Halcyon-class cruiser

"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 (hull classification symbol: C) was a distinguished class of light cruisers which saw service in the Insurrection and later the Human-Covenant War. Originally shot down by the UNSC on the grounds for its lack of tactical viability, the Halcyon would be mocked for being the slowest, most underarmed and underpowered cruiser developed of the twenty-sixth century. Notable only for its unusually-strong honeycomb superstructure, the Halcyon 's advantages would prove too limiting and it would be quickly replaced by its successor, the.

The Halcyon would embark on a limited production run, with only fifty ever being built. Although some would be hastily retrofitted with more weapons and hangars in an attempt to increase their combat viability, by 2521 the entire class was reassigned into reserve fleets. They would be saved from certain scrapping with the arrival of the Covenant, with their complicated superstructure actually allowing them to survive far longer than their replacements against their quarry's exotic weaponry. As a result, they were pulled out of the dockyards and refitted up to modern standards, and proved to be one of the most powerful ships at the UNSC's disposal. However, even these updated cruisers would take horrendous losses, ensuring that each Halcyon was deployed sparingly. Nevertheless, the class would become an icon symbolising durability, and would inspire the UNSC to adopt the similarly-shaped.

Armour and superstructure
Widely regarded as their sole meaning for existence, these cruisers became renowned for their durability. A sophisticated ecosystem of supporting skeletons, a mix of internal and external plating, and emergency repair systems work together to expertly hold the ship together while under fire - a configuration that continued to remain unique even decades after the Halcyon 's launch. Each component alone is capable of mitigating damage with greater efficiency than any other competitor on the market, but are combined to increase the tolerance so much that they exceeded the structural guidelines the Navy placed upon contemporary battleships and heavy carriers.

Variants
With the unexpectedly low demand found in the Halcyon-class, RMC took to invest in a number of potential hull upgrades to the class, and experimented in an effort to salvage the insane amount of money they lost developing them. Each of the Halcyon 's variants added an extensive amount of superstructure to the class, with most of it being fitted over the base hull in case the UNSC contracted them to upgrade them to a set standard.

Aegaeon-class carrier
Larger than even the later Autumn-class, the Aegaeon-class carrier is designed around an elongated first flight Halcyon hull, hollowed out to allow it to carry an extended amount of space fighters and material. Produced only in limited numbers, these carriers, like the ships they are built from, never saw extended production. However, the ships that were built went on to earn a mythical status within the fleets they served in.

Measuring nearly than 1,800 metres from fore to aft, the Aegaeon-class still features the same dense honeycomb superstructure which made the base design so durable. However, it does not retain it throughout its entire frame, and incorporated minor concessions in order to make the construction of a larger warship cheaper and thus more feasible. The defensive armaments have been improved and brought up to standards. It still retains a single MAC, but this has been upgraded to a heavier calibre and now runs almost half the length of the carrier, with thirty pods of Archer missiles and dozens of point-defence guns added. While this is nowhere near as powerful as a ship of its size should be, it can now adequately defend itself against more capable threats. Its reactors and engines are larger, although it is still considered slow for its size.