Basestar Type-D: the modern Cylon baseship

The Basestar Type-D, also known as the Modern Basestar or simply the baseship, was the primary capital ship of the Cylons at the time of the Fall of the Twelve Colonies and the war that followed. "Type-D" is a reference term used to tell it apart from earlier designs; on screen it is simply a basestar. It filled a role comparable to that of the Colonial Fleet's battlestars, serving as a fleet carrier and missile platform in one hull. Unlike the machines of the first Cylon War, it was partly organic and run not by a crew at consoles but by a Hybrid, a living Cylon wired into the vessel itself. (Battlestar Galactica miniseries; Battlestar Galactica, "Six of One"; "Guess What's Coming to Dinner?")

Origins#

The modern basestar was developed at some point after the end of the Cylon War, replacing the earlier generations of ship that had carried the basestar name through that conflict. Its lineage can be traced through those predecessors. The war-era basestars already carried missiles as their main weapons, an approach the modern ship kept. The ship seen over Djerba, known as the Type-B, shows an early form of the Y-shaped structure, and the Guardian basestar of the war's final days, the Type-C, closely resembled the modern ship in form, though it kept an industrial look, and it was the first known basestar to carry a Hybrid. (Blood & Chrome; Razor; Razor Flashbacks)

The modern basestar carried both inheritances to their conclusion. Where earlier Cylon vessels had been machines in the plainest sense, it was in part a living thing, and the Hybrid became the standard way of running the ship. (Battlestar Galactica, "Six of One"; "Guess What's Coming to Dinner?")

Design and the Hybrid#

Like much of the Cylon technology built after the Cylon War, the modern basestar was partly organic. Damage to the ship could heal over time in the manner of a wound, rather than waiting on shipyard labour. Within the central section lay living spaces for the Humanoid Cylons and their Centurion servants, together with the chamber housing the Hybrid. Wired directly into the ship, the Hybrid controlled its functions, from firing weapons to making FTL jumps, and the Humanoid Cylons treated it as the ship's mind. (Battlestar Galactica, "Six of One"; "Guess What's Coming to Dinner?"; "The Hub")

Hangar decks and air wing#

Above and below the central section turned two rotating structures, each extending three arms in a Y-shape. Raiders launched from storage bays along those arms in large numbers, and the series never gives an exact complement. The arms could also be entered from outside to reach a pressurised hangar deck where the organic elements of the ship lay exposed. On one Colonial mission to destroy a basestar with a nuclear bomb, the Raptor carrying the device set down inside the ship itself. (Battlestar Galactica miniseries; Battlestar Galactica, "Kobol's Last Gleaming, Part II")

Armament and resilience#

The basestar was heavily armed, able to fire large salvoes of missiles with conventional or nuclear warheads. It relied on that firepower and its Raiders rather than on armour, and it proved vulnerable when Colonial battlestars got in close without heavy fighter opposition. Its ability to heal itself made up some of the difference. (Battlestar Galactica miniseries; Battlestar Galactica, "Resurrection Ship, Part II"; "Guess What's Coming to Dinner?")

The Fall of the Twelve Colonies#

Basestars led the attack on the Twelve Colonies, the offensive toward which the Cylons had been building for years. Thanks to the Cylons' exploit of the CNP, the navigation program installed across most Colonial ships, Colonial vessels were disabled by the compromised software before they could fight back, and the basestars took little damage. (Battlestar Galactica miniseries)

After the Colonies fell, basestars kept harassing the battlestar Galactica and the civilian refugee convoy that had gathered around it. (Battlestar Galactica, "33")

The pursuit of the refugee fleet#

Individual basestars appeared again and again along the refugees' flight. Over Kobol, Lieutenant Sharon Valerii flew a Raptor into a basestar orbiting the planet and destroyed it with a nuclear warhead. (Battlestar Galactica, "Kobol's Last Gleaming, Part II")

At the Battle of the Resurrection Ship, basestars stood escort over the resurrection ship attached to the pursuing Cylon fleet. Galactica and Pegasus jumped in together and pounded the basestars at close range, while a Viper strike destroyed the resurrection ship itself. (Battlestar Galactica, "Resurrection Ship, Part II")

Later in the exodus, a group of basestars searching for the temple said to hold the way to Earth confronted the refugees over the algae planet. The standoff held until the nearby star went supernova and destroyed the planet. (Battlestar Galactica, "The Eye of Jupiter"; "Rapture")

The Cylon Civil War and the rebel basestar#

After the Exodus from New Caprica, the Cylon Civil War broke out and the basestar fleet turned its missiles on itself. Ships under the control of the Number One, Four and Five models fought those crewed by the Twos, Sixes and Eights, and the rebels were badly mauled in an ambush. (Battlestar Galactica, "Six of One"; "The Ties That Bind")

One basestar, the rebel basestar, crossed the line entirely and joined the human Fleet. Its crew offered to upgrade the Colonial FTL drives, and the ship took part in the attack on the Resurrection Hub. In time the rebel ship was granted a seat in the reorganised Quorum, its representative, Sonja, sitting alongside the delegates of the human ships. (Battlestar Galactica, "The Hub"; "A Disquiet Follows My Soul"; "Someone to Watch Over Me")

After the Battle of the Colony, it was uncertain how many basestars survived the war at all. The Centurions, freed from their servitude by the rebel Cylons, were given full control of the rebel basestar and jumped away into deep space to pursue a destiny of their own. (Battlestar Galactica, "Daybreak, Part II")