UNSC Gettysburg

The  was a Frigate in service with the UNSC Navy during the Human-Covenant War.

Sigma Octanus
On July 17, 2552, the Gettysburg, along with the, responded to a distress signal sent by Captain Jacob Keyes, who was a Commander at the time, from the Sigma Octanus system. The vessel later fought in the Battle of Sigma Octanus IV.

The vessel then returned to the orbital space dock of Reach, where it was heavily damaged in the Battle of Reach and her entire crew was killed.

Gettysburg-Ascendant Justice
Eventually, SPARTAN-117, along with several survivors of Battles of Installation 04 and Reach, used the Gettysburg, fusing it with the Covenant ship Ascendant Justice, thus becoming the first Human-Covenant hybrid vessel in history. It was used because the Ascendant Justice could not do the two Slipspace jumps in and out of a group of Covenant ships fast enough using just it's own reactor.

Operation FIRST STRIKE
Eventually, the vessel was unlinked from the Ascendant Justice so that Vice Admiral Danforth Whitcomb and First Lieutenant Elias Haverson could use the Ascendant Justice to lure a Covenant battle fleet to the Unyielding Hierophant, which was about to explode.

Return to Sol
After Operation: First Strike, the Gettysburg and it's extremely small amount of remaining crew headed back to Sol, Earth's home system.

It is unknown what happened after this, as it was probably scrapped for it's metal to make weapons, vehicles, and starships for the crumbling UNSC Defense Force. Possibly, it could've been reassigned to the UNSC Home Fleet just in time for the defense of Earth during the First Battle of Earth. However, the Gettysburg was heavily damaged and crippled, and the time it would take to refit the ship wasn't available to the Home Fleet.

Technology
The Gettysburg was refitted with the Slipspace engines from the Ascendant Justice prior to unlinking. Since Covenant Slipspace engines had always been faster than UNSC engines, the Gettysburg was the fastest ship in any of the Fleets of the UNSC Navy.

Trivia

 * It is named after the Battle Of Gettysburg. The American Civil War battle took place on July 1-3 1863, in Gettysburg, Pennsylvania, on Earth.