Commons R-01
From Halopedia, the Halo wiki
Commons R-01, also named Commons Red, was a United Nations Space Command commons module aboard Cairo Station. It consisted of a standard-sized rectangular room, with "islands" regularly spaced to the edges of the room. Security R-01 overlooked Commons R-01.
During the First Battle of Earth, Covenant boarders invaded the module, hampering SPARTAN-117s efforts at getting to the Covenant bomb.
