This is an idea I've had for some time now.
Its set in the space in the future where mankind has mined every aspect of Earths rare metals and have sought out in the space to supply earth with metals. Thus bringing humanity to the moons of Jupiter for mining Dysprosium, which is a rael metal found on the moon. Dysprosium is, in the story, found on in the Gallileian group of moons where there is 4 moons; Io, Europa, Ganymedes and Callisto.
But these moons, after being colonized for mining, tries to be free of Earths shackles and war break out. The moon miners fight for their freedom and Earth fights for needed supplies.