Editing Halcyon-class light cruiser

{{Title|''Halcyon''-class light cruiser}}
{{Status|Canon}}
{{Ship class infobox
|name=''Halcyon''-class light cruiser
|image=[[File:HR-UNSCPillarOfAutumn-Side.png|300px]]
|manufacturer=[[Reyes-McLees Shipyards]]
|class=[[Cruiser]]
|crew=2,200 sailors and marines<ref name="Warfleet">Halo: Warfleet, pg. 25</ref>
|role=* Naval engagements
* Troop carrier/supply carrier/escort
|length={{Convert|3840.64|ft|m|sp=us|sigfig=6|disp=flip}}<ref name="H1GameData">'''Halo: Combat Evolved''' 3D model data</ref>
|width={{Convert|1155.73|ft|m|sp=us|sigfig=5|disp=flip}}{{Ref/Reuse|H1GameData}}
|height={{Convert|1359.69|ft|m|sp=us|sigfig=5|disp=flip}}{{Ref/Reuse|H1GameData}}
|mass =11 million tonnes (2525 configuration){{Ref/Book|Id=Enc22|Enc22|Page=119}}
|engine=[[Fusion drive]]s
*[[Mark II Hanley-Messer DFR]] (3) {{c|pre-refit}}<ref name= "data drop">[https://www.halopedia.org/File:DDR-A340024-1115-08-27-52.pdf '''Halo Waypoint''': ''Data Drop 5'']</ref>
*Experimental reactor set {{c|1 primary, 2 secondary}} {{c|''Pillar of Autumn'' refit package}}<ref name="for274">'''Halo: The Fall of Reach''', ''page 274''</ref>
|slipspace drive= [[Shaw-Fujikawa Translight Engine]]
|hull=[[Titanium-A armor|Titanium-A battle plate]]; resistant to around 5 plasma bolts.
|armament= *[[2510]] configuration
**1 [[Magnetic Accelerator Cannon]]{{Ref/Book|Id=Enc11|Enc11|Page=261}}
**4 [[Shiva-class nuclear missile|Shiva missiles]]{{Ref/Reuse|Enc11}}
**180 [[Archer missile]]s{{Ref/Reuse|Enc11}}
*Alternate weapons configuration
**1 [[Magnetic Accelerator Cannon|Mark II 56A2D4 light MAC]]{{Ref/Reuse|Enc22}}
**4 [[Spitfire naval coilgun battery|Mark 33 Spitfire naval coilgun battery]]{{Ref/Reuse|Enc22}}
**4 [[Sentry autocannon|M66 Sentry autocannon]]{{Ref/Reuse|Enc22}}
**20 [[Archer missile|M58 Archer missile pods]]{{Ref/Reuse|Enc22}}
**40 [[M810 Helix point defense guns]] or [[M910 Rampart point defense network|M910 Rampart point defense guns]]{{Ref/Reuse|Enc22}}
|Complement=*[[D77-TC Pelican|Pelican]]s (6+) 
*[[GA-TL1 Longsword|Longswords]] (7+) 
*[[Single Occupant Exoatmospheric Insertion Vehicle|HEVs]] 
*[[M12 Force Application Vehicle|Warthogs]] 
*[[M808B Main Battle Tank|Scorpion Tanks]]
*[[UNSC Marine Corps|UNSC Marines]]
*[[Orbital Drop Shock Trooper|ODSTs]]
|misc-title=Sensors
|misc=*Radar
*Spectroscopes
|era= [[Human-Covenant War]]
|introduced= [[2510]]{{Ref/Reuse|Enc22}}
|affiliation=[[UNSC Navy]]
}}
{{Quote|A dozen [[Covenant]] superior battleships against a single Halcyon-class cruiser. Given those odds, I'm content with three...make that four kills.|[[Cortana]] during the [[Battle of Installation 04]].<ref name="TPOA">'''[[Halo: Combat Evolved]]''', campaign level ''[[The Pillar of Autumn (Halo: Combat Evolved level)|The Pillar of Autumn]]''</ref>}}

The '''''Halcyon''-class light cruiser''',<ref name="EVG">'''[[Halo: The Essential Visual Guide]]''', ''page 42''</ref> known as the '''Human Attack Ship class C-II''' by the [[Covenant]],<ref>'''Halo: The Flood''', ''page 4''</ref> is a [[United Nations Space Command]] cruiser starship classification designed by [[Robert McLees (ship designer)|Dr. Robert McLees]] before [[2507]], with a [[hull classification symbol]] of '''C'''. 

Their service lives were short due to a unique hull design that was costly to construct and maintain with low maneuverability, poor armament, and concerns about their tactical viability. They were replaced by the {{Class|Marathon|cruiser}}. Despite the disadvantages of the original design, the heavily modified {{UNSCShip|Pillar of Autumn}} proved to be one of the most effective, and costly, ships deployed in the war.

==Design details==
===Superstructure and hull===
''Halcyon''-class cruisers are composed of five hexagonal and octagonal sections mounted onto each other. The [[bridge]] is slung underneath one of the forward sections and eight [[Hangar bay|docking bays]] are distributed throughout the ship. There are also slots for eighteen lifepods on the ship's hull. Lastly, the [[Magnetic Accelerator Cannon|MAC]] cannon is visible as a bump on the bow.

The most noteworthy design feature was a series of internal cross bracings and honeycombs designed by [[Robert McLees (ship designer)|Doctor Robert McLees]].<ref name="HCESGuide">'''[[Halo: Combat Evolved: Sybex Official Strategies & Secrets]]''', ''page 60''</ref> This internal superstructure made the ships surprisingly resistant to battle damage; ships of the class were able to remain operational despite sustaining breaches to all compartments and losing 90% of their armor.<ref name="for238">'''[[Halo: The Fall of Reach]]''', ''page 238''</ref> The durability of the design was demonstrated by the {{UNSCShip|Pillar of Autumn}} when she survived a crash-landing on [[Installation 04|Alpha Halo]] after taking a tremendous beating at Reach and over the ring.  However, while the cruiser was intact, it was damaged beyond repair and could never fly again, although some systems were still online such as the fusion core, engines, and self-destruct.<ref name="maw">'''[[Halo: Combat Evolved]]''', campaign level ''[[The Maw]]''</ref>  Another example of the ship's durability was during the [[Fall of Reach]] when the ship took on an immensely powerful [[Kewu-pattern battleship|Covenant warship]]. Having wreaked havoc on Reach's defense fleet, this formidable Covenant warship breached the ''Autumn's'' hull with two piercing beam attacks, one of which severely damaged its reactors. Not only did the ''Autumn'' continue its engagement with limited loss of functionality, it destroyed the Covenant vessel after a protracted battle. However, the special superstructure was deemed unnecessarily over-massed and costly due to its cross-bracings and interstitial honeycombs. This led to the design being dropped from future models of ''Halcyon''-class ships. The ''Pillar of Autumn'' and 10/50 others were built with this type of superstructure.{{Ref/Reuse|HCESGuide}}

Corridors on the ''Halcyon''-class were segmented by several retractable containment bulkheads. In the event of an emergency, these bulkheads could be closed and affected sections sealed from the remainder of the ship. A potential application of this was during a hostile boarding action, where the atmosphere in the sealed sections could be vented via commands from the bridge, asphyxiating enemy troops.

A number of service corridors ran the length of the ship. Although normally restricted to personnel, they could be accessed by [[lift]]s in main engineering or connecting passageways from the docking bays. If necessary, these expansive corridors, including a [[Class Seven service corridor]] running along the dorsal structure of the vessel, could permit passage to Warthogs and some sections were large enough to accept Pelicans.{{Ref/Reuse|maw}} The corridors served a secondary purpose of lessening the ship's considerable mass, thereby increasing acceleration.

''Halcyon''-class cruisers were constructed in space and are not rated for atmospheric deployment;<ref>'''Halo: The Flood''', ''page 40''</ref> however, [[R7 thrust coupling]]s allow them limited atmospheric operation capabilities, as demonstrated by the ''Pillar of Autumn'' which was capable of achieving liftoff from [[Asźod]], supported by a series of rocket pods.<ref name="ReferenceA">'''Halo: Reach''', campaign level ''[[The Pillar of Autumn (Halo: Reach level)|The Pillar of Autumn]]''</ref>

===Complement===
Armories were located throughout the ship, holding a selection of small arms and their requisite ammunition. Eight docking bays allowed a number of [[Pelican]] dropships, [[GA-TL1 Longsword]] Interceptors, [[M12 Warthog]]s and [[M808B Scorpion]] tanks to be carried.<ref>It is unknown how many auxiliary craft and vehicles a ''Halcyon'' can embark. The ''Pillar of Autumn'', depending on the in-game cutscenes, missions, and novels, was shown to carry at least: twelve Longswords, seven Pelicans, four Scorpions, and perhaps in excess of forty Warthogs. The Warthog count is partially based on the text of '''[[Halo: The Flood]]''', ''pages 136-138''. The docking bays shown in the cut scenes each revealed berths for sixteen Pelicans as well.</ref> ''Halcyon''-cruisers were often found with eighteen [[Class-3 Enclosed Heavy Lifeboat, Controlled|Class-3 Bumblebee lifeboats]], in case the ship's crew must be evacuated. Because of the low number, these were likely used only as a last resort if Pelicans or other modes of transportation were not available.<ref>'''[[Halo: Combat Evolved Anniversary]]''' - ''[[Library (feature)|Library]]: Bumblebee''</ref>

===Power plant===
{{Main|Fusion drive}}
Sublight thrust is provided by nuclear fusion reactions which are channeled to two primary and twelve secondary adjacent exhausts at the ship's exterior stern.{{Ref/Reuse|ReferenceA}} There are six exhausts visible, two large and four small. These engines are powered by [[nuclear fusion|fusion reactions]] between atomic nuclei of the [[hydrogen]] isotope [[deuterium]].<ref>'''Halo: First Strike''', ''page 275''</ref> The main engine core consists of three underpowered Mark II Hanley-Messer reactors which provided 10% of modern engine output as of 2552.{{Ref/Reuse|for238}} 

On the refit ships, specifically the ''Pillar of Autumn'', the reactor system was one of the aspects which was heavily retrofitted. The ''Autumn'' was installed with an experimental reactor architecture which used a set of one primary reactor and two secondary reactors; when operating in concert, the magnetic fields of the secondary reactors could boost the main reactor's power generation capabilities up to 300%.<ref>'''Halo: The Fall of Reach''', ''page 174''</ref>

The class was also equipped with a [[Shaw-Fujikawa Translight Engine]] for [[Slipstream space|translight speeds]].

===Armament===
The primary armament of the ''Halcyon''-class was its single Mark II 56A2D4 light [[Magnetic Accelerator Cannon]]. It was armed with only twenty [[M58 Archer missile]] pods, which was far below standards at the time. Each pod would have contained several individual missiles. The class' firepower was further supplemented with four [[Mark 33 Spitfire naval coilgun batteries]] and four [[M66 Sentry naval autocannon]]s, with both types of turrets featuring two barrels each. The ''Halcyon''-class cruisers could also be equipped with forty point defense guns, using either the [[M810 Helix point defense gun|M810 Helix]] or the [[Rampart point defense gun#M910 Rampart|M910 Rampart]] point defense guns.{{Ref/Reuse|Enc22}} With the outbreak of the [[Human-Covenant War]], ''Halcyon''-class ships were put through extensive refits. At least one ship, the ''Pillar of Autumn'', had been upgraded with an improved Magnetic Accelerator Cannon capable of firing three rounds in quick succession. The ''Autumn'' now had 32 [[Archer missile#M58 Archer|M58 Archer missile pods]],<ref name="Warfleet"/> with each pod contained 24 individual devices. The ''Autumn'' was still armed with four Shiva nuclear warheads.<ref name= "data drop"/> One of these missiles was loaded aboard a Longsword fighter, which could be remote-controlled.<ref name="tfor275">'''Halo: The Fall of Reach''', ''page 275'' (2001 edition)</ref> The ship was also equipped with three [[HAVOK tactical nuclear weapon|HAVOK warheads]].{{Ref/Reuse|tfor275}}

==Service history==
At just over 1.17 kilometers in length, the ''Halcyon''s were the lightest of vessels to be designated and structured as cruisers. Compared to later capital ships, the original ''Halcyon''s were sorely underpowered and undergunned: their Mark II fusion engines provided but a tenth of the output of modern reactors and their armament consisted of a mere six [[Archer missile]] pods and a single [[Magnetic Accelerator Cannon|MAC]] gun. According to the AI [[Cortana]], these ships were considered subpar within the [[UNSC fleet]] by 2552.{{Ref/Reuse|for238}} A few dozen served in the UNSC Navy during its history.<ref name="Warfleet">Halo: Warfleet, pg. 25</ref>

When the [[Human-Covenant War]] erupted in [[2525]] a number of ''Halcyon'' cruisers were reactivated from storage and refitted. With the right upgrades, a ''Halcyon''-class cruiser could be a formidable foe. During the [[Battle for Arcadia]] in [[2531]], the {{UNSCShip|Pillar of Autumn}} teamed up with three other ships to destroy [[CCS-U321|a]] {{Pattern|Ket|battlecruiser}}, suffering heavy damage but remaining combat ready enough to provide ground support for the {{UNSCShip|Spirit of Fire}}. Notably, of the four human ships involved in the battle, it appeared to be in the best shape of the two surviving ships. Later, during the [[Fall of Reach]], the upgraded ''Pillar of Autumn'' was able to inflict damage far beyond its tonnage, engaging and destroying [[Covenant frigate]]s, a {{Pattern|Ruma|light carrier}} and a [[Kewu-pattern battleship|powerful warship]] of unspecified class. Later, in orbit above the Forerunner construct known as [[Installation 04|Halo]], the ''Autumn'' destroyed four additional ''Ket''-pattern battlecruisers under the guidance of the AI Cortana. While much of this success was due to the tactical genius of Captain Jacob Keyes and his crew, the upgraded ''Autumn'' was highly resilient and capable of unleashing tremendous artillery barrages. 

The ship's main Magnetic Accelerator Cannon was enhanced to fire in three-round bursts. While each individual round was weakened, this firing pattern typically ensured at least one projectile would penetrate a Covenant vessel's shields. Damaged, the targeted ship could then be overwhelmed with Archer missiles, nuclear weaponry, or further bombardment once the ''Autumn'' recharged its main batteries. Unfortunately, the ship and nearly all of its original crew were destroyed in an attempt to prevent the firing of the Halo ring, and to prevent the release of the parasitic life-form known as the [[Flood]]. The detonation of the ''Autumn's'' fusion reactors destroyed not only the ring, but the majority of the [[Fleet of Particular Justice|Covenant fleet]] which had pursued it from Reach.

The {{Class|Autumn|heavy cruiser}}, commissioned into service following the end of the Human-Covenant War, is based upon the ''Halcyon''-class cruiser ''Pillar of Autumn'' in both superficial design and name.<ref>'''[[Halo 4: The Essential Visual Guide]]'''</ref>

==Ships of the line==
Out of 50 Halcyon-class light cruisers built, the first 11 have the honeycomb superstructure while the other 39 have an unspecified one.{{Ref/Reuse|HCESGuide}}
===Honeycomb superstructure===
This is the list of Halcyon-class light cruisers with the honeycomb superstructure:
*{{UNSCShip|Halcyon}} - The [[Wikipedia:lead ship|lead ship]] of the class.
*{{UNSCShip|Pillar of Autumn}} (C-709) - Participated in the [[Battle for Arcadia]] in [[2531]], destroying [[CCS-U321|a]] [[Ket-pattern battlecruiser|Covenant battlecruiser]] alongside three other human ships and providing ground support for the {{UNSCShip|Spirit of Fire}}. After refitting in [[2552]], the ''Autumn'', captained by [[Jacob Keyes]], was selected as the [[SPARTAN-II]]s' chariot for [[Operation: RED FLAG]], due to its new resilience and firepower. Destroyed by [[John-117]] in the [[Battle of Installation 04]] through wildcat destabilization of the engines, as a means to destroy [[Halo Array|Halo]] [[Installation 04]]. 
*{{UNSCShip|Roman Blue}} - The first ship to be captained by [[Terrence Hood]]; participated in the [[Battle for Arcadia]].<ref>'''[[Halo: Escalation]]''', ''Issue #5''</ref> Shot down in battle between [[2535]] and [[2552]] and crashed on [[Eiro]]. Wreckage later salvaged by the ''[[Ace of Spades]]'' before an unknown vessel, possibly belonging to ONI, glassed ''Roman Blue's'' remains.<ref>'''[[Halo: Smoke and Shadow]]'''</ref>

===Unknown superstructure===
This is a list of Halcyon-class light cruisers that haven't gotten their superstructure confirmed yet:
*{{UNSCShip|Constantinople}} - Participated and destroyed during the [[Second Battle of Harvest]] in [[2526]].
*{{UNSCShip|Dawn Under Heaven}} 
*{{UNSCShip|Persian Gate}} - Participated in the [[Battle of Alpha Corvi II]] in [[2526]].
*{{UNSCShip|Toulouse}} - Participated in an engagement over an unidentified [[Forerunner]] installation with a Covenant fleet.

==Trivia==
{{Linkbox|gallery=yes|gallerypage=Images of Halcyon-class light cruisers}}
*"''Halcyon''" is derived from the Greek word "''Alcyone''", which means "''marked by peace and prosperity''".
*The scrapped hulls of several ''Halcyon''-class cruisers can be seen in the ''Halo: Reach'' campaign level ''The Pillar of Autumn'' and the multiplayer map ''[[Boneyard]]''.
*The ''Pillar of Autumn's'' model from ''Halo: Reach'' is considerably larger than its original ''Halo: Combat Evolved'' counterpart. Indeed, it is longer than even the ''Marathon''-class cruiser.
*The ''Pillar of Autumn'' plays a role in ''[[Halo: Combat Evolved]]'', ''[[Halo: Reach]]'' and ''[[Halo Wars]]''. In each game, the ship provides support to the player in some form.

==Gallery==
<gallery>
File:HWF_PillarOfAutumn_CrossSection.jpg|An internal cross-section of the refit ''Pillar of Autumn''.
File:PoA.jpg|The {{UNSCShip|Pillar of Autumn}}.
File:POA-InterdeckStructure.jpg|A vertical cross-section of a Halcyon-class ship, showing the honeycombed internal layout.
File:PelicanBay.jpg|A docking bay
File:PoA Crewmen.jpg|A typical internal corridor
File:Armory HCE.jpg|An [[armory]]
File:Origins - Defensive Measure.png|A Halcyon-class using its [[point-defense gun|50mm PDG]] against Covenant boarding craft in ''[[Halo Legends]]'': ''[[Origins]]''.
File:Boneyard Panorama.jpg|Halcyon cruisers sitting in a decommissioning yard on [[Reach]].
File:PoA Reach.jpg|The ''Pillar of Autumn'' in space in ''Halo: Reach''
File:HR_Holdout.jpg|A Halcyon class cruiser on the surface of Reach.
File:HR-UNSCPillarOfAutumn-Side.png|Right-side view of the ''Halcyon''-class light cruiser ''Pillar of Autumn'' in ''Halo: Reach''.
File:HR_PillarofAutumn_Drydock.jpg|Another view of a Halcyon class cruiser on [[Reach]].
File:HE13 Unknown Engagement.jpg|Halcyon-class cruisers during an unknown battle in ''[[Halo: Escalation]]''.
File:H2A -Halcyon.png|A ''Halcyon''-class light cruiser in ''[[Halo 2: Anniversary]]'' [[Terminal (Halo 2: Anniversary)|terminals]].
</gallery>

==List of appearances==
{{Col-begin}}
{{Col-2}}
*''[[Halo: The Fall of Reach]]'' {{1st}}
**''[[Halo: The Fall of Reach#2010 bonus content|Adjunct]]'' {{Mo}}
*''[[Halo: Combat Evolved]]''
*''[[Halo: The Flood]]''
*''[[Halo 2]]'' {{C|Flashback}}
*''[[Halo: Contact Harvest]]''
*''[[Halo 3]]'' {{C|Memorial only}}
*''[[Halo Wars: Genesis]]'' {{Mo}}
*''[[Halo Wars]]''
*''[[Halo Legends]]''
**''[[Origins]]''
**''[[Odd One Out]]'' {{C|Non-canonical appearance}}
*''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''
**''[[The Impossible Life and the Possible Death of Preston J. Cole]]''
{{Col-2}}
*''[[Halo: Reach]]''
*''[[Halo: Fall of Reach]]''
**''[[Halo: Fall of Reach - Boot Camp|Boot Camp]]''
**''[[Halo: Fall of Reach - Invasion|Invasion]]''
*''[[Halo: Combat Evolved Anniversary]]''
**''[[Terminal (Halo: Combat Evolved Anniversary)|Terminals]]''
*''[[Halo: Escalation]]''
*''[[Halo: Broken Circle]]'' {{Im}}
*''[[Halo 2: Anniversary]]'' {{C|Flashback}}
**''[[Terminal (Halo 2: Anniversary)|Terminals]]''
*''[[Halo: Fleet Battles]]''<ref name="orders">[https://www.halowaypoint.com/en-us/news/canon-fodder-taking-orders '''Halo Waypoint''': ''Canon Fodder - Taking Orders'']</ref>
*''[[Halo 5: Guardians]]'' {{C|Hologram only}}
*''[[Halo Mythos]]''
*''[[Halo: Fractures]]''
**''[[Into the Fire]]''
*''[[Halo: Smoke and Shadow]]''
*''[[Halo: Fireteam Raven]]''
*''[[Halo: Silent Storm]]'' {{Mo}}
*''[[Halo: Official Spartan Field Manual]]''
*''[[Halo: Lone Wolf]]''
**''[[Solace (TV Series)|Solace]]''
*''[[Halo: The Television Series Season Two]]''
**''[[Halo (TV Series)|Halo]]''
{{Col-end}}

==Sources==
{{Ref/Sources|2}}

{{Human Ships}}

[[Category:Halcyon-class light cruisers| ]]
[[Category:Cruiser classes]]
[[Category:UNSC ship classes]]