The stars have been brought low, and into our reach.
— An coil drive engineer
Coil drives are technological systems that are essential for interstellar travel. They allow spacefaring vehicles to "coil" their way through space, reaching across incredible distances in the blink of an eye.
A coil drive does not, despite popular belief, allow one to achieve faster than light travel. One can be forgiven for assuming this, considering that it does achieve a similar effect— reducing the vastest distances into mere seconds. In reality, what a coil drive does is a tad more complicated.
First, one must understand the core components of a coil drive— the engine, the coil, and the navigator. The navigator is simple, it's a small chip that can receive coordinates— which it uses to pilot the vehicle once the coil drive has been activated. Attempting to pilot a ship after the drive has been activated is nigh impossible, and the chip is also responsible for deactivating the drive, without one, a vehicle may find itself hurtling through space forever.
The coil is a cage of fibre wire that is wrapped in a coil within the ship's walls, attached at its back end to the engine. This effectively sets the boundary of the coil drive, anything outside a certain distance of the coil will not be carried with the drive's activation. The engine itself serves two purposes— one, as a source of more conventional propulsion when the coil drive is not active, and two, as a mass driver once it is.
With all this kept in mind, one can look at the function of the coil drive with clearer understanding. A coil drive takes the matter of a vehicle and "coils" it into what is effectively a tiny atom-thin string— starting at the front. This string is then passed through the engine as it is formed— which soon after rockets the string forward at an incredibly high velocity. The rest of the ship joins the string shortly after, and this tiny string is then able to move, frictionless, between other atoms to wherever it has been instructed to go.
No known person has truly "invented" the coil drive— rather, coil drives have been reverse engineered across the galaxy from those left behind by the now-transformed Ferajx.
It is believed that humanity, too, developed their coil drives in the same manner. Many believe that interstellar travel would have remained out of reach were these relics not left behind for sapient beings to come across, and pick apart.
There are several different types of coil drives, however, each still mimics variants invented by the Ferajx.