Japan Launches Spacecraft to Mars' Mysterious Moons for Soil Sample Mission
The ambitious five-year mission aims to collect samples from Phobos, one of Mars' two small moons, and return them to Earth.
A Japanese spacecraft embarked on a five-year mission toward Mars on Tuesday, with the ambitious goal of exploring the planet's two small moons and bringing soil samples back to Earth.
The Japan Aerospace Exploration Agency (JAXA) launched the spacecraft before dawn from the Tanegashima Island spaceport. Officials confirmed the mission's success about an hour later when the spacecraft successfully separated from the rocket's upper stage, leading to applause and celebration among flight controllers.
This mission, dubbed MMX (Martian Moons Exploration), is a collaborative effort involving five international space agencies. The spacecraft is scheduled to reach Mars by late next summer. Its primary objective is to attempt a landing on Phobos, the larger and closer of Mars' two moons, using a robotic prospector and a rover.
While NASA has a history of successful Mars landings and China achieved a touchdown in 2021, no spacecraft has yet landed on Phobos or its companion moon, Deimos. Furthermore, no mission has successfully collected and returned samples from the Martian moons.
If the MMX mission succeeds, fragments of dust, soil, and rock from Phobos are expected to arrive on Earth in 2031. This endeavor builds on Japan's prior success with two asteroid sample return missions.
The $578 million mission features a 5-ton spacecraft that will orbit Mars and then maneuver to Phobos. It will deploy a small, four-wheeled rover named Idefix, which is designed to hop across the moon's surface in its low gravity. Idefix will act as a scout for approximately 100 days, identifying a safe landing zone for the mothership.
The stationary lander is slated to descend to Phobos' surface in late 2028 or 2029. It will spend about two hours collecting at least 10 grams of material through drilling and vacuuming before launching back into space. The lander will also conduct flybys of Deimos before departing the Martian system in 2030.
Scientists hope that studying samples from Phobos will shed light on the formation of Mars' moons, potentially revealing whether they originated from the debris of an ancient collision or are captured asteroids. The samples may also contain traces of Mars itself, offering insights into planetary and moon formation processes and potentially the origins of life.
This mission is considered particularly challenging due to the moons' namesakes—Phobos, meaning fear, and Deimos, meaning dread—and past mission failures. Russia, for instance, experienced multiple setbacks in its attempts to reach Phobos. This mission's success would represent a significant achievement for JAXA and its international partners, including NASA, the French Space Agency, the German Space Agency, and the European Space Agency.
Japan is not the only nation with Martian sample return ambitions. China plans its own mission in 2028, and NASA is still determining how to retrieve samples collected by its Perseverance rover. Both Japan and China are targeting a sample return to Earth in 2031, potentially setting up a scientific race.
Japan is investing $350 million in the MMX mission, with significant contributions from its international partners. NASA is contributing $87 million, the French Space Agency approximately $68 million, the German Space Agency around $56 million, and the European Space Agency about $17 million.