Gladius-class heavy corvette

"We had four corvettes go up against a lone cruiser once, which caught us in a raid near Green Hills. But they clearly chose the wrong fish to catch - we ran rings around them, taking pot shots at every opportunity. And the best part is, they couldn't hit us at all."

- Anonymous Insurrectionist captain.

The Gladius-class heavy corvette is a line of heavy patrol ship used by the UNSC Navy. Developed in response to the limited effectiveness of Insurrection-era designs, the Gladius is notable as it possesses an unusually-large MAC, powerful engines and a small crew with no Marine complement. These qualities mean that the corvette, while not engaging in as many roles as more traditional models, is an exceptional combat ship, inflicting a disproportionate level of damage against larger opponents. This sees the Gladius deployed in low-priority escorts, patrols and interdiction missions. The only flaw of these vessels is their lightly-reinforced frame left them susceptible to more powerful weapons.

Seeing field testing in 2518, the Gladius was not an immediately adopted by the UNSC. Instead, these corvettes saw early service with planetary defence groups, who needed a more capable defender fight off larger, more threatening pirate raids. In this role, it excelled, either outright routing them or keeping them tied up until a better-equipped fleet could arrive. This proof of capability would inspire the UNSC to accept it into their fleets, phasing out the older yet still capable with the more useful Gladius. Fighting in dozens of battles, their notable stealth capabilities would provide invaluable preparation for successful operations behind enemy lines. After the Human-Covenant War, these were gradually phased out, and continued to see service with a number of independent human factions for many decades afterwards.

Development
Development of the Gladius-class heavy corvette began in 2511. The UNSC Navy, inspired by the effectiveness of their retrofitted Charon-class frigate, decided now was the time to phase out every ship smaller than a destroyer that was not armed with a Magnetic Accelerator Cannon. This was pushed by a number of factors, ranging from the marked effectiveness of the new weapon to the growing inadequacy of early Insurrection vessels such as the Mako-class light corvette. As a result, the UNSC Navy opened up two highly-profitable competitions for next-generation combat craft, including one for a next-generation corvette. Each submission was required to not only feature superior warfighting capabilities, but they must be designed to provide long-range relief of outposts. Border checks of freighters was not required, as the UNSC hoped to place outdated ships into planetary defense roles before their inevitable decommissioning.

Layout
Unlike most smaller warships like its predecessor, the Mako-class light corvette, the Gladius does not appear encased within a large armored shell; instead, the hull follows a basic, almost skeletal profile around the ship's MAC, reactor and engines. This design is inspired from modern frigates constructed by SinoViet Heavy Machinery, although it followed this trend to minimize construction time and materials. Indeed, unlike those vessels, the armored prow is not split in half but instead one large block, with the MAC running down the center of this structure rather than at the top or bottom.

At the very top of the prow is the corvette's small bridge, which is only just wide enough to have the pilot and navigation officer sit side-by-side at the front. The captain sits behind them in a command chair, where they have the best view in front and to their sides. Because the bridge is so small compared to other UNSC vessels, there are only three display screens that are designed to fold up when given the order from the captain's neural interface. Instead, the command chair connects with the captain's neural interface and beams the information directly onto their eyes, allowing the captain to see statistics without a holographic projector. Behind him on the sides are the weapons and the sensors/communications officers, which sit in dedicated stations in the back corner of the bridge. Unlike most UNSC ships, there is no holotable to plan the next course of action - instead, that's housed in the room right behind the bridge, before the main armory. There are two three-man escape pods located right behind the bridge for emergencies.

Extending below the MAC barrel is the corvette's primary communications array, which uses long-distance antenna and a high-powered Microwave receiver for receiving and decoding long and short-range communications, respectively. At the bottom is the main sensor array, a Mark-XXIV combined infrared/RADAR arrays with a FORESIGHT telescope, which are attached to the lower 'spine' that runs more than half of the ship's length. Both of these sensors are much more sensitive than the norm, as they do not need to filter out much radiation coming from the Gladius itself. Further down on the main body are the protrusions for the ship's Archer missile launchers, one on each side, which are outfitted to be effective against fighters, bombers and other ships at long- to mid-range. Above these is where the main shuttle bay is located. This isn't always here, as some owners rather turn the space into a games room or a cargo-bay, and instead place a massive sheet of armor over the door. Right behind this at the top are the crew quarters, which include zero-G hammocks, a basic kitchen and the cryotubes, and it is here where the crew not assigned to any jobs can be found eating, sleeping or relaxing. A direct staircase leads to four Class-I bumblebee escape pods, two on each side, allowing for quick and easy evacuation. Further below this is the Gladius ' modest cargo-bay, with an elevator and retractable stairs for the crew and passengers. This often holds satellites and parts for navigation buoys, as well as the fission fuel to keep them powered. The rest of the forward section is made up of the life-support system and capacitors for firing the main cannon, and as a result, there isn't much room for the crew to move around on board.

After the four escape pods is the technical aft section, which is where most of the engineers work. A smooth protrusion begin starts it off, and it is in this forward part where the Deuterium fuel is kept. Further back are where two of the M870 point defense guns are located, in prime position to offer defensive all but below the corvette. However, the overlapping fire leaves a massive blind spot towards the aft that can allow enemy fighters to close in on the corvette with minimal possible damage. Attached to the upper engines are also the two afterburner drives, with the back, smaller nozzle increasing the velocity of the corvette with a combined fusion-chemical mix, and a dedicated emergency chemical thruster occupying the larger front cone. The engine configuration leaves one at the bottom and a pair along the middle of the corvette, with the bottom exhaust extending the furthest. These are built around the corvette's large fusion reactor, which originally used Deuterium, however post-war models now accept the much more potent Helium-3 fuel. Resting on top of the reactor and forward of the upper fusion drives is the corvette's primary cloaking system - a PREY electronic warfare suite. This bland box can jam all nearby communications channels, issue RADAR and microwave jamming fields to fight sensor systems and if close enough, launch a cyber-warfare campaign on nearby ships, ensuring that the Gladius can only be detected by the most powerful of enemy warships. Further back from this are where the ship's consumables - food, fuel, and ammunition - are stored. A dedicated pod for ammunition exists are the very bottom of the corvette, and is protected by two M870 point defense guns to prevent it from being easily targeted. Should it ignite, the pod is designed to funnel the explosion away from the corvette, and the heaviest armor is mounted above it as well, ensuring minimal damage.

Role
The Gladius-class corvette is designed as a workhorse of colonial defense fleets, and frequently operates alongside the Stalwart-class light frigate. In battle, its primary role is to screen larger UNSC ships, such as cruisers and carriers, and keep them free of hostile strikecraft, missiles and other corvettes. To help with this, most of its Archer missiles have cluster-missile warheads designed to target and clear a large number of fighters at once, along with six M870 Ramparts to shoot down missiles and strikecraft that get too close. Of course, it lacks many dedicated anti-fighter missile defenses and so can be easily out-performed in this role by larger frigates. Instead, it would act in a corvette hunter role, using its oversized MAC while sitting on the edge of its effective range taking shots of opportunity at the smaller Covenant warships. Often-times, it will act like a heavy bomber, making strafing runs on Covenant ships and firing everything it has. However, because of its size, these are considered suicidal affairs and are discouraged by the UNSC Admiralty.

Outside of battle, the Gladius ' usefulness only increases. Because of their stealth-qualities and high-sensitivity sensors, these corvettes are used to patrol the fringes of Human space searching for Insurrectionist and Covenant targets, acting as yet another early-warning system. Their frequent use in counter-insurgent patrols means that they act as an emergency response unit, responding to hails for help and escorting damaged civilian ships back to the nearest colony. Despite their pitiful cargo-bays for a ship of its size, the Gladius can still fulfill the role of buoy tending, ferrying supplies to isolated stations and maintaining the UNSC's Universal Navigation Array network.

Propulsion
The Gladius-class corvette is an astonishingly fast craft, capable of easily keeping up with some models of gunships and bombers. This is specifically thanks to the corvette's extremely-light mass and powerful set of engines, each which are made from different manufacturers.

The main drives are both variations of fusion drives, which work by using the heat and pressure of the main reactor to fire off their highly-combustible propellant; in layman's terms, the ship is pushed by activating nuclear devices on its aft. The first is a Reyes-McLees Corporation's Mark-12 primary fusion drive. A closely related to the engines used on the, the Mark-12 uses twenty-four independent injection-valves set around a single main exhaust, which allows for faster, more fuel-efficient travel than simply using a single exhaust. This is made more efficient with the engine being made to burn hotter and subjected to higher pressures than required, which is what gives it its characteristic blue color. However, what makes the Mark-12 particularly popular is that it is equipped with integral stealth bafflers; this captures the radiation and emissions given off by the engine at low power, allowing it to move without being detected. While its too small to actually reuse the captured propellant, it can store it to be released at a safe location. The other two fusion drives, the Naoto Technologies' V5/Ultra-Light-DFR secondary fusion drives, are conventional fusion reactors that have none of these bonuses and simply push the ship forward as cheaply as possible.

Armament
Unlike most ships around its size range, the Gladius-class corvette's weapon systems are powerful enough to threaten ships as large as destroyers. Partially this is because the corvette is entirely built for combat and endurance, however, the main reason lies solely in its 20DA1C2 Magnetic Accelerator Cannon. The smallest axial coilgun that is classified as a MAC, the 20DA1C2 is a compact yet cheap weapon system that acts as the Gladius ' main gun. At 120 metres long, the 20DA1C2 uses a patented 'double-action' launch system to launch a roughly 400-kilogram Tungsten-Uranium slug at up to 20,000 metres per second. This is far lower than the energy given out by a frigate MAC, but it makes up for it with its fire-rate. The 20DA1C2 can charge and reset within a minute, allowing it to fire about two or even three times as much as a single frigate MAC. This makes it extremely resilient, although its proven to be less effective on shielded targets. Nevertheless, the addition of this weapon has ensured the Gladius is a threat even to opponents many times its size, especially when deployed in numbers.

Supporting this are two pods of M58 Archer missile pods, two on each side. A general-purpose missile equally effective against both strikecraft and warships, the M58 is not as large as the earlier M42 Archer, but is much more compact and easier to field in swarm tactics. However, the two pods on the Gladius are only capable of launching salvos of ten missiles at most, hardly capable to the swarms of hundreds even frigates can output. Instead, only seven missiles are fitted with high-explosive warheads, the rest being outfitted with Multiple Independently-Targeting Warheads, which utilize eleven Medusa micro-missiles to attack up to an entire squadron at once. A small handful of M4 decoy missiles are also carried, for distracting enemy ships that the Gladius cannot afford to engage.

The only other weapons the Gladius has are six M870 "Rampart" point defense guns, each with four 50mm barrels per turret. Covering most of the blind-spots on the corvette's aft, these are well-suited to destroying enemy fighters and missiles, especially since their barrels are designed to traverse more than 180 degrees before requiring the turret to turn around. However, these turrets are intended to also weaken incoming plasma torpedoes by firing magnetized slugs, potentially dissipating them before they can hit the corvette. They can fire up to 360 rounds per minute.

Countermeasures
While not technically classed as a stealth ship, the Gladius-class corvette does integrate many systems that are part of the standard loadout for infiltration vessels, making it difficult to detect on regular scans. While it has no way of masking itself physically, the vast distances of space ensure that it is very difficult to spot them even on a dedicated LIDAR scanner. Should it be spotted, the Gladius also carries a number of electronic warfare technologies to disrupt enemy targeting systems and better protect itself from much more powerful weapons which could easily obliterate the corvette in a single shot.

Located on the dorsal side of the corvette is a large electronic warfare pod, which is made up by a CAESAR-IV electromagnetic radiation jammer.

Cutlass-class attack corvette
The Cutlass-class attack corvette is a heavily-armed, better-armored version of the Gladius-class corvette. Packing two M40 Suppressor 330mm naval autocannons and four M910 Rampart 105mm point defense guns in the place of the M870s, and a modernized MAC, the Cutlass is specifically kitted out as a corvette and frigate hunter. Armour has been upgraded across certain parts of the hull, although it is still too fragile to reliably take hits. As it is more vulnerable to strikecraft, the corvette retains the external fighter docking claws below the forward section, which are capable of holding a single GA-TL1 Longsword or equivalent for defense.

The Cutlass did not see much use from the UNSC Navy, as they preferred to use the older Gladius for both corvette-hunting and anti-fighter roles. As a result, these corvettes are ironically more popular in planetary defense fleets, who use them as a counter to increased frequency of salvaged frigates being encountered in raids. While heavier destroyers would force them to flee, they needed a high-speed pursuit vessel to disable or destroy them - a role which the Cutlass excels at.