ID : 5209-010 TITLE : Space Weaponry, Overview of Current Systems AUTHOR: Seven Swords Special Service, Division of Official History DATE : 006/2349 CLASS.: Secret BRAVO INFORMATION IN THIS DOCUMENT IS CURRENT AND SENSITIVE.
This document is one of a series, meant to provide a brief and general overview of the state-of-the-art in weapon systems. There is no mention of particular models or manufacturers, except where this represents a new class of weapon. In this document, the emphasis is on space weapons, particularly ship-to-ship systems. Although most spacecraft are capable of carrying at least some types of weapons of mass destruction, these are described elsewhere (see 5209-006).
Laser/Maser
Lasers are a directed energy weapon utilizing intense beams of photons to vaporize the target. These weapons cause damage over a small area, but can provide enormous penetration. Because of their limited damage extent, they are most useful for attacks against small critical components; they are most commonly used in point defense systems. Masers are identical to a laser, with the exception of wavelength; lasers use visible light wavelengths, masers use microwaves.
Modern starship lasers are large, being based around a gas-filled lase cavity. Because of the gaseous lase material, the systems can generate far larger power outputs than solid lasers. A typical ship-borne laser can generate pulses roughly 1000 times the power of a personal lase weapon. Typical pulses are approximately 0.1 seconds in length, allowing for a normal firing rate of 5 pulses per second (50% duty cycle). Because of the high power of the pulses, focusing the beam is impractical - the focusing mechanism would melt from the waste heat generated by the passage of the beam. Instead, the laser cavity is shaped to provide sufficient collimation. This requires relatively long laser cavities, typically with a length of ~50 cm. The lack of additional focusing mechanisms also means that the laser beam has the same diameter as the lase cavity, which is normally around 2-5 cm.
Effective ranges of lasers is set by the dispersion of the beam. For standard geometries, dispersion limits the effective range to the order of 10,000 km. Larger, more powerful lase pulses have a larger effective range, as do systems with improved collimation. Some research by several Starguild Subcons shows promise in developing a collimation/focusing system based on a gaseous "lense". This has the potential to greatly increase the maximum range of laser systems; possibly to 100,000 km or more.
Due to the small beam size of laser and maser systems, these weapons are normally used for point defense or precision attacks against a fragile target (such as sensor arrays). The ideal wavelength of a laser/maser depends mostly on the target to be destroyed; wavelengths absorbed by the target are more damaging than reflected wavelengths. Because of this, lasers are more common than masers. However, maser pulses are known to quickly destroy radio systems in addition to the physical destruction of the antennas.
Both lasers and masers are usable in an atmosphere, although at greatly reduced ranges. Masers are slightly more sensitive to water vapor in an atmosphere, giving a shorter range than lasers.
Particle Accelerator
Particle accelerators accelerate a number of charged ions in a small cloud towards the target. Upon impact, the fast-moving particles dump their energy in the form of momentum transfer and electrical discharges. The result is a weapon shot (called a "bolt") that both knocks a target back and electrocutes it. The bolts emit a small amount of light as it interacts with surrounding gas and dust; combined with the great arcs from an impact, particle accelerators are among the most spectacular of weapons.
Accelerators use relatively large numbers of particles, all of similar charge. Particles can be scooped from nearby space or, more often, taken from a supply of reaction mass carried by the vessel. These particles are ionized, and then injected into an accelerator chamber. The particles, compressed into a small cloud by the injector, are accelerated by magnetic fields to high velocities (~0.1c = 30,000 km/s) and pointed towards the target.
Similar to lasers, accelerator bolts are subject to dispersion over distance, reducing the damage. Due to the unconfined nature of the particle cloud, dispersion is relatively rapid; effective ranges are on the order of several thousands of km. Attempts to improve the effective range by reducing dispersion are being researched, but little progress has been made. The most promising effort involves manipulating the particle cloud into a circulating toroid to self-generate a confining magnetic field. Initial results are promising, but the equipment to induce the toroidal circulation in the cloud has not yet been successful in field trials; the machinery is still too fragile. As the research effort (directed by Imperial Research & Development) has not had significant funding since 2345, there is little hope of a working system in the near future.
Accelerator bolts do damage through direct momentum transfer and electrical discharge. The momentum of an accelerator bolt can be significant; bolts are comprised of enormous numbers of ions moving at very high speed. A typical bolt has 0.1 kg of ionized gas, moving at 0.1c, which equals a momentum of 3x106 Ns. While 3 MNs cannot accelerate a starship, it can punch holes in armor plate when concentrated in the tiny cross-section of an accelerator bolt. In addition to the impact damage, accelerator bolts also dump significant electrical charge into a target. This concentrated charge often causes large currents between portions of a target, burning out electrical systems. This is only be a problem when an accelerator bolt actually penetrates the armored hull of a starship.
Due to the charged nature of a bolt, it interacts heavily with surrounding matter. This causes a slight loss of energy with range, although this effect is swamped by dispersion effects. More importantly, this interaction means that a particle accelerator has an extremely short range in an atmosphere; effective range is roughly 100 m in a Terran atmosphere. Thicker atmospheres reduce the range, sometimes to essentially 0. Thinner atmospheres increase the effective range, up to the maximum range for empty vacuum.
Plasma Projector
Plasma Projectors are a simple, close-range weapon designed to damage or destroy large numbers of small targets. The weapon is essentially a high-tech flame thrower that spews hot plasma into a small area in hopes of burning or melting a target. Plasma projectors require large amounts of hot plasma, virtually requiring a dedicated fusion reactor. Lack of any sort of confinement or collimation means that the emitted plasma is very diffuse, and so the effective range is measured in the tens or hundreds of meters.
The short range nature of the plasma projector, combined with the high plasma requirement, makes projectors unpopular. The major use for such systems is in last-ditch point-defense networks; projectors can saturate a portion of space near the hull with plasma, melting missiles and dispersing accelerator bolts. While expensive to install and maintain, this sort of system can provide a sort of "plasma armor" for a vessel expecting to see very heavy combat from all sides. Most fleet command vessels and the largest capital ships mount full projector systems on all sides.
Railguns
Railguns fire a conductive slug at high speed. The slug is fed into the weapon, where it completes an electric circuit between two superconducting rails. The rails run along the length of a magnetized barrel. The electric current interacts with the magnetic field to accelerate the slug down the rails and towards the target. Railguns are capable of achieving muzzle speeds of 0.01c (3000 km/s).
Railguns cause damage through pure impact. The slugs are simply chunks of conductor and have no explosive payload. Typical slugs mass 10-100 kg, and have muzzle velocities of 0.01c. The mass and speed result in enormous impact momenta; small starships have been noticeably moved by the impact of a railgun slug. Slug impacts normally punch through the hull of even capital warships, making railguns a feared weapon.
Unlike energy weapons, railguns do not lose strength with distance. They are affected by atmopsheres, in that the slugs experience atmospheric drag and heating. In an atmosphere, the maximum muzzle speed of a slug is limited by drag; excessive speed heats the slug to the point of vaporization. Hence, railguns are less threatening due to the lower damage caused by a slow slug.
The maximum range of a railgun is set by the maximum range a target can be reliably hit. Theoretically, a railgun slug could hit something halfway across a star system. In practice, predicting target positions for more than a few seconds is almost impossible. This sets the maximum useful range of a railgun to ~9,000 km (3 seconds of prediction).
Mag Cannon
Mag cannon are almost identical to railguns, with the exception of the slug that is fired. Mag cannon use superconducting magnets to create enormous magnetic fields along the length of the barrel. A warhead fed into the rear of the barrel is accelerated to high speed towards the target. Unlike rail guns, the warhead does not conduct current, and hence it must be ferromagnetic. Muzzle speed is comparable to a railgun.
Because the warhead of a mag cannon does not conduct the enormous currents of a railgun, it can be far more complicated and multi-material. Typical mag cannon warheads are simple shaped blocks of metal, but explosive payload warheads exist. The high magentic fields of the cannon can damage sensitive electronics, making it difficult to use nuclear (fission or fusion) warheads. However, simple impact and proximity fuses on a chemical explosive payload are common. Due to the strength of starship hulls, shaped charges are used exclusively in mag cannon warheads.
Unfortunately for mag cannon manufacturers, the cost of the warheads can become a major factor in deciding between railguns and mag cannon. Railguns, while not offering the flexibility of different warhead types, have the advantage of very cheap ammunition and easy storage of large quantities. Mag cannon can use simple metal warheads, but these are somewhat uncommon in combat loads. The explosive warheads are more hazardous and difficult to store, and more expensive to buy. Typical warships carry a mix of railguns and mag cannon, to provide some flexibility will keeping costs down.
Regardless of the type of warhead (simple metal or explosive), mag cannon have many of the same features of railguns, including the enormous impact damage and range constraints.
Introduction
Missiles are the most versatile weapon carried by spacecraft. Missiles come in many sizes, with diverse warheads and capabilities. In the modern world, where every spacecraft of note is equipped with a Shield Drive, it is the missile's ability to follow a complex flight path that makes them so valuable.
All modern missiles are highly autonomous, with advanced expert systems to guide their flight. These missiles are almost exclusively fire-and-forget, with the target signature or flight path programmed before launch. There are some craft which still use dumb-fire, unguided missiles for extremely close range assault. These weapons are officially classified as rockets (see below).
Missile Classes
There are 2 major classes of missiles, based partly on size and partly on task: anti-ship and planetary bombardment. Anti-ship missiles are the smaller of the two classes, and emphasize agility, acceleration, and accurate guidance. Bombardment missiles are large, slow, dumb, and powerful. Anti-ship warheads are smaller in yield, and consist solely of types that are effective against spacecraft in vacuum and atmosphere (such as fusion). Bombardment warheads are designed to obliterate large, fixed targets; they are as powerful as possible, and can include such types as chemical or biological delivery warheads.
Missile Guidance
Modern missile guidance systems can be separated into 2 types: sensor signature guidance, and pre-programmed flight path guidance. Sensor signature guidance is the more reliable and feared of the two, as these systems can hunt down even the most maneuverable of ships. Pre-programmed flight path systems are simple to build and program, but are unable to deal with rapidly maneuvering targets. Only the poorest of fleets use pre-programmed guidance as the sole option on anti-ship missiles. Pre-programmed paths are particularly useful for creating mine fields, launching bombardment attacks, and denying space to the enemy by creating concussion zones.
Sensor signature guidance systems exist for all major sensor types (EM, including light and radio; gravity gradient; magnetic), and most integrate multiple sensor types. All systems are capable of unattended hunt-and-kill behavior, where the firing ship programs the target's sensor signature and launches the missile. From then on, the missile guidance automation controls the missile engines and detonators. As long as the missile can detect the target signature, it will hunt it down and detonate. Most have target acquisition algorithms to attempt to reacquire a lost target.
All missile guidance systems seek to strike a target from the sides or rear, as it is assumed that the target has an operating Shield drive. For this reason, missile flight paths tend to have enormous arcs at the end, in an attempt to get around the Shield drive field, and reach the hull.
Missile Evasion
Because of the lethality of missile warheads, and the effectiveness of signature guidance systems, starships have devised several ways to defeat a missile, rather than try to outmaneuver or evade; although starships are capable of enormous accelerations with a Shield Drive, combat is virtually impossible at accelerations exceeding several dozen Gs. The primary defense of a ship targeted with signature guidance is to radically alter the ship's sensor signature, causing the missile to lose its target and wander space harmlessly.
Most signature guidance systems rely on a combination of gravity gradient and EM sensors; since the gradient is defined by the operating Shield Drive of a starship (and is very similar between closely sized ship classes), it is far easier to alter a ship's EM signature. Radio jamming, emission decoys, and chaff are common methods employed by ships to try to confuse the missile guidance. At long ranges, these can be effective, as missiles tend to rely on passive sensors. However, at close range, missiles switch to an active sensor array that is very difficult to jam or confuse. At these close ranges, ships are forced to rely on plasma projectors, point-defense systems, and hull armoring to defeat the missile and/or its warhead. It is also common for a ship to try to turn its Shielded front into the missile, protecting the hull from damage; this is basically impossible when attacked by more than a few missiles at a time.
A relatively new concept in counter-missile tactics is the notion of interception fire: using missiles to directly attack inbound hostile missiles. The idea is to intercept inbound missiles at a safe distance and destroy the flight. So far, a few commanders have used gravitic and fusion warhead missiles to acheive this, but only with a success rate of roughly 10%. Training and development of the tactic is increasing, as the newer missile guidance systems are becoming almost impossible to confuse or evade, and the latest warheads are growing significantly in power. With another few years of concerted development, there may well be new automation capable of plotting intercept courses with sufficient speed and accuracy to make interception tactics viable. If that occurs, space combat will undergo a dramatic shift as previously ample missile loads become tiny in the face of the enormous ammunition supply demanded by interception fire salvos. At least a dozen armament Subcons are already working on the automation systems and improving their missile fabrication capacities.
Missile Propulsion
Missile propulsion systems are virtually all short-duration fusion systems. These engines give a missile accelerations measured in the tens of Gs, with a typical anti-ship capable of 72 Gs, and bombardment systems capable of a more modest 30 Gs. Due to the constraints of a misile shell, fuel supplies are relatively limited. Typical missile systems carry enough fuel for 4 hours of burn, although extreme range missiles carry more. There is a StarTech extreme range missile body that has fuel for 28 hours at 72 Gs.
Even with a fusion engine, missiles are remarkably maneuverable. The plasma exhaust can be vented in almost any direction, allowing a missile to perform radical maneuvers with only a single fusion reactor. In general, anti-ship missiles are at least as maneuverable as a starship at similar accelerations. Bombardment missiles, with smaller engines relative to their mass, are less agile.
There are reports of a new sort of missile using a Shield Drive for propulsion, but this can neither be confirmed nor denied. If true, these missiles would be a grave threat to any ship, as the Shield Drive would protect the missile from direct assault and prevent any hope of target evasion.
Missile Warheads
Warheads are broadly classified by the type of missile they are designed to be mounted in: anti-ship or bombardment. Within these broad classes, there are multiple types of warheads available.
Anti-Ship Warheads
There are 3 major types of warheads available to anti-ship missiles: laser, fusion, and gravitic. Laser warheads carry a number of disposable laser systems, which are targeted and fired at the target once in range. Once activated, the lasers continue firing until the missile is out of fuel (and hence the fusion reactor shuts down). Targeting systems in the laser systems look for high emission points of the target, which normally indicate vulnerable locations (comm arrays, weapon ports, engine ports, etc.). While the lasers typically do not cause massive hull damage, they can significantly disrupt a ship's ability to fight. For this reason, these warheads are favored in situations where the aim is to cripple, not destroy the target ship. Pirates and raiders are enamored of this warhead, as they can use them to reduce a target's defenses enough to allow a boarding party to assault the ship. Because of the relative complexity of the laser and associated targeting systems, laser warheads are the most expensive type.
Fusion warheads are low-yield laser-ignited fusion weapons. Yields are typically in the megaton range, although some have been known to top 15 megatons. The smallest fusion warheads are only a few hundred kilotons, which is the minimum useful size for vacuum combat. Starship hulls are extremely tough and direct contact detonations difficult, making anything smaller than 100 kT virtually worthless against modern starships. Despite the enormous power of the fusion warhead, most hulls can withstand several near misses before breaching. This is one of the primary reasons for the advanced guidance systems on anti-ship missiles - a detonation in direct contact with a starship's hull can breach all but the thickest hulls. The guidance systems are necessary to both track an evading target, and also to evade the target's point-defense systems. In the past decade, the shift has been towards larger warheads (1-10 MT) that can cause significant damage from several hundred meters; this is most likely due to the lack of significant advancement in computing power (making better guidance systems difficult to build), and the more widespread use of plasma projectors. As the fusion warhead is the most common type, all sizes are relatively cheap and easy to acquire.
Gravitic warheads are essentially a portion of a Shield drive, rigged to destructively discharge. The result is an enormous gravity gradient near the target, which tends to cause significant structural damage. Unfortunately for attackers, starships with operating Shield drives are virtually immune to these warheads; the Shield drive compensates for the gravity gradient. Against targets without an operating Shield drive, these are very dangerous weapons. Large gravitic warheads have been known to rip space stations and crippled ships into small pieces. On the modern battlefield, these warheads have been all but replaced by fusion and laser types; most fleets maintain a small stock in a task force for use against unShielded targets. There are also some commanders who have used gravitic warheads in a defensive role, using them to attack inbound hostile missile flights. To date, this tactic has not been perfected by more than a handful of commanders, although training in the tactic is gaining popularity as missile guidance improves and warheads grow in power.
Bombardment Warheads
Bombardment missiles have a choice of 2 warhead types: fusion and bioweapon delivery. Fusion warheads are the big brothers of anti-ship missile fusion warheads. They have a typical yield of 100-1000 MT, although there are reports of multi-GT warheads being developed by several Subcons (e.g. Loki Arms). Despite their enormous warheads, fusion bombardment missiles are rarely deployed against starships, as their primitive guidance is easily avoided or intercepted by the target. Against fixed targets (space stations, outposts, cities, etc.), these missiles are exceptional. Note that the Starguild has not deployed these weapons in quite some time, as there is rarely a call for wholesale destruction of cities. The last deployment was against the Seven Worlds, and was minor in comparison to the devastation of the K.E. weapons used there. Despite the rarity of use, the Imperium does maintain several wings of warships outfitted to carry a large number of bombardment missiles, should their use become necessary. Reports from Spectral-invaded worlds indicate the Spectrals use bombardment warheads similar (or identical) to those mentioned here.
Bioweapon delivery warheads are a relatively new type, developed by TRIDENT/RMBK as a secret project on the world Rhand. From the records saved from the Spectral bombardment, the warhead is designed to deliver a bioweapon to a target planet atmosphere. It is capable of releasing in many ways, either altitude or pressure triggered. The delivery does not impose great stress on the payload, to maximize survival of the bioweapon. Moreover, much of the warhead is devoted to protecting the bioweapon payload from harm during launch and transit. RMBK engineers noted that they got the basic idea from the warheads used by the Spectrals to distribute the VISR pathogen on invaded worlds. These warheads could also deliver chemical weapons, although there is no mention of plans to use this capability.
Rockets
Rockets are unguided missiles with large warheads. As they are unguided, they have short burn-times and consequently an extremely short range. They are carried exclusively by small craft for point-blank assault. Rockets have auto-detonation triggers that explode the warhead when the rocket runs out of fuel. This prevents spent rockets from cluttering a battlefield with passive mines.
Typical range for a rocket motor is 1000 km, with an acceleration of 10g. Warheads are of chemical explosives, although they are relatively large - typically 5-10 times the power of a mag cannon warhead. Of the weapons available to spacecraft, rockets are by far the cheapest to install, maintain, and supply.
All mines are based around the idea of being invisible until a target approaches, at which point they detonate their warhead, hopefully destroying the target. Mines are covered in various types of stealth coatings to minimize EM and magnetic signatures, and they use passive sensors to make them radiate even less. The best mines are observable only by noting that some distant stars are obscured by their hull. Even cheap mines are difficult to detect; impossible with only passive scanners.
Warheads are typically fusion or gravitic, with fusion being the most common by far. The warheads are typically identical to that of an anti-ship missile, although some important systems/installations have minefields with bombardment fusion warheads. There is no known case of a minefield with a laser or bioweapon warhead.
Sensors are equal to those on an anti-ship missile, with much the same programming. Mines are set to detonate as a ship passes, to try to avoid the Shield effect of the vessel, and damage the hull. All known mine types use gravity gradient sensors to detect the passage of a ship, and EM sensors to determine the type of ship. Friendly ships traversing a minefield do so with IFF transceivers turned on, to prevent any accidents.
Mine deployment is rapid and easy, as most mines have very small fusion thrusters to aid positioning. Once positioned, the mine goes mostly dormant, saving its fuel. Most mines can remain dormant for 1-2 years with a full fuel load, and 3-4 hours of thrusting to maneuver. Carefully placed mines (that don't expend fuel thrusting) can remain dormant for 5-6 years.
Once activated, mines are notoriously difficult to shut down. Any method of turning off a minefield could be exploited by an enemy, and so mines have no "off switches". The only way to deactivate a mine is to wait for the fuel to run out, or destroy the mine with weapon fire. Enemy ships that find themselves in a minefield (and survive the first detonations) typically use missile volleys to try to blast a hole in the minefield. This often works, but is extraordinarily expensive in terms of missiles, leaving such a ship critically low on its primary ammunition.
Within the Starguild, mines are uncommon in the extreme. There is rarely a call for the extreme measures represented by mines. The major use is to protect secret military and research installations, and even this use is technically illegal. Because of the low demand, mines are relatively expensive to deploy in force, further hampering their use. Imperial ships have begun laying minefields in systems threatened by Spectral invasion, but no Spectral ship has yet to try to test them, so their effectiveness is unknown. With more systems being threatened each year, Imperial demand for mines is growing exponentially. It is expected that the major worlds in the Spectral invasion path will be fully encased in dense minefields in roughly ten years.
The final line of defense of every starship is its point-defense system (PDS). Comprised of anywhere from a handful to hundreds of small automated turrets and a massive expert system to coordinate the defense, PDSs represent a major portion of the expense of a warship. Every starship that expects to meet any danger carries a PDS, as they are useful against missiles, asteroids, and even small starships.
Several dozen Subcons manufacture PDSs in the Starguild, and the Seven Worlds had the most effecient types ever built. A small, civilian starship's PDS typically has 4-8 turrets, each covering one quadrant (octant) of the ship. Each turret has a laser, particle accelerator, or railgun; some systems have multiple weapons in each turret, sometimes of varying types. Large civilian craft have 8-30 turrets, depending on the size of the hull. Military and exploration craft have far more turrets for their size; small military craft start with 8-12 turrets, and capital warships can mount over 200 turrets.
All these turrets and weapons are tied to a massive automated targeting system, which controls the target acquisition and prosecution. These expert systems are programmed to have a threat heirarchy, so that anti-ship missiles are considered more dangerous than passing rocks. These systems are also the main point of differentiation between models. Good automation can make every shot count, vastly reducing the number of turrets needed to defend against a given threat. Poor automation can reduce an extensive PDS to nothing more than pretty lights. In this sense, the Seven Worlds, with their advances in automation, manufactured the most efficient PDSs ever seen. A typical 7 Worlds PDS had 1/2 to 1/3 the turrets of a Starguild equivalent, yet provided equal protection.
Because PDSs are expected to protect a ship from multiple threats for extended periods, most weapons are energy based to remove ammunition concerns. Some PDS installations have a few railguns with large ammunition bays to handle particularly difficult targets (such as large asteroids or small starships). Due to the power and reaction mass requirements of particle accelerators, lasers are the most popular choice.
The effective range of a PDS is based mostly on the range of its weapons and sensors, although none are reliably effective beyond 1000 km from the hull. Normal programming has the PDS begin engaging targets at maximum weapon range, just in case the system gets lucky. This means that anything within ~10,000 km of a ship is in danger from a PDS.
Despite the bristling turrets and advanced automation of a PDS, it is truly a last-ditch defense. Even the best PDSs have a difficult time hitting a modern missile, making it risky to rely on the PDS when facing hordes of inbound missiles.