[3][5] Developed by the Japan Aerospace Exploration Agency (JAXA) 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's climate.

[6] 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.

[1] The spacecraft will enter orbit around Mars, then transfer to Phobos,[7] and land once or twice and gather sand-like regolith particles using a simple pneumatic system.

[4][9] The spacecraft will then take off from Phobos and make several flybys of the smaller moon Deimos before sending the Return Module back to Earth, arriving in 2031.

The original image data will be stored in a recording device in MMX's return capsule and brought back to Earth as part of the sample-return portion of the mission.

[23] The Gravity GradioMeter (GGM), Laser-Induced Breakdown Spectroscope (LIBS), Mission Survival Module (MSM) were proposed as additional instruments.

[29] [30] P-SMP is installed close to the footpad of the landing leg, and uses an air gun to puff pressurized gas, pushing about 10 grams of soil into the sample container.