Summary
NASA is contributing a science instrument, sample-collection technology and communications support to JAXA’s MMX mission to study Mars’ moons and return a sample from Phobos. The spacecraft is targeting launch on Oct. 19, 2026, with sample return planned for 2031.
NASA will contribute a science instrument, sample-collection technology and communications support to Japan Aerospace Exploration Agency’s (JAXA) Martian Moons eXploration mission, or MMX. The mission aims to study Phobos and Deimos, determine their origins and bring a sample of Phobos back to Earth.
JAXA is targeting launch from Tanegashima Space Center at 3:41 p.m. EDT on Monday, Oct. 19, 2026 (4:41 a.m. JST on Tuesday, Oct. 20), NASA said. The spacecraft is expected to reach Mars in August 2027 and begin surveying its moons.
NASA’s instruments will study Phobos and collect material
One contribution is MEGANE, short for Mars-moon Exploration with Gamma rays and Neutrons. Developed by the Johns Hopkins Applied Physics Laboratory, the instrument will measure neutrons and gamma rays emitted from Phobos’ surface. Those measurements will help scientists determine the moon’s elemental composition, providing clues to what it is made of and how it formed.
NASA is also contributing the Pneumatic Sampler, or P-Sampler, a technology demonstration mounted on a spacecraft landing leg. It is designed to gather surface material by releasing bursts of high-pressure nitrogen gas. The system will complement JAXA’s C-Sampler, which is intended to extract cores from a few inches below the surface.
NASA says it will receive and curate about 15% of the returned sample at the Astromaterials Lab at Johnson Space Center in Houston, making that material available for research for decades. The agency is also providing communications and navigation support through its Deep Space Network and funding U.S. scientists taking part in the mission’s science team.
The mission will test competing ideas about the moons’ origins
Scientists have proposed two main explanations for Phobos and Deimos: they could be debris from a large impact on Mars, or asteroids captured by the planet’s gravity billions of years ago. MMX’s observations and returned Phobos material are intended to help distinguish between these possibilities.
The answer could offer evidence about the early history of the Mars system and the inner solar system. NASA’s MMX program scientist, Tom Statler, said understanding the moons’ origins could also illuminate the period when Earth and other inner planets may have acquired much of their water and organic compounds.
After surveying Phobos in detail, MMX is scheduled to attempt sample collection no earlier than December 2028. The sample is planned to reach Earth in 2031. These are mission plans and target dates; the returned material and its scientific findings are still in the future.