Battle Group Omicron

Battle Group Omicron was composed of nine ships and commanded by the late Admiral Carl Patterson. Its flagship was the carrier. On November 3, 2552, the battle group was deployed to Onyx to retrieve Dr. Catherine Halsey, a joint unit of SPARTAN-IIs and SPARTAN-IIIs, and (supposedly) examples of Forerunner technologies that had been excavated and recovered.

Battle of Onyx
The battlegroup rendezvoused with the prowler soon after entering the system. The UNSC ships engaged the Covenant fleet under Fleetmaster Voro Nar 'Mantakree and took losses, including the, which sacrificed itself to save Stalingrad from Covenant plasma torpedoes. Following this engagement, Admiral Patterson ordered a withdrawal. The battlegroup temporarily went into hiding.

The remaining UNSC ships hid behind Onyx's moon. Meanwhile, the Dusk prepared a nuclear minefield as a trap for the unsuspecting Covenant fleet. The UNSC lured the Covenant into the minefields, and used the nukes to destroy the entire Covenant fleet save for two badly damaged destroyers to the human four. The battlegroup moved in for the kill with six MAC rounds left. Unfortunately, at this point Sangheili reinforcements arrived in the form of over thirty warships. Battlegroup Omicron was swiftly and efficiently annihilated, with the sole exception of the Dusk.

Composition

 * One Carrier
 * One
 * Six destroyers
 * One Prowler
 * One Prowler
 * One Prowler
 * One Prowler
 * One Prowler

List of appearances

 * Halo: Ghosts of Onyx