Just implemented orbital buildings into our Artillery-RTS.
Basically the orbital buildings are an advanced version of the surface buildings but to prevent that people just spam orbital buildings in the late game, there is only a very limited amount of orbital building slots for every planet.

That looks pretty cool!

Two points you might want to consider though.
I'd maybe try to change the colour so it looks more like a paintjob.
Also I don't think the hexagon background fits that well. Did you try to use it just without any background?

Is it actually known how many votes you need to get greenlit?

We're currently working on a game set in a solar system where you build a base on your own planet and shoot missiles, lasers and even bigger projectiles at other planets.

All projectiles are affected by gravity of the sun and the planets so it becomes a nice challenge to actually hit your opponent's planet.
We're currently using "Barrage" as a name. What do you think?