Point Defense Technologies

Modern point defense systems trace their origins back to anti-aircraft-guns (AA) and anti-aircraft-artillery: flak guns (AAA) of the WWII Era. The first true point defense system was the Close-in Weapon Systems used aboard surface vessels in the second half of the 20th century. There are various types of point defense systems in use by UNON ships that can be classified based on their methods of operation.
Solid, Unguided: Unguided ordinance (slugs or shells) are rapidly fired at high speed on the projected trajectory of a missile or fighter by rotating or alternating gun barrels.  These guns can be either traditional propellant based or more advanced mass drivers. The sheer volume of rounds fired at the target means that the probability of hitting the target is high. This has the advantages of being cheap, and in the form of flak cannons, can quickly create a screen of explosions and shrapnel that is likely to destroy any incoming ordinance out of the sheer volume of fire. It is an easy system to maintain and has minimal power draw. Unfortunately, it is also quite limited in terms of range and accuracy and rapidly consumes munitions.
Solid, Guided: The vessel in question launches a missile or missiles to intercept an incoming target. These defensive missiles have the advantage of increased hit probability and can be fired from the same launchers or missile tubes as offensive variants. Missiles also have a larger effective range than traditional guns due to their ability to correct their trajectory until they run out of fuel. On the downside, missiles take up more space than shells and are far more expensive.
Beam: Lasers and particle beams are considered high-end defensive systems. While there is a range limitation due to both light lag and the diffusion of beams over distance, they are powerful and feature exceptional accuracy so long as the ship’s sensors and weapon are properly maintained. Unfortunately, heat buildup limits the effectiveness in protracted engagements, and the higher a laser’s power, the more heat is generated. Lasers and particle beams rely on expensive focusing elements to work properly, increasing their cost over other systems, and the power draw on a ship’s reactors can be substantial.