Starbase 257

Starbase 257 was a Federation starbase located in the Alpha Quadrant. It is a Sigma-class base, built to be a strategic outpost. While within its defense perimeter, ships had to remain at one-half impulse until they cleared the outer markers. This starbase was located in relatively close proximity to Deep Space 9.

The Sigma-class design was based on the R1-class space stations of the 23rd century. The primary hull was cone-shaped, with additional modules attached underneath, and topped by an antenna on top. Its characteristic feature was a ship-sized launch bay leading into the primary hull. That docking bay was used to service, store, and construct starships.

During the Dominion War, in 2374, this starbase was attacked by a wing of Jem'Hadar fighters.