Point-Defense Shield (PDS) systems are often installed onto ships as a means of basic, point-blank defense against ballistic weapons and direct-energy weapons. Every ship manufactured under HOA regulations have built-in PDS systems, and all space-fairing ships (regardless of manufacturer) are required to have bow-shields to deflect space debris during near-light and faster-than-light travel. There are two variants of PDS: plasma-wall, and magnetic field. The first human vessel to utilize a PDS system was the ESS Spirit of Discovery, which launched in the year 2082 CE with the intent of exploring beyond the Solar System.
Point-Defense Shields can be split into two distinct categories: Plasma walls and Magnetic fields. The latter is used almost exclusively on the bow (front) section of a ship, while the former is used predominantly on the stern (back), port, and starboard (sides) sections of a ship. It should be noted that PDS systems are designed to be used as a secondary defense in addition to a ship's material defenses, and are not intended to replace them entirely.
Magnetic field geneartors utilize superconductors to create a powerful magnetic field that can deflect small pieces of space debris and charged particles (such as from a nearby star). Even microscopic particles can cause large-scale destruction to a ship when moving at near-light speeds. Once the magnetic field has been created, it can be sustained indefinitely (assuming it is fed by a steady stream of power). Under the ISAT Standardizaiton Agreement, all ships, regardless of manufacturer, are required to have front-mounted magnetic shielding. The human-made Valiant Co. Model 93 is currently the most powerful, and widely-used magnetic shield system in use. ISAT standardized shield generators are generally about the size of an average refigerator, and are stored close to the ship's front, where they won't interact with most of its more vital electronics. Such generators have their own independant power supplies from the rest of the ship (and thus must be recharged separately); power cannot be re-routed to or from them.
Limitations and draw-backsEdit
Magnetic shields have limited uses, because they cannot protect a ship's crew from electrically neutral photons (such as those emitted by nearby stars). They also cannot protect against direct-energy weapons, with the notable exception of particle-beam weapons. Though rare, any electronics that do not have proper shielding of their own can potentially be damaged by a magnetic shield. Most front-mounted shields are situated well ahead of the remainder of the ship in any case, so this is seldom a major issue.
Plasma wall generators utilize "megaconductors" to create concentrated fields of plasma strong enough to vaporize anything they come into contact with. They can also be tuned to the frequencies of Electromagnetic (EM) weapons, neutralizing them in the process. These shield generators are often used to protect military vessels during combat, and are installed primairly on the port and starboard sections of ships. They often have hefty power requirements, and are rarely seen outside of a military setting as a result. Plasma shields are, in general, far more useful then their magnetic counterparts, because they can also deflect electromagnetic radiation (although they must be tuned to its frequency first). The Omorran-designed Type-9 generator is currently the most widely-used plasma shield generator within organizaitons such as the HOA and ISAT. Such generators often bring with them hefty power requirements, and thus are seldom seen on anything that isn't a military vessel. Even within this limitation, the megaconductors require so much energy that power is often automatically re-routed from a ship's warp dirve directly into the generator.
Limitations and DrawbacksEdit
While powerful, plasma shielding is not without its drawbacks, and the main area of concern in this regard is energy requirements:
- Power must often be re-routed form a ship's warp drive directly into the generators' feed channels, meaning that a ship cannot be traveling at FTL speeds and remain shielded at the same time. By extension, this also means that only ships with FTL capabilities can even use plasma shields in the first place (unless a sufficiently large power supply is installed in lieu).
- In addition to this, a tremendous amount of energy is required to even activate the shields in the first place. As such, the megaconductors are typically charged well in advance of use, so that they can be activated without worry. The time required to fully charge a single megaconductor varies depending on its size: For those used in detached command modules and small-crew pods (such as those used in evacuation devices or LOS shuttles), they can take upwards of 8 hours to fully charge; for those used in large-scale vessels such as the Lady Mercury or HOA capital ships, they can take upwards of 28 hours to fully charge.
- After activation, the shields can only remain active for a short period of time, before they completely drain their fed power supply. Again, this varies depending on size, but average "up-times" are between 60 - 80 seconds. A ship's crew is instructed to only activate plasma shields as a last resort defense, or if, "Overwhelming victory can be assured with the use, and absense thereafter, of plasma shielding."
Beyond this, there are a number of practical issues that come with plasma shielding:
- One a shield has been activated, it will reach temperatures upwards of 25,000K, and anything that comes into contact with it will be vaporized instantly. In the vacuum of space, it is rare that one will come across more than space debris. Nevertheless, ship captains are taught to exercise extremely caution.
- When used as defense against an EM weapon, the shield must be tuned to that weapon's precise electromagnetic frequency to completely neutralize it. In doing so, any radiation with a frequency less than the frequency of the shield is also cancelled out. For example, if an enemy ship fires a hypothetical "blue laser", and you tune your plasma shields to the frequency of "blue light", anything that emits green, yellow, and red light will be rendered invisible. Within a more practical scenario, activating shields tuned to infrared radiation (and anything above) will cancel out any incoming radiowaves, making comminucation between ships nearly impossible for a few seconds.
- FInally, the megaconductors strictly work on a "Point A to Point B" system, and must be mounted onto a flat surface. This means that there will inevitably be vulnerable "holes" between the plasma walls, which can be found and exploited. In addiiton, it is impractical to cover a ship entirely with generators, thus they are often mounted to only protect vital areas (such as a ship's warp drive).