UNSC Southern Cross

"Usque in finem."

- Ship motto

The UNSC Endeavor (hull code: DD-347) is a venerable Beagle-class assault destroyer, and one of two ships to have participated in the Harvest Campaign and the Siege of Sol. The latest in a lineage that hailed back to the seventeenth century, the Endeavor is one of thirty-five destroyers built to trial the installation of state-of-the-art hangar facilities on light-tonnage warships. While still possessing two full-sized fusion reactors, a relatively-high acceleration and as thick a hull as the baseline class, its armaments were lacking thanks to the removal of several Archer missile pods and the down-scaling of its Magnetic Accelerator Cannons. Despite these significant drawbacks, it remained a solid vessel which outlived the sisters it was built alongside.

Design
Like all Beagle-class destroyers, the UNSC Endeavor shares most of its hull and superstructure design with the Halberd-class destroyer. At 480 metres in length, it was only five metres shorter than the design it was based on. Past its arrowhead bow, the differences are minimal. This mainly involved replacing certain areas of the hull with 0.4 metres of durasteel armor, which sacrificed protection for speed, as well as a number of keel-mounted thrusters to hold it up while operating in a planet's atmosphere. The bow is slightly different, with a larger hangar bay that is half-again as large as on its more common counterparts, and a smaller upper hull. The hangar is divided into two sections; a long flight deck that is located on the upper floor, and a general-purpose bay that accommodated both dropships and ground vehicles on the lower one. Both decks use different airlocks, so they can launch and receive different squadrons at the same time. However, only aircraft entering the front hangar door can benefit from the advanced gravitic breaking system. The upper plate on the bow that ran between the raised plates of titanium-A battleplate is unusual in that had a series of automated elevators and armatures that could rearm and refuel up to three space fighters in the middle of battle. Intended as a forward-thinking feature, it was hoped that the UNSC would introduce a smaller interceptor model to take advantage of it. No such aircraft would ever reach the light of day, so the system lies unused. In homage to its maritime namesakes, the Endeavor is often seen sporting red-or-blue war paint resembling waves on its bow and wings.

In terms of armament, the UNSC Endeavor 's original ship-to-ship armament consisted of two Series-2, light coil MACs. The Series-2 MACs were intended for use on corvettes, and fired far smaller slugs in exchange for higher speed and quicker recharge times. Backing this up were 18 M58 Archer missile pods, each with five silos. These were general-purpose missile pods that are effective against other ships, but could also be used against larger gunships and space fighters if necessary. They could also carry a vast assortment of warheads, with armor-piercing and counter-shielding being the most popular. It lacks the M870 Rampart emplacements, and in their place are eight M37 Suppressor turrets, each with twin-linked 279mm naval autocannons. They could be used for defeating missiles, but they were intended for use against other ships and space fighters. Instead, 19 M710 20mm turrets were installed for this purpose. For use against far slower and heavier opponents, two M81273 fusion rockets were embarked, each with a variable payload. Like on regular Halberd-class destroyers, a Mark 45 fire director was used to vastly increase its accuracy at extended ranges of 50 kilometers or more.

Refits
As a former CMA warship, the Endeavor was typically initially passed over by UNSC officials when it came to upgrades, with any improvements made coming from reclaimed parts that belonged to scrapped vessels. This was partly fueled by their disapproval in combining the roles of destroyer and transport, as it was not able to fulfill either role as well as many other vessels already in service. However, as it continued to survive engagements with the Covenant, refits were eventually authorized that steadily built upon its capabilities, with these often being implemented between large-scale repairs.

By 2532, the Endeavor had received a small suite of improvements, as five years of constant action would obviously cause severe wear on its systems. While most of its systems replacements were minor and hardly affected its performance, with its powerplant, electronics, and even its superstructure being modified to some capacity, two significant changes were made. The first was the installation of a TN-91sy/n Triad targeting suite taken from the, an older computer network that allowed for better coordination of nearby Archer missile swarms and plotted more accurate fire from its naval autocannon battery. The second was a controversial array of radiators at exposed parts of the ship, which while it enabled the Endeavor to overclock its reactor and engines well above their designed limits, left holes in its armor that was never fully addressed over its lifespan. The only other noteworthy change was the increased complement of point defense guns, in a desperate attempt to better protect it from plasma torpedoes and the unexpectedly-resilient Covenant strikecraft. Because the shipwrights had to rely on whatever weapons were available, it was not composed of one homogeneous type of turret, including others such as the M810 Helix and various models of Rampart guns.

In 2532, after suffering extensive damage following the Battle of Boundary, the Endeavor limped to the regional shipyards of Passage, where she underwent its first major refit. This was an expansive affair, involving the modification of vital internal equipment, the movement or mutation of its armor and hull, and the removal of dozens of makeshift repairs made over the last seven years. Most prominently, its forward bow was angled downwards and expanded in size, originally to allow for the installation of a third MAC. However, high demand for such weapons saw the space being given over to supercapacitors, munition storage, and more accommodations for Marines and pilots.

Construction and commissioning
The destroyer that would be christened the Endeavor first began construction in orbit of Chi Rho by the local construction company Diadel Systems, who had been subcontracted by SinoViet Heavy Machinery to construct a number of modified destroyers for the Colonial Military Administration. It was first laid down on August 22, 2518 as the third of the thirteen destroyers built of its batch, which ended with the completion of the UNSC Heart of Midlothian in late-2522. As its previous two sisters allowed Diadel to identify and fix many issues with manufacturing and shipping of parts, the destroyer would suffer no construction delays, with its fabrication actually being accelerated at least two months ahead of schedule. It was launched on January 27, 2519 to complete the fitting-out process.

As construction came to a close, the destroyer was subjected to a rigorous set of space trials, intended to test the operation of its systems and general integrity. This consisted of a series of hard burn accelerations, sensory tests, and close-orbit passes. The third trials were notable in that the ship was caught in an intense comet bombardment that saw large and small shards of rock impacting to the destroyer's hull, forcing it to undergo extreme evasive maneuvers to escape damage. One of these turns saw it unintentionally collide with the MSV Ivory Tower, a large maintenance tug that attempted to rescue it. The damage would delay its commissioning, but the minimal, almost superficial extent showed that the destroyer was much more ruggedly built than was first believed by the shipbuilders. It was commissioned as the CMA Endeavor on March 19, 2519, and was delivered to the CMA a mere three days later. It would depart the Ectanus 45 system, manned by a new rookie crew under the command of Lieutenant Commander Asia Vespa.

Insurrection
The CMA Endeavor first served in the 173rd frigate flotilla, a light naval unit that operated in the Lurone, Rawadi, and Rowena Sectors of FLEETCOM Sector 2. In this guise, it was primarily used to conduct light troop movement through the region, where it ferried elements of the 276th Colonial Army Battalion towards unrest hotspots on Pumice and Cadence. It lent naval support where possible, but thanks to the small-scale of the fighting, and the Endeavor 's lack of atmospheric thrusters, its support was generally limited to logistics and coordination. Other tasks included convoy protection duties to the habitats of Campbell's Landing, in an effort to deter losses to piracy in a navigational hazard zone around it. Most of these tasks were quiet affairs, as nobody realistically wanted to pit themselves against a Colonial Navy destroyer.

In October 2521, the Endeavor was reassigned into the 114th Rapid Strike Squadron, the largest and most active CMA naval unit in the Asgard Stratum, as a replacement to the. This reassignment was also to partially cover the refit of the carrier, with the Endeavor taking over some of its servicing duties for the four months it was in dock. Within the 114th, the destroyer was supposed to assist any starships in distress, where it would quickly move to dock and embark any crew and cargo that can be saved from disabled craft and fight off any attackers. The agricultural content of these freighters meant that it was vital that shipping losses were kept to a minimum, and the Endeavor was involved with the rescue of 19 civilian freighters and four warships during 2522 alone. However, the 114th's power meant that its escorts were responsible for tracking and hunting down any significant insurgent elements in the region, as well as reinforce any CMA garrisons that were struggling to put down unrest. For this need, the destroyer participated in putting down the insurrections of Madrigal, Green Hills, and especially Redstow VI, where it supported ground incursions with orbital strikes at the cost of escalating civilian casualties. However, the sudden increase in readiness and activity, as well as the now-notoriously low standard of training given to CMA recruits, meant that the Endeavor 's largely-inexperienced crew were seen as both incompetent and lazy. This was almost dangerously so, as it almost fired upon allied vessels on several occasions; this reputation would only be erased following the start of the Human-Covenant War.

In February 2523, Vespa stepped down as the Endeavor 's commanding officer, and was replaced by Lieutenant Commander Chi Kariuki. An ambitious officer, it was under her leadership that the destroyer became host to sympathizers of the Biko Independence Army. At first, the only assistance the crew offered were leaked communiques sent through the squadron, and Kariuki's desire to impress saw these quickly shut down. It was only through negotiations and bribery of her communications officer, Lieutenant Patryk Adamczyk, that operations escalated. Throughout the rest of the year, the Endeavor actively assisted the BIA's efforts by providing dead drops of infantry equipment and firearms, starship munitions such as Archer missiles, and even entire vehicles and dropships when possible, all of which was smuggled back to Biko. This assistance was also afforded to other Insurrectionist groups, where it misdirected CMA and UNSC forces by providing false sensor reports. It even faked the deaths of Godfrey's Commandos during Operation: THUNDERBIRD, one of the Secessionist Union's most elite forces, where the commandos were temporarily folded into the ship's crew following the destruction of their corvette.

All of this eventually culminated in a scandal. In early 2524, the BIA used many of the weapons they stockpiled in their fifth uprising, and were swiftly put down by UNSC forces. Analysts from ONI Section One were brought in to scour through the wreckage, as well as interrogate one of the captured insurrectionists for information. While they were able to determine that the equipment was stolen from the CMA, the exact origin was ultimately unknown as their prisoner did not survive. As a result, ONI covertly seeded teams of investigators among CMA garrisons to hunt it down. One of these teams, composed of Chief Warrant Officer 4 Kores Van Schalkwyk and his Navy handler Lieutenant Theodora Papadopoulos, were officially serving as trainers for the Endeavor 's when they were captured by the ship's crew. It was only when they escaped and intercepted one of the weapons drops left behind that they obtained solid proof that connected the destroyer to not only the BIA, but also exposed the rampant insurgent activities in the region. The Endeavor was immediately suspended from operations, and its entire crew were detained and interrogated by Section 1. Many would be pressured into resigning from the CMA, LCDR Kariuki and several of the senior officers were court-martialed for negligence, and the few that were released were reassigned. The ship itself was thoroughly swept of any listening devices, and its databanks were recovered for further analysis. When it finally returned to service in January 2525, it would be under an entirely-new crew.

Human-Covenant War
The CMA Endeavor 's first actions in what would become known as the Human-Covenant War occurred in May 2525, when it was sent to investigate the loss of the CMA cruiser Urban Encroachment in the Upada Sector. A four-week search was extended into six when a second starship, the CMA Empyrean Jewel, disappeared in the same region. No traces of either starship were discovered, which worried the regional command that both ships had been hijacked. As a result, it was ordered to rendezvous with the frigate CMA Raltstown to escort merchants through the Asgard Stratum in hopes of deterring raids.

However, when the civilian craft of the CAA Astrography Charting Mission deployed to the Aurna Sector failed to check in, the entirety of the 114th Rapid Strike Squadron was sent in to locate them on July 13. After 16 days of searching, the Endeavor reported the recovery of Item-291X - an alien fragment that appeared to be some sort of hull fragment. Two days later, the destroyer met up with another CMA corvette to verify the discovery of the wreckage belonging to one of the Mission's command ships, the CAA Babyloniaca. In addition, preliminary analysis of the damage was undertaken, where it was discovered that it had been subject to an intense bombardment of high-temperature bolts, which breached all decks and fused a number of crucial propulsion systems. More importantly, the Endeavor 's weapon officers and chief engineer both noted that the damage could not have been caused by any known weapons they were aware of. The Endeavor towed the wreckage back to their home base at Biko so it could be analyzed further. Both Item-291X and the Babyloniaca were instrumental in convincing the regional CMA command to permit the 114th Squadron to remain in the area, although no further ships would be dispatched to assist them. This was because they believed that an unprecedented Insurgent operation was underway, which led to more squadrons and armies being deployed in the adjacent Mid-Rim colonies instead.

On October 26, the Endeavor arrived in the CRT-99-LP system to exchange supplies with the corvette CMA Johnston, where it participated in the short Skirmish of CRT-99-LP. In an action lasting a minute and a half, the destroyer took several blows with the much smaller alien ship, breaching D-deck on the bow and killing 4 people. Meanwhile, the only hits from the human side were from a salvo of one of the Endeavor 's naval autocannons, as its missiles were either shot down or jammed. While it did force the raider to flee, no damage was registered. Once it disengaged, the destroyer immediate began a rescue of the Johnston 's 13-strong crew, although only a single comatose survivor was recovered.

Both ships returned to the nearest CMA outpost in the Gibson system, although the Johnston had to be towed back, where they filed an urgent report to CMA Command regarding engagement with unidentified alien vessels. This was not long after the CMA Heracles returned from Harvest, where its crew claimed that a massive alien capital ship had routed its Battle Group. Surprisingly, all three ships received orders by the UNSC High Command, signed by the UEG Minister of Defense, to head with best possible speed to the nearest UNSC naval base. ONI Section One teams were dispatched to recover any information they could on the aliens; the crews were thoroughly interrogated, the computer readings were downloaded, and repairs were temporarily halted while the investigators and scientists were finished.

On November 1, the UNSC declared a state of emergency, forcibly placing all CMA personnel and property under its direct jurisdiction. As a result, the destroyer was rechristened the UNSC Endeavor, and major software upgrades were implement to allow it to interface with the UNSC battlenet and communications systems.