The fusion drive is the primary propulsion system of spacecraft in the Homeworld universe.
Moving a ship in the cold depths of space is a serious undertaking. Several key factors must be considered, the size of fusion reactor that can be carried, the stress the frame of the craft can take before oscillation instabilities tear the ship apart, and the size of the craft itself.
The smaller the ship, the higher the speeds it is capable of. The disadvantage of smaller craft, usually classified as strike craft, is they can't carry a fusion drive capable of producing a self-sustaining drive torch, which means they must carry fuel, which limits their range from carrier ships capable of refueling them. This changed during the Beast War, with the widespread deployment of the Acolyte Fighter Drive, which didn't possess such limitations.
Capital Ships, super capital ships, and motherships all possess drive systems capable of producing a self-sustaining drive torch. The disadvantage of these drive systems is they can't accelerate the ship to strike craft speeds, due to the size of such ships and risk of shattering the structure with oscillation instabilities.
Fusion drives come in several sizes.
The fighter drive is used to propel fighters to combat speeds, due their small size, they have tremendous maneuverability and speed. Their high maneuverability makes them the only class of ship capable of complex flight maneuvers. The downside is, they can't carry sufficient reactor mass to produce a self-sustaining drive torch, limiting their range from their carrier. With the widespread implementation of the Acolyte Fighter Drive, fighters and microships ceased to possess such range restrictions.
The corvette drive is used by the larger corvettes and gunships. The corvette drive is a good deal more efficient than the fighter drive, but still can't carry sufficient reactor mass to produce a self-sustaining drive torch like the fighter drive. As with the fighter drive, this changed with the deployment of the Acolyte Fighter Drive. The corvette drive is also capable of supporting more advanced weaponry.
The capital ship drive is used by Capital Ships, like frigates, and the largest support vessels. The capital ship drive is the first drive design capable of producing a self-sustaining drive torch, eliminating the need for refueling. However, the size of such ships limits them to slower speeds and limited flight maneuvers. The true advantage of the capital ship drive is its ability to support the most powerful general deployment weapons possible, like the Ion Cannon.
Super Capital Ship and MothershipEdit
The super capital ship drive is used by super capital ships. The super capital ship drive combines the efficiency of the capital ship drive with power plants in league with Mothership Class vessels, which creates a drive system capable of pulsing and shaping torches to produce one coherent thrust factor while still accelerating the huge mass without tearing the structure apart with oscillation instabilities. This also makes the drive capable of supporting the most powerful weapons possible and starship foundries on par with a mothership.
A mothership, on the other hand, possesses the largest fusion planets possible, but due to its tremendous mass, its only capable of very limited sublight movement, the real drive system that makes a mothership possible is the hyperdrive.