In an alternate timeline, the Vulcan-Andorian Empire was an interstellar state controlled by the Vulcans and Andorians. It existed centuries before the 24th century. In the primary universe a temporal rift opened on the surface of Coridan III in 2381 due to the temporal core implosion of a crashed 36th century observation craft. The subspace fissure reached centuries into Coridan's past, albeit into an alternate quantum history. There, the Vulcan-Andorian Empire operated a massive space station in the planet's orbit. (DTI novel: Watching the Clock)