Pillar of Autumn



The Pillar of Autumn is a heavily modified United Nations Space Command Halcyon-class cruiser in the Halo: Combat Evolved video game.

Structure
Prior to the war with the Covenant, the Pillar of Autumn was due to be decommissioned. Instead, in 2550 it was refitted to serve in active duty.

When first conceived in 2520 the UNSC forces considered the ship a joke. It was exorbitantly expensive, suffered from poor maneuverability in combat situations and was woefully lacking in firepower. In its favor, the ship's superstructure was honeycombed with Titanium-A, giving it superior structural integrity and making it resilient to any attack. The superstructure was laced with struts, bulkheads and pressure doors, making it nearly impossible to destroy completely, as sections could be isolated independently from each other. Reports had Halcyon-class cruisers operating with breaches on all decks and 90% of the ship damaged.

As part of its 2550 refit, the ship had its archer missile pods and Magnetic Acceleration Cannon upgraded to serve in the Human-Covenant war. After its refit the Pillar of Autumn was much more formidable in combat. Modifications to the ship included increased archer missile capacity, a greatly improved power plant with unique cooling methods and an upgraded Magnetic Accelerator Cannon capable of firing three "shredder shots" on a single charge. Overall, the ship's armaments consist of an advanced MAC cannon, 128 Archer missile pods, 40 50mm cannons, and 4 Shiva nuclear missiles. These modifications occur in the book Halo: The Fall of Reach. The ship is also featured in the novel tie-in Halo: The Flood.

The Pillar of Autumn's engines were replaced with a prototype design. Instead of more traditional cooling systems, "a laser-induced optical slurry of ions chilled to near absolute zero" cools the engine cores. The lasers draw power from the reactors, resulting in a system more efficient than previous coolant driven systems. Two smaller, secondary reactors "come online to supercharge the main reactor." This enables the new engines to run at 300% for an unstated amount of time, something no other UNSC ship can do.

Halo
The Pillar of Autumn was one of only a few ships to escape the Covenant armada following the fall of the planet Reach. The ship made a 'blind' jump through Slipspace (though it was actually a calculated guess by the AI Cortana, who interpreted a sequence of characters gained from a Forerunner artifact) to the gas-giant Threshold, location of Halo Installation 04. The Covenant believed the ring world was their religious icon "Halo", capable of carrying out their "Great Journey".

Covenant battleships, already at the ring due to much faster Slipspace engines, intercepted the Pillar of Autumn upon its arrival at the planet Threshold. Reluctant to use their more powerful weapons for fear of causing collateral damage to "Halo", the Covenant armada attacked with relatively light fire in coordination with numerous boarding craft filled with assault troops. The boarding parties were charged with retrieving senior officers, including the commanding officer Captain Jacob Keyes, for interrogation. they failed in this attempt. Outmatched on their own ship, Captain Keyes later had the Autumn's crew and marines escape using the remaining lifeboats.

Keyes and the rest of the command staff managed to crash the ship on the surface of Halo while the many surviving Marines quickly formed a formidable resistance movement. But their only chance of holding out was to search and salvage the grounded Autumn for additional weapons, vehicles and equipment for their base, before the Covenant could claim the entire ship. After 343 Guilty Spark's true intentions of activating Halo were revealed, Cortana and the Master Chief manually detonated the ship's fusion reactors in order to destroy Halo, thus preventing the escape of Flood and Covenant forces, as well as preventing the galactic devastation that would have resulted from the ring's activation.

The Pillar of Autumn's sister ship was the Dawn Under Heaven.