# Japan Launches Historic MMX Mission to Retrieve Martian Moon Samples The H3 rocket mission aims to solve the mystery of Phobos' origins by 2031. - **Source:** [Slashdot](https://brifing.si/source/0f34d58e-1ccd-45a6-ab82-2de4065dc7ad) - **Published:** 2026-10-20 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/9708e21b-ed42-45fc-afce-3f4197a98b19 ## Successful H3 Rocket Launch Japan successfully launched the MMX mission using its two-stage H3 rocket, developed by JAXA and Mitsubishi Heavy Industries. The 63-meter vehicle followed a nominal trajectory over the Pacific Ocean, jettisoning its four solid boosters within two minutes. This launch marks the tenth flight of the H3 system, confirming its operational reliability for deep-space exploration. ## Mission Objectives and Timeline The spacecraft is currently on a ten-month transit toward Mars, with arrival scheduled for August 2027. Once in the Martian system, MMX will spend three years conducting scientific observations. The primary goal is to land on Phobos, collect surface samples, and return them to Earth, with a planned landing in Australia by 2031. ## Orbital Insertion and Navigation Upon reaching the Martian system, the propulsion module will execute an orbital insertion burn to enter a quasi-satellite orbit around Phobos. This specific positioning allows the spacecraft to remain within the moon's immediate vicinity while both bodies circle Mars. This complex maneuver is essential for the subsequent mapping campaigns and the eventual surface touchdown. ## IDEFIX Rover Deployment The mission includes the IDEFIX rover, a collaborative project between French and German space agencies. Scheduled for deployment in late 2028 or early 2029, the rover will explore the surface of the 22-kilometer-wide moon. This deployment provides critical ground-level data to support the selection of optimal landing sites for the primary MMX sample-collection phase. ## Sample Collection Mechanism MMX will perform two separate touchdowns on the surface of Phobos to gather geological material. These samples will be stowed securely within the spacecraft's return capsule. After completing the collection, the craft will briefly return to its quasi-satellite orbit before transitioning to a more elongated trajectory that intersects with the smaller moon, Deimos. ## Deimos Flyby Operations During the final months of its mission, MMX will conduct a series of flybys around Deimos, which measures only 14 kilometers in diameter. These maneuvers allow for extensive mapping and data collection before the spacecraft departs the Martian system. The mission is set to leave for Earth in November 2030, concluding its orbital research phase. ## Scientific Significance of Origins Scientists aim to resolve a decades-old mystery regarding whether Phobos and Deimos formed from a giant impact or were captured asteroids. By analyzing physical samples returned directly to Earth, researchers expect to gain definitive insights into the moons' formation history. This data will refine current planetary science models regarding the evolution of the Martian system. ## Strategic Aerospace Collaboration The MMX mission highlights the integration of Japanese launch technology with international scientific cooperation. By utilizing the H3 rocket for deep-space logistics, JAXA demonstrates a robust capability in interplanetary mission architecture. The successful return of the capsule in 2031 would represent a significant milestone in robotic sample-return technology and planetary exploration capabilities. ## Sources covering this story - https://science.slashdot.org/story/26/10/20/0522251/japan-launches-historic-mmx-sample-return-mission-to-mars-moon-phobos?utm_source=rss1.0mainlinkanon&utm_medium=feed — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._