Hangar A-01
From Halopedia, the Halo wiki
Hangar A-01, also known as Hangar Bay A, was a two-story United Nations Space Command Longsword and Pelican hangar aboard Cairo Station. During the First Battle of Earth, Covenant boarders invaded Hangar A-01. A Covenant Boarding Craft had docked and sent forth waves of Grunts and Elites. Marine defenders, equipped with Battle Rifles, SMGs, and even a Machine Gun Turret, were being overwhelmed at their position at the second floor when SPARTAN-117 came to assist, killing all the Covenant and repulsing them back to their landing ship. SPARTAN-117 then moved to adjacent Hangar A-02.