Screenshots

This is actually a fighter death sequence hot-rodded beyond recognition. It spawns an spinning asteriod with a glow around it. As the rock tumbles through space, it leaves blue smoky trails and you can see the rock cool and the glow fade. The hit event is also suitably impressive. The effect has been picked up by the Dark Age, Great Wars, and The Dilgar Invasion mod teams.

Instructions

The mass driver is in the laser weapon slot to minimize conflict with most weapons packs, but it's a projectile weapon, while the Laser is usually a beam weapon. It won't mind being converted to a projectile weapon, but you'll need to make sure none of your SHP files are using the Laser as a beam weapon, lest Homeworld crash. This looks best with large mass, low speed, and big damage.

Unzip these files into homeworld\etg\

Open r1.script. Find the Laser, and replace that block of text with this:

[Centauri Mass Driver]
setBulletEffect         R1,GS_Laser,bulletMassDriver.ebg
setBulletEffect         R1,GS_Laser,bulletMassDriver.ebg
setBulletEffect         R1,GS_Laser,bulletMassDriver.ebg
setBulletEffect         R1,GS_Laser,bulletMassDriver.ebg
setBulletEffect         R1,GS_Laser,bulletMassDriver.ebg
setHitEvent             R1,GS_Laser,HitMassDriver.ebg
setHitEvent             R1,GS_Laser,HitMassDriver.ebg
setHitEvent             R1,GS_Laser,HitMassDriver.ebg
setHitEvent             R1,GS_Laser,HitMassDriver.ebg

That's right, there is no fireevent specified. That won't hurt anything. Now scroll all the way to the bottom, to [EFFECTS LOADING] and add this line:

LoadEffect mdfireball.ebg