Hangar C-01
From Halopedia, the Halo wiki
Hangar C-01 was a two-story United Nations Space Command Longsword and Pelican hangar aboard Cairo Station. SPARTAN-117 was able to take the Covenant bomb from Firing Control by wresting it from the hands of its Elite and Grunt guards, and then activated the zero-g door, explosively decompressing the bay. The SPARTAN-II was miraculously able to guide his trajectory to intersect with the damaged engine of a nearby unshielded Covenant Assault Carrier. He then drifted away to the UNSC In Amber Clad and detonated it, destroying the heavy warship.