2550

January

 * The Banished raid the UNSC's Carter Guard Armory, with Atriox personally killing a group of Orbital Drop Shock Troopers defending it with his bare hands. Helmet cam footage from Sergeant B. Wright, an ODST killed in the raid, provides the Office of Naval Intelligence with its first look at Atriox, who is identified to agents by a captured Banished Unggoy.

February

 * February 11: Dr. Catherine Halsey determines that Cortana, by disabling the viral termination code in her matrix, may be able to overcome the AI's typical seven-year life cycle.
 * February 15: Helmet cam footage from Sergeant B. Wright, an ODST killed in the raid on the Carter Guard Armory, provides the Office of Naval Intelligence with its first look at Atriox, who is identified to agents by a captured Banished Unggoy.

April

 * April 5: Miranda Keyes is awarded the Silver Star and promoted from Lieutenant to Lieutenant Commander in a ceremony in downtown Quezon on Reach.

June

 * June 3: Professor Laszlo Sorvad starts his archaeological survey of a meteorite debris field near Visegrád, Reach.

August

 * August 23: The construction of Cairo Station begins.

November

 * November 17: Seven Covenant-held locations have been raided by the Banished by this time, the most recent of which was a forward outpost meant to be attacked as part of Operation: SLOW DIVE.
 * November 23: The Official Secrets Act is passed.
 * The  is refitted for service near the Zeta Doradus system.

Unknown Date

 * At some point after July 9, Minab is glassed by the Covenant.
 * Lieutenant Wagner suffers severe plasma burns to a third of his body.