The ring structure is what would be called the Solar Sail in Battle Tec. In that game the big ships have to jump from Star system to system. Thus they deploy the sail after they have make a jump and it charges up the jump drive. Think in terms of what happens on the show Star Gate. This ring was the only way I could think of creating the sail. The ring would be at the stage were the sail is ready to be taken into storage for the jump. Or the sail is to be deployed for the charging. I did a cute design trick for the sail to be where it is. One thin pole coming out of the back end. The rigging for the sail would be of momofilimant cable and thus invisible to the eye.
In Battle Tec, the Warships and Jumpships are so large that they can not land of a planet. That is what the Dropships are for. They are too small for the jump drive and thus. piggyback on the bigger ships. The largest Dropship would be about the size of the Nimitz Carriers. The largest Jumpship can carry 25 Dropships.