From Halopedia, the Halo wiki
Universe and lore
The map is set on an unknown human colony within Launchsite 2A, a facility utilized by the 22nd First Response Wing of the local UNSC Planetary Defense force. One corner of the map features a FSS-1000 Sabre that is preparing to launch from Launch Pad 03. The facility also includes a hangar with a retractable set of tracks that are used to move the Sabres into position on the launch pad.
The following are locations on the map that are so named on the player's heads-up display during gameplay: