Jumpgate (Babylon 5)
A Jumpgate is a fictional static emplacement in the science fiction television series Babylon 5 and Crusade, the Jump Gate creates an energy vortex, called a Jump Point, to allow vessels to travel to and from hyperspace for interstellar travel. In the Babylon 5 universe, hyperspace is a universe that is adjacent to the normal universe. Jumpgates also have beacons that vessels in hyperspace can lock on to. Since hyperspace is utterly featureless, the beacon network is the only practical means of navigating it. Amongst the "younger" races of the galaxy, jumpgates are a vital part of interstellar travel.
For most ships, a jumpgate is required for interstellar travel. While the more advanced races - such as the First Ones - are able to install jump point generators in even their smallest vessels, for younger races the energy cost means that only the largest vessels have the capability to create their own jump points. It wasn't until the White Star, that any smaller vessels were fitted with jump point generators.
The jumpgates are also vital for the beacon signals that they provide. The beacons allow ships to navigate through hyperspace without drifting so deep into hyperspace that they become permanently lost. If enough jumpgates were destroyed the entire jumpgate/beacon network would fall apart. Vessels would then be unable to make their way through hyperspace. For that reason jumpgates are usually considered neutral territory, and it's considered very uncivilized to attack them.
Configuration
A jumpgate is typically made of four long independent pylons that form a circle. Some races use different configurations; a Narn jumpgate employs three pylons. When a jumpgate is activated, an energy pulse runs down each of the cylinders, until it reaches the end of the cylinder. It then separates from the cylinder, and travels out to a point where it meets with the other energy pulses. The energy pulses together provide enough energy to create the vortex. The vortex will be yellow if a ship will be entering the point and going into hyperspace, and will be blue if a vessel is exiting hyperspace. The jumpgate will provide the energy to keep the jump point open until a vessel has completed transit.
A vessel wishing to enter a jump point will usually send a signal to the jumpgate to activate the gate. If a private vessel is entering a gate, a fee is charged for the use of the gate. If for whatever reason those in control of the gate wish to keep a certain vessel from entering hyperspace, the computers on the gate can be programmed to reject an activation signal from that vessel. However vessels are not normally kept from exiting hyperspace, nor is a fee charged, especially since the jumpgate represents the only way to leave hyperspace for most vessels, and if a ship's power failed the ship could become forever lost in hyperspace. In either case, the gate's computers do record each ship that enters or exits the gate, and such records can be used to establish presence in legal settings.
Larger ships that have their own jump point engines will normally use a jumpgate if one is available. This is because the onboard jump point generators require a large amount of energy to operate, and using a jumpgate saves energy. However if such a vessel wanted to keep its arrival off the official records, it would then use its own generators to keep a record from being made by the gate.
A jumpgate can be turned on or off, but it takes 4 days to power up and 2 days to power down. To either power them up or down too quickly would most likely result in the gate destroying itself in a large explosion. The pylons are also movable, if an exceptionally large vessel needs to exit the gate the pylons would be moved to accommodate this vessel.
Vessels equipped with their own jump point generators avoid opening their own jump point within an active jumpgate; to do so would trigger a catastrophic release of energy and destroy the jumpgate and any nearby vessels. Earth Force did experiment with the idea during the Earth-Minbari War. After learning about the consequences, they labeled their failure the "Bonehead Maneuver." This maneuver was once successfully performed by a White Star under the command of John Sheridan at the Markab jumpgate, in order to destroy a pursuing Shadow vessel - unlike war-era Earth Force vessels, the White Star was fast enough to escape the blast radius before the jumpgate exploded.
Whilst morally questionable, given the potential consequences for hyperspace travellers due to the loss of the Markab beacon, Sheridan justifies this decision as a means of keeping "graverobbers" away from the Markab system, following the death of the entire Markab race in a recent plague.
References
ru:Зона перехода (Вавилон-5)