Spacedock type

The Spacedock type was a Federation space station class, a starbase and spacedock in Starfleet service in the 23rd and 24 centuries. This enormous spacedock was placed in planetary orbit, mushroom-shaped, and large enough to berth several starships inside. 

History and specifications
The mushroom-shaped station had a draft (height) in excess of 6 kilometers, and a beam (width]] of around 3.9km. The crew complement in 2410 amounted to 312,000.

A station of this type, missing wide umbrella-like head, was in United Earth Starfleet service in 2159, and served as an operations center for Starfleet during the Earth-Romulan War. 

Earth Spacedock was under construction in 2257. 

During an assault on Allied homeworlds by the Undine in 2410, Earth Spacedock broke in two, with the bottom half of the lower stalk detached from the rest of the station.