UNSC Relentless

"A forerunner for the future of space warfare."

- Anonymous

The UNSC Relentless was a revolutionary capital ship that entered service during the UNSC-CMA Cold War, and could arguably be considered the first modern cruiser. She was one of only two Relentless-class large command cruisers built, with the other being the UNSC Mirata.

Built during a time when the UNSC was actually far smaller than their CMA rivals, the Relentless simply had no equal or effective counter when it was introduced. Though a cruiser, unlike its contemporaries it was no mere escort, with the size and capabilities to act as a capital ship in its own right - something that had not been seen since the days of the Interplanetary Wars. This was combined with an unrivaled slipspace suite and high speed, along with the first MAC ever fitted to a warship, to enable it to strike at previously-unapproachable carriers or arsenal ships and destroy them. So effective was it that all future vessels were forced to consider fighting Relentless-like vessels, leading to the wider proliferation of naval arms and defenses across all ship classifications.

For a ship that such an effect on naval history, the Relentless herself led a rather disappointing history. Placed at the head of cruiser squadrons operating in contested regions, its purpose was more symbolic, being used for "showing the flag" throughout human space in order to arouse UNSC support. It did see some action, notably in detaining the ships behind the nuking of Far Isle, but by the turn of the century it had long been supplemented by newer vessels that far exceeded its capabilities. It was taken out of active service in 2509 to be used as a training ship, and then decommissioned in 2521 to serve as a barracks ship above Chi Rho. It was brought back into service when the Covenant was discovered, and was subsequently destroyed during the opening minutes of the Battle of Midvale.

Specifications
The Relentless was, compared to modern cruisers such as the Halcyon- and Marathon-classes, a rather frail vessel, with a pronounced sword-like shape that tapered to a point near the top. Parts of its hull had been cut out for weight considerations, and at places only the thick supporting beams could be seen. It had a number of archaic features that would soon be changed or shed, including an uncowled engine arrangement, the use of exposed, unprotected sensor/communications towers, lacking many overlapping hull sections, and no internal hangar bays, with fighters instead docking onto the exterior hull of the ship. Perhaps its most distinguishing feature is its peacetime paint scheme, which was a bright silver, with blue and gold accents to reflect its loyalty to the United Earth Government. This would only be replaced by the standard military grey in the 2490s, as the status symbol was no longer as useful as its pragmatic qualities.

Armament
The UNSC Relentless was the first human warship that incorporated a Magnetic Accelerator Cannon, the Mark I heavy coil that ran along most of the dorsal side. This was the only weapon that elevated its weaponry from mediocre to excellent; no armor system at the time could successfully resist a full charge using its 400-ton slugs, and even low-powered firings could cause extraordinary damage to the unfortunate target. However, beneath this laid a whole suite of problems. Because the cruiser hadn't actually been designed to make use of it (as it was instead grafted on while under construction), it was actually too powerful for the Relentless. Bulkheads warped and glass shattered, and the mountings for the magnetic rings frequently buckled. Solving these problems took the better part of ten years to complete. In addition, the charging cycle was glacial, better measured in hours than minutes. As an artifact of being the first of its kind, it could only use tungsten slugs of various sizes.

To back up the MAC, and to fight at extended ranges, the cruiser had a modest complement of missiles. 20 cells of M360 Javelin anti-ship missiles made up its primary striking arm against ships: eight on the bow, and fifteen per side. Though effective at the time, being designed during a period where protection was light meant that Javelins quickly became ineffective when Titanium-A battleplate became widespread. 16 pods of M31 Loki missiles, each with six missiles, were also carried. Most Lokis had non-lethal warheads aimed at disabling their targets, largely because doctrine at the time was to capture a ship than destroy it. The missile layout was archaic, as regulations for minimum spacing and protection of cells at the time were far more accommodating than when they were revised in the 2510s. As a result, a wildcat chain reaction destroying most of the ship was possible if the ship was loaded with missiles that were substantially more powerful than what the cruiser was initially built for. Which was one of the reasons that led to its destruction.

A small reason why the Relentless was such a threatening ship was because of its heavy counter-munitions and counter-fighter arsenal, which made the cruiser all but immune to carrier attacks. It had a heavy (at the time) dual-purpose battery of eight M17 Qiang 127mm/24 cal naval coilguns to defeat strikecraft, cutters, and corvettes at medium ranges, all mounted in single-turrets to allow each gun to select individual targets. These were then organized into two broadside batteries that had the ability to direct all fire forwards, although there was no aft coverage as it was felt that the cruiser would usually be charging directly at its opponents. These were then paired with 45 twin turrets of rapid-fire M6 Aegis 25mm/40 cal close-in weapon systems, which formed the last line of defense against any incoming threats that bypassed all other defenses. It was the first ship to also incorporate the M340 Streak anti-fighter missiles, in thirty cells that were designed for four devices but could carry double that number if needed.

By 2500, the Relentless was reequipped to better deal with the ships that had emerged after its commissioning. Its Javelins were replaced on a one-to-one basis with the powerful M380 Ares missiles, while the Lokis were replaced with the new M58 Archer missile. In both cases, the cells and pods were upgraded to accommodate them, although size limitations restricted the number of Archers per pod to ten rather than the standard 26 or 30.

Defenses and countermeasures
As a ship trialing so many untested features, it was no surprise that the Relentless had protection that only its sister shared, and for good reason. Its primary protection was fairly conventional, with whipple shielding, grapheel plates, a double hull and other techniques. Structural supports were secure and rather dense, but ultimately no different to what had been done before. However, it utilized a unique system of tracks and motors to drag protective plates to shore up areas around the hull, with mechanical locks and electromagnets securing them into place when needed. Developed by a Siberian engineer, the Ivangorod system proved to be effective and resilient in service. That said, it was expensive and relied on complex machinery to function requiring constant maintenance to prevent any number of small breakdowns that could compromise the entire system. In the 2510s, the armor plating was replaced with Titanium-A1 battleplate, though the infrastructure for the Ivangorod system remained.

Slipspace capabilities
The Relentless was the first human warship to be equipped with a practical CODEN-IV translight engine, the XTM-#8112 built by Deimos Special Projects Division. Developed in secrecy over the course of a decade, when the Relentless launched it held the record as the fastest ship in slipspace. In mere days, it could cross distances that would've taken its contemporaries weeks if not months to reach. More importantly, it had been created in concert with a sophisticated navigation suite, one whose very fine control of the drive's operation was supposed to dramatically reduce the "drift" between its plotted destination and where it actually arrived. Taking the form of large room directly forward of the machinery section, the complexity of the system required almost a dozen engineers and officers to man it, along with a controlling Volitional Intelligence to process the complex algorithms and commands. This allowed the cruiser to consistently arrive within 80,000 kilometers of its target - short of the UNSC's 50,000km target, but still impressive. Moreover, the combined system was far better able to resolve gravitational interference, allowing for closer arrivals to large bodies such as planets and stars.

Behind these flashy statistics, however, there were problems. For one, the drive itself was prone to breakdowns and the Relentless frequently had to cruise on its backup translight engine instead. Which was not a problem as even this device was more than able to keep up with the UNSC fleet of the time. The larger problem were that traditional issues that limited the tactical value of in-system jumps - lightlag and lack of supraluminal communications - could not be rectified with technology of the time. Finally, although the navigation suite was impressive, it was not cost-effective to deploy across the fleet, and the UNSC would instead focus on more compact, automated alternatives that traded away accuracy.