Holodeck

Hologrid — An inactive Federation holodeck, pre-2371

Holodeck in Emissary — An alternate holodeck design

The holodeck has given us woodlands and ski slopes... figures that fight... and fictional characters with whom we can interact.Jean-Luc Picard

A holographic environment simulator, re-creation room or holodeck was a holographic simulation room designed and used by the Federation Starfleet which ran holographic programs. They were installed aboard starships, space stations, and at Starfleet institutions during the mid-24th century for use in entertainment, training, and investigative purposes, after decades of improvements prompted by a failed experiment in 2261. (SNW: "A Space Adventure Hour"; TNG: "Encounter at Farpoint")

History

Xyrillian holodeck — A 22nd century Xyrillian holo-chamber

In 2151, the Starfleet vessel Enterprise NX-01 encountered a vessel belonging to the Xyrillians, an alien race who had advanced holographic technology in the form of a holographic chamber, or holo-chamber for short, which was similar to the holodeck technology commonly used by Starfleet two centuries later. (ENT: "Unexpected")

A holo-chamber was later installed aboard a Klingon battle cruiser after an encounter with a Xyrillian vessel discovered "hitchhiking" behind their ship. (ENT: "Unexpected")

Lorca and Tyler on holodeck — Captain Lorca and Lieutenant Tyler exiting a holographic combat simulation

By the 23rd century, battle simulators, equipped with holographic technology including holographic communications and combat training simulations, were installed on starbases, as well as the Crossfield-class science vessel USS Discovery. (DIS: "Lethe"). However, they usually used a huge amount of energy and processing power, and despite being more limited in function (ie: only combat training), ship-based versions were only used during downtime.

By 2261, a prototype holodeck had been developed from the battle simulator, with Starfleet planning fleet-wide distribution as they believed that it would provide games and entertainment for distraction and stress relief purposes, and thus allow ships to embark upon missions longer than five-year missions. To that end, Starfleet assigned the USS Enterprise to test the prototype holodeck while the Enterprise conducted a parallel mission of studying a neutron star to ensure the holodeck could work under genuinely rigorous circumstances. Lieutenant La'An Noonien-Singh tested it through a 20th century murder mystery scenario, but became trapped in the holodeck which took up an enormous amount of processing power from the ship's computer as well as a lot of the ship's power, threatening its safety. After La'An solved the mystery, she was able to deactivate the holodeck. Subsequently, La'An and acting chief engineer Montgomery Scott advised against implementation of the holodeck in active starships for the time being, although Scott had a theory on how to fix the problem – namely, servers and a power supply independent of the rest of the ship. (SNW: "A Space Adventure Hour"). Due to this, prior to the late 24th century, Federation starships were not equipped with full holodecks. (VOY: "Flashback")

By 2270, the recreation room aboard Constitution-class starships employed holographic technology. The Enterprise had a recreation room located in Area 39 of the ship. In comparison to the full Holodeck, the rec room is limited to pre-programmed holographic simulation of environments, simulated weather including wind and temperature, and sounds played from audio tapes. The scenes it created included an 18th century European hedge maze, forests, blizzards, and a beach with seagulls. Even though the scenery extended beyond the room, one would still be able to walk up to and touch the walls during a simulation. (TAS: "The Practical Joker")

By 2364, technology had improved enough to allow Starfleet to begin installing fully-functional holodecks aboard their vessels. (TNG: "Encounter at Farpoint")

During the 2360s and 2370s, a starship could have one or more holodecks depending on the vessel's size or purpose. For example, the compact Defiant-class USS Defiant did not have a holodeck while the larger Galaxy-class USS Enterprise-D had at least seven. (TNG: "The Perfect Mate")

In 2366, Data and Deanna Troi brought Lal to the holodeck in order to choose an appearance. (TNG: "The Offspring")

The Intrepid-class USS Voyager had at least two holodecks. The holodecks on Voyager were the only places other than sickbay where The Doctor was able to exist (prior to obtaining his mobile emitter) after his program was modified by the crew so he wasn't so tightly tied into the sickbay's systems. (VOY: "Night", "Heroes and Demons")

B'Elanna Torres used the Voyager's holodeck for a holographic orbital skydiving session. (VOY: "Extreme Risk")

Prometheus-class starships were equipped with holoemitters on every deck to allow an EMH a higher level of access and free movement around the ship. (VOY: "Message in a Bottle")

The USS Protostar was equipped with a holodeck for training and entertainment purposes. Amongst the scenarios programmed in were the Kobayashi Maru scenario and the fox, chicken and grain problem. Rok-Tahk was able to watch a recording of the fox, chicken and grain problem training session while stranded alone due to a temporal anomaly. (PRO: "Kobayashi", "Time Amok")

The Diviner was able to upload the Solum-1 holoprogram to the Protostar holodeck to show Gwyndala the reason behind their mission. The holodeck was later able to play back a recording of this visit for the crew. (PRO: "A Moral Star, Part 2", "Let Sleeping Borg Lie")

The USS Dauntless was equipped with holodecks. The status of the holodecks, and other areas, of the ship were reported on the master situation display. (PRO: "Mindwalk")

A clear view of the MSD was provided by Dominique Rossier of Wardenlight Studio. [1]

The location of the holodeck in the Lamarr-class science vessel USS Voyager-A was labeled in the ship's master systems display. Voyager had multiple holodecks as well as holographic projectors throughout the ship that allowed programs to exist outside of it. (PRO: "Into the Breach, Part I", "Imposter Syndrome")

A clear view of the MSD was provided by Dominique Rossier of Wardenlight Studio. [2]

Purpose

Design

The prototype holodeck tested on the USS Enterprise in 2261 drew on an enormous amount of processing power from the ship's computer as well as the ship's overall power, such that during the pre-arranged test of running the holodeck while Enterprise studied a neutron star placed the ship in danger. As the holographic character needs to be very detailed, Lieutenant Montgomery Scott created the characters for the program using the bio-signature of people from the pattern buffers of the Enterprise's transporter. The ship's AI controlled the program and wouldn't allow the holodeck to be shut down without the scenario being completed. These design flaws led to Scott and La'An Noonien-Singh recommending against the holodeck being installed upon active ships for the time being, although Scott came up with a theory about how to potentially fix them – namely, servers and a power supply independent of the rest of the ship. (SNW: "A Space Adventure Hour")

Galaxy class holodeck arch — The arch in an inactive holodeck, pre-2371

A typical holodeck consisted of a room equipped with a hologrid containing omnidirectional holographic diodes, enabling holographic projections and holograms. Elements of transporter technology and replicators were used to create holodeck matter by the manipulation of photons contained within force fields to give objects the illusion of substance as well as actual matter. This matter could exist outside of the holodeck for brief periods of time (such as snow) before they would lose cohesion and revert back to energy without the support of the hologrid. (TNG: "Encounter at Farpoint", "The Big Goodbye", "Elementary, Dear Data") Tractor beams are also used. Incorporating the 2261 recommendation, holodecks were powered by holodeck reactors, which were independent of, and incompatible with, the ship's main power, with a side benefit of providing a kind of sanctuary for the crew in times of distress. (VOY: "Parallax", PIC: "No Win Scenario") They were also equipped with biofilters which had to be periodically removed and emptied of waste matter. As removing the filter could momentarily expel a cloud of odorous gas, this was generally considered a highly undesirable task. (LD: "Moist Vessel")

Holodecks had databases to store programs, holograms, and holographic templates. (VOY: "Renaissance Man") A holobuffer stored complex holograms when inactive. (VOY: "Lifesigns", "Latent Image", "Inside Man") Due to the ability to store highly complex energy patterns, it was possible in some cases to store a person's physical parameters from his or her transporter pattern in the holodeck database. This could, in turn, be available for use in creation of holograms. (DS9: "Our Man Bashir") While viewing programs, a user could delete holocharacters using character deletion algorithms. (DS9: "Badda-Bing, Badda-Bang")

Holodecks had general systems and modes of operation that were used in holographic programs. They employed spatial orientation systems to simulate parts of a holocharacter, such as left- or right-handedness. (TNG: "Ship In A Bottle") Holodecks could also have a program element called a perceptual filter to hide anachronisms to the program's time period, such as uniforms and communicators, in order to prevent them from raising the character's ire and curiosity. (VOY: "Spirit Folk") Among the viewing modes on a holodeck was objective mode, in which the user didn't interact with the characters, and subjective mode, in which the viewer could interact with the characters as well as alter his or her surroundings. (ENT: "These Are The Voyages...") Holodecks could be equipped to change gravity in three dimensions. (VOY: "Extreme Risk")

The holodeck could be controlled from an exterior control panel, the interior arch control, or through bridge control relays in some designs. The arch could be summoned at any time to change the parameters of a running holoprogram. Matter and energy were interchangeable as such objects created on the holodeck could be either matter or energy. (TNG: "Elementary, Dear Data"; VOY: "Heroes and Demons", "The Killing Game"; Star Trek: Insurrection) Holodecks included components such as bi-converter interfaces. (TNG: "The Big Goodbye")

Riker Jungle Holodeck 2364 — William T. Riker entering a holodeck simulation in 2364

When a user experienced a holographic environment, the holodeck walls could generate holographic images that appeared to extend for an unlimited distance, seemingly much larger than its own dimensions. The walls could be revealed if someone took an unexpected action in the program which hit the wall, for example if a person were to throw a holographic rock at the walls and the program was not able to react to show the rock continuing into the holographic image it created. (TNG: "Encounter at Farpoint")

End program — A holodeck program in the process of shutting down

Holodecks were equipped with safety protocols to prevent serious injury during their use, though these could be disengaged by the user when required. When protocols were deactivated, holographic obstacles had the same effects on a person as the objects or instances they simulated; holographic bullets or a steep drop could be fatal in such a scenario. (TNG: "The Big Goodbye"; Star Trek: First Contact; VOY: "Extreme Risk") Communication to the ship can also be disabled due to safety protocol malfunctions.

How the security protocols were circumvented differed; in one instance, it required the voice authorization of two senior officers, (TNG: "Descent") while in others the authorization of the individual such as the ship's captain, or the person who started the program was enough. (VOY: "Extreme Risk") Safety protocols could also be unintentionally disabled due to software errors or physical damage to the holodeck's hardware system. The status of safety protocols could be reviewed by the computer upon the request of an operator. A tricorder could also be used within the holodeck to query the current safety protocol status.

While it was noted by Geordi La Forge that there was no specific prohibition against creating images of people that existed in reality, some people such as Commander William Riker and Leah Brahms would take offense to people doing so. Lieutenant Barclay apparently had no problem creating holograms of the Enteprise D's crew, while Quark did not have easy access to Major/Colonel Kira's image in a program to rent to one of his customers.

Abilities and limitations

Even during the prototype phase of 2261, the holodeck was capable of generating realistic sensations, including smell. As it was based on a battle simulator, the prototype holodeck was able to predict and anticipate the way its users thought, which helped provide challenges even in strategic scenarios such as a murder mystery. (SNW: "A Space Adventure Hour") However, for a long while, even as late as late 24th century, users needed to wear costumes when entering the holodeck.

By the 2370s, holodeck technology was able to have fine enough control over magnetic containment fields that holographic objects could interact with matter on a biologically small level, for example, in replacing a person's organ with a simulated one that mimicked its functionality. (VOY: "Phage")

The computer used large magnetic bubbles to simulate surfaces and textures rather than creating an object at the molecular level. However, objects created within the holodeck did not exist beyond the holodeck itself, as they only existed as energy. (TNG: "The Big Goodbye") Holodecks also had access to extensive databases and archives and could recreate most historical scenes nearly exactly as they had occurred according to official records. This included material sometimes down to the smallest details, such as casual conversations by random people in public places, although in certain recreations the character names and appearances were slightly changed. (TNG: "We'll Always Have Paris")

Since holodeck technology could be used with replicator technology, there were some instances where real objects were replicated within the holodeck and used to interact with the holographic program and/or users for a more realistic experience; since these objects were real material composed of matter, they could leave the holodeck fully intact. Examples of this include Wesley Crusher still being wet after leaving the holodeck after falling into replicated water, (TNG: "Encounter at Farpoint") Lieutenant Commander Data being able to take a drawing of the Enterprise on a piece of paper out into the hallway, (TNG: "Elementary, Dear Data") and a wayward snowball being able to pass through the holodeck doors and strike Captain Picard. (TNG: "Angel One") Scents were also simulated in this way.

A holodeck could also modify the appearance of persons within it.

The holoprogram depicting the final mission of the NX-class starship Enterprise NX-01 could project uniforms suitable to the participants' role over them. (ENT: "These Are The Voyages...")
A holodeck was able to superimpose an entirely different appearance over a participant. (TNG: "The Offspring")
Tom Paris' holoprogram Captain Proton existed as a monochromatic environment. (VOY: "Night", "Bride of Chaotica!")
As part of The Big Good-Bye, appropriate attire could be projected over participants of the program. (Star Trek: First Contact)
Simulations could also be projected inside living organisms, including that of pregnancy. (VOY: "The Killing Game")
B'Elanna Torres' leg appeared to dematerialize while she was participating in the holonovel Photons Be Free as the holographic main character. (VOY: "Author, Author")
Seven of Nine used the holodeck to hide her cybernetic implants. (VOY: "Human Error")
Hologram Janeway was able to use the holoprojectors on the USS Protostar's bridge to project the consoles of a mid-23rd century Constitution-class starship over the bridge consoles and have them relay actual commands to the ship. (PRO: "All the World's a Stage")

Holograms could be augmented with force beams to simulate solid, tangible objects or with replicator technology to create actual solid matter such as foodstuffs. All food eaten on the holodeck were replications. No other type of simulation could survive outside of the holodeck. ^{(citation needed • edit)}

A holodeck also had the ability to create holodecks within holodecks, and holodeck programs were able to be saved to a tech cube that could be inserted into an enhancement module to form an optronic data core with information to "last a lifetime." (TNG: "Ship In A Bottle")

The holodeck reactor, which powered the holodeck on 24th century Federation starships like Voyager, was incompatible with other ship systems. (VOY: "Parallax")

Failure of a holodeck's matter conversion subsystem could cause the loss of solid objects within the holodeck environment. Materialization errors occurred in the USS Enterprise-D holodecks in 2370 following the ship's exposure to plasmonic energy in the atmosphere of the planet Boraal II. (TNG: "Homeward")

The holodeck could populate holoprograms with procedurally-generated background characters to complement a story. However, it was not designed to generate an unplanned full narrative, especially not one that diverged too much from the primary narrative's premise. If a user were to make decisions that forced it to do so, the resulting secondary narrative would become increasingly bizarre and incoherent as it progressed, with strange or even nonsensical plot developments, delays as it generated backstory for what had originally been a background character, and reliance on stock phrases to maintain some semblance of understandable dialogue. (LD: "Crisis Point 2: Paradoxus")

Even though holographically created characters, just like characters in a story book, were never self-aware and never knew that they were not real, there were a few rare instances in which that rule did not hold true. During a Sherlock Holmes holodeck simulation in the late 2360s, Geordi La Forge and Doctor Katherine Pulaski argued that playing with Data was impossible and unfair to them as he had memorized all the Sherlock Holmes novels and could easily solve the cases. In order to level the playing field, La Forge requested that the holodeck create an opponent intelligent enough to defeat Data.

Even though La Forge meant Holmes, his request had specifically noted Data. As a result, the holodeck created a self-aware holographic character of James Moriarty who was not only fully aware of his own consciousness, but who subsequently argued that he had a right to exist and leave the holodeck to pursue his life as he wished. (TNG: "Elementary, Dear Data", "Ship In A Bottle") Another holographic writer, known as Felix, created the fully self-aware program of Vic Fontaine for the crew of Deep Space 9, Vic being completely aware of his holographic nature despite being a 1960s lounge singer, often offering the crew personal advice on relationship issues. (DS9: "His Way", "Badda-Bing, Badda-Bang", "It's Only a Paper Moon")