Sounds like Saturn and Jupiter from WTS World Mod. (In that mod, The Solar System is split into 4 actual systems highlighting Earth, Jupiter, Saturn and "Outer Solar System").
Hey. Is it just me or do I mention WTS all the time? It's not that good, actually.:P
If you want me to take some screenshots of those systems, feel free to ask and I'll see if I can be bothered, but basically they're structured around a humongous* gas giant with a few moons (some populated) and bases around it. Saturn also has a giant, awesome looking ring.
* (by Freelancer's standards. In reality they're probably about as big as, say, the smallest planets in our real-life Solar System)
Known as on Discovery RP 24/7: Thomas_Hill - Train [KNF]TakajiKimura - Chimera
You may also know me elsewhere as I'll Begin or something including "Volbeat"