The Martian Moons Exploration is a robotic space probe set for launch in 2024 to bring back the first samples from Mars' largest moon Phobos. Developed by the Japanese Aerospace Exploration Agency and announced on 9 June 2015, MMX will land and collect samples from Phobos once or twice, along with conducting Deimos flyby observations and monitoring Mars' climate. The mission aims to provide key information to help determine whether the Martian moons are captured asteroids or the result of a larger body hitting Mars. The Japan Aerospace Exploration Agency and other Japanese government officials officially approved the MMX project to proceed into development on 19 February 2020, according to a post on JAXA's website.
Overview
The spacecraft will enter orbit around Mars, then transfer to Phobos, and land once or twice and gather sand-like regolith particles using a simple pneumatic system. The lander mission aims to retrieve a minimum of samples. The spacecraft will then take off from Phobos and make several flybys of the smaller moon Deimos before sending the Sample Return Capsule back to Earth, arriving in July 2029. The mission architecture uses three modules: propulsion module, exploration module and the return module. With the mass of Deimos and Phobos being too small to capture a satellite, it is not possible to orbit the Martian moons in the usual sense. However, orbits of a special kind, referred to as quasi-satellite orbits, can be sufficiently stable to allow many months of operations in the vicinity of the moon. The mission leader is Yasuhiro Kawakatsu..
International collaboration
, ESA, and CNES are also participating in the project, and will provide scientific instruments. The U.S. will contribute a neutron and gamma-ray spectrometer called MEGANE, and France the Near IR Spectrometer. France is also contributing expertise in flight dynamics to plan the mission's orbiting and landing manoeuvres. Development and testing of key components, including the sampler, is ongoing. As of 2020, MMX is scheduled to be launched in September 2024, and will return to Earth five years later.
Scientific payload
The scientific payload consists on Japanese and international contributions. They will be powered by solar arrays.
Gamma rays and Neutrons Spectrometer - developed by NASA
Additionally, the Gravity GradioMeter, Laser-Induced Breakdown Spectroscope, Mission Survival Module were proposed as additional instruments. Following a study by the French CNES space agency, it was decided that the spacecraft will deliver a small rover provided by CNES and the German Aerospace Center. The rover will be equipped with cameras, a radiometer, and a Raman spectrometer for in-situ surface exploration of the Martian moon.
Sampling
MMX's sampler is equipped with two sampling methods: the Coring Sampler to gain regolith at depths deeper than 2 cm from the Phobos surface, and the Pneumatic Sampler from the Phobos surface. The robotic arm will collect regolith from the ground by shooting the C-SMP mechanism. The C-SMP mechanism is designed to rapidly perform subsurface sampling to collect over 10 grams of the regolith. It is equipped with an ejecting actuator that uses a special shape memory alloy, SCSMA. P-SMP that is installed nearby the footpad of the landing leg uses an air gun to puff pressurised gas, pushing about 10 grams of soil into the sample container. Both C-SMP and P-SMP can collect samples quickly because the entire sampling procedure shall be performed only in 2.5 hours. After taking off from the landing site, the equipped robotic arm transfers both C-SMP and P-SMP canister to the sample return capsule. The spacecraft will then take off from Phobos and make several flybys of the smaller moon Deimos before carrying the Sample Return Capsule back to Earth, arriving in July 2029.
