Starbase 84 was a Federation Spacedock-type starbase that was administered by Starfleet. This starbase was capable of handling major starship refits. The base orbited a planet.
The USS Enterprise-D visited this starbase in 2364. (TNG: "Heart of Glory")
In 2370, a new warp core was installed on the Enterprise-D here. (TNG: "Phantasms")