Phoenix-class colony ship

"The end of an age. Almost 140 years after they were first laid down, the last of the pre-war colony ships has finally been retired from service. The venerable Triskelion was an enduring icon of the Pax Humana, seeding nearly a dozen distinct worlds and establishing hundreds of habitation stations throughout space. Her databanks still contain entries that reference the brightest - and the darkest - years of our spacefaring history."

- Newsanchor Julita Ryba, reporting on the announced scrapping of the UNSC Triskelion.

The Phoenix-class colony ship was a classification of colony ships that were operated by both the United Earth Government and the Colonial Administration Authority. It was the most successful class of its type since the launch of the in the 24th century.

Specifications
The Phoenix-class colony ship was one of the first large starship lines to incorporate zenostium paragravity plating, which provided true artificial gravity to its passengers and crew. This had huge ramifications on its overall design, such as orienting its decks lengthways rather than aligned with its direction of thrust, and early examples required a larger fusion reactor to sustain their operation for extended periods. Initially, these plates were only installed in major passageways, workstations, and some of the cargo-bays where they were deemed to be useful, so all other rooms needed to take into account zero-G movement. As the cost decreased, they were eventually applied to the entire ship, and were organized into primary, secondary, and tertiary networks for power-saving purposes.

Iliad-class superfreighter
The Iliad-class superfreighters were extremely-large container ships that reused many components and hull structures found on the Phoenix-class. Measuring between 2.8 to 3 kilometers in length, their design was one that maximized internal space, with a bloated keel and continuous spine. As their purpose is so single-minded, a crew as small as 300 people is enough for optimal operation, which varies depending on the requirements and operating procedures of their owner. However, they lacked antigravity plates and so were restricted to spatial travel.

Introduced in 2461, the Iliad-class has been adopted by both private shipping companies and government-owned organizations, moving between major trade centers that can accommodate their immense size. Those owned by the UEG or CAA have large databanks installed to carry messages and cultural articles throughout Human Space. Although fairly cheap considering their tonnage, by the dawn of the 26th century they were considered slow with high operating costs, thanks to their use of old, inefficient fusion reactors. Enough remained that by the start of the Human-Covenant War, they were pressed into service with the UNSC Navy. The majority were refitted into heavy carriers or troop transports, and received standardized upgrades that gave them 350mm of armor and armed them with two light MACs, 24 quad turrets of M112 Viper naval coilguns, 24 pods of M42 Archer missiles, and 20 M810 Helix point defense guns. These ships also received distinctive shield plates at the front to protect the bridge and vulnerable sensor and communications equipment. The last Iliad was destroyed in 2539, rendering the class extinct.

Military refits
A number of Phoenix-class colony ships, reclassified as Phoenix-class support ships and given the hull classification symbol of "CFV", were procured for military service in the UNSC Navy during the Insurrection. They were all unique ships even within their own class, with each being modified to specialize into an urgently-needed role. Each ship was phased out as soon as a purpose-built replacement entered service, though this practice ceased with the beginning of the Human-Covenant War.

Designated as Phoenix-class support ships, all of these vessels received a number of standardized upgrades that better improved them for military service. They were protected to basic levels, with titanium-A1 battleplate fitted that varied in thickness between 350 and 900 millimeters, and a battery of obsolete M800 Rampart 40mm point defense guns mounted in quad turrets could fight off both missiles and light fighters. A small network of anti-ship missile pods, using one of the Archer models or M280 Ares, gave them a minimal ability to fend off enemy warships. A suite of active countermeasures, composed of Mark 371 Universal Countermeasure and Decoy Launchers and emergency thrusters, was also fitted. While the reactor and engines were usually left untouched at first, an auxiliary fusion reactor provided power for all the new electrical systems. Minor improvements usually included an enhanced communications array, the installation of a command-and-control deck used for coordinating fighters and ground troops, and modifications to the factory and refinery units so they could operate while the ship was underway. Later in the Human-Covenant War, all remaining vessels would receive a MAC to give them some sort of protection against Covenant ships.