After seeing Kyro's addition of asteroids to the mix I had to try a rock-themed fleet.

City-style asteroid colony.

"Tower ship" miner. This one looks very cool hovering over asteroid fields, since the beam usually emanates straight down from the base of the tower.

Just a little orbital communications satellite with a defensive armament.

Base constructor platform. This was very fun to build.

Not entirely happy with this freighter. Has a nice look, but seems like a more traditional ship than the others, which have a more "built into the existing rock" feel to them.

A small ship frame strapped to a spaceborne rock. It probably give it all sorts of special surveying mineral harmonicisms and resonations. Or something.

I've always been bothered by the fact that these huge transports simply disappear after they land on an enemy planet. I suppose you could assume that they are immediately broken down into war-making equipment after landing, but I like this explanation better - the one-way trip Cataclysm Class troop transport. For when you want to make an entrance with a bang.