Command Carriers are the capital ships of the Peacekeeper fleet in the fictional Farscape universe. They appear in numerous episodes as threats in pursuit of Moya and her crew, particularly the Carrier under the command of Bialar Crais.
Command Carriers serve as a mobile base of operations for the Peacekeepers; they are immense ships with a crew complement of about 50,000. Many Peacekeepers live their entire lives on a command carrier, and they have all the creature comforts needed to sustain their large crews (including large indoor "gardens" that simulate a planet's surface and which are also used for combat training exercises).
Command carriers primarily rely on their large complements of Prowlers and Marauders to project Peacekeeper power where needed. They are however powerful battleships in their own right, armed with Frag Cannons, each mounted on a track that allows them to move along the horizontal axis of the ship to engage targets both directly in front of, behind or to either side of the ship (though not directly above or below the ship). They are protected by powerful defence screens. Frag cannons are the heavy artillery of the Peacekeeper fleet, and are primarily used to engage capital ships. Against enemy fighters, strike craft and other lighter classes their tracking speed and rate of fire is too low to be of much use.
They are also quite fast, as the crew onboard Moya have to routinely starburst away when a command carrier gets too close, but they never seem to stay ahead of them for very long. While used as a plot device in the series, this indicates that Command Carriers and most other space vessels in the Farscape universe are not equipped to achieve instant FTL speeds, as possible in other popular science fiction universes. They can however accelerate to FTL speeds.
Larger variants of Command Carriers exist and are attached to fleets as flagships. If these vessels are destroyed whole fleets can be thrown into disarray and will eventually crumble.