Tachyon gate

Tachyon gates (colloquially referred to as "t-gates") converted a vessel to tachyonic matter, which travelled many times faster than the speed of light crossing a thousand light years inside 5 minutes.

There were two known types of tachyon gates, inter-system and inter-sector. Inter-system gates were fixed, linking to one other gate in the network. Inter-sector gates were capable of directing a vessel to one of several gates linked to it.

History
The tachyon gates were built several thousand years prior to the Foundation Era by an enigmatic race referred to as the Gatebuilders.

Prior to the activation of the tachyon gate network, galactic society moved slowly, using standard FTL to get from system to system, taking years. With the introduction of tachyon gates galactic society expanded rapidly, with empires rising and falling in a matter of months. After 30 galactic standard years the political situation began to stabilize and 5 empires came out on top.

The time period spanning 2000 years after the activation of the gate network was referred to as the Foundation Era.

Mechanism
Very little was known about how tachyon gates work aside from the fact that they converted a ship from normal baryonic matter into tachyonic matter; how this was done is unknown.

A ship approaching an inter-system gate had to simply approach the aperture. After crossing the threshold the gate scanned the ship to acquire its mass and molecular configuration. Once the scan was complete (usually only a few seconds for most ships) the gate converted the ship to a stream of tachyons and sent it on its way.

Once the tachyon stream reached the receiving gate, the gate would "catch" the stream and using the scan from the transmitting gate, convert the stream back into baryonic matter. To the occupants of the ship, the entire journey happened instantly, although several minutes may have passed in reality.

The process for travelling via inter-sector gates was identical, except a vessel needed to transmit its destination to the gate and wait for it to align.

Tachyon gates were powered by tapping into strong gravity wells, such as those produced by large gas giants, black holes, or stars.

Side effects of tachyonic travel
Generally tachyonic travel was typically very safe, but accidents were known to happen.

The worst thing that could happen while travelling via the tachyon gate network was having the receiving gate destroyed before it could "catch" the tachyon stream. In the event of a destroyed or malfunctioning receiving gate, a ship would remain a stream of tachyons forever.

Very occasionally a ship would be converted back into baryonic matter in an incorrect configuration. Sometimes this resulted in something minor; such as chairs swapping places. Other times, it caused devastating hull breaches upon reintegration - killing the occupants.

The most commonly experienced side effect occurred when a member of a viviparous species travelled via the tachyon gate network while carrying an unborn offspring causing a mutation. The mutation's severity varies from something minor such as a gender change, to life-threatening birth defects. This is caused by the tachyon gate's inability to properly distinguish between two beings occupying the same body. The gate simply "guesses" how to reconfigure the being and 99% of the time it gets it right.