Enter the Fray/JoinUNSC

You begin your schooling with the Navy just weeks after high school and just barely graduate four years later due to some academic troubles. You are assigned to the UNSC Nebraska as the Weapons Officer. In other words, you control the two MAC's of the destroyer unless the Captain intervenes. In addition, you also control the other minor weapons systems, though these will be maintained for the most part by the shipboard AI.
After three weeks of "routine boredom," your ship is deployed to what's left of the Covenant territories (the Sangheili had been gnawing away at the empire for years). The Nebraska pops out of Slipspace and you are released from the cryo tube and slowly make your way to your station.