UNSC Of Uncommon Courage
From Halopedia, the Halo wiki
UNSC Of Uncommon Courage was present during the Covenant's invasion of the Epsilon Eridani system in the summer of 2552. During the series of battles that occurred throughout the system, the United Nations Space Command became aware that the Covenant carrier Splendid Intention carried plans for new Sangheili weapons that were powerful enough to allegedly render the Covenant's contemporary energy projectors obsolete.
In response, a team of Spartan-IIs were dispatched from UNSC Of Uncommon Courage and tasked with infiltrating Splendid Intention to steal the plans and deliver them to the UNSC. During the raid, a series of events occurred which are classified by the UNSC, though it is known that the mission did not go as planned. Ultimately, Of Uncommon Courage sacrificed itself to ensure that Splendid Intention was downed in the southern waters of Cortez Ocean on Beta Gabriel, a watery planet and human colony in the system. After the Covenant War, staff aboard Fathom Station—an underwater research facility on Beta Gabriel—were tasked with locating the crashed Splendid Intention and Of Uncommon Courage, and eventually began searching for the Covenant weapon plans carried by the carrier after doing so.