Tannhouser gates
The atypical globular cluster known as Enders Cluster has more oddities within it's bounds than just it's odd stellar composition. the cluster is subject to what have been termed 'Aether storms' (Aether being spacers parlance for space-time). large regions in which the fabric of space-time is disrupted and 'ripples' in random patterns that cause destructive interference to space warping based faster than light drives, such as contra-gravitic drive. this interference can be compensated for in sublight drive modes, but prevents the formation of a 'warp bubble' for FTL travel. these storms are widespread in the cluster, and form, spread, shift, and dissipate in a fashion that bears similarities to planetary weather patterns.
One side effect of this exotic stellar activity is the formation of 'Aether streams', regions of space which form naturally occurring space warps, which possess physical laws slightly different from the rest of local space. these tunnels of warped space twist through the cluster, linking locations separated by vast distances. these tunnels are isolated from normal space time once formed, and normally would be undetectable were it not for naturally occurring weak spots in their structure that interpenetrates with normal space. these doorways allow objects from normal space to enter and exit the Aether streams, and travel along them. while inside the Aether stream, a ship's affective velocity is increased 1000x. a vessel traveling at .0001c (about 100 palladium mach) would effectively travel at .01c (about 100,000 mach) when determining the elapsed time experienced by the crew and the outside distance covered. a vessel traveling at a mere .001c (1000 mach) within the stream is equivalent to traveling at the speed of light (1,000,0000 mach.) This allows extremely rapid travel between the stars, limited only by the locations of the doorways. however, it is possible to come to a relative stop within the stream (velocity under 1 mach), although such slow velocities provide little benefit to the traveler. the interior of an Aether stream is a tunnel eight to ten thousand kilometers wide, with distorted images of the outside visible on its wall. these are blueshifted and redshifted relative to the heading of the craft one is on. the 'walls' of the Aether stream are intense regions of spatial warping, and will destroy any object that penetrates them. however, they are bordered by a repulsive effect out to 100 kilometers, which prevents most objects from reaching the 'walls' themselves. hitting this border will cause the object to 'bounce' back towards the center of the stream, gain 1 mach in velocity, and take 1D6x100 megadamage to the main body. attempting to remain in the boundary region through the use of active thrust to counter this repulsive force requires successful piloting skill rolls each melee, and the vessel will take 1D6x100 megadamage per melee, as well as gain 1 mach per melee in acceleration (about 2g's.) inside the stream, a doorway is visible as a tunnel branching off from the stream. these tunnels gradually narrow down to be only a hundred kilometers wide, with a 'border' of only a few hundred meters (hitting this border will only inflict 1D6x10 megadamage, and will not accelerate the ship. attempting to remain in the border inflicts only 1d6x10 megadamage per melee.) a naturally occurring doorway viewed from the outside is a faintly glowing region of space. the glow is cherenkov radiation, and is directional, originating from an otherwise undetectable semi-circle of space (often giving the glowing region a conical appearance). passing through this point in space from the side emitting the glow allows the ship to enter the Aether Stream. passing through the other direction has no effect.
Tannhauser gates are ancient ring shaped devices that hold open artificial doorways into Aether streams. Their common reporting name is taken from a report filed by the CCW physicist that identified their operating principles. lacking a common local name for the gateways, he attributed to them a name drawn from an ancient terra Prime media entertainment. The Tannhauser gates vary in design, but all take the form of large rings 100 kilometers across, and about one kilometer thick and deep. They are constructed of a ultra-strong material (5000 M.D.C. for each 1/2 kilometer section of ring. the full circumference of the ring is 1256.5 kilometers. the material the gateway is energy absorptive, taking 1/10th damage from energy weapons such as lasers and particle beams, and also damps down kinetic and thermal attacks such as rail guns and explosives by 1/2.), and possess no openings, hatches, or apparent external components. examination of damaged and destroyed gateways indicate that the functional mechanism of the gateway is a massive solid state device of unknown operation. destruction of any one section of the ring will result in the doorway contained within vanishes. Many races that employ Tannhauser gateways for interstellar travel graft locally built space station components onto the rings, to provide traffic control for managing incoming and outgoing vessels, as well as defense systems to protect the gateway from harm. Adding the components to the gate itself is a must, as Tannhauser gates and aether stream doors are fixed in place relative to their position within the cluster. they do not orbit stars or planets, instead orbiting the core of the cluster at the same rate as the nearby stars do. as a result, stationing mobile forces to defend the gateways thus requires constant thrust and maneuvering to maintain position. since modules attached to the gateway, or ships docked to it, are held in place by the gateway itself, it becomes an anchor for defensive components.
Due to the difficulty in using Contra-Gravitic drive within the cluster, CCW exploration vessels have confined most of their travels to locations along the currently known Aether stream courses. It is believed the Trans-galactic Empire has also adopted this approach, however the information about TGE presence in the Cluster is thus far too small to confirm any such statements.