Warp drive is by far the most widespread method of faster than light travel used in the alpha quadrant. Invented in 2063 by Zephram Cochrane of Earth1 (and later of Alpha Centuri)2
, the first of his warp drives used a fission reactor to create a low energy plasma stream. This was split into two and directed through a pair of warp coils to produce a field around the ship which propelled it - briefly - faster than the speed of light.
Humans subsequently sold warp drive ships to many other cultures, and this technology has become common within the quadrant with over 2,000 species using it. The present day state of the art is not fundamentally different from Cochranes original system; ships today generally use matter / antimatter reactors rather than fusion ones, and dilithium has allowed more advanced power systems. The warp coils themselves have also become more numerous and complex in design.
For the future, many developments are possible. Over a century since it was first envisaged, transwarp drive remains seemingly just beyond the reach of Federation science.3 Other lines of research involve soliton wave drive, which would allow warp travel without ships having to carry warp drive4, co-axial warp cores, which allow instantaneous travel over sizeable distances5 and slipstream technology6, variants of which could theoretically allow travel at hundreds of light years per second. If this latter technology ever came to pass, it would make travel on an intergalactic scale easily feasible.7 On the other hand, the idea of generating stable artificial wormholes for interstellar travel is also being researched and if successful this may render warp drive totally obsolete.8
There are two distinct fuel storage systems on board any starship; the matter storage is generally a single large fuel tank holding a large amount of slush Deuterium - in the case of the Galaxy class there is 62,500 m3 of actual Deuterium within 63,200 m3 of tankage space - the rest being accounted for by internal compartmentalisation of the fuel tank.9 The ship thus carries 12,500 metric tons of fuel, sufficient for a mission period of seven years at the cruise speed of warp 6.10
The antimatter is contained within much smaller pods; the standard starship antimatter pod is capable of holding 100 m3 of fuel for a total of 3,000 m3 in a Galaxy class Starship.11 Starfleet is somewhat reticent about revealing exactly how much antimatter is kept on board its starships, as this would allow threat forces to make detailed estimates of the total output of a ships power systems. In the event of a systems failure which threatens antimatter containment, the pods can be thrown clear of the ship by emergency systems of considerable reliability.12
Fuel from the pods is sent to the reactant injectors; these are designed to condition and feed streams of matter and antimatter into the warp core. The matter reactant injector is located at the top of the warp core; it is a conical structure some 5.2 metres in diameter and 6.3 metres high. The injector is constructed of dispersion strengthened woznium carbmolybdenide. Shock attenuation cylinders connect it to the deuterium fuel tank and the skeletal structure of the ship, allowing it to 'float' free within the structure.
Within Starfleet vessels, the MRI contains redundant sets of crossfed injectors. Each injector would consists of a twin deuterium manifold, fuel conditioner, fusion pre-burner, magnetic quench block, transfer duct/gas combiner, nozzle head, and related control hardware. Other designs are in use by civilian craft and other species. Although operation varies from class to class, in general slush deuterium enters the inlet manifolds and is passed to the conditioners where heat is removed. This brings the deuterium to just above solid transition point; micropellets are formed and then pre-burned by a magnetic pinch fusion system. The fuel is them sent on to a gas combiner where it reaches a temperature in the region of 106 K. Nozzle heads then focus the gas streams and send them down into the constriction segments.
Starfleet safety protocols require that should any nozzle fail, the combiner can continue to supply the remaining nozzles which would dialate to accommodate the increased fuel flow. The present generation of nozzles are constructed of frumium-copper-yttrium 2343.
The antimatter injector lies at the lower end of the warp core. Its internal design is distinctly different from that of the matter injector owing to the dangerous nature of antimatter fuel; every step in manipulating the antihydrogen must use magnetic to keep the material from physically touching any part of the structure. In some ways the ARI is a simpler device requiring fewer moving components. It uses the same basic structural housing and shock attenuation as the matter system, with adaptations for magnetic suspension fuel tunnels. The structure contains three pulsed antimatter gas flow separators; these serve to break up the incoming antihydrogen into small manageable packets and send them up into the constriction segments. Each flow separator leads to an injector nozzle and each nozzle cycles open in response to computer control signals. Nozzle firing can follow highly complicated sequences resulting from the varying demands of reaction pressures and temperatures and desired power output, amongst other factors.13
The magnetic constrictors make up the bulk of the warp core. They provide physical support to the reaction chamber, pressure containment for the whole core and, most importantly, guide and align the fuel flow onto the desired location within the reaction chamber.
The matter constrictor is typically longer than the antimatter constrictor, as antimatter is easier to focus and so requires a shorter distance for the same accuracy. Typically, the magnetic constrictors are divided into segments; each segment will contain several sets of tension frame members, a toroidal pressure vessel wall, several sets of magnetic constrictor coils and related power and control hardware. Constrictor coils will have dozens of active elements, and on more advanced designs these will be configures to contain the magnetic field almost wholly within the constrictor, with minimum spillage into the exterior environment. Starfleet warp cores usually have the outermost layers of the constrictors constructed of a semi-transparent layer which allows harmless secondary photons to escape from the inner layers, creating a glow effect. This gives an immediate visual cue to the current activity rates within the warp core.
As the fuel is released from the injector nozzles, the constrictors compress it and increase the velocity considerably. This ensures the proper collision energy and alignment within the reaction chamber.14
This is in many ways the "heart" of the ship. The principle function of any reaction chamber is to allow the matter and antimatter streams to come together and direct the resultant energy flow into the power transfer conduits. This apparently simple task is rendered highly complex by the need to allow the various sensor and other monitoring and control equipment to function within the chamber. The addition of dilithium to regulate and control the reaction, while allowing far higher efficiency and so increasing the power output, has also lead to ever more complex designs - most especially in more recent starships which are designed to allow continual recompositing of the dilithium whilst in use. Nevertheless, reaction chambers of today perform fundamentally the same task as those of a century ago or more.15
Dilithium is a key factor in the design of any efficient matter / antimatter reactor, and has been incorporated into Federation Starship designs since it replaced lithium crystals in 2265.
The key to the success of dilithium lies in the remarkable properties of this material. When subjected to a high frequency electromagnetic field in the megawatt range, dilithium - or 2<5>6 dilithium 2<:> diallosilicate 1:9:1 heptoferranide to give it the full scientific name - becomes completely porous to antimatter. The field dynamo effect created by the iron atoms within the crystalline structure allows antimatter atoms to pass through without actually touching it; it is thus the only known substance which does not react to the antimatter fuel commonly used in Starships. Dilithium can thus be used to mediate the reaction, boosting efficiency.16
Early reactor designs used naturally occurring dilithium, and considerable time and effort was spent in locating sources of dilithium ore. This led to confrontations between major powers seeking to secure new sources, most especially between the Klingon Empire and the Federation.17 The Federation was largely successful in these efforts, and the Klingon Empire was forced to expand its mining operations on the few sources it did have access to. Such over mining was a major contributory factor in the catastrophic explosion on Praxis in 2293, which ultimately led to peace between the two powers.18
Eventually reliance on natural dilithium was reduced after breakthroughs in nuclear epitaxy and antieutectics made it possible to synthesize dilithium for Starship use through theta-matrix compositing techniques utilizing gamma radiation bombardment.16 However, refining dilithium ore is a procedure which is still viable for Starships which are unable to obtain synthetic dilithium from a Starbase or other manufacturing facility. This is not generally a problem within known space, but USS Voyager has resorted to collecting dilithium ore to aid her in the long journey back to the Federation.19
The power transfer conduits are similar in nature to the magnetic constrictors of the warp core, in that they are ducts designed to use high energy magnetic fields to carry energetic plasma from one point to another. But where the magnetic constrictors operate only across relatively short distances and require a very high degree of precision with a comparatively low energy plasma, the PTC's must carry very energetic plasma across large distances with - relatively speaking - far less finesse.
Federation starships are equipped with a separate PTC line for each nacelle, a measure which increases resistance to battle damage or other failures. Since most Starships have twin nacelles, two PTC's will typically be arranged to be symmetrical about the ships centreline. These will proceed through the bulk of the engineering hull and along the connecting struts, if any, to the nacelles themselves.
Smaller versions of these heavy duty systems are also used to carry power to components such as the phasers, shields, and high energy scientific laboratories.20
At the terminus of the Power Transfer Conduits are the plasma injectors. One of these devices is fitted in each nacelle, and has the task of sending a precisely aimed plasma flow through the centre of the warp coils.20
Because of the relatively low accuracy with which the plasma flow is usually controlled by a PTC, the plasma injector system must often be designed to re-condition the fuel flow in order to dampen down turbulence and so ensure a smooth flow through the warp coils. In many Starfleet designs, most especially those systems with the highest raw power output, the plasma flow from the PTC is split into two parts and sent through swirl dampers before being recombined during the injection process. Long experience has found that this method reduces the size of the required hardware to a reasonable minimum.
After its long journey from the fuel systems, the flow is finally directed down the warp coils. These devices are large split toroids which take up the bulk of the nacelle. In order to increase efficiency they are usually made from multiple layers of various materials; this complicates the manufacturing processes greatly and has - so far - kept the replication of warp coils beyond Federation science.
The warp coils generate a multi-layered set of fields around the craft, creating the propulsive forces that enable a Starship to travel beyond light speed. Manipulation of the shape and size of the field determines the velocity, acceleration and direction of the vessel.21
Warp coils are composed of verterium cortenide, a densified composite material composed of polysilicate verterium and monocrystal cortenum.22
Once the energy of the plasma is transferred to the warp coils it is used to create a warp field which encompasses the vessel. The field is what drives the shp to warp speeds.23
The Bussard collector is a device which is designed to collect interstellar gases - usually hydrogen - for use as fuel. They are not really intended for general use, but are rather an emergency system which can let a Starship limp to a nearby base if the standard fuel supply has been exhausted.24 On Federation vessels the Bussard collectors are usually situated at the front of the nacelles, and are typically visible as a large red-glowing dome. As well as being used to collect gas, the collectors are capable of being back-flushed to expel gas into space.25
In the event of an emergency, Federation Starships are able to dump the plasma overboard to facilitate the fastest possible shutdown of the main power system. The system differs from ship to ship; on a Galaxy class vessel each nacelle has a single plasma vent below the plasma injectors26, whilst on the newer Intrepid class plasma can be vented from the entire length of the nacelle simultaneously.22
In extrem situations where a breach of the warp core is imminent, Federation Starships are designed to be able to disconnect the core from their supporting systems and eject it into space. On occasion this will allow both core and ship to be preserved, allowing the core to be recovered and re-mounted.27 Sovereign class starships could remote-detonate their cores after ejection if required.25 Core ejection systems were not always effective, and could be neutralised by battle damage.28