Halcyon-class Light Cruiser

* Experimental reactor set (1 primary, 2 secondary) (Pillar of Autumn refit package)

### Sensor systems

* Radar
* Spectroscopes

### Armament

* Magnetic Accelerator Cannon (1)
* Shiva missiles (4)
* Archer missile pods (6)
* M910 Rampart point defense guns

## Usage

### Role(s)

* Naval Engagements
* Troop Carrier
* Supply Carrier
* Escort

### Affiliation

United Nations Space Command

*“A dozen Covenant superior battleships against a single* Halcyon*-class cruiser. Given those odds, I'm content with three… make that four kills.”*— Cortana during the Battle of Installation 04
The Halcyon-class cruiser is a United Nations Space Command cruiser starship and one of the most iconic in the UNSC Navy. Unique due to its honeycomb design which makes the ship incredibly durable and tough for a UNSC vessel.

## Class History

### Human-Covenant War

A Halcyon-class Light Cruiser called the Pillar of Autumn was notable in the Human-Covenant War for being the first Human vessel to discover the Forerunner Halo Installations. After crash landing from Covenant assaults, it was left abandoned and was taken over by the Flood. John-117 managed to overload the fusion reactors and caused the Pillar of Autumn to detonate, destroying Installation 04 before it could fire.

## Design

### Characteristics

As aforementioned, the Halcyon had a unique honeycomb design which was costly to construct and maintain with low maneuverability, poor armament, and concerns about their tactical viability. Its superstructure was composed of five hexagonal and octagonal sections mounted onto each other. The bridge is slung underneath one of the forward sections and eight docking bays are distributed throughout the ship. There are also slots for eighteen lifepods on the ship's hull. Lastly, the MAC cannon is visible as a bump on the bow.

The most noteworthy design feature was a series of internal cross bracings and honeycombs designed by Doctor Robert McLees. This internal superstructure made the ships surprisingly resistant to battle damage; ships of the class were able to remain operational despite sustaining breaches to all compartments and losing 90% of their armor. The durability of the design was demonstrated by the UNSC Pillar of Autumn when she survived a crash-landing on Alpha Halo after taking a tremendous beating at Reach and over the ring. However, while the cruiser was intact, it was damaged beyond repair and could never fly again, although some systems were still online such as the fusion core, engines, and self-destruct.

Corridors on the Halcyon-class were segmented by several retractable containment bulkheads. In the event of an emergency, these bulkheads could be closed and affected sections sealed from the remainder of the ship. A potential application of this was during a hostile boarding action, whereas the atmosphere in the sealed sections could be vented via commands from the bridge, asphyxiating enemy troops.

A number of service corridors ran the length of the ship. Although normally restricted to personnel, they could be accessed by lifts in main engineering or connecting passageways from the docking bays. If necessary, these expansive corridors, including a Class Seven service corridor running along the dorsal structure of the vessel, could permit passage to Warthogs and some sections were large enough to accept Pelicans. The corridors served a secondary purpose of lessening the ship's considerable mass, thereby increasing acceleration.

### Armament

The primary armament of the Halcyon-class was its single Magnetic Accelerator Cannon. It was armed with only six Archer missile pods which was far below standards at the time. Each pod would have contained several individual missiles. The class was equipped with four Shiva-class nuclear missiles and numerous M910 50mm point-defense guns.

With the outbreak of the Human-Covenant War, Halcyon-class ships were put through extensive refits. At least one ship, the Pillar of Autumn, had the following armament one upgraded Magnetic Accelerator Cannon capable of firing three rounds in quick succession. The Autumn now had 300 M58 Archer missile pods, which were arranged in thirty columns and ten rows. Each pod contained 26 individual devices, equaling 7800 missiles.

The Autumn was still armed with four Shiva nuclear warheads. One of these missiles was loaded aboard a Longsword fighter, which could be remote-controlled. Forty M910 50mm point-defense guns were installed, with overlapping fields of fire for point defense against single ships. The ship was also equipped with three HAVOK warheads.

## Ships of the Line

* Pillar of Autumn (Lone light cruiser that crash landed on Installation 04)

## Trivia

* The map redesign in both The Pillar of Autumn and The Maw has made the Pillar of Autumn a far bigger ship on the inside.