The main obstacle facing a civilization seeking to expand its influence beyond its home star is the vast distances between star systems. Due to the consequences of the Theory of Relativity, it is normally impossbile for a starship to accellerate past the speed of light, and even travelling at the speed of light it will take a ship years to reach any meaningful destination.
There are numerous possible solutions to this problem, such as using wormholes to bypass the space between two destinations. The most practical solution discovered so far, however, is the use of hyperspace drives.
Hyperspace drives operate using Vedihno's Theory of Hyperspace. According to the theory, hyperspace exists as layers, called Scalia, both "above" and "below" normal space. See the article on Hyperspace for more details on the theory.
Early hyperspace drives, such as those used by the Shyedarians before their Renaissance, worked by piercing the Vedihno Boundary between normal space and hyperspace. The ship would then pass through into hyperspace, and travel at constant speed until it reached its destination, where it would shut down its hyperspace drive and drop back into normal space.
A revolution in hyperspace drive design occurred when Mirrax, a Shedarian starship engineer and physicist, discovered that rather than piercing the Vedihno Boundary, it was possible to instead bend it, creating a mobile bubble of normal space within hyperspace. Rather than the ship moving through hyperspace, it was this bubble of normal space which moved, with the ship relatively stationary inside it. When the bubble reached its destination, it collapsed, releasing the ship back into normal space.
There were two major advantages to Mirrax's design. First, bending the Vedihno Boundary requires much less energy than actually piercing it, so ships using Mirrax's design had far lower power requirements. Second, because this type of hyperspace drive did not pierce the Vedihno Boundary, it was possible for it to reclaim the energy used to create the normal space bubble when the bubble collapsed. So the only net loss of energy to a starship using Mirrax's drive design was the energy used to keep the ship in hyperspace while it travelled. Because of these advantages, nearly all hyperspace drives used in the Zulu Sector operate using some variation of Mirrax's theories.
As described in the previous section, modern hyperspace drives operate by bending the Vedihno Boundary between normal space and the layers of hyperspace, known as Scalia, creating a bubble of normal space within hyperspace where the ship remains at rest. Due to the properties of hyperspace, this bubble moves at a constant speed at all times. The hyperspace drive provides energy to overcome the "frictional force" experienced by an object moving through hyperspace, until the ship reaches its destination, at which point the normal space bubble is allowed to collapse, letting the drive reclaim the energy used to make it.
So the process of engaging a hyperspace drive has several distinct steps, each with their own energy requirement:
To meet the high energy requirements of hyperspace drive operation, the most common energy source used is the matter/antimatter reactor. They are the only energy source available using currently understood technology that can meet the hyperspace drive's power requirements while still remaining portable.
Because the Scalia in Vedihno's Theory are isolated from normal space, it is not possible to detect a ship in hyperspace directly. However, it is possible to detect the disturbance in the Vedihno Boundary caused by the bubble the ship is travelling in, and this disturbance is proportional to the mass within the bubble. Thus a ship or space station in normal space can, if it monitors the Vedihno Boundary, detect any ship in hyperspace using Mirrax's drive theories. (Monitoring the Vedihno Boundary is also how interstellar communication is achieved.) A hyperspace drive that pierces the Vedihno Boundary instead of merely bending it, on the other hand, becomes undetectable in normal space.
Because normal space and hyperspace are separated by the Vedihno Boundary, they do not normally interact. A ship in hyperspace can pass right through a planet in normal space and be unaffected. However, the Vedihno Boundary itself is associated with both normal space and hyperspace, so anything that affects the Vedihno Boundary on one side also affects the other side.
One consequence of this fact is what happens when two ships travelling in hyperspace meet. When the normal space bubbles around both ships touch, they instantly collapse, causing both ships to drop back into normal space. While the odds of this occurring randomly in space are generally negligible, it is a highly effective tactic for stopping an approaching starship intentionally. Of course, this leaves the ships in very close proximity to eachother, which can itself be a dangerous situation.
Similarly, planets and space stations can apply power to bend the local Vedihno Boundary in order to prevent starships from operating a hyperspace drive in its vicinity. In fact, this is common practice, in order to allow traffic control centers to more effectively manage the movement of starships in their area. These kinds of hyperspace restriction fields also provide security from attack, since once a threatening ship has been forced out of hyperspace, it is vulnerable to attack by conventional weapons.
One of the urban myths of the galaxy states that due to the nature of how this method of travel works, travel outside of The Annulus proves to be futile via this conventional method. Attempts by those races close enough to the edges of space have brought them outside of Hyperspace and unable to re-enter the zone. This usually results in a very long time period of travelling in normal space back to The Annulus. If true, faster than light communications with this method to other galaxies isn't possible.
This is not the only known way for Going Faster Than Light or travelling without consequence of time dilation.