Operation: FIRST STRIKE

This operation is among the UNSC's most incredible raids, conducted by only a handful of Marines and Spartans. The mission resulted in the Spartans overloading the fusion reactors on the Covenant combat station Unyielding Hierophant. With the odds on the Covenant side, the infiltration force succeeded with overwhelming results. Only weeks later the Covenant find the human homeworld, Earth, and assault it. The initial attack, led by the Prophet of Regret, is a massive failure.

Timeline

 * O510 Hours: SPARTAN-117 officially presents the plan to the crew of the Gettysburg-Ascendant Justice. After much hesitation, Admiral Whitcomb approves.
 * 0530 Hours: The hybrid vessel passes through the Covenant armada in Slipspace. They are undetected, however a single Spirit launches from a hangar in the vessel. The dropship contains SPARTAN-117, SPARTAN-104, SPARTAN-058, SPARTAN-093, and SPARTAN-043. The dropship is undetected by the Covenant forces. The hybrid ship hides behind a nearby moon.
 * 0610 Hours: The dropship docks aboard the Unyielding Hierophant The Spartans make their way through access pipes and conduits.
 * 1551 Hours: The Spartan team enters a temple inside the station. They are ambushed by a group of Brutes. First encounter of Brutes in combat situation.
 * 1555 Hours: SPARTAN-093 is killed by a Brute Shot fired by the Brutes.
 * 1600 Hours: The Spartan team fights into the reactor room, where Cortana's copy initiates an overload of all 512 fusion reactors.
 * 1610 Hours: The Gettysburg and Ascendant Justice unlink. The Justice heads into the Covenant fleet, hoping to draw more Covenant vessels close to the station as it is detonating. Aboard are Admiral Whitcomb and Lieutenant Haverson.
 * 1620 Hours: The Spartan team uses Banshee fliers to escape the station.
 * 1625 Hours: The Unyielding Hierophant explodes, destroying 488 of the 500 vessels in the area and heavily damaging the remainder.
 * 1630 Hours: The Gettysburg heads to Earth, carrying with it the only four Spartans actively in combat and confirmed alive besides Gray Team, along with Sergeant Johnson and the surviving Covenant Engineers. The Gettysburg is outfitted with the Slipspace equipment from the Ascendant Justice, making it the fastest ship in the UNSC.

UNSC

 * Vice Admiral Danforth Whitcomb
 * Lieutenant Haverson
 * Sergeant Johnson
 * Cortana
 * Spartan-117
 * Spartan-104
 * Spartan-058
 * Spartan-093
 * Spartan-043