JAXA, Japan’s national space agency, has just approved a robotic mission to visit the Martian moons Phobos and Deimos and retrieve a small sample from the former to bring back to Earth.

The mission plan: It’s called Martian Moon eXploration, or MMX. JAXA currently plans to launch MMX in 2024 and make it to the Martian system the following year. MMX will spend three years in the system studying and mapping the moons. The mission will make use of 11 different instruments, including a NASA-funded instrument called MEGAE that will measure the elemental composition of both bodies (perhaps revealing signs of ancient water).

The mission will also deploy a small rover to zip around the surface of Phobos, not unlike what JAXA’s Hayabusa2 mission deployed on the surface of the asteroid Ryugu.