A force field is an energy barrier with many applications and varying degrees of strength. Although force fields had been in use for many years, Starfleet did not begin research on such a device until 2147. By the 24th century, Federation Starfleet force fields were commonplace and were rated by intensity, ranging in strength from level 1-10. A level 10 force field is the strongest and would be used, for example, during a scientific experiment of which the outcome is unknown, or known to be explosive in nature. Applications range from creating holograms to sealing a hull breach to personal force fields designed to keep potential assailants at bay.
The effects of a force field on its surroundings vary greatly. Contact with a force field may cause anything from a slight tingle to death. Most force fields are non-lethal, although some civilizations such as the Dominion prefer the lethal variety. If a force field is active, an object or transporter beam generally cannot pass through it, although this is not always the case. The Borg are known to not be hindered by most force fields; they can adapt and simply walk through the field. However, a Borg drone can be cut off from the Borg Collective if it is surrounded by a Starfleet level 10 force field.
Force fields can be activated from various locations. On Starfleet starships there are emitter points at almost every junction along every corridor. The computer can be programmed to run a series of force field activations and de-activations within the ship, effectively creating a protected corridor which can follow a person. Commander Data used this technique with great control when he commandeered the USS Enterprise-D on stardate 44085.7. He also demonstrated another technique involving instructing the computer to implement a scan-series of force field activations, activated by his movements along a short distance of corridor, thus forcing the security team to back away from him.
When various security measures left over from the Cardassian occupation came online on Deep Space 9, Elim Garak was recognized as a person of sufficient importance by the computer to have the force fields dividing the station drop when he approached.
If necessary, a transporter platform can be completely enclosed within a force field, to, for example, contain an alien subject, or prisoner during transport.
Force fields are also capable of selective positioning, allowing the majority of it to cover a secure location, while a smaller portion is deactivated to allow transport of food, drinks, and other items; particularly used when it would be considered dangerous to deactivate the entire force field.
A containment field is essentially a force field used to prevent the escape of matter or antimatter. Containment fields are usually raised when cargo bay or shuttlebay doors are opened to keep them pressurized, although the containment field is partially disengaged when a shuttlecraft passes through it. Unfortunately, eighteen engineers from the crew of the USS Yamato were killed when the containment fields in a shuttlebay failed after the ship was infected with an Iconian software transmission. A containment field can be manually activated and deactivated should the need arise. Containment fields would be used by Starfleet personnel to isolate an area for investigation, such as using a field to isolate a transporter room pad to beam aboard a sample of an object.
Containment fields can also be used to reinforce antimatter containment, although they cannot prevent an impending warp core breach. Lt. Cmdr. Data raised a level 3 containment field around the warp core of the Enterprise-D in 2369 when the ship was facing destruction by a core breach. By 2379, it was a standard procedure on the USS Enterprise-E for the warp core to be reinforced by a high-level force field before engaging in battle.
Inertial dampers, structural integrity and emergency force fieldsEdit
The inertial dampening system consists of a network of variable-symmetry force fields that continually adapt and compensate for the inertial effects of interstellar travel. They are almost entirely controlled by the ship's computer, which allows for instantaneous fine tuning of these fields' geometries, and to even anticipate resultant forces from the engines. In 2366, in an attempt to escape a Menthar booby-trap, the Enterprise-D had to jump to full impulse for a split-second. Commander Riker warned the crew that the inertial dampers might not react quickly enough to compensate for the acceleration. Also, if an inertial-damping system generator went off line or malfunctioned, a back-up generator was to immediately activate to prevent injuries to the crew or damage to the ship.
In the event of an outer hull breach, emergency force fields are automatically deployed to protect the damaged part from the influences of space; at the same time they prevent decompression of the entire deck by keeping the atmosphere in. During critical situations, such as ship-to-ship battles, if the main defensive force field is ruptured and a section of the ship is destroyed, it takes longer for the computer to re-establish the structural integrity field than usual because of the large energy demands already placed on the vessel. In this short space of time, sections of a vessel can indeed be exposed to the vacuum of space. Captain Kirk was lost to the vacuum of space in this way, in 2293, when the USS Enterprise-B was struck by the nexus energy ribbon.
A lieutenant aboard the Enterprise-E was blown out into space in 2379 before an emergency force field could be activated when the bridge front wall and viewscreen were destroyed by the Reman warbird Scimitar. A similar incident happened when an alien ship was disabled by the Krenim timeship's conventional weapons, and collided with the almost-already-crippled USS Voyager's bridge front/viewscreen and portions of her decks. Fortunately, Captain Janeway was not blown out into space, due to the quick activation of the emergency atmospheric force-fields. A plasma leak caused by an explosion on the USS Defiant was covered by a level 8 force field, which Jadzia Dax then walked across in order to tend to Dr Lenara Kahn.
On stardate 49263.5, the USS Defiant, under the command of Captain Benjamin Sisko, descended into the atmosphere of a Class-J gas giant with 10,000 kilometer per hour wind speeds. The emergency force field that was erected to save the ship from decompression due to a hull breach was not able to withstand the pressure for more than a few minutes.
Starbases, starships, shuttlecraft, and even advanced weaponry are often equipped with external force field emitters, which, when activated, produce a "bubble" around the generating object, known as defensive shields. These shields are variable, and can even be extended to encompass a nearby vessel or object. Defensive force fields can be penetrated in two ways. The most conventional method involves firing energy weapons at the shielded object, which weakens the field. The other method is achieved by matching the frequency of the shield to the weapon used. Chroniton torpedoes cannot be stopped by normal shielding but require modifications to enable temporal shielding.