A cloaking device was a technology utilized by numerous species to render ships, stations, equipment, personnel and even planets invisible to the naked eye and/or sensors.
Cloaking devices were most commonly employed on starships, often for purposes of subterfuge, allowing a vessel to move unhindered by unaware opposition. However, cloaking devices have also been used for various other purposes to make best use of the technology.
The power consumption of cloaking devices was often seen as a limiting factor, making even cloaking small starships difficult, however, with the correct technical expertise it was possible to cloak much larger objects. The planet Aldea was equipped with a cloaking device capable of making the entire planet invisible, though it did have the unfortunate side effect of damaging the planet's ozone layer, resulting in widespread radiation poisoning from the Aldean sun's ultraviolet rays, resulting in the Aldean race become sterile. (TNG episode: "When the Bough Breaks")
The 22nd century
Humans first encountered cloaking technology in confrontations with the Suliban Cabal who used the technology on their cell ships and stealth cruisers. After their initial encounters, the Enterprise was fitted with quantum beacons (provided by temporal agent Daniels) capable of penetrating Suliban cloaks. (ENT episode: "Shockwave", et al.)
The Enterprise encountered three other species, the Xyrillians, the Sphere Builders, and the Romulans who employed stealth technology (analogous to cloaking technology): The Xyrillians, who used it to hide out of fear rather than for great tactical advantage (ENT episode: "Unexpected")
The Sphere Builders were an extra-dimensional race who used cloaking fields to hide their space transforming spheres in the Delphic Expanse. The spheres had been placed in the expanse approximately a thousand years ago and the Sphere Builders had temporal technologies so the origins of this particular type of cloak are as mysterious as those of the Suliban. (ENT episodes: "Anomaly", "Exile")
In 2152 the Enterprise stumbled into a cloaked Romulan mine field. By using the quantum beacons they could successfully detect the mines but not the two birds-of-prey in the area. This encounter was a one off though, Romulan stealth technology was still very much in its infancy, the cloaked mines were considered a relative success but the power requirements for cloaking a whole ship were problematic; sometime after the encounter with the Enterprise, the prototype cloaking ship Praetor Pontilus was destroyed in an antimatter containment failure caused by its stealth systems. It would be decades until a successful system could be developed. (ENT episode: "Minefield"; ENT novel: The Good That Men Do)
An arms race
In 2256 the USS Shenzhou encountered a cloaked Klingon vessel (DSC episode: "The Vulcan Hello"). The Klingon cloak used gravitational bending to conceal the ship from sensors and was a key tactical advantage to the Klingons during the Federation-Klingon War of 2256. In early 2257, at the Battle of Pahvo, the USS Discovery devised a method of penetrating the Klingon cloak, destroying the Sarcophagus. This put the two sides on a more even footing once again. (DSC episode: "Into the Forest I Go")
The Romulans finally developed a successful cloaking system by 2266, which they tested on a next generation bird-of-prey, that they dubbed a ghost ship, in raids against Federation outposts along the neutral zone. (TOS episode: "Balance of Terror"; TOS comic: "Alien Spotlight: Romulans")
The new Romulan cloak used so much power it precluded the use of weaponry and warp drive and the USS Enterprise was able to track it. However it could still be considered a success and the Romulans quickly advanced the design to make its use more practical. (TOS episode: "Balance of Terror")
While the Romulans were developing their new device Klingon agents became aware of it and the Klingon operative Korlat was sent to begin talks with the Romulans to make an alliance between the two powers, with the Klingons hoping to gain access to the technology in the process. The alliance was agreed upon by the power-hungry new praetor, though other parts of the Romulan government saw other advantages in the alliance, such as "containing" the Cardassians. (TOS comic: "Alien Spotlight: Romulans"; DS9 novel: A Stitch in Time)
With two enemy states using cloaking technology, the Federation was keen to find ways to detect cloaked vessels to the extent that they even stole a Romulan cloaking device from a Romulan battlecruiser in 2268. (TOS episode: "The Enterprise Incident")
Over the next few decades the Federation learned to detect sensor blips associated with cloaks; in return, cloaking technology advanced. In 2293 the Klingons successfully modified a bird-of-prey to be able to fire torpedoes while cloaked. Captain Kirk and his crew eventually defeated this vessel by using a specially modified torpedo which tracked the ships plasma exhausts. (TOS movie: Star Trek VI: The Undiscovered Country)
For a significant period of time Dr Scott Heisenberg was credited for single-handedly refining Starfleet's sensors to detect Romulan cloaking devices. However this period came to an end when the Romulans retreated behind their borders following the Tomed Incident. (TLE novel: Catalyst of Sorrows)
By the 24th century cloak detection was becoming commonplace; Federation borders used gravimetric sensor nets and interphase scanners. The Romulans countered this by improving their interphase generators. In 2368 the USS Enterprise-D's chief engineer Geordi La Forge developed a more advanced technique, the tachyon detection grid, using tachyon beams transmitted between different locations to expose cloaked vessels. (TNG episode: "Redemption")
By 2379, the latest iteration of the cloak had overcome all these problems. The Warbird Scimitar's cloak did not give off any tachyon emissions or residual antiprotons, making it undetectable. In addition, the Scimitar could maintain shields and fire through its cloak. The Scimitar was only stopped by the heroic efforts of the USS Enterprise-E's crew, in particular Commander Data, who sacrificed himself to destroy the Warbird. (TNG movie: Star Trek Nemesis)
In 2382, when a Romulan vessel managed to penetrate the Mars Defense Perimeter to retrieve an operative at Utopia Planitia, Admiral Alynna Nechayev suspected from sensor scans that the Romulans were seemingly putting phase cloaks in active service. (ST novel: Zero Sum Game)
In 2387, while being modified at the Vault, the Romulan mining vessel Narada was equipped with a cloaking device which allowed it to fire through the cloak. Upon observing this ability, General Worf of the Klingon Defense Force said that the Romulans "must have stolen that trick from us!" (ST - Countdown comic: "Number Four")
In an alternate future created by the formation of the Red wormhole (which started the War of the Prophets), by 2400 the Romulan Star Empire had developed a more advanced effective cloak known as a transmorphic cloaking device, which used biogenic components obtained from Grigari technology. These transmorphic cloaks made the ships virtually undetectable. This future timeline was erased by the crew of the USS Defiant. (DS9 novel: The War of the Prophets)
- The novel does not specify how transmorphic cloaks differed functionally from standard cloaking devices.
The Federation and cloaking technology
Under the Treaty of Algeron, the Federation was banned from using cloaking technology without the explicit permission of the Romulans. However, before and throughout the 24th century, the Federation was active in the development of cloaking technology but did not implement it in the fleet. (TNG novel: Resistance)
During the USS Enterprise's pursuit of Lieutenant Saavik while she was undergoing Pon faar, Admiral James T. Kirk orders Montgomery Scott to "...activate cloaking device..." and later, to "...disengage cloaking device..." Scott also warns, "We've not enough power t'use this cloakin' device much longer!" No other mention is made of the device, or its origin. (TOS comic: "Blood Fever")
The Federation also secretly developed an interphase cloaking device in 2358. However, the test ship for the device, the USS Pegasus, was lost. The Pegasus was rediscovered in an asteroid field in 2370, where the USS Enterprise-D recovered and used the interphase cloak before making its existence known to a Romulan Warbird in the vicinity. (TNG episode: "The Pegasus")
Both incarnations of the Defiant-class ships Defiant were fitted with Romulan cloaking devices, under special arrangement with the Romulans that the cloak only be used in the Gamma Quadrant, and that Starfleet share all intelligence thus gathered with the Romulans. Such restrictions, however, did not prevent occasional unauthorized use of the cloak by Defiant commanders Benjamin Sisko and Elias Vaughn. (DS9 episode: "The Search"; DS9 novel: Twilight, et al.)
Following the Dominion War the Romulan Senate moved to allow the Defiant to keep the cloak, recognizing the importance of the vessel, and DS9, as the first line of defense against further Dominion attacks. (DS9 novel: Avatar, Book One)
In 2375, a cloaked Federation holoship was discovered on planet Ba'ku, though this vessel was initially utilized by Section 31, who frequently bypassed legality in favor of their goals. (TNG movie: Star Trek: Insurrection; DS9 novel: Abyss)
- The use cloaks in isolation suits may suggest the Treaty of Algernon cloaking ban only applies to larger scale employment on starships and facilities.
Throughout the 2370s, the Federation encrypted the means of cloaking in the computers of all new starships so that it would be available to Federation vessel in cases of extreme need, although the data could only be accessed with the access codes of an admiral. In 2380, the USS Enterprise-E was authorized by Admiral Kathryn Janeway to use this data to cloak the ship for a sneak attack on a Borg cube.
On Stardate 72487.91, the USS Kelso was destroyed when an experimental cloaking device was destroyed due to a coolant leak. The outrage from both the shattered Romulan Star Empire and the Klingon Empire lead to President Okeg to outright ban cloaking. (ST website: The Path to 2409) However, the existence of both the Defiant-class and the Galaxy-X-class seemed to hint otherwise. (Star Trek Online)
In the Delta Quadrant
In her time in the Delta Quadrant, the USS Voyager encountered relatively few species with cloaking technology. Delta Quadrant species known to use cloaking technology include the Ba'neth, the Kraylor and the Hierarchy. (VOY episodes: "Riddles", "Nightingale", "Tinker, Tenor, Doctor, Spy", et al.)
- It is also worthy of note that the Borg, in their thousands of years of existence and many recorded encounters with cloak capable species, must have at some point assimilated cloaking technology. Though to date they have not been depicted using the technology. It is possible that with their general technological superiority, the Borg Queen sees no need to 'sneak around' to assimilate others.
In alternate realities
In the Kelvin timeline the Romulan Star Empire had cloaking technology in wide use by the 2250s. Centurion-class, Cetratus-class, Gladius-class, Patronus-class and Securis-class starships could all be fitted with cloaking devices. At this time the Romulans had to drop their cloaks to fire weaponry. (TOS video game: D-A-C) It was also revealed that some Gorn had personal cloaking ability. (TOS video game: Star Trek)
In an alternate timeline where Montgomery Scott went back in time to rescue James T. Kirk before his absorption into the Nexus, the Cardassians had developed cloaking technology. Former Alliance Council member Zarcot issued a distress call from a lifepod close to the Nexus in an attempt to get the Wisdom to lower its shields so that a cloaked Cardassian vessel could assassinate the Supreme Arbiter of the Alliance Sarek, who was aboard the ship. (Star Trek novel: Engines of Destiny)
In an alternate timeline in which the Cardassian Union did not withdraw from Bajor in 2369, the Federation began outfitting its ships, including the USS Enterprise and the USS Defiant, with cloaking devices months after the war between the major Alpha Quadrant powers (instigated by the Dominion) resulted in abrogation of the Treaty of Algeron. (TNG - Myriad Universes novel: A Gutted World)
In the mirror universe
In the mirror universe cloaks were also used by the Suliban in the 22nd century. The ISS Enterprise (NX-01) used a Suliban cloaking devise from a captured cell ship to enter Tholian space in 2155. The Enterprise was able to use weapons through the cloak. (ENT episode: "In a Mirror, Darkly")
In the 23rd century the Klingons, like their regular universe counterparts, developed a cloak which could be fired through. They planned to use a fleet of these vessels to attack the Terran Empire. However, the fleet in construction was destroyed when Praxis exploded. (TOS novel: The Sorrows of Empire)
The Klingon-Cardassian Alliance of the 24th century also had cloaking technology used on number of ships. However, in 2375 the Alliance kidnapped the regular universe Grand Nagus Zek to blackmail Quark into stealing a Klingon cloaking device from a regular universe vessel. (DS9 episode: "The Emperor's New Cloak")
- This was either a slightly different mirror universe (several variations of the mirror universe have been established) or just as in the regular universe cloaks and sensors had advanced to a point where a new type of cloak was required.
Variations on cloaking technology
- See main article: Interphase cloaking device.
Along side the development of standard cloaks all three of the major powers experimented in the development of interphasic cloaks. An interphasic cloak will not just make the target invisible but also capable of passing through solid materials. The Federation was successful in developing the technology in 2358 though that fact was unknown to them for some time when the test ship for the device the USS Pegasus was lost. The Pegasus was rediscovered in an asteroid field in 2370 where the Enterprise-D recovered and used the interphase cloak before making its existence known to a Romulan Warbird in the vicinity. (TNG episode: "The Pegasus")
The Klingons also tried and failed to develop their own phase cloak, as did the Romulans. The Klingons abandoned their attempts while the Romulans' initially failed. By 2376, the Romulans had succeeded and implemented phase cloaks in Tal Shiar Shadow-class vessels. (TNG episode: "The Next Phase"; TNG video game: Armada)
Dark Matter cloaks
A new form of cloaking technology was developed by the Romulan Star Empire in 2356 with the aid of the rogue Shepherd Ambassador Lhiau. This form of cloak was undetectable by normal means and was capable of firing when cloaked. This was available to at least thirteen Romulan warbirds which were interfaced with advanced Shepherd technology. There were numerous complications with this form of cloaking as it produced a mutated strain of Dark matter that infected the crew causing madness as well as death. (VOY novel: Cloak and Dagger) This brought about an end to this program which was discontinued considering the dangers of dark matter. (VOY novel: Shadow of Heaven)
A new form of cloaking was created by the New Romulan Star Empire in the alternate future produced by the War of the Prophets. This technology was virtually undetectable by its enemies but was only possible through the addition of Grigari organic components. (DS9 novel: The War of the Prophets)
The Tantalus mask was another form of cloaking technology used by the First Federation which was undetectable by gravimetric distortions or radiation making it superior to the standard cloak. (TOS novel: Preserver)
Users of cloaking technology
- Cardassian Union
- Klingon Empire
- Klingon-Cardassian Alliance (MU)
- Romulan Star Empire
- Sphere Builders
- Suliban Cabal
- cell ship • stealth cruisers
- The Terran Empire (MU)
- The United Federation of Planets
- Vau N'Akat
- Tars Lamora Mining Labor Camp
- See also: Holographic masking system