Achilles

***Achilles*** was a unique 'command battleship' built by the Terran Alliance to experiment with dedicated flagship-model combat starships, reflecting the ever-increasing size of fleet engagements. The predecessor of the later experimental *Minerva*-class flagships and the production *Hyperion* class, she was a testbed design fielding new laser cannons of advanced design plus an advanced, beam-reflective armour scheme derived from that originally installed on the battlecruiser *Furious*.

## Design

### Design History

Initially projected as a battlecruiser - and rated as such in some circles - the *Achilles* was a significantly smaller ship overall compared to the standard *Mars*-class battleship design: though she exceeded them slightly in length, she had only about 75% of the mass, allowing her to mount smaller and more efficient thruster units and power systems. This in turn was derived from her reduced armour- though she sported superior armour thicknesses from the front, her sides and rear were significantly reduced, reflecting the trend towards end-on warfare. Her mostly recessed and hidden gunports reflected long experience with the *Furious* and was contemporary to other experimental warships such as the *Belladonna-* she also sported greater redundancy in her power plant, thanks to its smaller size requiring an additional reaction core to operate subsystems at full efficiency.

In terms of command and control capabilities - the focus of her design - only *Furious* outstripped *Achilles* in her day: the latter sported a comprehensive suite of integrated sensors for enemy detection and fire control as well as large-aperture-type navigational sensors: she also had long-range experimental tachyonic gun-direction sensors in order to take full advantage of her laser cannons, previously unachievable. Mated to these was a largely experimental communications array which could bypass the normal chain of *Tethys*-class comms cruisers, relaying orders directly throughout a battlefleet in real time.

### Dimensions & Role

At 1,520 metres in length, *Achilles* was slightly longer than a *Mars*-class battleship: however, thanks to her reduced armour and overall slimmer hull, she sported only 75% the mass. The basic shape was derived from that of the *Iapetus* design, scaled down: its four engines, however, were in two pods in a stacked arrangement at the rear of the craft, giving it a distinctive appearance. Unlike most contemporary Alliance warships, but like many experimental vessels and specialized classes, the *Achilles* favored a single-hull configuration: her ventral communication array was plated over, giving her a distinctive 'fin' to break up her otherwise boxy profile.

As a flagship, *Achilles* was not meant to ever directly engage in combat: though she was a powerful warship, her design focused on maneuverability and the ability to reposition herself quickly over heavy armour and survivability, allowing her advanced comms systems to do her primary task of fleet coordination.

### Power & Propulsion

As with all of the most modern Alliance warships that were not produced with the aid of foreign technology, the *Achilles* sported a Terran version of an ionization reactor: her **reaction core** was a substitute for all of the matter/antimatter annihilation reactors and cold fusion technology used up to that time. As her reaction cores were smaller than the standard model as used on the most modern *Iapetus*-class battleships, she required two to operate all of her subsystems at maximum capacity.

For forward thrust, *Achilles* was well-equipped with four smaller ion-drive thrusters of an enhanced design compared to that being used on *Iapetus*: though costing about twice as much as the regular model, they conserved over 70% of propellant compared to the standard type, allowing the battleship to achieve considerable fuel economy when compared to the antimatter-hungry *Iapetus* or even the older, efficient *Mars*. Maneuverability was achieved with the standard array of shuttered ion drive panels and vents alongside steam jets and Vernier directional thrusters: additionally, *Achilles* was equipped with a prototype directional electromagnetic field that could alter the thrust patterns of her four primary engines, allowing her to make rough course adjustments without using excess propellant.

### Artillery

Though she did not carry a superlaser, *Achilles* was nonetheless formidably armed: her primary battery of twenty-six 380-megaton heavy laser cannons together unleashed more energy than all the atomic testing of 20th-century Terra in a single volley. Twelve of these guns were mounted in turrets: beam collimation chamber miniaturization allowed for the size of the turrets to be significantly reduced, and she carried two dorsally and two ventrally on the centreline. The rest of her guns were mounted in her prow and on her canards, fixed-forward in recessed, hidden gunports: this gave her a forward punch unparalleled by even the *Iapetus* class (discounting their boring laser) while retaining a respectable broadside.

For her secondary armament, *Achilles* sported a battery of 12.5-megaton laser turrets: single/twin-mounted and strewn across the hull in a mix of disappearing mounts and casemates, they were a new development within the Alliance, handier than the 15-megaton weapon while being considerably more powerful than the old but reliable 10.5-kiloton weapons. They were a reliable threat against smaller cruisers and destroyers of all descriptions, though they could not be counted on against larger warships except for in precision destruction roles against vulnerable subsystems.

Point-defense armament was handled by a comprehensive battery of medium- and small-calibre laser cannons: 'snapper balls' - so-called because they could snap a crewman from their seat if their harness was incorrectly secured - had been a mainstay of the Alliance's fleet for two generations of warships at this point, but with no new designs in development, the lesser-powered systems had to be installed. Later on, eight prototype railguns firing explosive shells for ballistic defense were also provided.

Additional armament was backed by large numbers of standard 5-megaton laser blasters and not-so-standard isokinetic missiles; the former were for close-range broadside combat, where their relatively slow firing rate for calibre (only about 3,000 shots every minute) was made up for with hitting power: they could burn cleanly through a metre of starship hull armour if given a continuous track on the same spot for less than seven seconds. However, these weapons were not particularly effective against shields.

### Complement

*Achilles* came equipped for the newest generation of experimental Alliance starfighters: I-3e *Stiletto* strikefighters were the successor generation to the highly valued I-1 *Poniard*, boasting even higher maneuverability and heavier weapons, while the *Spatha* was the successor design to the *Broadsword* bomber. Two squadrons of the former and a single of the latter were normally embarked; in times of war, however, surge capacity could bring those numbers to twice that capacity, though the actual strike would be limited as this included broken-down fighters in transport condition. Conventional *Poniard* fighters and *Broadsword* bombers could also be carried at a slight reduction in capacity.

### Protective Systems

Sporting the same design principles as those initially developed for *Furious* but on a smaller scale for a cost-feasibility analysis, *Achilles* was surprisingly well-protected despite her status as a 'thinner skinned' starship: this only held true in the Alliance, as compared to her foreign contemporaries she was still impressively armoured. A twelve-layer 'sandwich' construction of classified monocrystalline metals and foam ceramic composites formed her outer skin: the heaviest of this was situated around the bow, bridge, engines, and other critical areas, approaching about a metre and a half in thickness at its greatest points. The remainder of the ship, though still armoured in the same manner, received significantly less: the maximum thickness was 600 mm, thinning to 330 mm in the least critical portions.

To her impressive armour was mated an equally-impressive shielding system: a prototype for upgrades to the standard *Prydwen* shield generator, it combined directional gravity fields, electromagnetic shielding, and the standard sectored energy fields to create a barrier against any kind of incoming fire. Long experimentation with cooperation from the Veydreth ensured that the normal vulnerabilities of large starships - primarily to ion cannons - would be minimized under these new shields. Though too costly to implement on a full-scale basis, these were made the standard shields for all of the succeeding flagship models.

### Other Details

#### Bridge Section

*Achilles* sported a different bridge design from the standard Alliance battleship: in terms of form, function, and design, it was closer to *Furious* or *Belladonna*, including in its proximity to the outer hull. As the ship was designed without regards to mass production costs, significant quantities of black marble were used in her bridge: they formed the floor, walls, and ceiling as false paneling for the durasteel beneath, while the latest in sensor imaging systems created a seamless picture between the columns. The appearance of standing in an ancient pavilion amid a sea of stars was not lost on the fleet, which considered the practice extravagant and unwarranted: her *Antigone*-like construction was not repeated.

#### Known Weaknesses

Analysis by surviving Directorate starships after the action off the Xurian Maw indicated that *Achilles* was, as a consequence of her reduced armour, vulnerable to high-powered cannonfire, but that achieving such hits would be difficult at best due to her superior mobility.