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, often referred to as the "POA" for short.

Spoiler warning: Plot or ending details follow.

The Pillar of Autumn was one of few ships which escaped the fall of the planet Reach. The ship made a slipstream jump to the planet Threshold, location of Forerunner Installation 04, which the Covenant believed was their religious icon "Halo." The remaining crew believed the jump to be random, in order to avoid leading the Covenant to Earth as per the Cole Protocol; in actuality the AI Cortana interpreted symbols on an alien artifact into map coordinates.

Modifications to the Pillar of Autumn include reinforced armor, increased missile capacity, an improved Shaw-Fujikawa engine, and a Magnetic Accelerator Cannon capable of firing three "shredder shots" on a single charge.

The Pillar of Autumn is a relatively small ship for its class, but the reinforced hull and armor place it in a higher tonnage range in the Terran fleet.

Before the modifications to the vessel, the ship was was due to be scrapped–the Halcyon-class was widely regarded as a joke by UNSC officers and crewmen. The refitted Pillar of Autumn, however, was one of the most powerful ships available to the UNSC.

The Pillar of Autumn suffered severe damage from Covenant forces orbiting Threshold and crashed on "Halo". Cortana and the Master Chief manually detonated the ship's nuclear fusion engines in order to destroy "Halo" and prevent Flood and Covenant forces from escaping.

The Pillar of Autumn is currently presumed destroyed along with most of the crew (including Captain Jacob Keyes, Commanding Officer of the POA).