this planetary defense weapon used a huge powerplant to drive a firing mechanism. In most situations, the powerplant was buried underground, as were the weapon's ray- and particle-shield generators. This substructure supported the weapon during firing, when it blasted super-accelerated slugs at its target. The HVG could fire up to 120 slugs per minute, in between shield bursts. The slugs could penetrate ray shielding, and could make quick work of most particle shields. During the height of the Galactic Civil War, the Empire built several hypervelocity guns into orbital space stations, providing the weapons with additional mobility.