To Phobos and Back
MMX, short for Martian Moons eXploration, is JAXA's mission to the two small moons of Mars. It launched on an H3 rocket from Tanegashima on 19 October 2026 at 19:41 UTC (20 October in Japan), deployed its solar arrays two days later and is due to reach Mars in August 2027. After surveying Phobos from close range it is to land twice and collect at least 10 grams of its surface, observe Deimos, then head home: the return capsule is due to land in Australia in 2031.
Where Did the Moons of Mars Come From?
Phobos and Deimos may be captured asteroids, or debris thrown up by a giant impact on Mars. Samples studied on Earth could settle the question. MMX carries instruments from Japan, the United States, France and Germany, including a NASA gamma-ray and neutron spectrometer, a second, NASA-provided sampler that uses bursts of gas, and Idefix, a 25 kg rover from the French and German space agencies that is to spend about 100 days driving on Phobos.