Starship Weapon Systems
Weapons systems are highly varied and differ greatly by the groups that field them, but have a few marked similarities.
In general, most weapons fall in to one of two categories: projectile and non-projectile.
Projectile Systems
Any time a ship fires a solid, non-reusable object, it is considered a projectile. Projectiles themselves are generally differentiated by guided and unguided.
Unguided Projectiles
Rail guns are the most common, where in a metal 'slug' or bullet is proppelled by passing a current between two rails. Magnetic guns are also common, and while less efficient, their do exist gravity guns(which use artificial gravity to propel a projectile. All of these weapons are typically small, turret mounted affairs and commonly used for point defense or close-in ordnance. Because they are relatively easy to build and maintain, this is also the most common armament fitted to civilian ships.
While much less common, there have also been many notable examples of "space guns" fielded by different powers. Good old fashioned nitro-cellulose(smokeless gunpowder) works perfectly well in outer space, and in a vacuum can propel a large projectile to very dangerous speeds.
While effective range is not a major issue(in space, an object in motion remains in motion), unguided projectiles are still considered only a short-range or close-in weapon. The primary problem with these weapons is aiming; since the projectiles travel much slower than the speed of light, it becomes nearly impossible to hit distant targets.
Guided Projectiles
Guided projectiles typically consist of missiles or torpedoes, and may or may not carry a warhead. A key difference between the two is size and payload: torpedoes are generally much larger than missiles.
The addition of a guidance system makes range considerably less of an issue. The deciding factor then becomes delta-V budget; how much can the projectile change it's relative velocity? Pure chemical-based motors have extremely low delta-V compared to their nuclear counterparts.
Missiles
The most common guided weapon is a kinetic missile, which consists of a rocket motor, guidance system, attitude control system, and an inert "impactor" usually made of some dense, heavy metal. These missiles kill with pure kinetic energy, relying entirely on the speed of the missile and the speed of the ship launching them.
Kinetic missiles are popular because they are cheap, easy to build, an effective against most targets. Chemically-driven kinetic missiles can, at close range, inflict serious damage; and much like railguns are popular "civilian armaments" in the Merchant Marine.
In fact, kinetic missiles are so efficient that chemical explosive warheads are almost never used. The most powerful and sophisticated non-nuclear explosives simply don't add enough to be worthwhile. The exceptions are whenever the function of the payload is strictly destructive against another ship. Some small SIMs are equiped with a chemical explosive payload and designed to produce a cloud of shrapnel; these are seen most often on weapons fitted to stunt-fighters designed to take out other stunt fighters.
Larger missile payloads are often nuclear, with most space navies fielding some form of N1 missile. Interestingly, most N1 missiles are complete ineffective on anything other than a direct hit. An N1 warhead exploding only "near" a ship hardened for the kind of radiation encountered in deep space(E.G.: All ships) would be unaffected by the radiation, and there is almost no shockwave to speak of.
To counter-act this, N1s are usually surrounded by a "burner" or fuel layer made of some dense material, usually a heavy elemental metal. In the explosion, the burner is vaporized and turns into a shockwave of energetic plasma. This is an important feature as it turns a "near miss" into at least some damage.
- The Gudersnipe Foundation fields an N1 missile with a shaped tungsten or depleted uranium cone that functions much like the penetrator in a rocket-propelled grendade anti-tank weapon. When the warhead explodes, it creates a white-hot jet of plasma capable of penetrating most Starship Shield Systems and doing significant damage to an armored hull.
Less common as missile warheads are N1.5, or hydrogen fusion bombs. They are effective in that a powerful plasma shockwave is created, but finding a second-stage fissile material capable of fitting on a usually relatively small missile is extremely challenging and out of the capability for even most nuclear-armed forces.
Alliance combat ships rely heavily on very small N1s with burners and mostly use kinetic missiles. While the Foundation fields all of the above, its main-stay weapon is the N2 variable-yield warhead. Much like an N1.5, N2s produce a very powerful and devastating plasma shockwave, while also being relatively similar in side. The infamous Scion-Sending Missile fielded early in the Kamian Succession Wars combined an N2 warhead with the shaped burner shell from the armor-penetrating N1.
Torpedoes
Torpedoes are, of course, the main-stay of the ship-killer weapon; a single good hit from a torpedo can generally take out anything smaller than a cruiser.
The difference between a missile and a torpedo in space is largely academic. The Foundation classifies a torpedo as being "any weapon fired from a powered launcher with an engine capable of multiple re-starts". Propellant-system re-start is the main determining factor for most space navies, though many cultures simply do not differentiate between the two weapon types. The Foundation primarily keeps the two as separate categories due to a long naval tradition.
Launcher
The Foundation's torpedo system is too-stage: a compressed gas explosion coupled with a magnetic coil. The space in front of the torpedo is also exposed to the vacuum of space, and the combination of factors gives it a fractional speed of light acceleration. This allows the torpedo to be launched without engaging it's own motor, which makes the initial launch more difficult to detect.
Launchers are typically protected behind heavy armor plates which must be retracted in order to fire. Since the plates are a sizable fraction of the hull, this represents a detectable change in surface geometry. The same is usually true for missile bays. Opening of bay doors is usually considered a sign of aggression, since it signifies the intent to launch a torpedo.
In addition, the tube itself, since it contains sensitive equipment, is often pressurized while not in use(to allow for maintenance access), depressurizing the tube by venting into space is another detectable event. Some ships are equipped with vacuum pumps that can clear the tube without venting, but most prefer to simply go into battle with bay doors open and tubes emptied.
Engine
Foundation torpedoes typically use a Deuterium Drives, being small, compact, and very powerful. The Foundation's variant uses a small amount of anti-matter to spark the reaction, while many operators use laser fusion initiators. The anti-matter systems are actually more expensive to operate, but the Foundation uses them because the restart cycles are much faster.
Payload
Kinetic torpedoes are not a thing. If you are going to launch a torpedo at someone, you'd best strap a nuke on it. Most operators use the largest N1.5 warheads they can find, the Foundation uses N2 warheads "or better".
Foundation payloads typically consist of a large, variable-yield N2. The "workhorse" torpedo of the Crimson Blade is a variable forty to one hundred and twenty megaton N2 in a thick, hardened tungsten casing. While the casing ads very little to the yield when vaporized, it does protect the torpedo from counter measures, and can allow it it to better penetrate into a hull.
The torpedo is also the standard delivery system for the Nova Bomb. Though they have been fitted to missiles, torpedoes are preferable for their improved capabilities.
The foundation also fielded the "Scion Torpedo", which borrowed from the shaped-charge design of the Scion-Sending Missile. This weapon eventually evolved into the modern Skipper Missile, a long-range hunter-killer torpedo.
Non-Projectile Systems
This section refers to directed energy weapons. Anything that created an explosively-formed projectile would belong in the projectiles section. Very few cultures ever field simple "lasers" as weapons; the space-gun of choice is typically a plasma-based compressed energy weapon or "beam cannon".
Beam Cannon
The term 'Beam Cannon' is often used as a sort of catch-all. Strictly speaking, most of the weapons discussed bellow can be accurately described as beam cannons.
A beam cannon is the simplest type of compressed energy weapon typically employed by starships, mecha, and sometimes tanks. Because of shielding and power requirements, handheld or even man-portable or crew-served beam cannons are unavailable. They are generally not considered effective in-atmosphere as passing through gasses severely limits the range. The power requirements are also enormous.
The "ammunition" for a beam cannon is plasma, generally of much higher power than dry plasma produced as part of an engine firing stage. While some variants do use anti-matter to spark the initial plasma reaction, the prefered method involves a laser array and a powerful electrical arc.
A typical design uses primary and secondary ignition chamber, followed by an alignment chamber, or barrel.
Primary Ignition Chamber
In the primary ignition chamber, ignition starts by arcing a powerful electrical current through a gaseous field. Dozens or sometimes hundreds of small, powerful laser beams are also pointed along the ignition stream, which rapidly converts the gas into ionized plasma.
Secondary Ignition Chamber
In the secondary ignition chamber, additional gases are added to be converted into plasma. This has both the effect of making the beam "heavier" while also helping to normalize it, or bring it to within a common power level. The plasma reactions in the primary ignition chamber can be highly erratic, the goal of the secondary chamber is to produce a highly consistent stream.
Alignment Chamber
The primary reason for the name "cannon" comes from the long barrel of the weapon. The interior of the barrel is lined with powerful force-fields, and may not be straight but use a series of ridges designed to deflect the ionized particles into a coherent stream. The fields determine final beam compression and are often adjusted, much like a lens.
Firing Parameters
The beam that ultimately leave's the mouth of the barrel quickly looses cohesion and scatters into a conical shape. A more focused beam has a greater effective range, but is also more likely to drift. Gun crews, having chosen a target, have only a matter of seconds to make adjustments for the best possible shot.
The beam can further be adjusted to arc, accounting for drift, and someimes even allowing a target to be hit around an obstruction. "Curving the beam" is something only elite gun crews aboard capitol ships are capable of, and it requires a deep knowledge of both physics and the field of fire.
Gun crews are also known to exploit the cohesion problem by firing a "scatter-shot" - a beam intentionally formed with very low cohesion that is designed to immediately scatter into a wide cone. While useless against other capitol ships, this method is highly effective at destroying enemy fighters caught in the cone.
Firing pressure is also a factor; a "low-pressure" shot can have far greater range but does less damage. A high-pressure shot will spread much faster. The makeup of the gasses also effects this heavily(see Ammunition bellow). Generally speaking, the fire-control crew will include a "gas man" who's job is to monitor the contents of the coming shots and provide adjustments to the rest of the crew accordingly. Gun crews use a series of pre-calculated tables to determine how different plasma makups will affect their shot. The medium the beam must pass through is also accounted for, as it affects all of these factors as well.
Fixed Parameter vs. Variable Parameter
The large cannons mounted about capitol ships are typically variable-parameter, capable of dynamically adjusting firing parameters to achieve different effects. Smaller ships carry "fixies" or fixed-parameter cannons, that are pre-configured for the greatest possible range. These are ideal on smaller ships that do not have dedicated gun crews, and sporting weapons that, given their smaller size, are virtually no use at anything less than their maximum effective range.
One common exception to this rule are "Fast-Attack Ships", which are very small vessels that field large, variable-parameter cannons for use against much larger ships
Cannon Classifications
Beam cannons are classified by three factors: barrel length, aperture diameter, and maximum pressure levels. Wyrick Balnor, CTO of IFA(a major manufacturer of beam cannons) has pointed out that "Gun crews generally take that last rating more as a 'suggestion'; I've met shooters who's SOP was twenty percent over max." Wyrick, who had a significant impact on weapons design during the Kamian Succession Wars, discretely had the maximum pressure level for IFA weapons reducied by about ten percent of the design limit, "splitting the difference" as it were.
As improvements in alignment chamber have progressed, barrel length has had less of an impact, making the final factors, diameter and pressure, the most important
