Quantum Torpedo
The quantum torpedo was a tactical weapon used by at least the Federation Starfleet, the Terran Rebellion and the Cardassian Union.
Specifications
Federation quantum torpedoes apparently use the standard photon torpedo casing. (DS9: "Valiant")
Nog modifies unspecified torpedoes with photon torpedo casings in this episode. When they are fired the effect is identical to the quantum torpedo. A line in DS9: "For the Uniform" suggests the quantum torpedo might be some type of plasma torpedo as plasma warheads on quantum torpedoes 3 and 4 were mentioned in the episode. Even a direct hit from a quantum torpedo might not destroy solid neutronium. (DS9: "To the Death")
History
Quantum torpedoes were considered an upgrade to the standard photon torpedo. Deployment began throughout Starfleet in the beginning of 2371. In the same year, the mirror universe Terran Rebellion obtained quantum torpedo technology by stealing it from the Federation, along with the plans to build a Defiant-class starship. (DS9: "Defiant", "Shattered Mirror")
Quantum torpedoes have been carried aboard Defiant- and Sovereign-class vessels, the USS Lakota, and the Federation attack fighters. The Cardassian mobile weapon Dreadnought carried quantum torpedoes. The Cardassian torpedoes would have needed modifications in order to be launched from a Federation torpedo launcher. (DS9: "Paradise Lost", "Sacrifice of Angels", VOY: "Dreadnought", Star Trek: First Contact)
Torpedoes fired by the Federation attack fighters were identified as quantum torpedoes in the script of the Sacrifice of Angels.
Applications
In 2371, after hijacking the USS Defiant and taking it deep into Cardassian space, Thomas Riker utilized the ship's quantum torpedoes against a modified Keldon-class cruiser just outside the Orias system. The Defiant fired four torpedoes at the cruiser; two hit the ship's ventral hull, and two hit the tail. The damage from these four torpedoes knocked the ship's defense systems offline and caused the loss of main power. (DS9: "Defiant")
The following year, Captain Sisko utilized the Defiant's quantum torpedoes against the Klingons, as he attempted to rescue the Detapa Council from the Cardassian ship Prakesh. (DS9: "The Way of the Warrior")
Sisko ordered Chief O'Brien to rig the Defiant's two atmospheric probes with quantum torpedo warheads. (DS9: "Starship Down")
After he traveled back to Earth, in 1947, Quark offered to teach General Rex Denning how to make quantum torpedoes – for the right price. (DS9: "Little Green Men")
By mid-year, the USS Lakota had received a major upgrade, including a full complement of quantum torpedoes. Admiral Leyton suggested that Captain Benteen should use the increased firepower provided by the Lakota's quantum torpedoes as a means to destroy the Defiant outright. (DS9: "Paradise Lost")
Later that year, Lieutenant Commander Worf destroyed a Klingon civilian transport ship that suddenly decloaked in front of the Defiant, with a full spread of quantum torpedoes. (DS9: "Rules of Engagement")
The USS Enterprise-E firing quantum torpedoesIn 2373, the USS Enterprise-E used quantum torpedoes in the Battle of Sector 001 to destroy a Borg cube. They were later reused over Earth of 2063 against a Borg sphere that had traveled back in time to sabotage First Contact. Four quantum torpedoes were sufficient to destroy the latter vessel. (Star Trek: First Contact)
Later that year, Benjamin Sisko ordered Worf to attach a cargo pod containing two hundred kilograms of Trilithium Resin on to two quantum torpedoes. These torpedoes were designed to detonate in the atmosphere of Solosos III, causing the planet to be uninhabitable for humans, and forcing the Maquis colony there to be evacuated. (DS9: "For the Uniform")
In 2374, the USS Valiant utilized quantum torpedoes in its engagement with a Jem'Hadar fighter. (DS9: "Valiant")
Later that year in the First Battle of Chin'toka six quantum torpedoes were used by an unknown ship to destroy one of the off-line Cardassian orbital weapon platforms. (DS9: "Tears of the Prophets")
In 2375, the Defiant destroyed a Breen warship with a spread of quantum torpedoes during the Second Battle of Chin'toka, before it was destroyed by the Breen's new energy dampening weapon. (DS9: "The Changing Face of Evil")
As the new USS Defiant pushed on towards Cardassia Prime, during the final battle of the Dominion War, Worf reported that the ship had used all but forty-five of its quantum torpedoes. (DS9: "What You Leave Behind")
As of 2379, quantum torpedoes had yet to completely replace the photon torpedo on the largest Starfleet vessels. The USS Enterprise-E had only one quantum torpedo bay located on the lowest deck of the saucer module, just forward of the deflector dish. (Star Trek Nemesis)
Background
Quantum torpedoes were first mentioned and seen in DS9: "Defiant". The effect used to display the torpedoes of the Federation attack fighters attacking the center of the Dominion lines had a yellowish halo instead of the bluish seen elsewhere.
In the first draft of the script of Star Trek: First Contact. A fleet of borg ships is defeated with the new quantum torpedoes. Entire Borg cubes are destroyed with single hits. Quantum torpedoes are described as oscillating and changing shape and color as they streak towards their targets, piercing through the hull like armor-piercing shells, exploding the borg ships from within in an explosion visually resembling a supernova. A similar concept of a highly destructive weapon, the transphasic torpedo, was later on used in VOY: "Endgame".
Technical Manual
The Star Trek: Deep Space Nine Technical Manual states that the basic mechanism of the quantum torpedo was first operated experimentally in 2236. The first warhead application was tested in 2355, afterwards the mass fabrication started. The Federation quantum torpedo model is called "Pho-torp Mark Q-II" and it has a casing differently shaped from the photon torpedo.
The quantum warhead relies on rapid energy extraction from zero-point vacuum. This is established from an 11-dimensional space-time membrane, twisted into a Genus-1 topology string, housed inside the ultraclean vacuum of a 1.38 meter-long teardrop shaped zero-point field reaction chamber. The detonation of a photon torpedo warhead, enriched with fluoronetic vapor, inside the torpedo powers a continuum distortion emitter. It expands the membrane and pinches it out of the background vacuum. The membrane forms into subatomic particles accompanied by a high-explosive energy release.
The Isoton figures given in the Star Trek: Deep Space Nine Technical Manual are much smaller than the ones stated on-screen. (VOY: "Scorpion, Part II") The enriched photon warhead for example is rated only at 21.8 isotons and the membrane energy potential upon detonation is rated to be only at least 50 isotons.
Propulsion system of the quantum torpedo is a warp sustainer engine and four microfusion thrusters. The engine coils of the warp sustainer grab and hold a hand-off warp field from the torpedo launcher tube's sequential field induction coils. A miniature matter/antimatter fuel cell adds power to the hand-off field. When launched in warp flight, torpedo will continue to travel at warp, when launched at sublight, torpedo will travel at a high sublight speed, but will not cross the warp threshold. The quantum torpedo uses a bio-neural gel processor for flight control, and a thoron web to block countermeasure radiation.
Deep Space 9 was armed later on with quantum torpedoes. Class-8 and class-9 probe variants also use the quantum torpedo casing. There are apparently also micro quantum torpedoes. (pg. 77, 82, 85, 86, 130 and Star Trek: The Next Generation Technical Manual pg. 129)
