Tylium is a material used to fuel the propulsion systems of Colonial and Cylon spacecraft. At least three forms exist: tylium ore, refined tylium precursor, and refined tylium (the fuel itself).
Typically, tylium ore is mined from asteroids and is apparently not found on the Twelve Colonies natively. Large tylium ore deposits can keep fleets fueled for years (TRS: "The Hand of God"). In its raw form, tylium is a relatively fine, powdery substance that is liquefied and refined by refinery ships. Care needs to be taken to not introduce impurities into the fuel, which can cause engine malfunctions (TRS: "Dirty Hands").
According to Dr. Gaius Baltar, tylium has the following characteristics:
- Tylium ore is rendered inert and unusable when exposed to nuclear radiation
- Refined tylium precursor is more unstable and much easier to ignite than the finished fuel itself
- Refined tylium has a tremendous enthalpy to the order of approximately half a million gigajoules per kilogram, or about 6 times greater than uranium-235 and 81% that of deuterium fusion.
- A tylium detonation results in no radioactive fallout (TRS: "The Hand of God")
Pure tylium can be easily detonated by a conventional warhead. Moreover, igniting fuel lines on spaceships usually quickly result in their loss (TRS: "Miniseries, Night 1"). The fuel can also be used to construct improvised mines (TRS: "The Eye of Jupiter").
Practically nothing on the fuel is mentioned in the Original Series.
In the Original Series, the term was pronounced as "TIE-lee-um" as opposed to "TILL-lee-um" in the Re-imagined Series, as heard in "Saga of a Star World".
- Enthalpy describes the thermodynamic potential of a system (H), and its simplest definition is the sum of the system's internal energy (U), and the product of its pressure (p) and volume (V): H = U + pV.
- The official series web page on the Sci-Fi Channel web site incorrectly spells the substance as "tyllium" in the description of the mining ship on the ships page. As the Original Series DVD material, as well as labels seen in "Dirty Hands", show the spelling as "tylium," Battlestar Wiki contributors should use "tylium" as the correct spelling.