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Tpol utilizing her science station viewer

Commander T'Pol utilizing her viewer in 2154.

A viewer was an instrument that could commonly be found on the bridge of a starship in the 22nd and 23rd centuries. Usually used to scan outside the ship, the device was often included among the arsenal of tools utilized by science officers in both centuries, as well as by helmsmen and chief engineers in the 23rd century. (Star Trek: Enterprise, Star Trek: The Original Series)

22nd Century Viewers


In "Broken Bow", the first episode of Star Trek: Enterprise, two different styles of viewer can be seen - one design is used in closeup shots, while another can be seen in several other, more distant shots and was used in every appearance of the viewer in subsequent episodes of Enterprise. There is no explanation for the alterations between the designs in "Broken Bow", however, and the changes consequently create a continuity error that is avoided in this section by assuming that the design seen in closeup shots preceded the viewer's other style.

A 22nd century viewer integrated into the science station of an NX class starship.

In the mid-22nd century, viewers had two halves whose exteriors were separated by a thin metallic silver divider. The exterior of the top half contained a brown eyepiece, through which the user directly looked, and an outer metallic silver grip. The lower half had a black outer casing and, while the device was not in use, was lowered into a hidden recess below the level of the surrounding console. When pressed, a control on the console, slightly to the left of the viewer, raised the device's lower half out of its recess, extending the viewer to its full and operational height. Simultaneously, a yellow light would activate from within the viewer, enabling visibility of its contents from the other side of the eyepiece. The viewer was not entirely silent, as it produced a faint noise when being activated or deactivated. (ENT: "Broken Bow")


A later version of the 22nd century viewer.

Between April and May of 2151, the eyepiece was enlargened in depth, its diameter was reduced, and a ribbed effect was added to the outer sides of the component. The eyepiece was also darkened in color so that it matched with the black of the lower half. A metallic silver component, much like the section dividing the two halves of the device, was introduced near the top of the viewer's exterior, separating the eyepiece from the device's lower sections. (ENT: "Broken Bow", "Fight or Flight")

After "Broken Bow", most episodes show the viewer being held at or near the top of the device's higher half, as opposed to the method seen in "Broken Bow" - with both hands holding the device amid the top half. This suggests that the second metallic divider was added to allow a higher grip, a reason that may also explain the change in depth of the eyepiece, as its exterior is often used as a place where the user can position one or several of their first fingers, such as their thumbs.
File:Viewer with buttoned top (Civilization).jpg

Additionally, sometime between May and July of the same year, several square controls were added to the top of the viewer, arranged in two generally straight clusters along either edge of the device's top half. (ENT: "Unexpected", "Civilization") Each cluster included four adjacent black controls, each of which were positioned lower than and, from the user's perpective, behind a similar white control. Next to each row of black and white controls, three light grey buttons were aligned in a slightly differing arrangement from each other - on the right, comparative to the user, the grey buttons were situated next to the white control, as well as by the second and third lower black controls, while the grey buttons on the left were beside the first, third and fourth black controls. (ENT: "Civilization")

In August of that year, the viewer's lower half was slightly increased in length, effectively making the top section higher when the device was operational. (ENT: "Fortunate Son", "Silent Enemy")

The viewer is lower in "Fortunate Son" and earlier episodes than in both "Cold Front" and "Silent Enemy", as well as subsequent episodes. Although the device was heightened for production on "Cold Front", "Silent Enemy" is established as being set before that episode (for more information, see 2151).

Between July 2151 and October 2152, the grey controls atop the viewer were colored a darker grey that was more similar to the shade of the top half's outer grip. (ENT: "Dawn")

In February 2154, the light within the viewer changed color from yellow to pale blue. (ENT: "", "Zero Hour")

It seems slightly odd that Enterprise's viewer suddenly changes while the ship is in the Delphic Expanse, but perhaps it was part of the general repair work the crew completed after the vessel obtained damage in battle.

These styles of viewer were successively implemented aboard the NX class starship Enterprise, where science officer T'Pol used the device during the starship's mission from 2151 until 2161. (ENT: "Broken Bow", "These Are the Voyages...") The latter style viewer was also used aboard Enterprise of an alternate timeline until 2165, when the starship's bridge and, shortly after, the entire ship itself were destroyed in a battle with several Xindi vessels. (ENT: "Twilight") Other NX class ships using the latter style viewer include the ISS Enterprise (NX-01) and the ISS Avenger, until they were both individually destroyed in 2155 of the Mirror Universe, as well as Columbia, aboard which a viewer was installed several months before the ship's launch. (ENT: "In a Mirror, Darkly", "In a Mirror, Darkly, Part II", "Home")

Of these examples, only the viewer aboard Enterprise, both that of most episodes and of the alternate timeline seen in "Twilight", is shown being used. It is therefore uncertain whether Enterprise's viewer differed in use from those seen aboard Columbia, the NX class ISS Enterprise and/or the ISS Avenger.

Although these styles of viewer had become antiquated by 2370, one could still be found in a holoprogram depicting Enterprise's final voyage to Earth by way of Rigel X, a simulation set in 2161. Despite the holographic nature of the program's environment, the viewer was interactive, allowing a user to automate the device at will. (ENT: "These Are the Voyages...")

The contents of a viewer's eyepiece was shown twice in episodes of Enterprise. "Fight or Flight" revealed how a long range tactical scan appeared through the device and "Dawn" showed the viewer's display of a thermokinetic analysis.

History of Uses


T'Pol using viewer

Subcommander T'Pol using her original viewer in 2151.

When, in April 2151, the NX class Enterprise unexpectedly started trembling after having entered the atmosphere of a gas giant, T'Pol used her viewer to ascertain that the shaking was due to the ship having penetrated a layer of liquid phosphorus. Soon after, when the ship's crew were tasked with recovering Captain Archer and Commander Tucker, T'Pol used her viewer to locate the ignited thruster exhaust of Archer and Tucker's commandeered Suliban cell ship and to obtain co-ordinates where Enterprise could rendezvous with the Suliban craft. (ENT: "Broken Bow")

Tactical scan in viewer

A long range tactical scan, as seen through T'Pol's viewer.

The next month, T'Pol used her viewer to see a long range tactical scan, showing Enterprise's position and that of an unidentified craft that had actually been manned by an Axanar crew which was now entirely deceased. After Enterprise approached the ship and received no response to hails, T'Pol looked through her viewer's eyepiece to help the senior officers determine whether holes surrounding a hatch on the vessel were venting ports or hull breaches. By using the viewer, she learned that residue near the holes indicated the possibility that weapons had been fired at the alien craft. (ENT: "Fight or Flight")

T'Pol also used her viewer to determine that an unnamed planet, later called Archer IV, had an atmosphere largely consisting of oxygen and nitrogen, confirming that a Human landing party from Enterprise would be able to breath easily on the planet's surface. (ENT: "Strange New World")

The planet is named Archer IV in Captain Archer's biography, seen in the ENT Season 4 episode "In a Mirror, Darkly, Part II".
Viewer with bare top

T'Pol using her latter-style viewer.

While Enterprise was plagued with malfunctions, T'Pol's viewer helped the crew discover that the problems were due to a disruption in the plasma flow being caused by the presence of a vessel hidden aft of the starship's warp nacelles. When a male member of the vessel's Xyrillian crew later explained that his craft's engines were damaged, T'Pol used her viewer to ascertain that the vessel's warp reactor was off-line, supporting the crew member's claim. (ENT: "Unexpected")

While attempting to locate a group of missing Human colonists who had settled on the planet Terra Nova, T'Pol used her viewer to learn that, although the colony seemed intact, Enterprise was not detecting any biosigns from the planet. (ENT: "Terra Nova")

T'Pol later used her viewer to measure a comet, one previously undiscovered by Vulcans and Humans, as having a diameter of 82.6 kilometers, bigger than any comet Humans had ever seen. (ENT: "Breaking the Ice")

File:Viewer with buttoned top (Civilization).jpg

When Enterprise encountered a populated planet, T'Pol's viewer determined that the inhabitants of the planet, the Akaali, were a pre-industrial civilization. However, T'Pol later detected neutrino emissions from a city on the planet and speculated that they could be due to an antimatter reactor, suggesting that technologically advanced visitors had found the planet before Enterprise's crew. In an attempt to determine whether her theory was accurate, T'Pol used her viewer to scan the planet's surface for non-indigenous biosigns. Although the device did not detect any, T'Pol was uncertain of the reliability of its results, due to Enterprise's range from the planet. (ENT: "Civilization")

It is not certain whether T'Pol was using her viewer when she first detected the neutrino emissions, as she is not seen discovering them and is only shown telling Archer of her findings. However, her viewer is deactivated at the start of the scene in which she informs Archer of her discovery.

While approaching the Earth freighter Fortunate, T'Pol's viewer distinguished that there were twenty-four biosigns aboard the craft. Enterprise later left the Fortunate but, upon returning to the freighter, T'Pol reported that long range sensors, which she observed through her viewer, were detecting weapons fire - Enterprise's first indication that the freighter was being attacked by a Nausicaan craft. (ENT: "Fortunate Son")

In late August of the same year, Enterprise, having previously established the subspace amplifier Echo 1, deployed Echo 2 and had several encounters with a mysterious, hostile alien ship. Upon encountering the ship for the third time, T'Pol used her viewer to determine that the vessel was dead astern. Shortly thereafter, T'Pol's viewer determined that both Echo 1 and Echo 2 had been destroyed. (ENT: "Silent Enemy")

In early September, T'Pol peered through her viewer's eyepiece, occasionally using the instruments on the panel right of the viewer, while Enterprise was being escorted by a transport ship around the edges of the Great Plume of Agosoria. (ENT: "Cold Front")

When Enterprise encountered an alien craft of pre-warp design, T'Pol used her viewer to learn that there were two very faint biosigns aboard the vessel. The occupants of the ship were actually two Valakians, members of a civilization afflicted by plague. (ENT: "Doctor's Orders")

Long Viewer (Sleeping Dogs)

T'Pol using her viewer, now upgraded with a longer support beam, to track a probe entering the atmosphere of a gas giant.

After Enterprise discovered a gas giant, T'Pol tracked a probe launched from the starship, by using her viewer and the controls at the top of the device, as the probe entered the planet's outer atmosphere. Soon after, T'Pol also learned from her viewer, again using the controls atop the device, that there were, in the planet's lower atmosphere, the anomalous power signature of a starship, with several biosigns aboard. The ship was later determined to be of a Klingon design that Enterprise had not previously encountered, explaining the anomalous nature of its power signature, as seen through T'Pol's viewer. (ENT: "Sleeping Dogs")

While Commander Tucker and Lieutenant Malcolm Reed were stranded in a shuttlepod in November 2151, Tucker remarked that the pod would probably only appear to Enterprise, being two days away at warp three, as "a nice little blip on T'Pol's viewer". As a method to alert Enterprise's crew to the shuttlepod and influence them to increase the starship's speed, Reed suggested firing the pod's weapons. Commander Tucker, however, argued that the shuttlepod's plasma cannons had a range of less than ten kilometres - less than what was needed to make both the weapons and the shuttlecraft appear as more than a single "blip" on T'Pol's viewer. Ultimately, Tucker and Reed decided to ignite their shuttlepod's engine and both officers were subsequently rescued by Enterprise. (ENT: "Shuttlepod One")

At the end of the episode, it is established that Enterprise witnessed the explosion of the shuttlepod's engine. Given Trip's knowledge of starship technology, however, his suggestion that he and Reed would probably only appear to Enterprise as a small blip on T'Pol's viewer may suggest that it was that device that detected their explosion.

While Enterprise initially encountered the Vulcan civilian transport Vahklas, T'Pol was able to see through her viewer that the ship, occupied by Vulcan V'tosh ka'tur, belonged to a class of vessel that had not been used for a long time. (ENT: "Fusion")

Enterprise later investigated the planet Kantare, the site of a crashed ship that the Starfleet crew had been informed was possibly haunted. Upon entering orbit of the planet, T'Pol used her viewer to confirm that Kantare's atmosphere was thin, but breathable. (ENT: "Oasis")


In April 2152, Enterprise ventured into a planetary system that neither Vulcans nor Humans had previously charted. After the ship approached a volcanic, uninhabited Minshara class planet in the system, T'Pol deactivated her viewer, moments before Enterprise disastrously struck a cloaked Romulan mine. (ENT: "Minefield")

As she is only shown deactivating her viewer in "Minefield", it is unclear whether T'Pol had been using the device earlier, although such a possibility does seem probable.
Just after deactivating her viewer, T'Pol presses several controls on the panel to the right of the viewer and then looks up at a monitor above the device. It is unclear if she was using the controls to alter the display on the monitor or if she was resetting the controls, after having changed them while using her viewer.

In need of repairs due to damage caused by the mine, Enterprise headed to an alien space station that T'Pol scanned with her viewer, determining that the station's interior had a liquid helium atmosphere. (ENT: "Dead Stop")

After discovering a trinary star system that included a black hole, T'Pol began to study the phenomena with her viewer, using the controls to the right of the device, but she was interrupted from her work. T'Pol later used the device to navigate a safe course through a debris field and away from the black hole. (ENT: "Singularity")

While Enterprise pursued a Retellian freighter, the alien vessel released a cloud of debris that covered Enterprise's viewscreen. By using her viewer and a control panel directly below it, between her and the device, T'Pol was able to identify the debris as dilithium hydroxyls and ionised pyrosulfates. (ENT: "Precious Cargo")

Thermokinetic analysis

A thermokinetic analysis, as seen through a 22nd century viewer.

After Commander Tucker went missing in a shuttlepod while in a system consisting of a gas giant and many moons, Enterprise's crew searched for him but they experienced interference while attempting to use their ship's sensors. T'Pol utilized her viewer to learn that many of the moons in the system had atmospheres containing selenium isotopes, the factor most likely affecting the ship's sensors. While the search continued, T'Pol later peered through her viewer's eyepiece, while using the controls atop the device, to observe a thermokinetic analysis of the moons. She showed Captain Archer the same demonstration and explained that she, with the use of her viewer, had learned that, although the moons' surfaces were moderately cool at night, they could become extremely hot during the day, reaching temperatures possibly as high as 170 degrees. (ENT: "Dawn")

T'Pol later looked through her viewer's eyepiece during Enterprise's first encounter with a Tholian starship. After a craft, one that was supposedly from the future and highly sought after by the Tholians, was armed with a torpedo warhead and dropped through one of Enterprise's launch bay doors, T'Pol used her viewer to ascertain that the Tholians had neutralised the warhead. (ENT: "Future Tense")

While Enterprise was trapped inside a vast alien vessel, T'Pol determined, using her viewer, that vapour inside the alien craft only contained elements that Enterprise's sensors could identify and that the vessel contained an atmosphere mostly consisting of helium, but with trace amounts of xenon. (ENT: "The Crossing")

During an attack by a Klingon D5 class battle cruiser, named the Bortas, Enterprise maneuvered into the rings around a planet, where T'Pol utilized her viewer to inform the other officers on the bridge that their starship was approaching a large, rocky fragment, 600 meters in diameter. Essentially acting on the information from T'Pol's viewer, Captain Archer subsequently issued orders to hide the starship behind the rocky fragment. (ENT: "Judgment")


In January 2153, Enterprise's crew studied an imminently volcanic planet. When the volcanoes on the planet began to erupt, T'Pol used her viewer, discovering biosigns on the planet that appeared to be those of several microbial species that usually resided under the planet's surface but were being unearthed by the volcanic activity. (ENT: "Horizon")

Later the same year, T'Pol was able to analyse a dying hypergiant star with the aid of her viewer. She saw, through the device's eyepiece, that the star was losing mass at an extraordinary rate, leading her to conclude that it would go supernova in one or two hundred years. (ENT: "Cogenitor")

T'Pol also looked through her viewer's eyepiece while Enterprise was approaching the thermobaric clouds that surrounded the Delphic Expanse. During the starship's subsequent journey through the cloud layer, T'Pol detected three energy signatures that she was able to examine with her viewer. She was only able to differentiate the readings from those of a communications buoy the starship had recently launched because she was detecting three energy signatures, not just one. (ENT: "The Expanse")

Early in their search for the Xindi superweapon, Enterprise's crew was provided with coordinates to the Xindi homeworld but, while the ship was approaching the coordinates, T'Pol discovered with her viewer that there were no planets in the area. The crew ultimately learned that this was because the coordinates were for the previous Xindi homeworld, which had been destroyed. (ENT: "The Xindi")

After Enterprise had a hostile encounter with an Osaarian starship and its piratical crew, T'Pol used her viewer to help track the alien craft's ion trail to the edge of a cloaking barrier. On the other side of the barrier, Enterprise's crew first discovered a Delphic Expanse sphere, whose interior T'Pol tried to scan by utilizing her viewer. She found that the starship's sensors were being deflected, but the viewer later proved useful in locating a portal, 22 degrees north from the ship's position, that would allow access to the sphere's interior. Following Captain Archer's decision to ambush the Osaarian ship in close proximity to the sphere, T'Pol used her viewer to determine that the alien craft, as it entered the cloaking barrier, had not yet detected Enterprise. (ENT: "Anomaly")

After the Starfleet craft tracked the course of a Xindi-Arboreal ship to a planet that the Xindi vessel had last visited before being destroyed, T'Pol found, with the use of her viewer and the controls to the right of the device, that the planet had a prolific ecosystem, including several million chromophyllic plant species. (ENT: "Extinction")

Enterprise later discovered the Vulcan starship Seleya, inside an asteroid field where T'Pol utilized her viewer, and at least one of the controls atop the device, to ascertain that the asteroids were moving in a chaotic fashion on paths that were unpredictable. (ENT: "Impulse")

As the result of a disastrous experiment with Enterprise's warp core, the ship entered an anomaly that T'Pol identified, by using her viewer, as a polaric field, approximately 11,000 kilometers in diameter. Even though her viewer helped to ascertain the nature of the field, the device was unable to instantly determine the field's composition and T'Pol required substantial time to complete a detailed scan. (ENT: "Similitude")

In December 2153, Enterprise was forced to traverse an exceptionally intense anomaly field. T'Pol prepared for the perilous journey by constructing a changeable map of the area. She looked at the map through her viewer's eyepiece and simultaneously used the controls atop the device to relay directions to Ensign Mayweather at the helm. While using her viewer, T'Pol witnessed an anomaly form, expand and merge with other anomalies, a sight which she had never seen before. She became unable to provide the helm with directions from her viewer when the anomalies began to grow too rapidly. As they engulfed Enterprise, causing the ship's bridge to violently tremble, T'Pol gripped to a metallic grab bar above and to the left of her viewer and was able to return her gaze to the device's eyepiece. (ENT: "Proving Ground")


While Enterprise was approaching a solar system containing Azati Prime in early 2154, T'Pol used her viewer to discover that there seemed to be considerable activity around two of the system's inner planets - the first indication of numerous Xindi ships in the area. As Enterprise hid from the ships behind a nearby planetoid, it was decided that Commander Tucker and Ensign Mayweather would fly a previously commandeered Xindi-Insectoid shuttle into the system and attempt to locate the almost completed Xindi superweapon. Shortly thereafter, T'Pol began to gaze through her viewer, pressing several of the controls on the console right of the device, but she was distracted by Communications Officer Hoshi Sato, trying to study the Xindi-Insectoid language at her own console, and subsequently deactivated her viewer. (ENT: "Azati Prime")

While tasked with accessing a one-way subspace corridor that extended from a nebula inhabited by hostile Kovaalans to a distant location not far from the Xindi Council planet, Enterprise encountered a version of itself from an alternate timeline. As the two ships traveled into the nebula, they clustered together in an attempt to fool the Kovalaans into believing the alternate Enterprise was a sensor reflection. Moments before the Kovalaan ships attacked, T'Pol activated her viewer and looked through the device's eyepiece, while operating at least one control on the console directly in front of her and several of the controls atop the viewer, to see that Enterprise's sensors were detecting multiple images, confirming that the strategy was working. (ENT: "")

Commander Tucker later used Enterprise's viewer, and one of the controls to the right of the device, in order to monitor the destruction of Sphere 41, while the ship was in an anomaly field. (ENT: "Zero Hour")

After Enterprise came across a debris field in November 2154, T'Pol saw through her viewer that the wreckage included significant quantities of duranium alloy. This was because the debris was the remainder of an Andorian warship, the Kumari, which had been destroyed by a Romulan drone-ship. (ENT: "Babel One")

Upon encountering another debris field, the result of the drone-ship's destruction of the Earth freighter Ticonderoga, T'Pol learned, by using her viewer and the controls directly in front of her, that the wreckage consisted of hull fragments, nacelle casings and several Human bodies. When Archer instructed her to search for the drone-ship's warp signature, T'Pol again turned her gaze to the viewer but momentarily stopped using the device to turn back to the captain. She was later able to utilize the viewer to detect a ship that seemed to be a Tellarite freighter as it dropped out of warp nearby. However, the craft was actually the Romulan drone-ship, using holographic projectors on its hull to disguise itself - a fact that T'Pol's viewer was unable to ascertain. (ENT: "The Aenar")

23rd Century Science Viewers


In 2254, some starships, including the Constitution-class Enterprise, were not equipped with a viewer. (TOS: "The Cage")

Spock with earpiece and scope

Spock at his science station, outfitted with a viewer (2265).

TPol at Defiant station

T'Pol at Defiant's Science Station w/viewer

By 2265, however, a dark blue, featureless viewer had been introduced at the science station of most Federation starships. This device jutted out of a console at an elevated angle, camouflaged well into the darkness of the console. Unlike the viewers of the previous century, this style of viewer was stationary and its contents could be seen from a further distance. As direct contact with an eyepiece was not necessary, two people could simultaneously view the device's display. (TOS Season 1)

In 2267, the shaft that comprised the science viewer's exterior was recolorized to a light grey, consequently becoming more easily recognized within its console. Also, a circular control was added to the device's exterior on the left side of the shaft, comparative to the user's position. (TOS: "Catspaw", et al.)

These styles of viewer were consecutively utilized during the Enterprise's five-year mission by the vessel's science officer, Mr. Spock. (Star Trek: The Original Series, Star Trek: The Animated Series)

In 2268, science viewers of the second configuration could also be found aboard the Constitution-class starships Lexington and Defiant. (TOS: "The Ultimate Computer", "The Tholian Web") After the latter craft journied to 2155 of the Mirror Universe, the Defiant was discovered and commandeered by members of the Terran Empire including science officer T'Pol, who subsequently utilized the vessel's science viewer. (ENT: "In a Mirror, Darkly", "In a Mirror, Darkly, Part II")

History of Uses


In 2266, Spock used his viewer to determine that there was no sign of a cube that, until the Enterprise destroyed it, had been blocking the starship's path and endangering the vessel's crew with high levels of radiation.

Spock later used the viewer to analyse an object approaching the Enterprise that was larger than the cube but was in the same area of space. Using the viewer, Spock reported that the starship was receiving an exceptionally strong signal from the object but that a visual representation of the object was not yet available. (TOS: "The Corbomite Maneuver")

After Crewman Darnell mysteriously died while accompanying Captain Kirk and Doctor McCoy on a visit to Robert and Nancy Crater's home on the planet M-113, Spock peered through his viewer to examine the ship's record tapes and, by doing so, identified a plant found in Darnell's mouth as a Borgia plant, disproving a possibility that the plant had caused the crewman's death. In a virtually simultaneous capacity, Spock also used the viewer to review the history of Robert Crater and his wife, discovering that there was no apparent reason to suspect the couple of involvement in Darnell's death.

As Spock only tells Kirk of his findings regarding the history of the Craters and since it is not established how he came to those determinations, it is not completely certain whether he used his viewer to check the couples' history. However, such a possibility seems likely.

While later monitoring M-113 with his viewer, Spock noticed the strange fact that the ship was detecting only one person on the planet, after having been told by Kirk that the planet was inhabited by the two Craters. Spock showed Kirk his viewer's perspective and was able to see through the device that the sole remaining inhabitant of the planet, whom he estimated was most likely Robert Crater, was circling, as if searching for something. Spock operated several controls at the right of the viewer to exapnd the device's search radius. Eventually, he determined that, unless the ship's equipment was at fault, there was only one person within a 100-mile circle. This was because, as ultimately learned by both Kirk and Spock, "Nancy Crater" was actually a shapeshifting creature that had killed Crewman Darnell and had come aboard the Enterprise, disguised as various crew members. (TOS: "The Man Trap")

As the Enterprise orbited Psi 2000, a planet nearing the end of its ancient life, an officer named Joe Tormolen stabbed himself. While investigating the incident, Spock used his viewer to study Tormolen's psychiatric file and personality quotients. Spock also showed Kirk the files on Tormolen, displayed within the Enterprise's viewer. Spock later used his viewer to monitor the imminent breakup of Psi 2000, as the planet began to condense at an increasing rate. (TOS: "The Naked Time")

Romulan Neutral Zone map

A map of the Romulan Neutral Zone that was seen on screens throughout the Enterprise, and through Spock's viewer.

While the Enterprise headed towards the Romulan Neutral Zone in response to a distress call from Outpost 4, Spock looked at a map of the area through his viewer and, at Kirk's request, transferred the same map to screens throughout the ship, including the bridge's viewscreen, while continuing to observe the diagram through his viewer. Although the map was initially a still image of the appropriate star sector, Spock added a moving, blinking white mark to represent the Enterprise and its position in the area.

After finding that both Outposts 2 and 3 were no longer present and that the asteroids they had been constructed on showed signs of having been pulverized, Spock utilized his viewer to determine that Outpost 4 fortunately remained. However, the fourth outpost was soon destroyed by the same Romulan Bird-of-Prey that had pulverized the second and third outposts.

After tracking the Romulan ship to a comet, Spock used his viewer to determine that the Enterprise was losing sensor contact with the Bird-of-Prey as it entered the comet's tail. Spock also used his viewer to see that the Romulan ship was continuing on a course straight towards the Neutral Zone. However, after the Enterprise opened fire on the Bird-of-Prey, Spock saw in the device that a signal, representing the Romulan vessel, on the starship's motion sensor had halted.

Among debris encountered outside the Enterprise, Spock, by using his viewer, was able to distinguish vessel wreckage and a body, although he also used his viewer to determine that the wreckage was of insufficient mass to have been an entire vessel. With this information, Spock deduced that the debris was most likely the result of an attempted trick to fool the Enterprise's crew into believing that the Romulan ship had been destroyed. When he tried to locate the Bird-of-Prey by checking the perspective of the Enterprise's sensor probes through his viewer, Spock detected no motion in the Starfleet ship's vicinity. After relocating the Romulan craft, Spock again used his viewer to analyse debris launched from the Bird-of-Prey, this time including a nuclear warhead that the viewer detected as a metal-cased object. Although the weapon struck the Enterprise, the Starfleet ship was the ultimate victor as the Romulan vessel self-destructed. (TOS: "Balance of Terror")

Spock may have also used his viewer to track the Romulan Bird-of-Prey to the comet as, in the shots in which he reports the Bird-of-Prey's movements, it is unclear whether he is looking at the device or another part of his console.
Also notable is that the word "blip", used by Spock to describe the representation of the cloaked Romulan warbird on the Enterprise's motion sensors, is the same noun used to describe the appearance of a shuttlepod on a viewer in ENT: "Shuttlepod One".

Shortly before departing the planet Tantalus V, the crew of the Enterprise accidentally brought aboard Simon Van Gelder, an escapee from the Tantalus colony. On the way back to Tantalus V in order to return Van Gelder to the colony, Spock peered through his viewer while he reported to Kirk that the ship would arrive at its destination in fifty seven minutes, thirty seconds. Through the use of his viewer, Spock fascinatedly examined an identification tape from the ship's library on Van Gelder, learning that he was actually a doctor who had been assigned to the Tantalus colony six months earlier. (TOS: "Dagger of the Mind")

While the Enterprise received an Earth-style SOS distress signal, Spock used his viewer to ascertain that the source of the signal was not a vessel, but a nearby planet. As the ship approached the planet, Spock again utilized the device to measure the planet's circumference, mass and mean density, as well as to determine that the planet was spheroid-shaped and had an atmosphere consisting of oxygen and nitrogen, much like Earth. (TOS: "Miri")

Engineering Viewers

Aboard either some or all Starfleet vessels, a secondary viewer was introduced at the bridge's engineering station in 2267. Another viewer was added to the environmental engineering station around this time. The appearance of these devices was identical to the science viewer's second configuration. (TOS: "Catspaw", "The Doomsday Machine")

It is not entirely clear when exactly the viewer at the environmental engineering station was added, due to the fact that the station does not appear in every episode and, when it does, is usually manned by an officer, physically hiding whether the viewer is present or absent. The first episode in which that particular device can clearly be seen is "The Doomsday Machine"; the viewer at the engineering station first appeared in "Catspaw".

Tactical Viewers

Mayweather Viewer

The helmsman on a Constitution class ship uses a tactical viewer during battle.

Lieutenant Sulu on the Enterprise used a tactical viewer when the ship was engaged in battle. The viewer, which was stowed inside the helm/navigation console, would unfold at the push of a button. (Star Trek: The Original Series)

In the Mirror Universe, Sergeant Mayweather used the USS Defiant's tactical viewer during battle with rebel ships fighting the forces of the Terran Empire. (ENT: "In a Mirror, Darkly, Part II")

Other Variations

In 2266, three white scopes were used, rather than a main viewscreen, aboard the Romulan Praetor's flagship that attacked several Federation outposts along the Romulan Neutral Zone. The scopes were each connected by and positioned around a thin, white column whose base, on which each scope sat, was much like a table. Each scope consisted of a control surface and a large, higher screen similar to a 23rd century Starfleet science or engineering viewer, in the way its featureless exterior jutted out of the control surface. In normal operation mode, the screens would constantly change color, slowly filtering through the visual spectrum. Although the colors on each screen would change simultaneously, individual controls below every screen could be altered at each user's discretion.

The controls were dark brown dials, three of which were precisely arranged adjacent to one another near each scope's base, while a fourth could be found above the innermost and middle of the lower controls. The other section of the control surface, between the four controls and the screen, was flat and featured thin strips of colored light - one on either side, and another at the top, just below the screen.

On the sides of each scope were twistable, metallic handles that each officer could grip if the bridge was shaking, such as during battle situations. When the Romulan flagship became damaged in battle, the screens lost power and darkened. They emitted smoke and sparks shortly before the vessel's destruction. (TOS: "Balance of Terror")

Only two scopes were seen at any one time, though the presence of an additional scope can be determined by the positioning and viewpoint of the Romulan officers present. The visual devices are named as "screens" by one of the officers.
The column of scopes was designed to resemble a submarine periscope, as "Balance of Terror" was influenced by the submarine warfare movie genre, with the warbird acting in a similar capacity to a submarine.

Notable Appearances



According to Matt Jefferies, a production designer and art director of Star Trek: The Original Series who designed the original Enterprise, Spock's viewer is reminiscent of RADAR stations used by World War II naval ships. Because early RADAR imagery was very weak, ambient room light typically overwhelmed and "washed out" the RADAR screen. Rubberized viewing hoods were needed to allow the RADAR operator to see images. These viewing hoods are no longer required, as LEDs used by modern RADAR are brighter.

The fictional Star Trek device was named as a "viewer" both in script sources and in ENT: "Shuttlepod One", which finally established a name for the device in Star Trek canon. However, the word was also used on several occassions to describe a viewscreen, even in two Season 2 episodes which were both produced and aired after the first season's "Shuttlepod One". In his written adaptations of The Original Series episodes, James Blish refers to Sulu's scanner as a "gooseneck viewer".

According to the subtitles commentary for "Broken Bow" written by Michael and Denise Okuda for the ENT Season 1 DVD, the "hooded scanner" that T'Pol uses both in the episode and in the rest of the series was "inspired by Spock's viewer on the original Enterprise bridge". In the same episode's DVD audio commentary, Rick Berman describes T'Pol's viewer as "a little homage to the viewer that Spock will have in a hundred years". The link between the two viewers, notably both used by Vulcan science officers who at some point joined Starfleet, was also established in canon; in ENT: "These Are the Voyages...", Deanna Troi likens the viewer found in a holographic simulation of the NX class Enterprise's bridge to a photograph she once saw of a similar device that had been used on "Kirk's ship".

Both science viewers had only a light bulb inside. Although an actual video screen was at one point planned for installation inside T'Pol's viewer, someone pointed out that the audience had never seen the inside of Spock's viewer and the plan was consequently scrapped. Special effects technician Wil Thoms, who operated many of the "automatic" doors on Enterprise, was also responsible for the fact that T'Pol's viewer was rigged to extend on command.

The viewer has been the subject of many parodies, particularly of The Original Series. It has also been featured in several serious fan productions, including the New Voyages fan films. The helm viewer prop used in the ENT Season 4 episode "In a Mirror, Darkly, Part II" was donated to the production by the makers of that particular fan series.


In the Pocket ENT novel Surak's Soul, Hoshi Sato uses a viewer in a small laboratory set up next to Enterprise's sickbay. She uses the device, which reads tapes and has both audio and visual output, to study medical log entries made by members of the Oani, but is shocked by having just witnessed their species' extinction. In the same scene, Captain Archer visits the lab and, on his way out of the room, he pauses to glance at an image on the viewer. Although the device is described as a "viewer", it does not seem to have much in common with the viewer used by T'Pol at the ship's science station, which only one person could use at any one time. Additionally, T'Pol's viewer does not have audio output and is never established as being able to replay recordings.

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