2551


 * Pawel Czernek enters active service with the UNSC Marine Corps.
 * Concord is attacked by the Covenant; the Venator MJOLNIR variant gains prominence in the attack.
 * Gray Team is deployed on a mission against a Covenant facility within humanity's former territory.
 * February 19 - The SPARTAN-IIIs of Gamma Company begin their week-long augmentation process on the as part of Project CHRYSANTHEMUM.
 * May 8 - Dr. Catherine Halsey undergoes the Hemley & Aubourn Behavior Analysis; the results make ONI increasingly wary about her reported unreliability.
 * November 24 - Mark V[B], the initial production model of the Mark V MJOLNIR armor, enters service.
 * December 22 - The Car & Pilot Magazine releases its December 2551 Edition. This includes a review of the new 2553 edition of the Civilian "Hog".