Weapon:Heatseeker
A missile which locks onto a heat source -- a ship's engines, for example -- rather than a radar or IFF signal. The Heatseeker is not as vulnerable to ECM as torpedoes, IFF or other guided missiles are. Damage is respectable for their small size. They are also relatively inexpensive and widely available. Most effective against light and medium ships. They are best used in salvos rather than individually. One missile often will weaken the target's defenses enough to let the others get through and do damage to the ship itself.
CAUTION: If you are attacking targets near a friendly capship, heat seekers launched at targets within a few hundred meters from the capship may well lock onto the capship instead. That tends to get you talked about by the capship.