecraft will arrive near Mars in August next year, where it will orbit Phobos before conducting a landing operation to collect at least 10 grams of surface material during its three-year mission.

Origins of the Martian Moons

JAXA hopes the mission will reveal how Mars and its two moons formed, testing competing theories about their origin. One hypothesis suggests Phobos and Deimos formed after a celestial body collided with Mars in a "giant impact," while the alternative "capture" theory postulates they are asteroids pulled in by Martian gravity. Determining which theory is correct will help reveal "how a habitable environment for life might have arisen on the terrestrial planets," JAXA said, referring to the four rocky worlds closest to the Sun.

International Context and Future Exploration

The mission represents a collaboration with US and European space agencies, as well as numerous universities and technology companies, aiming to lay groundwork for eventual human exploration. JAXA noted the project will explore using Phobos as a "natural space station" by establishing requirements for a round trip deemed essential for crewed Mars missions. The effort comes as NASA's sample return mission was effectively cancelled by the Trump administration in January, while China's Tianwen-3 spacecraft is scheduled for launch around 2028 with hopes of returning Mars samples by 2031.