Railgun

The railgun is a turret, also the only turret with a GUI. It doesn't use a turret AI chip and telemetry, rather it uses a target designator, like the one for missiles. It shoots deterium plasma capsules. If you insert a target designator and hit the blue button, the railgun appears to be pointing upward and makes a sound. You can also fire without a designator, but that doesn't work very well. It needs energy. To fire, insert a deterium plasma capsule and hit the red button. When you do, lightning comes out of the muzzle and then it shoots a blue plasma upwards.

After a while, the plasma lands where you set the target, and makes an explosion.