Firing control

Firing Control is a generic United Nations Space Command term for any center or position referring to the operations of weapons systems aboard a starship, such as a UNSC Frigate or Orbital Defense Platform.

UNSC Starship Firing Control
For example, the Firing Control Officer, or simply Weapons Officer, aboard a frigate or destroyer is rank of Lieutenant, like Lieutenant Hikowa of the. They are in charge of Archer Missile and Magnetic Accelerator Cannon firing solutions.

Cairo Station Firing Control
Cairo Station Firing Control was the United Nations Space Command Magnetic Accelerator Cannon firing control station of Cairo Station. During the Battle of Earth, Covenant boarders invaded Firing Control, killing all the Marines (except one who was hiding behind a set of stairs) stationed there and planted a large bomb (stronger than a nuclear bomb according to the cinematic) planned to destroy the orbital station, similar to how the nearby Athens and Malta Stations were destroyed. SPARTAN-117 and Cortana managed to disarm the bomb in nick time and redeploy it to destroy a Covenant Assault Carrier.