Close Quarters Defense System

The Close Quarters Defense System (CQDS - pronounced "seek wads" or "see quads") is a multi-functional armament equipped on military starships. The CQDS is primarily oriented towards point defense, but it can also be used offensively in close ranged combat.
The current generation of CQDS turrets employed by TASA ships have three weapons:

High Powered Laser Emitter

A laser emitter sits atop the CQDS turret as a cupola. It can track targets independently from the main turret assembly, or remain fixed on a target while the conventional weapons lead the target. The CQDS laser is mainly used to defeat incoming missiles by blinding their targeting systems or inducing enough heat to cause catastrophic damage. The laser emitter can do the same to hostile ships, blinding or damaging sensitive sensor equipment with relative ease and causing heat damage to the ship over time. An emerging tactic is to use the CQDS lasers to target enemy point defense systems one by one, diminishing the enemy's ability to stop incoming fire.
The laser is the longest range weapon in the CQDS package, but it does not have a hard range where it suddenly becomes ineffective. With increasing distances, the laser will increasingly longer time to impart the same amount of heat energy onto a point target. This also means that the laser will become increasingly lethal as targets approach the point of origin, making it more likely to render a kill the closer an enemy missile gets. Multiple CQDS turrets can concentrate their lasers together to overwhelm a single target faster. The predictability of an enemy's movements also plays a large factor in the laser's range. At 1 light second away (~300,000 km) the CQDS laser can essentially track any course corrections by a missile or ship fast enough to maintain a constant beam. At increasing distances, a target can make randomized evasive maneuvers to shrug off the beam before the laser can reacquire. Missiles blindly vectoring towards their target or ships on a fixed path with no deviations can be theoretically targeted out to any distance (although this is true of projectile weapons as well).
The largest drawback of the laser emitter is that it is almost entirely ineffective against purely kinetic weapons such as rail gun or coil gun slugs. A laser emitter could melt the slug, but the molten material would still be traveling at almost the same velocity and impact with almost as much mass. The laser could cause deviations in the projectile's trajectory slowly over time, but an evasion by the targeted ship would be more effective at the ranges necessary. Kinetic Kill Missiles can still be defeated by laser if their thruster is damaged, their guidance system is blinded, or their propellant tank is ruptured.

Rotary Cannon

The second and most prominent weapon of the CQDS system is a 20mm rotary cannon that uses conventional propellant combustion (PropCom) ammunition to achieve a spectacularly high rate of fire. The rounds are dual-purpose kinetic kill slugs with explosive tails that are fused to impact. A threat traveling on a known vector can be targeted with a precise burst of fire, but more evasive threats require the CQDS system to saturate an area with a scattered arc of projectiles to decrease the evader's options and increase the likelihood of a round finding its target. Rotary Cannons travel significantly slower than the speed of light, so their effective range against evasive targets is only a few hundred kilometers (depending largely on the size and max acceleration of the target). Dumb-fire kinetic projectiles like rail gun slugs can even be targeted by the CQDS system, provided the ship's sensors can accurately detect and track the incoming round in time to fire an intercepting burst.
Like the CQDS' laser, the rotary cannon can be used to deal damage to enemy ships at close range (or even far ranges if the enemy fails to maneuver since the projectile will travel at a near constant velocity until it hits something). The 20mm rounds deal a relatively light amount of damage to enemy ships, and cannot defeat composite armor even half a meter thick. The goal of targeting enemy ships with a CQDS cannon is to hit unprotected subsystems such as sensors or weapons, or to find gaps in enemy armor coverage that can result in hull penetration. Once the round penetrates, it can deal damage to internal systems, personnel, and cause atmosphere to vent. CQDS cannons are most deadly to enemy ships at extremely close quarters, such as during ambushes at orbital ranges or in boarding action. Extremely small craft such as Sleds or drones and enemy personnel conducting EVA are particularly susceptible to CQDS cannon fire.
Aside from the range limitations, the main drawback of the CQDS cannon is the need to carry large amounts of ammunition. A CQDS cannon can go through thousands of rounds in under a minute of sustained fire. Smaller ships in particular must use their CQDS cannons wisely and avoid wasting ammunition with long bursts. A particularly cunning captain might use more expendable projectiles to use up an enemy's cannon ammo before launching a lethal volley.

Canister Rail Gun

Informally known as the "punt gun", the CQDS last line of defense is a short range rail gun that fires a cluster of micro projectiles. The goal of the punt gun is to create a small cloud of fast moving material on an intercept course with the enemy projectile in order to shred the target. As the punt gun is usually a weapon of last resort, it carries only a small amount of ammunition (usually a drum of 12-24 canister rounds). The punt gun can be manually reloaded if necessary.
The punt gun is harder to evade, but loses effectiveness much more quickly as the cloud of projectiles grows further and further apart like a shotgun firing buckshot. The punt gun is generally only useful at less than 100 km, but has considerable effectiveness at these ranges since incoming projectiles are usually locked in on their final approach by that point.
Like the other parts of the CQDS system, the canister rounds can be used against enemy ships at very close ranges to shred external hardpoints and unarmored hull.

Item type

Weapon, Ranged

Owning Organization

TASA Space Corps