At the onset of the series, "Galactica"s last operational squadron of Mark VII Vipers participated in the decommissioning ceremony before departing the ship for reassignment. The squadron was redirected to intercept a group of Cylon fighters and was subsequently disabled by the Cylon computer virus and destroyed. The Mark II Vipers meant for "Galactica"s museum display were pressed into service to defend the ship; these and a small number of Mark VIIs comprised the ship's fighter complement until the arrival of the Battlestar "Pegasus" midway through the second season. "Pegasus" possessed construction facilities and flight simulators that allowed it to build and train new Mark VII vipers and pilots to strengthen the squadrons of both ships. When "Pegasus" was destroyed during the liberation of New Caprica, her nearly intact squadrons were transferred to "Galactica", giving the latter a full complement of Vipers. By the time of the episode He That Believeth in Me, there were more Vipers available than qualified pilots, and trainees were pressed into service to defend the fleet. A significant number of pilots participated in the mutiny led by Tom Zarek and Felix Gaeta. The pilots who refused to assist William Adama in retaking the ship were court-martialed and incarcerated aboard the fleet prison vessel. The further reduction in manpower forces Adama to allow Cylon heavy raiders from the renegade basestar to assist in CAP duties alongside "Galactica"s regular pilots.