Photon torpedo
The photon torpedo, an fictional weapon popularized by the Science Fiction saga Star Trek, is a space torpedo armed with an antimatter bomb. In Star Trek, these weapons are often part of a starship's and space station's armaments.
Background
Photon torpedoes are most useful for combat while ships are engaged in warp speed travel, as phasers, which are confined to the speed of light, are not generally usable. (The Starfleet Technical Manual does list a number of ways a phaser can be used at greater-than-light speeds, though, as several television episodes have violated the prior "rule.")
Starfleet, the military/exploratory arm of Federation, uses a number of different versions of the photon torpedo with various guided, un-guided, and high-speed versions. The Mark IV and Mark V torpedoes are micro torpedoes that are used aboard small ships like Danube class runabouts and shuttles.
The photon torpedo was first introduced during the first season episode "Arena" of Star Trek: The Original Series. During the run of DS9, photon torpedoes began to be replaced by more powerful quantum torpedoes, which have also been used in the more recent Star Trek films. The Romulans have never used photon torpedoes, instead relying on plasma bolt type weapons.
Star Trek: Voyager had an ongoing story of a limited supply of photon torpedoes as they were impossible to replicate. Of the 38 torpedoes Voyager was stated as carrying, 93 were used in the course of the series, implying that this problem was somehow overcome off-screen. This is further supported by the fact that the self-replicating mines used in the Star Trek: DS9 episode Call To Arms are essentially photon torpedoes without the propulsion system.
During their mission, the starship Enterprise, NX-01, encountered two species that used matter/anti-matter weaponry, the Klingons and Vissians. When the Enterprise was reassigned to the Delphic Expanse, Starfleet technicians installed this new weaponry, which were named photonic torpedoes, the differences between photon torpedoes and photonic torpedoes are unknown.
Photon torpedo specifications
Photon torpedoes are launched from specific launchers usually installed on ships or stations. For example, the Intrepid class starship has four launchers, two forward and two rear of the spoon-shaped saucer. These launchers can typically fire multiple torpedoes simultaneously or single torpedoes in rapid succession. A photon torpedo is usually self-guided, though in some situations it can be directly controlled by the ship that launched it.
A typical photon torpedo is an elongated elliptical tube that measures 2.1 m in length, 0.76 m in width, 0.45 m in height, and 247.5 kg in dry mass. These launchers are also used to launch similarly shaped science probes and can perform burials in space.
Note: The typical tube-shaped torpedo casing was first alluded to in Star Trek: The Motion Picture and actually seen in Star Trek II: The Wrath of Khan. It was never seen in Star Trek: The Original Series, nor was there any implication of an actual casing that was used during TOS.
Photon torpedo casings are known to be extremely tough, capable of surviving intact high-speed entry into the atmosphere of an M-class planet. A photon torpedo can also survive the subsequent high-speed impact into the surface and burial deep in the liquid core of said planet, such as in the episode Pen Pals. Torpedo casings are also often used for various probe designs - e.g. the Class IX Long-Range Multimission Warp Probe.
A standard Next Generation photon torpedo holds 1.5 kilograms of small pellets of anti-deuterium and 1.5 kilograms of similar deuterium suspended in a magnetic field. Yield is reduced by including fewer pellets. The torpedoes do not have their own warp drive, but they do have a warp sustainer engine that can keep them going at faster than light speeds, if launched by a ship at those velocities.
The emissions created by a photon torpedo detonation can be modified on demand, though the modifications can often take several hours.
Photon torpedo physics
Through basic calculations we can derive that the maximum energy produced by a detonation of a TNG photon torpedo. The basic power of the annihilation of 1.5 kg of deuterium by 1.5 kg of anti-deuterium [citation needed] is approximately 64.53 megatons (E=mc²). Unfortunately, currently Starfleet does not appear to have the ability to focus the blast photon torpedoes at a single target (ref. TNG episode "The Nth Degree" ). Therefore, in an optimum situation we can expect the shields of the target vessel to receive about 30% of the energy, with the rest of it dispersing uselessly.
To delve deeper into the subject, consider the fact that the resulting energy is emitted in various ways (such as gamma rays and exotic particles). At the same time we know that photon torpedo casings are extremely tough and dense - as mentioned above, one survived a fall from orbit into an atmosphere of a planet, completely intact. This density allows us to estimate that the photon torpedo casing can absorb a significant amount of the energy emitted by the deuterium-antideuterium annihilation.
For an approximation, lets assume that only 90% of the energy is absorbed by the casing. Just as during a nuclear detonation process, the result of this absorption will create a plasma fireball traveling at an enormous velocity composed out of the superheated torpedo casing. If we assume the same time scale as for a standard nuclear weapon, the plasma ball will expand at 30 km/s, impacting the target of the photon torpedo.
If we continue the analogy with nuclear weapons, the fireball at the same time emits various types of radiation, the types of which are dependent on actual torpedo casing composition. The fact that Starfleet can somehow control the emitted radiation of a photon torpedoes is also confirmed by the "Redemption" (Part 2). During that episode Data fires torpedoes with the radiation tuned to detect cloaked Romulan starships, though the exact mechanism of the tuning is unclear.
To sum up, these calculations tell us that a photon torpedo detonation will deliver approximately 17 megatons of energy (64.53 * 0.3 * 0.9) to the target vessel in the form of a physical impact and various types of radiation.
Note: In the Deep Space Nine episode, "Apocalypse Rising", Damar states that a "full spread" of photon torpedoes is suffient to destroy the "Klingon High Command and everyone else within a few hundred kilometers". To which Chief O'Brien replies that attacking Ty'Gokor, a heavily fortified, planetoid-based facility, would be futile as the Bird of Prey starship they are on will likely be shot down before it can even get off a single torpedo, and that the facility's shields can readily withstand "a dozen" photon torpedoes. Photon torpedoes creating devastation across hundreds of kilometers (assuming no shields), indicates that even several torpedoes from a relatively small klingon vessel can still manage to create a potential combined firepower in the hundreds of megatons. For comparison, the Tsar Bomba of the Soviet Union was intended to be a demonstration model for a 100 megaton weapon, which in theory could level urban areas out to a distance of some 60 kilometers wide, and cause further devastation out to 100 kilometers. [1]
Funerals
- In Star Trek II: The Wrath of Khan, Spock's dead body is "buried in space" with a photon torpedo casing as a casket. The Deep Space Nine episode "Tears of the Prophets" features Jadzia Dax's body in a photon torpedo casing, although the actual burial (if any) is not observed. Although not a main character, in the Voyager episode "One Small Step" early space explorer Lieutenant John Kelley is given a space burial in a photon torpedo casket. Also, the body of Dr. Ira Graves from the TNG episode The Schizoid Man buried in a photon tube, although instead of being launched from the ship's torpedo room (possibly an custom reserved for Starfleet personnel), he was simply beamed into space. In the Star Trek: Enterprise episode Similitude, a clone of Trip is "buried" in much the same manner.
Trivia
- In Xenosaga references to photon torpedoes are made, likely an intentional nod to Star Trek.
- The sound effect was originally used for The Martian Skeleton-beam in War of the Worlds