Freighters are light escort and scouting vessels. They often have extensive scanning systems to provide anti-fighter screening for capital ships, and carry a squad of marines for security and groundside duty. Unlike larger vessels, frigates are able to land on planets.
The most important role filled by frigates is reconnaissance. Sensors, unlike ships and communications , are limited to the speed of light. Subsequently, a stationary observer can only detect a vessel one light-year away when its light arrives at the observer’s location, one year after leaving said vessel.
Because faster-than-light attackers always arrive before defenders can detect them with luminal sensors, attackers can always surprise defenders. For defense, fleets surround themselves with spheres of scouting frigates scanning for enemy ships and transmitting warnings to the main body.
Frigates achieve high FTL cruise speeds because of their high-performance drives. They also have proportionally larger thrusters and lighter design mass, allowing them greater maneuverability. In combat, speed and maneuverability make frigates immune to long-range fire of larger vessels.
In fleet combat, frigates are organized into “wolf pack” flotillas of four to six. Wolf packs speed through enemy formations, hunting enemy vessels whose kinetic barriers have been taken down by fighter-launched disruptor torpedoes. The wolf pack circle-strafes vulnerable targets, using their superior speed and maneuverability to evade return fire.