Deep Space 3 was a Federation space station located near a black cluster. Deep Space 3 was commanded by Admiral Marcus Holt in the late 24th century. The station hosted the palio of 2370, where the Ferengi were accused of trying to bribe the Breen pilot into throwing the race.
In 2370, the USS Hera, commanded by Captain Silva La Forge, left Deep Space 3 on a courier mission and disappeared shortly after. (TNG: "Interface")
- Deep Space 3 is mentioned in Max Grodénchik's "Rom's Song", as the station where Odo moves to.
From Memory Alpha, a Wikia wiki.