Basilisk Traffic Control was a Manticoran space station placed in order to police the terminus. The terminus was annexed by the Star Kingdom of Manticore, but due to political controversy, the rest of the system was merely placed under a protectorate. Manticore did not initially annex the system or the planet Medusa.
This oddity of sovereignty allowed the People's Republic of Haven to openly establish an embassy and trade outposts on Medusa. These were used to support Operation Odysseus, presaging war between Manticore and Haven.
In 1900 PD, the terminus was the object of Haven's attempt to seize Medusa, thus taking control of a second terminus of the Manticore Junction (the other having been the Trevor's Star Terminus). The Royal Manticoran Navy was able to stop them. (HH1, HH3)