Japan launched Mars mission to study Phobos
- Despite their potential importance, Martian moons have never been fully investigated, JAXA planetary scientist and MMX project manager Yasuhiro Kawakatsu told the Associated Press.
- The $578 million mission is a collaborative effort involving space agencies and research institutions from the United States, Europe, Germany, and France, according to the Irish Examiner.
- Exploring Phobos presents severe engineering hurdles due to extreme temperature swings exceeding 360 degrees Fahrenheit in seven hours and a microgravity environment less than one-thousandth of Earth's pull,...
Despite their potential importance, Martian moons have never been fully investigated,
JAXA planetary scientist and MMX project manager Yasuhiro Kawakatsu told the Associated Press. They are known as the most important unclimbed mountains in the solar system.
On Oct. 20, 2026, Japan launched the unmanned Martian Moons eXploration spacecraft aboard an H3 rocket from the Tanegashima Space Center, beginning a five-year mission to land on Phobos and return material to Earth, USA Today reported.
Spacecraft Journey and International Collaboration
The $578 million mission is a collaborative effort involving space agencies and research institutions from the United States, Europe, Germany, and France, according to the Irish Examiner. The five-tonne spacecraft consists of a propulsion module, an exploration module, and a return module, as detailed by the Japan Aerospace Exploration Agency. NASA astrophysicist Tom Statler described the collective excitement surrounding the launch, noting that the project generates significant adrenaline and anticipation. The mission timeline maps out roughly two years of travel to reach Martian orbit by August 2027, followed by three years conducting observations, deploying rovers, and collecting samples from the larger moon.
Phobos Surface Operations and Low Gravity Challenges
Exploring Phobos presents severe engineering hurdles due to extreme temperature swings exceeding 360 degrees Fahrenheit in seven hours and a microgravity environment less than one-thousandth of Earth’s pull, according to USA Today. To prepare for landing, the spacecraft will deploy a 55-pound four-wheeled rover named Idefix, developed jointly by the German Aerospace Center and France’s National Center for Space Studies, as reported by the Irish Examiner. Because gravity on Phobos is so weak, the rover will weigh only about 15 grams on the surface and will bounce for several minutes before beginning a 100-day survey of terrain, minerals, and chemical elements. To secure samples, the main lander will spend approximately two hours utilizing two collection systems—one firing bursts of nitrogen gas to vacuum up surface dust and another drilling several inches below the surface.
Origin Theories and the Search for Solar System Clues
Scientists remain divided on whether Phobos and Deimos formed as captured asteroids pulled in by Martian gravity or as debris ejected from a massive celestial collision with Mars, according to RTE.ie. Determining the correct hypothesis will help researchers understand how habitable conditions arose on terrestrial planets across the early solar system. The spacecraft will also observe the smaller moon, Deimos, during several flybys before departing the Martian system in November 2030, as noted by the Irish Examiner. Initial remote-sensing data will be beamed back in real time by instruments such as the MEGANE spectrometer to detect volatile elements like hydrogen, sodium, and chlorine, CNN reported.
Sample Return Timeline and Global Mars Exploration
After completing its surface work, the MMX spacecraft will release a sample return capsule designed to plunge through Earth’s atmosphere for recovery around 2031, according to CNN. This timeline places the Japanese return effort in a tight international race alongside China’s planned Tianwen-3 mission, which aims to return Martian samples by 2031. Meanwhile, NASA’s Perseverance rover continues to cache samples on the surface of Mars, though its own return mission faced congressional hurdles in January 2026. Data gathered by the MMX mission will also help establish the technical requirements for using Phobos as a natural space station, which JAXA considers essential for future crewed expeditions to the Red Planet.
Markus Grebenstein, the Germany Space Agency’s rover chief, said it was a once-in-a-lifetime chance to be part of the first sample return mission from the Martian system.