http://www.indiedb.com/games/age-of-asteroids - atch a Orbital Space Fight with cinematic camera mode. For demonstration purposes this is an FFA Battle and every ship is equally equipped using blaster weapons.
Each Ship is hunting down its target like a player would do in hope for realistic looks. If you see the on or other laser beam (red) appearing this is a surface mounted defense tower shooting on ships in its range.
In the future there will be other ship classes and even Battle Ships are in planning. They will be more stationary but will have defense towers mounted. There will be heavy fighter ships which can be equipped with space/space torpedos for being effective against battle ships.
Bigger Ships cannot be built on the asteroid itself and cannot land in the hanger, instead you need to build an orbital station/dock to build those bigger ships and they will need a lot of resources to get constructed.