Specifications – LY589B Hellion-II advanced extreme-range cruise missile
Key Data
Diameter: 53cm
Length: Without booster: 5.6 m
With booster: 6.45 m
Powerplants:
Primary: AB113 turbofan
Secondary: AB114 air breathing ramjet
Fuel: EER-10
Launch mass: 1585kg
Wingspan: 2.7m
Warhead: Variable
Guidance: GPS, INS, Cromwell 2 (if available), DSMAC, ARH, IR, TERCOM, IMU
Fuses: Variable, depending on warhead.
Speed:
Cruise: 840kph
Terminal: Mach 4
Range: 3080km
Active ECM: ZLQ-88 shortwave EW module
Conceptualisation
For several years the primary weapon of first strike for the Lyran Protectorate and many of its client states around the world, the LY589 Hellion-series has become arguably the world benchmark in long-range, all-weather, multi-role cruise missiles. Designed and built by Lyran Arms for a wide variety of roles, it was designed primarily as a medium- to extreme-range, low-altitude, surface-to-surface or air-to-surface missile that could be launched from a variety of platforms against a variety of targets. During initial concept development, the missile changed from a fairly conventional (albeit advanced) cruise missile into arguably the most intelligent and technologically sophisticated multi-role guided weapon on the planet.
The –B upgrade, itself several years in the making, features adjustments and upgrades to the software and electronic warfare suites, enhancements to the low-observability characteristics of the missile, and, most substantially, a complete overhaul of the powerplant and propulsion system.
Background
In the years since the introduction of the LY589, it has become very clear that the weapon itself was one of the most effective and practical weapons within the Protectorate’s arsenal. With world-benchmark range, adaptability, precision and payload, the Hellion, in conjunction with many separate firing platforms, air-, land- and sea-, has been responsible for more aggregate destruction than all other munitions in the Protectorate’s service combined.
Despite the low attack speed (a scant 880kph), the relatively low RCS and adaptability of the AI suite enabled the Hellion to maintain an acceptable (naval) interception rate of 80% in analysed combat conditions, a figure implying that of every five missiles fired at hostile ships, one hit. This is despite the presence of CIWS, RAMS, AEWACS and aerial interception. Yanitarien Aerospatiale theorised the interception rate of the Hellion at 90%, estimating that only one in ten would penetrate naval anti-missile defences. This was, however, considered more than satisfactory, considering the enormous range of the weapon, and its heavy payload. By means of illustration, utilising that figure, the 10,000 Hellions carried by a single Longsword-class supercapital guided-missile ship would thus be able to reliably hit with 1000 of its weapons. Given the high yield of the unitary high-explosive anti-ship warheads carried, it is likely that only one weapon would reliably mission-kill most sub-capital platforms, and as little as two would render most aircraft carriers unable to operate their air wings. Thus the payload of a single Longsword could, according to Yanitarien Aerospatiale, reliably neutralise 500 aircraft carriers, or 1000 smaller combatants, or any combination within that range. A NS$900m destroyer or frigate would thusly be neutralised by NS$30m worth of Hellions. A good trade, in anyone’s book.
However, despite this rosy outlook, the figures as demonstrated on operations were actually considerably better, with interception rates closer to 80% than 90%, reflecting effectively twice the anti-ship potency, and itself reflective of the inherent difficulties in intercepting a weapon that is inherently extremely hard to detect, which flies very low, and rarely emits electronic signals at a detectable level. The result being a theoretical alpha-strike mission-kill figure of 1000 heavy warships, or 2000 light vessels, a net increase of 100% on the theoretical statistics.
As combat experience would have it, despite the limitations of the Hellion’s slow cruise and comparatively even slower terminal stage, there has not been a single instance where a fleet fired upon by a Lyran-commanded Longsword-class warship has been able to continue its mission. Entire fleets have been sent to the bottom by the combination of Longsword and Hellions, with a prime example being the complete destruction of a World Soviet Party carrier battle group to no Lyran or Lyran-allied loss. The potency of this system has resulted in several instances where the arrival of a Lyran fleet within a theatre of operations has led to the immediate surrender of opposing forces. The most notable manifestation of this was the surrender of Anemos Major to the Lyran 2nd Order, without a single Lyran shot being fired, during the brief hostilities between the states in 2008.
However, Lyran combat doctrine emphasises full-spectrum overmatch, and steps that can be taken to improve combat performance of any system are always on the drawing board.
In the case of the Hellion, despite its remarkable successes and utility, the low terminal speed remained an issue. Attempts to bolster the terminal speed were successful, but almost universally resulted in a decrease in range, a compromise which was not acceptable to Executive Command, and which led to considerable research to rectify.
The upgraded weapon, eventually, became different enough to be considered a new weapon; the LY589B, Hellion II.
Warheads
The Hellion II, as with its predecessor, can carry a very wide range of warheads, including (but not limited to) HEDP submunitions, thermobaric warheads, high-yield unitary anti-ship, tandem-charge anti-shipping, area-denial, delayed-fuse/bunker-buster munitions, wide-area guided anti-vehicle (WAGAV), or variable-yield nuclear.
HEDP (High Explosive, Dual Purpose) sub-munitions are, in effect, a large number of smaller explosives that are scattered by the Hellion at a designated location, covering a wide area with explosive ordnance. Effective at attacking large numbers of infantry or light-to-medium vehicles in open or semi-open terrain, HEDP submunitions are cheap on a per-unit basis, and can turn vast amounts of ground into killing zones, with monodirection cover offering little-to-no protection against the vicious interlocking blast and shrapnel patterns.
The Hellion is also often equipped with thermobaric warheads. Thermobaric weapons go by several other names, including fuel-air explosives, fuel-air munitions, high-impulse thermobaric weapons, vacuum bombs, or heat and pressure weapons (from which the word ‘thermobaric’ is derived ‘thermos’ – heat and ‘baros’ – pressure). Thermobaric weapons distinguish themselves from conventional explosive weapons by using atmospheric oxygen, instead of carrying an oxidiser in their explosives. They produce more explosive energy for a given size than do other conventional explosives, but have the downside of being less predictable in their effect. A typical fuel air explosive device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the thermobaric device). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud, creating a massive blast wave. (For a demonstration of a thermobaric explosion, "http://www.nawcwpns.navy.mil/clmf/faeseq.html".) The blast wave destroys unreinforced buildings and equipment and kills and injures personnel. The antipersonnel effect of the blast wave is more severe in foxholes, on personnel with body armor, inside unsealed vehicles, and in enclosed spaces such as caves, buildings, and bunkers.
Based as it is on the LY4045 anti-ship cruise missile, the Hellion continued to excel in the role, and the Hellion II pushes the performance envelope still further. Anti-ship missiles use several means of causing damage to shipping, including igniting unspent fuel, concussive shock and standard HE effects. Anti-ship Hellion variants are time-delayed, semi-armour-piercing high explosive, and are very closely related to the LY4045 missiles upon which the Hellions are based. The weapons rely on kinetic energy, provided by the high-speed AB114 ramjet and its resultant Mach 4 performance, to pierce the deck or hull of a ship, then detonate the warhead in the ship's interior. They are very long ranged, sea-skimming, high subsonic weapons, with very low radar reflectivity, and jamming-resistant guidance modules, with the added potency of high-speed terminal effects for active and passive defence penetration.
Area denial warheads scatter sub-munitions over a wide area, set with proximity fuses coupled with inertial sensors. After the warheads stop moving, as determined by the inertial systems, the proximity fuses and motion sensors are activated, and any further disturbance triggers the explosive. Area denial munitions are deployed to prevent enemy movement through a given area without extensive delay. The submunitions can be set to last for up to a week, before self-destructing, thus ensuring that any given area is not rendered hazardous to civilians into the medium term.
Delay-fuse warheads operate similarly to anti-ship warheads, in that they delay the ignition of their explosive natures, so as to allow the warhead's kinetic energy to cause penetrate into its target prior to detonation. Similar weapons have been dubbed “bunker-busters” for their ability to destroy hardened targets. These weapons are also highly effective at cratering airfields, thus rendering them temporarily inoperative.
Wide area guided anti-vehicle warheads (WAGAVs) are a relatively newly developed Lyran warhead, based upon the long-known SADARM concept. Generally equipped with 30 HEAT submunitions WAGAV-equipped Hellions are targeted from launch as normal, but these submunitions, while still onboard the Hellion, are assigned targets as located by either the Hellion's own integral sensory systems, which include radar, IR, thermal imaging and visual recognition programs, or by designator from friendly forces by laser, satellite, GPS or Cromwell. Upon arriving at the appropriate target area, Hellion triggers the release of the submunitions. Once fired, they independently track, close, correct and engage their targets from above. These warheads have been specifically designed to destroy hostile armoured units, or dispersed high-value targets such as anti-aircraft batteries, emplaced command and control facilities or ammuntion and fuel resupply areas. A conceptual illustration of how WAGAV warheads would operate in the field is given below.
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As with the BGM-109 Tomahawk, the LY589B is able to mount nuclear warheads as well, in this case the LY4011 ‘Sunrise’ 10-90kT variable yield system. Similar to the W88 in nature, the LY4011 is a two-stage tritium-injected device, offering a wide range of low-to-medium yield options for operational and strategic-level commanders, while maintaining the highest levels of shelf-life and accidental detonation security. Access to the ‘Sunrise’ system is only available to states in a formal alliance with the Lyran Protectorate.
Guidance, Networking and AI
Hellion II utilises the AI package of the Hellion I without change, and it remains arguably the most advanced artificial intelligence software package of any combat munition in existence. Utilising EMP-resistant InGaAs (Indium Gallium Arsenide) circuitry and an uplink to the Cromwell II battlespace information system, the Hellion-series represents a benchmark in precision and networked high-lethality firepower delivery.
The centrepiece of Hellion as a weapon system is its artificial intelligence, networking and sensory sophistication. By channelling a portion of the computational power delivered by the massively parallel processing capability generated by the Cromwell 2 battlespace integration system, Hellion features the most adaptive and responsive artificial intelligence system the Lyran Protectorate has devised or encountered, and offers the firing entity many unique and versatile means of achieving target destruction, along with a whole host of other combat effects.
The command-linked automatic inputs to Hellion's AI enable the missile itself to plan, recalculate, analyse, abort, re-target, evade and engage autonomously. Continual uplinks from the Cromwell II allow the on-board computer system to remain completely aware of the battlespace situation, including known and estimated enemy force concentrations or positions, anticipated rates of advance, combat air patrols, detection equipment and so forth. The missile then, while enroute, and cogniscent of entered rules of engagement and theatre target priorities, can adjust its course in-flight to avoid located enemy positions, respond to a more urgent or alternate target request, or, upon detection of a more crucial target, autonomously engage it.
Hellion's integral sensory suite enables the missile itself to perform IR, active and passive radar, EM, EW, MAD and thermal information reconnaissance itself, often precluding the use of further assets for co-ordination of ensuing strikes.
The system, at any point during its pre-flight or mid-flight engagement sequence, can be over-ruled, altered, aborted or otherwise directed by the firing vehicle, although such input is not required to maintain targeting feasibility.
The constant information stream and computational sophistication serves to maximise the Hellion's probability of successful engagement, and, together with a veritable host of direct sensory input on the missile itself, allows each individual Hellion to, in conjunction with its peers and the wider Cromwell datalink, determine how it may best serve the interests of its firer, by assessing the available range of targets, on a millisecond-by-millisecond basis.
Propulsion
It is in the propulsion systems that the Hellion II differs most from earlier models. Where the baseline LY589 utilised the Lughenti Aerodrome AB112 turbofan, along with a solid-fuel booster, the -589B has made numerous changes to the systems and their supporting components to generate an increase in range, and simultaneously generate increased terminal stage sprint speeds.
The most important change is the provision of dual engines for the –B, a low-thrust, high-efficiency cruise engine, the AB113, and a very high thrust terminal stage engine.
The AB113 is considerably lower power than the AB112 (fitted as the sole engine on the baseline Hellion), rated at 10kN rather than 56kN. This has a slight negative effect on cruise speed, which is down by 40kph to 840, a net-positive effect on range, and a fairly dramatic effect on acceleration, which is now considerably poorer. However, the advantage is that it has allowed the weight of the primary engine to drop from 590kg (over a third the weight of the weapon) in the -589 to 105kg in the -589B. This is not solely a product of downgrading of maximum thrust, but is also the result of Lughenti Aerodrome being remarkably anal in the weapon’s construction.
The AB113 also differs from the AB112 by the utilisation of a feature pioneered by the Yanitarian We-38, the burning of a tetrahydromethylcyclopentadiene dimer/exo-tetrahydrodicyclopentadiene fuel. Dubbed EER-10 in Lyran parlance, it is a 74/24 mixture, and is notably lower viscosity than most available fuelling alternates, as well as being considerably less likely to ignite unintentionally. This lower viscosity improves flowrates, enabling lighter and less bulky pumping equipment, and smoother consumption curves, as well as improving fuel gauge accuracy. The remaining 2% of the fuel (by weight) is a blend of C5-C7 alkane and cycloakane, and a smaller by weight percentage of a tripartite oligomer of cyclopentadiene and methylcyclopentadiene, which serves as a fuel enrichment agent and startup assist.
The AB113 utilises a number of innovations borrowed from the L-116 engine of the LY910 Shadowhawk, with integrally bladed rotors, and disks and blades fashioned from a single piece of high-durability metal, both factors generating improved fan performance and appreciably less air leakage, while simultaneously decreasing the likelihood of catastrophic failure along connection points such as weld-seams. Wider and stronger fan blades have eliminated the requirement for the inclusion of an engine shroud, which has also served to push engine efficiency up by improving air flow, and thus providing it with greater power and range than an engine of its weight would lead one to expect.
Also carrying on from the L-116 has been the direct implementation of Pratt & Whitney’s high-strength ‘Alloy C’ titanium alloy in a number of engine components, including compressor stators, augmentors and nozzles, allowing the engine to run hotter and faster, permitting improved thrust-for-weight, greater durability and improving engine efficiency still more. Similarly, the combustion chamber features thermally-isolated panels of high cobalt, oxidation-resistant material, which provides a similar downward pressure on maintenance, and improves overall reliability.
The second engine, the unoriginally named AB114, has borrowed considerably (under license, rather than espionage – a rarity for the Protectorate) from the Hellion’s sole serious conceptual competitor, the We-38 ‘Francisque’, and, more particularly, its WeRR-8MC air breathing ducted ramjet. With a dry weight of 550kg, the -114 is over 500% heavier than the -113 engine, but generates 330kN of thrust, enough to push the Hellion II to speeds in excess of Mach 4. The -114 is, however, ten times as fuel consumptive, and would go through the entire fuel supply for the Hellion in only 300km. As such, the -114 is only engaged when the Hellion’s sensor suite determines that the missile has been detected (assuming sufficient range remains to engage the target at higher speeds), or as part of the Hellion’s attack run.
By the combination of the two engines, together weighing only 75kg more than the AB112 of the LY589, the -589B is able to travel essentially the same range, while gaining a terminal sprint capacity to bypass or defeat anti-missile defences.
The weapon is in no way required to utilise all the available power, nor all available fuel, and, particularly where thermobaric warheads are loaded, may well attempt to add its own fuel stockpile to the strike.
When taken as a total package, the Hellion II offers very slightly increased total range over the Hellion I (3040km, as opposed to 3000km), but with the final 40-50km (on average) flown at sprint speeds of Mach 4, giving point defence systems far, far less time to respond to the threat presented by the weapon.
Despite these upgrades, the modular nature of the Hellion remains, however, allowing for the substitution of alternate engines, should local conditions or manufacturing preferences dictate.
Armour and protection synopsis
The LY589B, as with the baseline -589, features an extensive suite of active and passive protection systems. The primary means of protection is integral to the weapon's AI. In essence, the most obvious line of protection is the system reacting intelligently, addressing or responding to manifesting threats quickly and in accordance with pre-existing rules of engagement and target priority assessment parameters. Hellions under fire automatically manoeuvre to maximise their operational success likelihood and deploy active ECM, flares and chaff as appropriate to the threat environment. In certain circumstances, dependent upon the nature of the threat (and thus most commonly in response to surface-to-air systems), one or more Hellions may detach from the salvo and engage the systems which are firing, neutralising the nature of the threat to ensure the success of the strike, rather than seeking to press their own individual attack in the face of resistance. This aggressive defence may result in the loss of several Hellions, but serve to ensure the overall success of the strike, and simultaneously further suppress hostile anti-missile systems.
The intelligence and adaptability of the system goes further than that, and the LY589s may ignore systems that do not pose a threat or present an opportunity, while simultaneously uplinking the details to the battlespace management system. For example, ground-surveillance radar from a known hostile position may be ignored in favour of continuing on an offensive action.
Further to the Hellion's adaptability, however, are the more direct means. Each is equipped with a ZLQ-88 short-wave ECM module, but usually only a small number from a given flight will activate ECM for a given threat. Should an incoming flight of anti-missile missiles, or other targeting systems for that matter, switch to home-on-jamming, then only a small number of Hellions will be struck by the defences, while the remainder of the Hellion salvo goes on to target.
Chaff dispensers are fitted as standard, with each missile able to release twice before the dispensers are exhausted.
Flares are also fitted as standard, as a means of anti-IR evasion, should the threat be detected or calculated as relying on IR or TI-based target tracking.
Signature Reduction
While the baseline Hellions were not considered ‘stealth’ platforms, the same cannot be said for the –B variant. Extreme care has been given to the design of the weapon with regards to radar cross-section, and Hellion II also makes extensive use of radar absorbent material to reduce its signature still further. Given the missile's already relatively small size, regular use of a lo-lo flight profile and adaptive AI, detection of a Hellion strike is usually very late indeed, and often as a consequence of the ignition of the platform’s sprint engines. By this stage, scant seconds will usually remain before the strike impacts.
In the broadest sense, there are two primary approaches to the implementation of passive radar cross section reduction. They are;
1. Shaping, which adjusts shape to minimise the strength of returning radio waves to a detector, and
2. Coating, which aims to achieving absorption or cancellation of incoming, returning and outgoing emissions.
Both of these approaches have to be utilised coherently and in an integrated and whole-of-package fashion to achieve the greatest feasible low observable levels over the appropriate frequency ranges in the electromagnetic spectrum. The utmost care is exercised to ensure that there are no salient features to contribute to the platform’s detection. As in a blackout, the game can be given away by one chink of light. Fortunately, low observable technology has matured sufficiently that conventional or para-conventional aerodynamic configurations can be implemented incorporating low observability without considerably negative aerodynamic performance or increasing costs significantly in the production phase.
Unlike the first-flight Hellions, Hellion 2 intakes for the engine are submerged into the structure of the weapon, dramatically lowering both thermal and radar cross section. The inlet paths are serpentine, by virtue of this, and conceal the engine and fan-face from radar, while simultaneously redirecting radar waves into the engine, rather than back to the receiver.
Wing-type control surfaces are trapezoidal, and employ axial symmetry, a further downward pressure on RCS, and one of the first platforms anywhere in the world to employ this feature.
Hellion 2 has made a very extensive use of composite materials, with nearly a full third of its weight, and just over 80% of its outer surface being composed of such materials. Most of the structural composites are bismaleimide and composite epoxy material, both of which are also employed on the LY910 and F-22, in conjunction with low-maintenance structural fibrous matting, rather than the alternative high-maintenance radar-absorbent metallic paint. The net effect is almost identical, but the fibre mat is far less maintenance intensive and environmentally sensitive, and does not require such careful management or storage to maintain its properties. Panel edges are serrated, in order to minimise returns from panel boundaries, a feature particularly visible on payload bay doors (where carried).
A ceramic-matrix RAM is on the engine exhaust nozzles to reduce radar and IR signatures, and a very large amount of wide-band RAM is used structurally on the leading and trailing edges of the control surfaces.
Export
The LY589B Hellion II is, like the earlier variants, one of the Lyran Protectorate's most carefully guarded and rigorously controlled pieces of equipment, representative as it is of the most current and versatile means of extreme-range battlefield offensive support.
Sale is thus only permitted to states or national/transnational entities that the Protectorate has both dealt with before, and that Executive Command considers trustworthy. On-sale is strictly prohibited without the express authorisation of Lyran Arms.
Only nations with whom Lyras enjoys a formal alliance in the true sense of the word are permitted DPRs to the Hellion system. Again, distribution and on-sale is strictly prohibited. If such an action is required, please contact the Executive Command Staff for approval. Should a state not be eligible for DPRs, purchase of batches of Hellions is still permitted, should Executive Command's stated considerations be met.
Each Hellion II sells at NS$3.5m.
DPRs to the LY589, to allies only, are available at NS$150bn.
Queries or purchases through Lyran Arms.
