NASA is playing an important role in JAXA’s (Japan Aerospace Exploration Agency) MMX (Martian Moons eXploration) mission, to advance our understanding of Mars’ moons and build on the agency’s long history of exploring the Red Planet.

The mission aims to characterize and determine the origin of Mars’ moons Phobos and Deimos and deliver a sample of Phobos to Earth. The MMX spacecraft is targeting launch from JAXA’s Tanegashima Space Center in Japan at 3:41 p.m. EDT on Monday, Oct. 19 (4:41 a.m. JST on Tuesday, Oct. 20).

“The samples from MMX will bring forth paradigm-shifting science on the Mars system for generations to come, especially as NASA prepares to send the first humans to Mars,” said Nicky Fox, associate administrator, Science Mission Directorate, NASA Headquarters in Washington. “The NASA-JAXA sample curation partnership is extremely valuable, and I am proud that NASA Science is supporting MMX sample curation and will be sharing portions of these samples for study as we continue to expand humanity’s understanding of the universe for the benefit of all.”

NASA’s contributions to the mission include the Mars-moon Exploration with Gamma rays and Neutrons (MEGANE) spectrograph instrument, the Pneumatic Sampler (P-Sampler) technology demonstration, and communications and navigation support from the agency’s Deep Space Network , as well as funding United States scientists participating on the MMX science team.

Scientists have long debated the origin of Mars’ two moons. The data and samples collected by the MMX mission will help answer essential questions about the origins of these moons and the history of the solar system.

“Phobos and Deimos may be the remains of a massive impact on Mars that sent material into orbit around the planet, or they could be ancient asteroids that were captured by Mars’ gravity billions of years ago,” said Tom Statler, MMX program executive and program scientist at NASA Headquarters. “Having the answer will help illuminate that early era when Earth and the other inner planets may have been acquiring much of their water and organic compounds.”

The MEGANE (pronounced meh-GAH-nay, the Japanese word for eyeglasses) spectrograph will help scientists “see” what Phobos is made of by measuring neutrons and gamma rays emitted from the moon’s surface and determining its chemical elemental composition, which will provide important clues about its origin.

Mounted on one of the spacecraft’s landing legs, the P-Sampler is designed to collect a ground sample from Phobos. The system gathers surface material using bursts of high-pressure nitrogen gas, complementing JAXA’s C-Sampler, which will extract cores from a few inches deeper. NASA will obtain and curate about 15% of the total returned sample at the agency’s Johnson Space Center Astromaterials Lab in Houston, making it available for research for decades.