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Battlestars of Galactica's class are armed with at least twelve missile tubes. These are located behind the bow of the battlestar, at the fore of the vessel's midsection, with the tubes' launch doors opening on the dorsal side of the hull. As the outer doors open, the missiles are moved forward into launch position by powerful hydraulic rams.
Once the missiles are loaded into the tubes and are ready to be fired, they must be armed with a target package and a point of aim. This is typically ordered by the vessel's Commanding Officer, with the order being relayed by the Tactical Officer.
It is likely that Colonial battlestars have the ability to launch missiles, either at ground targets or suitable spaceborne targets, armed with conventional, non-nuclear warheads.
While not strictly the same type of ordnance, other battlestars have been seen to fire ship-to-ship missiles (Hero). From this point, it seems likely that other, non-nuclear missiles exist for orbital bombardments as well.
With nuclear ground strike missiles loaded in the tubes and ready to launch with the appropriate target information, the command authority must then specifically authorize the release of such weapons.
Following authorization, the safety protocols on both the launch systems and the warheads themselves are disabled by the Tactical Officer, following the CO's order.
The two most senior officers aboard ship, usually the Commanding Officer and the Executive Officer, then input their firing codes. The final stage is for the firing key to be inserted into the master control console and turned, thus initiating the launch sequence. The order to fire is given by the CO ("The Eye of Jupiter", "Rapture").
The missile tubes can also fire on enemy vessels, although it is unclear if the same missiles as for planetary bombardments are used (Razor).