Propulsion

Propulsion systems are powered by fuel refined from tylium ore. A ship's primary propulsion systems, referred to as "sublight engines", allow it to travel at a slight fraction of the speed of light, which is sufficient to traverse the distances between planets in a solar system in relatively short timeframes. Most ships in the series also have a secondary system, called a faster-than-light drive (or "FTL"), that enables a ship to travel interstellar distances almost instantaneously, by "folding up space" in between the ship and its destination. Since, under normal circumstances, a ship that has used its FTL drive cannot be followed without explicit information about its destination, this technology is used extensively in strategic and tactical manoeuvres. 
==Sublight propulsion==
All ships have some manner of sublight flight ability. Sublight propulsion is convenient for intra-solar system travel (such as to or from the planets that comprise the Twelve Colonies), but cannot be used for travel outside of a solar system as the time to arrive at a destination may exceed the fuel supply of the ship or the lifetime of the crew that fly the ship.
Sublight engines work in an atmosphere as well as in space. A Battlestar is never seen doing this, and its large mass might prohibit planetary landings altogether, but it employs sublight engines for normal spaceflight. Smaller vessels are known to employ rocketry-based RCS thrusters for manoeuvring and small course adjustments.
Vipers are equipped with a thrust reversal system to counteract or arrest their forward momentum. No such mechanism exists on capital ships, but such vessels might turn by 180° to decelerate.
 
Cylons baseships do not have any visible exhaust nozzles or other external structural mechanisms that suggest propulsion ability. It is possible that force fields of the artificial gravity generators are the source of the sublight propulsion. 
Both Colonial and Cylon missiles used in combat appear to be rockets, leaving a trail of gas behind them.
The law of conservation of momentum requires that any propulsion system which adds momentum to a spacecraft or missile in one direction must equal the amount of momentum that is imparted in the opposite direction to something else, as in the example of the controlled combustion of rocket fuel creating thrust in the opposite direction of a ship's or missile's movement. battlestars, for example, possesses two very large thrusters on the bow of the ship to counteract the force of the main engines. However, many other vessels don't appear to have such thrusters.
==Faster-Than-Light travel==
FTL is a acronym for Faster-Than-Light. The term refers to a means of interstellar propulsion utilized by the Cylons and the Colonials. A common shorthand term for FTL travel is "jumping", as this space-folding drive involves making instantaneous "jumps" across vast distances in space.
The FTL drive makes interstellar travel possible for both the Colonials and Cylons. No longer confined to their own home solar system, the Cylons managed to avoid Colonial interference for 40 years after the Cylon War and establish their own home-world. However, not all ships — from small to large — are outfitted with these drives. 
It is likely that FTL drives are not commonplace on many civilian ships because of the costs involved in using and maintaining the drive and the amount of fuel available. For some civilian ships that travel comparatively short distances between some destinations FTL may simply be impractical or unnecessary.
The technology behind FTL systems is such that, providing the relevant data is known, ships can jump with a high degree of accuracy, allowing ships to rendezvous in space and even "park" in a synchronous orbit directly above a given point on a planet's surface. Proper FTL use even enables vessels to arrive in crowded areas, such as the middle of an asteroid field or other ships, without the risk of collision and damage.
 battlestars have two FTL drives, and other smaller or civilian ships have a single drive. FTL drives are "spun up", suggesting the application of electromagnetic or rotational principles. Similarly it may be just a turn of phrase.
FTL jump drives can be used within an atmosphere. This Colonial tactic is used often to evade Cylon detection. Raptors primarily perform these kind of jumps.
=== Colonial Limitations ===
* Colonial FTL systems are not small-scale, and cannot be installed into vehicles such as the Viper. They can, however, be used on vehicles the size of a Raptor, which is limited to brief, short-distance jumps. Raptors can make a sequence of short FTL "hops" in a row, to reach the same destination as a capital ship with a full-sized FTL drive. 
* Colonial FTL systems cannot be used multiple times over a long period of time, for they are prone to breakdown after excessive, repetitive use.
* FTL jumps can apparently induce nausea or discomfort in some people.
* When "jumping" the Colonial drive systems are limited in size; this defines the maximum size to which a colonial vessel can be built (hence the need for certain battlestars to retract their landing pods and reduce their overall cross-section prior to a jump.
* Colonial FTL systems appear to be a holdover from the Exodus from Kobol, and their current designs have been developed to meet the needs of jumping between the Twelve Colonies, and their outposts in other star systems. Colonial FTL capabilities have defined limits, referred to as the Red Line, beyond which jumps may not be possible or could result in damage to a vessel's drive system or lead to navigational inaccuracies that might put the ship at risk.
* Navigators must be careful to plan FTL jump paths in order to keep a safe distance from planets or other large objects.
* "Spooling up" a Colonial FTL drive takes at least 20 minutes when the drive has been offline. Because of this, when ships enter dangerous situations, they keep their FTL drives "spun up."
Knowing the limitations of their own FTL drives, a team apparently led by Lieutenant Felix Gaeta successfully refitted a Raptor with the navigational computer from a captured Heavy Raider (presumably the one used by Kara Thrace to return from Caprica in "Home, Part I"). They later use its improved jump plots (with the aid of the cooperative copy of Sharon Valerii) to coordinate a squadron of Raptors to fly back to Caprica for a rescue mission to retrieve a team of resistance fighters there (Lay Down Your Burdens, Part I). Despite the accuracy of the advanced Cylon FTL technology and Valerii's aid in marking the jumps, two Raptors do not complete the mission. One obtains corrupted jump data and finds itself within a nebula and a undiscovered habitable planet, and is forced to return to the Fleet. The second Raptor also receives corrupted coordinates and materializes inside a nearby mountain on the final intra-atmosphere jump to Caprica, with the loss of ship and crew.
=== Cylon Advantages in FTL ===
* Cylon FTL systems can be manufactured on a smaller scale to their Colonial equivalent, thus allowing the Cylon Raider to be outfitted with an FTL drive.
* Cylon FTL drive systems are far more efficient than their Colonial equivalent. Raiders can jump the distance from Kobol to Caprica in one jump.
* That superiority however does not stem directly from the FTL drives, but mainly from the superior Cylon navigation system, resulting in more accurate jump calculations. Colonial vessels interfaced with a Cylon computer can increase their jump range by a factor greater than ten.
Given that the Cylons left Colonial space to find their own planet, it is possible that their longer-range FTL capability was created in response to a desire to be able to cover the distance between their homeworld and those of the Twelve Colonies with a single jump.
The Cylons may also be capable of faster-than-light communication.
==Background to FTL - Out of Character==
In establishing the series the creators of the new Battlestar Galactica determined to keep everything within the show very "natural". This means steering away from the standard clichés of television science-fiction: no bumpy-head aliens, no remarkable technology such as matter/anti-matter conversion, etc. So how is the concept of faster-than-light travel possible within this precept?
===Underpinning Theories===
The FTL drive technology used within the Re-imagined Series appears to be based on the use of Superstring Theory and M-Theory that essentially enable the "jump drive" systems to "fold" space, reducing the distance between any two points by creating a "corridor" through space that links them together (essentially forming a wormhole, or Einstein-Rosen Bridge). Such "corridors" are allowed by the general theory of relativity; what M-Theory does is provide a way to change the topology of space-time dynamically.
The use of such wormholes is based on the tenet that space is curved. Hence the term "wormhole", which arises from the analogy that space can be seen as an apple. A worm can travel from one side of the apple to the other in two ways:
* By crawling over the surface, or
* By burrowing through the apple (creating a "wormhole").
Obviously, the second option is considerably shorter than the first.
===Relativistic Acceleration===
A key point concerning the use of wormholes within the new Battlestar Galactica is that they do not break the fundamental limiting factor of our universe: the speed of light. Vessels in Battlestar Galactica do not accelerate to faster-than-light velocities. Rather, they use the wormhole to reduce the distance to their destination, thus giving the impression of faster-than-light travel. 
However, the FTL jumps in the series do allow information to be sent faster than light can send it, which results in a violation of causality within the special theory of relativity. (ie. If event A comes before B from one viewpoint, there will be other equally valid viewpoints where event B takes place before A.) Causality is not violated by FTL in a universe that has a special fixed reference frame, however this contradicts current understanding.
This is the reason why FTL jumps are virtually instantaneous within episodes. It also means that the only direct form of propulsion available for vessels is generated by their sublight drive systems. In turn, this is why vessels exiting from a jump are traveling at the same velocity as when they committed to the jump.
===Feasibility===
While the use of wormholes in this manner is not currently possible, work is progressing on superstring and M-Theory which may make the creation of wormholes possible in the future. The limiting factor is the ability to generate negative energy densities, which are allowed (though severely restricted) by quantum mechanics. As such, the use of such systems again meets one of the stated desires of the the producers of the new Battlestar Galactica: not to rely on the "traditional" trappings of science-fiction that require exotic science and technology. Theoretical physicist Kip Thorne has carried out extensive research into wormholes, and helped develop a scientifically-consistent means of wormhole travel used by Carl Sagan in his novel "Contact" which bears a remarkable similarity to the technology employed within Battlestar Galactica.
==See Also==
*Combat jump
*Jump formation delta
== External links ==
* FTL at Wikipedia.
Category:Technology
Category:Terminology