I think it would be interesting to have factories for generating exotic particles at some locations. These could be enormous colliders - linear colliders or even rings around moons. The products could be essential to fuel manufacture. This might lead to some interesting gameplay around attacking/protecting these fuel sources. In the right location, the colliders might just be a series of accelerator magnets without needing shielding as they do in atmosphere - you could watch the collisions and particle capture machines in action.