The first would be a spy-satellite. This would essentially just be a radar that doesn't require anything to be built on the ground and could be controlled using some sort of item that would tell the satellite where to 'scan' allowing for rail lines or areas far away to be watched. You could also, using an upgrade to the night vision goggles module, view the scanned area as if you were at that point.
To balance it, it can only move once every 24 in game hours and the controller can only select an area on screen, so to scout an enemy base you must first infiltrate it or get near a biter nest that you may be worried about.
The second would be a communications satellite
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)
The third and most powerful would be the orbital laser cannon
![Twisted Evil :twisted:](./images/smilies/icon_twisted.gif)
A missile could also be added (with great expense) that could take down a single satellite (requiring a rocket) to cripple enemy networks or defenses.
Note: all of this research would come after the rocket and possibly require a sort of 'orbital lab' that you must launch first and would supply data. This data would unlock the satellites, first the communications one, then the spy and finally the orbital laser.
Just my idea for additional end game stuff to make the circuit network better and clearing late game biters easier as well as providing a use for satelites in the short term.
![Smile :)](./images/smilies/icon_e_smile.gif)