Editing Installation 00

{{Status|Canon}}
{{Center|For the campaign level, see [[The Ark (level)]].}}
{{Megastructure infobox
|image=[[File:TheArkHW2.png|300px]]
|description=Disk with a hollow core and eight curved arms
|location=[[Intergalactic space]], over the galactic plane, 262,144 light years from galactic center
|anchor=
|type=[[Ark|Ark installation]]
|function=Conservation installation, Lifeworker research station, Halo construction foundry and remote activation facility
|caretaker= [[000 Tragic Solitude]] {{c|destroyed}}
|constructed=c. [[98,445 BCE]]-[[97,445 BCE]]{{Ref/Note|The original Halo Array was created after the extreme faction of Builders won their political battle with the Prometheans and the Didact was forced into exile, in approximately 98,445 BCE. Installation 00 and its newer array of six rings was created some time after the first Ark, placing its time of construction sometime in the millennium before the firing of the Halos.}}
|destroyed-title=Heavily damaged
|destroyed=[[2552#December|December 11, 2552]]<ref name="Fortitude">[http://halo.xbox.com/en-us/intel/featured/video/herofortitude/bfe5038b-314a-4f17-a6be-f7613e0e3788 '''Halo Waypoint''', ''Hero-Fortitude'']</ref><ref name="Array">[http://halo.xbox.com/en-us/intel/featured/video/the-halo-array/7ec5ea56-3d8c-4644-a760-5baa8f35166c '''Halo Waypoint:''' ''The Halo Array'']</ref><ref name="Brutes">[http://halo.xbox.com/en-us/intel/theuniverse/characters/video/the-brutes/60f8041d-9d28-47bc-9447-65ba3d133abd?page=1 '''Halo Waypoint:''' ''The Brutes'']</ref><ref name="vis">'''[[Halo: The Essential Visual Guide]]''', ''page 14''</ref> {{c|Fully repaired by [[2559#March|March 2559]]}}{{Ref/Reuse|HW2}}
|diameter={{Convert|127530|km|mi|sigfig=5}}<ref name="vis">'''[[Halo: The Essential Visual Guide]]''', ''page 14''</ref>
|surface width=35.3 hours {{c|adjustable}}{{Ref/Reuse|mythos ark}}
|surface width-title=Day length
|gravity=1G{{Ref/Reuse|vis}}
|surface temperature=-30°C to 50°C (-22°F to 122F°){{Ref/Reuse|vis}}
|atmosphere=1.0 ([[Wikipedia:Nitrogen|N<sub>2</sub>]], [[Oxygen|O<sub>2</sub>]], [[Argon|Ar]]){{Ref/Reuse|vis}}
}}
{{quote|multi=yes|Miranda Keyes|343 Guilty Spark|q1=Where would someone go to activate the other rings?|q2=...Why, the Ark, of course.|[[343 Guilty Spark]] to [[Commander]] [[Miranda Keyes]].{{Ref/Reuse|Journey}}}}
'''Installation 00''', also known as '''the Ark''', the '''neoteric Ark''',{{Ref/Book|Id=Enc22P343|Enc22|Page=343}}{{Ref/Site|Id=CFEklund|URL=https://www.halowaypoint.com/news/canon-fodder-eklunds-ensemble|Site=Halo Waypoint|Page=Canon Fodder: Eklund's Ensemble|D=24|M=08|Y=2022}} '''the Great Foundry''' by the Covenant,{{Ref/Game|HI|Audio log (Halo Infinite)#Outpost Intel 9|Banished Audio log|Detail=Outpost Intel #09 - Unnatrual Defenses}} '''Oth Liqattu''' by the [[Banished]],{{Ref/Book|Enc22|Page=444}} and sometimes translated as '''Waypoint''',<ref name="CatalogWaypoint">[https://web.archive.org/web/20141014090727/https://forums.halowaypoint.com/yaf_postst248110_Query--Catalog-old.aspx '''Halo Waypoint''': ''Query: Catalog (old)''], [https://web.archive.org/web/20141013192621/https://forums.halowaypoint.com/yaf_postsm2963929_Catalog-Interaction.aspx#post2963929 '''Halo Waypoint''': ''Catalog Interaction'']</ref> is a [[Forerunner]] installation from which the entirety of the [[Halo Array]] can be activated.<ref name="Journey">'''[[Halo 2]]''', campaign level ''[[The Great Journey]]''</ref> Installation 00 also functions as a potential safe haven from the Halo Array's strategic pulse, and as a facility to construct replacement Halos if necessary. The Ark is situated [[Intergalactic space|outside]] the [[Milky Way|galaxy]], about 2<sup>18</sup> (262,144) light years from the galactic center.<ref name="The Ark">'''[[Halo 3]]''', campaign level ''[[The Ark (level)|The Ark]]''</ref> Although later universally known as "the Ark", Installation 00 was originally one of two installations identified as [[Ark]]s, the other being the older [[greater Ark]]. Due to this, Installation 00 was also referred to as the '''lesser Ark''' to differentiate it from the much larger greater Ark, whose foundry produced the original array of rings 30,000 kilometers in diameter, as opposed to the 10,000 kilometer-wide foundry of Installation 00.<ref>'''[[Halo: Primordium]]''', ''pages 343-344''</ref>

==Overview==
[[File:HW2 Ark1.png|250px|thumb|left|The Ark.]]
The Ark was designed with a number of functions, one of which is to remotely activate the Halo rings from outside the array's blast radius. Installation 00 can be placed on standby mode via a fail-safe system that is activated by an aborted firing such as the one that occurred at the end of the [[Battle of Installation 05]]. In addition to serving as the firing control center for the Halo array, Installation 00 functioned as an automated factory to construct Halo installations, thereby ensuring that the Halo Array was always ready to fire.<ref name="Covenant">'''[[Halo 3]]''', campaign level ''[[The Covenant (level)|The Covenant]]''</ref>{{Ref/Level|Id=Halo|[[Halo 3]]|[[Halo (Halo 3 level)|Halo]]}} While originally designed solely as a construction and control center for the Halos, due to the [[Librarian]]'s influence, the Ark was given a secondary function as a safe haven for life in the galaxy in the case of a galaxy-wide activation of the Halos; this is also the source of the name "the Ark".<ref name="c274">'''[[Halo: Cryptum]]''', ''page 274''</ref> Knowing that the Array would defeat the [[Flood]] through sterilizing the galaxy of any neurologically complex life, the Forerunners planned to preserve all life by storing it on the Arks and other preservation facilities. According to this plan, known as the [[Conservation Measure]], the Librarian was to index every [[Sentience|sentient]] species in the [[ecumene]] and bring specimens of each to the Ark. These sentient species would be stored on the Ark and would later be reseeded on their original homeworlds after the Halo Array had been activated.<ref name="Terminals">'''Halo 3''', [[Terminal (Halo 3)|Terminals]]</ref>

===Topography===
[[File:Ark surface 3.jpg|thumb|250px|A surface view of Installation 00's arms. The installation's artificial star can be seen in the sky.]]
====Ecology====
The Ark has a habitable surface on each of its spokes and on the majority of the inner circle, apart from the foundry. This terrain was intended to support cataloged life forms prior to being reseeded throughout the galaxy.<ref>'''[[Halo: Cryptum]]''', ''page 334-336''</ref> These landscapes and biomes are as diverse as those of Earth and of the Halos, including deserts,{{Ref/Reuse|The Ark}} taiga,{{Ref/Reuse|Covenant}} and deciduous forests.<ref>'''[[Halo 3]]''', multiplayer level ''[[Isolation]]''</ref> Several bodies of water occur across the installation. As such, the Ark can sustain its own ecosystem, providing a variety of habitation for many kinds of life.

Like most Forerunner constructs, the Ark's atmosphere is similar to that of Earth, being mostly comprised of [[oxygen]] and [[Wikipedia:Nitrogen|nitrogen]]. This means that all known sentient species, with the exception of the [[Unggoy]], can survive on the surface without any form of protection. As with the Halos, Installation 00 features a widely varying range of climates.

The activation of [[Installation 08]] inflicted substantial damage to the Ark. While some life support units remain intermittently active, they were in severe disrepair. Combined with the artificial sun's weakened output, weather conditions on the surface have became highly volatile. Most indigenous fauna have perished, either from the Halo pulse itself or the extreme weather that came afterwards.{{Ref/Reuse|EH}} However, some wildlife survived and were seen during [[Operation: FAR STORM]].{{Ref/Reuse|Hunters}} After the destruction of [[000 Tragic Solitude]], [[Luther Mann]] stated a belief that it was in fact the rogue [[Monitor]] who was behind the weather conditions as part of his plan for revenge. Once Tragic Solitude was destroyed, the weather returned to temperate conditions.<ref>'''[[Halo: Hunters in the Dark]]''', ''pages 345-346''</ref>

While under repair by [[Retriever Sentinel]]s, there would be a new shift in the Ark's surroundings as the Sentinels repaired and rebuilt the Ark. Dense forests sprang up from pit-black, barren terrain over the course of a week and a particularly virulent strain of weed was checked by the reintroduction of voracious, insectoid parasites before it could strangle the budding plants nearby.{{Ref/Reuse|Healing of Old Wounds II}} The Ark showed itself to be remarkably adaptable to change, with giant tectonic plates rearranging, shifting and unfolding to form a new pathway across a chasm.{{Ref/Reuse|Healing of Old Wounds III}} Having begun in [[2557]], the process was completed by the arrival of the ''Spirit of Fire'' in [[2559]], leaving the Ark fully repaired and habitable again, though wreckage from the [[Battle of Installation 00]] persisted across the Ark's surface.{{Ref/Reuse|HW2}}

====Locations====
*[[Mahsko]]
*[[Foundry (location)|Foundry]]
*[[Fort Jordan (location)|Fort Jordan]]
*[[Central Hub]]
**[[Installation 00 Citadel]]
*[[North Spire]]
*[[South Spire]]
**[[Henry Lamb Research Outpost]]
**[[Ship Graveyard]]
**[[Forerunner Treatment Installation]]
*[[Epsilon Spire]]
**[[Refugia Epsilon 001]]
***[[Reef of Thieves]] 
****[[Ridge Nineteen]] 
***[[Drifting Lands]]
****[[White Dune]]
***[[Chasm Lands Biome]]
**[[Refugia Epsilon 026]]
***[[Epsilon Cartographer]]
**[[Refugia Epsilon 050]]
***[[Broken Plain]]
*[[Epsilon Wedge]]
**[[Refugia Core 000]]
***[[Epsilon Clarion]]
****[[Outer Gallerium]]
**[[Refugia Core 001]]
**[[Refugia Core 010]]
***[[Maze Rift]]
**[[Refugia Core 101]]
**[[Refugia 500]]
*[[Site Ricochet]]
*[[Translocation portal Epsilon]]
**[[Long Valley Moor]]
***[[West Ridge Observation Point]]
**[[Terminus Basin]]

===Astronomy===

==History==
===Forerunner-Flood war===
[[File:Array.png|thumb|left|250px|Installation 00 sending the Halo Array through a [[slipspace portal]] during the [[Forerunner-Flood war]].]]
{{quote|Every vessel we can fill, we send to the Ark. I dare not cease the mission. Not now, not until I've done all I can. Each one of these souls is finite and precious. And I'm close. Close to saving them all.|A message from the [[Librarian]] to the [[IsoDidact]].<ref>'''Halo 3''', [[Terminal (Halo 3)/One|Terminal One]]</ref>}}

Like the rest of the newer, more efficient Halo installations, Installation 00 was constructed sometime between [[98,445 BCE]] and [[97,445 BCE]] under orders of [[Master Builder]] [[Faber]], to address problems with the [[greater Ark]] and its larger Halos. While plans for the second Ark had existed for some time, its construction was delayed by the [[Old Council]] to avoid the Builders from gaining too much power.<ref>'''[[Halo: Silentium]]''', ''page 45''</ref> The lesser Ark, as it was known at the time, was designed to produce smaller but much more powerful Halo rings, which could be transported more efficiently and could deal far more widespread damage. Until the very last days of the [[Forerunner-Flood war]], the lesser Ark, its new Halos, and its location were kept a well-guarded secret; only the most top-tier Forerunners knew of its existence, and the only one who knew the exact coordinates of the installation was Faber. Whereas the greater Ark acted as the Forerunners' final line of defense and command center, the lesser Ark would serve the function of a last fallback point where its own array of rings could be swiftly distributed to their designated locations across the galaxy and fired to cleanse the galaxy of all sentient life as a last resort.<ref>'''[[Halo: Silentium]]''', ''String 33''</ref>

[[File:HM LastTimeYouAskedMe.jpg|thumb|250px|The IsoDidact activates the Halo Array from Installation 00's citadel.]]
In the endgame of the Forerunners' war with the Flood, the Forerunner {{Class|Contender|artificial intelligence}} [[Mendicant Bias]], which had been [[logic plague|corrupted]] by the [[Gravemind]] and defected to the Flood, attacked and destroyed the greater Ark, killing the majority of the remaining Forerunners who had taken refuge there. Using coordinates provided by the Master Builder, a handful of survivors, including the [[IsoDidact]], managed to escape to the lesser Ark where they prepared their weapons of last resort. In order to buy the IsoDidact time, the Librarian traveled to [[Earth]], broadcasting a feint transmission intended to draw the Flood's attention to her. She spent her last days in the plains near [[Mount Kilimanjaro]], near the site of the [[Portal at Voi|slipspace portal]] to Installation 00. Mendicant Bias knew of the secret Ark and how to access it through the [[Keyship]]s, though he did not know of its exact location. In order to devise the best possible defense against Mendicant Bias, the Forerunners deployed [[Offensive Bias]], a military AI formerly in control of the greater Ark and Mendicant's replacement, and sent it to counter Mendicant Bias' fleet in advance before it could reach the Ark. While Offensive Bias [[Battle of the Maginot Sphere|engaged Mendicant's fleet]], the IsoDidact completed preparations for the Halo Array and fired the rings from the Ark, purging the galaxy of all life.

Following the Array's firing, Offensive Bias defeated Mendicant Bias within minutes. Offensive decided to spare the last portion of its opponent and delivered it to Installation 00 for study. There, the remaining Forerunners, led by the IsoDidact, held a trial for the AI for betraying the ecumene. The Didact decided to keep Mendicant alive as it had intimate knowledge of the Flood and could be called upon in case of their return. Bias was entombed in the installation with only one thought allowed to him: atonement.<ref>[http://www.youtube.com/watch?v=a3YLl2NLVFA '''Halo Waypoint''' - ''The Trial of Mendicant Bias'']</ref>{{clear}}

===Battle of Installation 00===
[[File:H3 ArkBattle.png|thumb|left|300px|The Fleet of Retribution and Truth's fleet meet above the Ark.]]
{{Main|Battle of Installation 00}}
Following the [[Prophet of Regret]]'s botched [[Battle for Earth|invasion of Earth]] on [[2552#October|October 20, 2552]], the [[Prophet of Truth]] dispatched a [[Jiralhanae]]-led [[Truth's fleet|support fleet]] to pick up what is left of the Regret's [[Fleet of Sacred Consecration|forces]] at [[Kenya]] and to uncover what he believed to be the Ark.{{Ref/Film|Id=Oct20|Film=Halo Waypoint|Story=Ten Twenty|StoryLinkText=Ten Twenty}} By [[2552#November|November 17]], the [[Covenant]] had uncovered the structure they had spent the last month unearthing. Truth, through his [[Forerunner Dreadnought]], activated the device, which was actually just a [[Portal at Voi|portal-generating structure]] which led to Installation 00.{{Ref/Level|Id=TheStorm|Game=Halo 3|Level=The Storm}}

Truth led his fleet through the portal; after defeating a Flood invasion of the town of [[Voi]], a joint [[United Nations Space Command]] - [[Fleet of Retribution|Sangheili]] strike force followed the Prophet's forces.<ref name="Floodgate">'''[[Halo 3]]''', campaign level ''[[Floodgate]]''</ref> Upon their arrival on [[2552#December|December 11]],{{Ref/Reuse|Fortitude}} the latter force were attacked by the Covenant, which held a 3:1 numerical advantage.{{Ref/Reuse|The Ark}} Despite this, the [[Sangheili]] [[Fleet of Retribution]] and the UNSC [[Battle Group Victory]] crushed Truth's forces.{{Ref/Reuse|The Ark}}

After engaging the Covenant across the installation, [[SPARTAN-II program|Spartan]] [[John-117]] and [[Arbiter]] [[Thel 'Vadam]] entered [[Installation 00 Citadel|the citadel]], where they found Truth, who had become infected by the Flood and deactivated the array. Soon after 'Vadam killed the Prophet, effectively destroying the Covenant and ending the war, he, the Master Chief, and [[343 Guilty Spark]], the former [[monitor]] of [[Installation 04]], discovered that a [[Installation 08|replacement Installation 04]] was being constructed by the Ark's [[Foundry (location)|Foundry]].{{Ref/Reuse|Covenant}} The Spartan and the Arbiter soon rescued the AI [[Cortana]], who held Installation 04's [[Activation Index]], from the Flood-infested Covenant capital city, [[High Charity]].<ref>'''[[Halo 3]]''', campaign level ''[[Cortana (level)|Cortana]]''</ref> They, with [[Sergeant Major]] [[Avery Johnson]], assaulted the Halo's [[Control Room]] to activate the ring, destroying both the Flood and the remaining Covenant forces. They succeeded, though Johnson was killed by the monitor. While Guilty Spark refused to allow ''his'' new Halo to be destroyed, he also implied that he was protecting the Ark. The partially constructed installation's activation tore the ring apart and severely damaged the Ark.{{Ref/Reuse|Array}}{{Ref/Reuse|Brutes}}{{Ref/Reuse|Halo}}
{{clear|left}}

===Post-battle===
[[File:HaloLegends-Origins-ArkHalo.png|250px|thumb|Installation 08 fires over the Ark, severely damaging it.]]
In [[2553|March 2553]], the [[Office of Naval Intelligence]] deployed an automated probe-carrying spacecraft to the damaged Ark using advanced slipspace technology. The ship arrived in November and dispersed its probes, although all communications with the devices were cut off after initial transmissions confirming the Ark's survival. In response, the {{UNSCShip|Rubicon}} was sent from [[Luna]] in December 2553 to conduct a more thorough investigation of the installation's ravaged surface.<ref name="hitd c2">'''[[Halo: Hunters in the Dark]]''', ''Chapter 2''</ref> Due to the damage dealt to the Ark's life support systems and its artificial sun, heavily inclement weather became the norm.<ref name="EH">'''[[Eleventh Hour reports]]''', ''part 4''</ref>

The {{UNSCShip|Rubicon}} carried several [[remote contact team]]s, who landed on the damaged Ark and attempted to find the source of the mysterious signal. After about eight days, contact with all teams was lost; only one team, [[RCT-06]], returned, having sustained heavy casualties and carrying with them a device of unknown nature. The armature's origin was subjected to debate, but it was believed by the team to be the source of the beacon picked up by the initial investigative group.{{Ref/Reuse|EH}} The device, actually a broken, barely active [[monitor]], began to relate its past life as a human: [[Chakas]]. Though the ship's ONI attaché initially doubted the veracity of the monitor's account, the science team leader pointed out that it was consistent with the "[[Halo: Cryptum|Bornstellar Relation]]" found on [[Onyx]].

[[File:TSPL.png|250px|thumb|left|000 Tragic Solitude observes the heavily damaged Ark.]]
Eventually, the monitor revealed that it was none other than [[343 Guilty Spark]] himself. Claiming that he knew the location of the [[Librarian]], whom he believed to be alive, Spark subsumed the ship's AI, knocked out the crew via the life support systems, and hijacked the ship.<ref>'''[[Halo: Primordium]]''', ''pages 377-379''</ref> Communications with the ''Rubicon'' halted within 48 hours of its last report. Search and rescue teams were then deployed to the site, but reported no findings.{{Ref/Reuse|EH}}

The last of its ground team, [[Bobby Kodiak]], was left stranded when the ''Rubicon'' left, and mortally wounded by attacking [[chaefka]]. It was then that he was contacted by the Ark's monitor, [[000 Tragic Solitude]], who had survived the Ark's devastation and sought to repair the station and get revenge. Offering him a chance to live, Tragic Solitude rescued Kodiak and mended his body with cybernetics, turning him into a cyborg and putting him under the monitor's control. For the following two years, Tragic Solitude partially repaired the Ark and prepared for an attack on the galaxy. Tragic Solitude was able to repair the Ark end of the [[Portal at Voi]] and increase its power so that the portal would transport objects near-instantaneously between Earth and the Ark, but he could not activate the portal as the firing of Installation 08 had severed the monitor's control over it.<ref name="Hunters">'''''[[Halo: Hunters in the Dark]]'''''</ref>{{clear}}

===Operation: FAR STORM===
[[File:Hunters in the Dark full cover.jpg|thumb|300px|[[N'tho 'Sraom]] and [[Frank Kodiak]] engage [[morolaath]] during Operation: FAR STORM.]]

{{Main|Operation: FAR STORM}}
In [[2555]], the Ark was partially restored and Tragic Solitude enacted its plan. Using Kodiak to activate the process, Tragic Solitude initiated a countdown to the rings' firing in several weeks. This was so that someone within the Milky Way galaxy would open a portal to the Ark in an attempt to stop the countdown, allowing the monitor to dispatch its [[Retriever Sentinel]]s to kill all sentient species and mine their planets to repair the Ark. The countdown was discovered on the intact Halo rings soon after and a human-Sangheili joint task force departed to the Ark through the [[Portal at Voi]]. The expedition's ship was intercepted and brought down above the Ark by Tragic Solitude's Retrievers, but the crew survived and managed to reach the Array's control center and stop the countdown. However, the portal was still open and Tragic Solitude deployed a fleet of Retrievers to Earth in an attempt to mine the [[Sol system]]'s worlds, causing heavy damage to the region surrounding the portal as well as the [[UNSC Home Fleet]]. However, the UNSC-Sangheili crew managed to thwart the monitor's plan and the Retrievers were recalled, with the monitor ending up destroyed. UNSC reinforcements were deployed through the portal to the Ark soon after and rescued the expeditionary crew. With Solitude destroyed and the Retrievers now dormant, the UNSC began to establish research facilities on the Ark and study the Sentinels in hopes that they could be commanded to continue repairing the installation by strip-mining lifeless systems so that no one would be harmed in the process.{{Ref/Reuse|Hunters}}

===Repairing the Ark and research===
In [[2557]], a human research team traveled to the Ark aboard ''[[Eden Rising]]'' to establish a permanent base on the Ark, the [[Henry Lamb Research Outpost]]. The scientists reactivated the dormant [[Retriever Sentinel]]s which were dispatched to lifeless systems to strip-mine them for the needed resources and under the guidance of the [[Smart AI]] [[Isabel]], began nudging along repair efforts.<ref name="Isabel">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Isabel''</ref> However, over time, the process became fully automated and the scientists could simply sit back and watch the wonder of a world being reborn.<ref>'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''The Healing of Old Wounds I''</ref> Within three months of the establishment of the [[Henry Lamb Research Outpost]], there would be a new shift in the outpost's surroundings as the Sentinels repaired and rebuilt the Ark. Dense forests sprang up from pit-black, barren terrain over the course of a week and archeologist [[Nathaniel Palmer]] monitored a particularly virulent strain of weed that was checked by the reintroduction of voracious, insectoid parasites before it could strangle the budding plants nearby.<ref name="Healing of Old Wounds II">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''The Healing of Old Wounds II''</ref> The Ark showed itself to be remarkably adaptable to change, with Palmer witnessing as giant tectonic plates rearranged, shifted and unfolded to form a new pathway across a chasm.<ref name="Healing of Old Wounds III">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''The Healing of Old Wounds III''</ref>
{{Clear}}

===New arrivals===
[[File:SOFaboveArk.png|thumb|left|300px|Captain James Cutter and Dr. [[Ellen Anders]] survey the Ark from high above it.]]
{{Main|Second Ark Conflict}}
{{Quote|And now the Ark's defenses stir, sensing the [[Banished|shadow of a threat]] that moves in spaces [[Cortana|Her]] eyes cannot see, intent on seizing the great factory of the Forerunners.|[[Curator]] on the Created and the Banished.<ref name="Mythos202">'''[[Halo Mythos]]''', ''page 202''</ref>}}
Following the [[Created conflict|Created takeover]] of human space on October 28, [[2558]] the Ark's failsafe measures prevented Cortana and her allies from being able to access the installation.{{Ref/Reuse|Mythos202}} A month later, the [[Banished]], led by the Jiralhanae warlord, [[Atriox]], [[Attack on Installation 00|laid siege]] on the UNSC bases on Installation 00, among them the [[Henry Lamb Research Outpost]].<ref>[http://www.gamespot.com/articles/halo-wars-2-new-story-details-and-images-revealed/1100-6440811/ '''GameSpot''': ''Halo Wars 2 New Story Details and Images Revealed'']</ref> Shortly after the Banished's attack, the {{UNSCShip|Spirit of Fire}}, drifting in space for 28 years, was abruptly transported to the Ark by a mysterious entity. Those on board the ''Spirit of Fire'' came into conflict with the forces of the Banished on the surface soon after. During the battle, it was discovered that the Ark had constructed a [[Installation 09|new replacement Halo]], which was launched by Professor [[Ellen Anders]] in an effort to deploy it to the [[Soell system]] and raise a [[distress beacon]] to the UNSC. However, the Halo was intercepted on the way to Soell by a [[Created]] [[Guardian]], while the forces of the ''Spirit of Fire'' and the Banished remained in conflict on Installation 00.<ref name="HW2">'''[[Halo Wars 2]]'''</ref>

During this time, the [[Flood]], who had survived aboard the ruins of [[High Charity]], were inadvertently released by [[Voridus]] and [[Pavium]] when they breached the [[containment shield]] around the structure with a Scarab and deactivated the Ark's Sentinel defense network in the process. The Flood began a second rampage on the Ark, forming a [[Proto-Gravemind]] that quickly began turning into a [[Gravemind]]. Voridus and Pavium managed to reactivate the Sentinel defense network and with the help of a [[Retriever Sentinel]], killed the Proto-Gravemind before it could finish its transformation into a Gravemind. With the Proto-Gravemind dead, the Banished and the Ark's Sentinels were able to contain the Flood once again and seal off High Charity.<ref name="Awakening the Nightmare">'''[[Halo Wars 2: Awakening the Nightmare]]'''</ref>

In [[2559#October|October 2559]], Banished forces [[Raid on Anodyne Spirit|raided]] the ''[[Anodyne Spirit]]'' for the shards of the [[Menachite Forerunner crystal]] recovered from [[Reach]] before Atriox managed to send a message to [[War Chief]] [[Escharum]] in the Milky Way ordering him to locate the [[Menachite portal complex|Portal Under the Mountain]] on Reach.<ref name="Sacrifice">''[[Sacrifice]]''</ref> Atriox's stated intention was to open a slipspace portal between the Ark and Reach in order to bring more Banished reinforcements to the Ark. At the same time, [[Blue Team]] visits Reach on [[Operation: WOLFE|a mission]] of their own and inadvertently lead the Banished and their allies the [[Keepers of the One Freedom]], [[Legion of the Corpse-Moon]] and the [[Clan of the Ravaged Tusks|Ravaged Tusks]] to the portal complex. Using one of the [[Ferret]]s, secretly undercover in the Keepers, as a [[Reclaimer]], the Keepers were able to open the portal which Atriox used the crystal shards to connect to the Ark. Atriox and several of his top officers flew through the slipspace portal to Reach in a [[Banished Lich]], but Atriox chose to depart in Escharum's [[intrusion corvette]] in favor of a more important mission, leaving behind thousands of Banished forces to continue to hold the Ark in his absence rather than returning to the Ark with reinforcements.

After Atriox's arrival on Reach, his Lich was stolen by [[Castor]] and his detachment of the fanatical Keepers of the One Freedom who intended to use the Ark in order to fire the [[Halo Array]] and begin the Great Journey. Despite Atriox's warnings of the Banished still on the Ark to stop them, Castor's remaining Keepers nevertheless traveled to the Ark through the portal, accompanied by the Ferrets who remained undercover in their ranks. Shortly thereafter, the slipspace portal closed, preventing further travel to or from the Ark through it.{{Ref/Novel|Id=SoR|SoR}}

Shortly after arriving on the Ark, the Castor and his forces allied themselves with the Covenant loyalists and set out to use [[Epsilon Clarion]] to fire the Halo Array. The allied forces were combated by both the Banished and forces from the ''Spirit of Fire'' who both sought to [[Battle of Epsilon Clarion|prevent them from succeeding]]. Both the Banished and the allied Keepers and loyalists suffered heavy casualties, but with the help of the Forerunner [[archeon-class ancilla]] [[Intrepid Eye]], the latter faction nearly succeeded. However, on [[Veta Lopis]]' signal, the ''Spirit of Fire'' launched an orbital bombardment against Epsilon Clarion with EMP rounds from its MAC gun. The bombardment destroyed both the facility and Intrepid Eye while Castor and [[Inslaan 'Gadogai]], now aware of the truth behind the Halo Array and the only survivors of the Keeper detachment, abandoned their pursuit of firing the rings and ended their alliance with the loyalists. With the entire Clarion network now either inoperable or inaccessible, the Ark was left without the ability to fire the Halo Array while the surviving Ferrets joined the crew of the ''Spirit of Fire'' and their continuing fight against the Banished for control of the Ark.{{Ref/Reuse|DW}}

{{Clear}}

==Design details==
[[File:HW2 Ark2.png|300px|thumb|The Ark's surface.]]
Installation 00 resembles a massive flattened dish with a series of eight curved arms, known as spires, four large and four small, arranged around its rim, similar to the petals of a flower. The entire upper surface is [[Terraforming|terraformed]], with oceans, forests and deserts.{{Ref/Reuse|The Ark}}{{Ref/Reuse|Covenant}} Installation 00 is {{Convert|127530|km|mi|sigfig=5}} in diameter and thus one of the largest known Forerunner constructs.{{Ref/Reuse|vis}} Spread throughout the installation are hundreds of [[refugia]], artificial biomes designed to sustain diverse flora and fauna as part of the Conservation Measure. Each of these refugia are separated by massive quarantine walls.<ref name="mythos ark">'''[[Halo Mythos]]''', ''pages 122-123''</ref> Twelve refugia are located on the central hub, while an additional twenty are located on the arms of the structure.<ref name="Refugia">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Refugia''</ref> The various refugia are intended to mimic common planetary environments - one such refugia known as the Halo Refugia<ref name="HaloRefugia">'''[[Halo Wars 2]]''', ''[[Phoenix Log]]'' - ''Halo Refugia''</ref> bore a notable similarity to Earth's climate, though much more extreme; mountains are higher, chasms are deeper and the sea and sky are a deeper blue.{{Ref/Reuse|HaloRefugia}}

At the center of the installation is the [[Foundry (location)|Foundry]], an enormous circular facility used to construct Halos. The core of the 10,000-kilometer-wide Foundry is a hollow space, home to a stripped remnant of a material-rich celestial body used to obtain the vast amounts of resources required for the construction of a Halo ring. When active, the Foundry generates so much heat that the Ark requires multiple cooling stations. At least two such systems span a snowy gorge; it is possible that the massive cooling systems caused this icy climate.<ref>'''[[Halo 3]]''', multiplayer level ''[[Narrows]]'': ''"Without cooling systems such as these, excess heat from the Ark's forges would render the construct uninhabitable."''</ref>

Like the [[shield world]]s, Installation 00 possesses an [[Astroengineering#Stars|artificial sun]].{{Ref/Reuse|The Ark}}{{Ref/Reuse|Covenant}}{{Ref/Reuse|Halo}}

Like the Halos, Installation 00 features multiple [[Cartographer]] facilities, map rooms that can pinpoint any location on the installation.{{Ref/Reuse|The Ark}}<ref name="The Cartographer">'''[[Halo Wars 2]]''', campaign level ''[[The Cartographer]]''</ref><ref name="Cartographer PL">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''The Cartographer''</ref> Similarly to the Halos, the Ark features a control room from which the array could be activated. This facility, known as [[Installation 00 Citadel|the citadel]], is protected by a system of [[Barrier tower|energy shield barriers]] that encircle the center of the disk. These barriers are controlled by towers that circumscribe the center of the installation.{{Ref/Reuse|Covenant}}

The Ark also possesses a vast network of power grids beneath its surface. These grids can be tapped into by structures on the surface known as [[Power Node]]s when extra locational power is needed in emergencies. These nodes were co-opted by UNSC and Banished forces in 2559, though Banished [[Power Extractor]]s were also able to tap into these power networks.<ref name="PowerNode">''[[Halo Wars 2]]'', ''[[Phoenix Logs]]'' - Power Node</ref><ref>'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Power Extractor''</ref>

The megastructure is also surrounded by numerous other secondary installations, which are used for various support functions. During the [[Second Ark Conflict]], these installations were occupied by the [[Banished]].{{Ref/YouTube|Id=stream|fYaxRoAf96s|Channel=Halo|VidName=Halo Lore Stream: The Halo Array|Time=4251|Quote=There's some stuff in the secondary materials for Halo Wars 2, regarding the fleet that actually went to the Ark with the Enduring Conviction. [...] some of those ships are out at other installations that are near the Ark. So there's the Ark, and there's facilities that are out near the Ark that we don't see - some of those ships are out there doing that. You could say it's a cost function of how many ships we could show in the cutscenes and stuff. Yeah, it [Enduring Conviction] wasn't the only ship that was there.
|Quotee=Kenneth Peters|Detail=1:10:51}}

===Defenses===
[[File:FOR-ArkAI-logo2.png|thumb|left|240px|The avatar icon of [[000 Tragic Solitude]].{{Ref/Reuse|Terminals}}]]
Similar to most Forerunner installations, the Ark had its own [[monitor]], [[000 Tragic Solitude]], charged with the facility's defenses. For the most part, Solitude reacted little when humanity and the Covenant arrived at the Ark, though when 343 Guilty Spark attempted to access the Ark's systems during the Battle of Installation 00, Tragic Solitude threatened to add the monitor to the facility's targeting ledger if he persisted.<ref>'''Halo 3''', ''Terminal 3''</ref> After the Ark was severely damaged by the destruction of Installation 08, the latest on a line of destroyed Forerunner relics, Solitude grew bitter and viewed all sentients in the galaxy as incapable of being peaceful.{{Ref/Reuse|Hunters}} The arrival of the Human-Covenant War to the installation additionally prompted the activation of [[Terminus]]', structures that are designed to perform tireless cataloging, recording of indexing of events in an attempt to prepare countermeasures and defenses for future possible scenarios. These records are cross-references with existing records of historical events and battles to perform simulations and predictions of potential outcomes - losing a terminus would result in a massive loss of operational capability for the installation.<ref name="Terminus">'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Terminus''</ref>

The Ark's small defenses were [[Aggressor Sentinel]]s created by numerous [[Sentinel manufacturing facility|Sentinel factories]] just like at the rings. The [[Retriever Sentinel]]s could also be used offensively, though they were not usually outfitted with weapons until Solitude began arming them. The Ark was also guarded by [[armigers]], humanoid defense droids that were capable of attacking with energy rifles and staves. Tragic Solitude could also take control of the Ark's wildlife and even people through manipulating their brain waves.{{Ref/Reuse|Hunters}}

After the [[Battle of Installation 00]], Tragic Solitude had a [[containment shield]] erected around the ruins of the Covenant holy city of [[High Charity]] to contain any surviving [[Flood]] within. He also had the Ark's Sentinels raze the perimeter and modify the refugia so that no sentient life survives nearby to deprive the Flood of any host bodies in close proximity to their prison.<ref>'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Idle Hands II''</ref>

Another method of defense are [[particle cannon]]s upon the Ark's surface. After discovering the location of one through one of the Ark's Cartographers,{{Ref/Reuse|The Cartographer}} the smart AI [[Isabel]] had Professor [[Ellen Anders]] use it to attack the {{Class|CAS|assault carrier}} ''[[Enduring Conviction]]''. The cannon alone was not powerful enough to destroy the ship, but after thirty minutes of sustained fire could take down its shields and leave the ship vulnerable to other methods of attack.{{Ref/Reuse|Hold the Line}}<ref>'''[[Halo Wars 2]]''', ''[[Phoenix Logs]]'' - ''Enduring Conviction Battle Reports''</ref>

The Ark also possesses a Sentinel defense network that coordinates Sentinels to assemble and attack anything deemed a threat to the Ark. [[Isabel]] utilized the network to destroy the ''Enduring Conviction'' by firing the assault carrier's [[energy projector]] at the Ark, alerting the Sentinels in the area.<ref name="Under the Dark">'''[[Halo Wars 2]]''', campaign level ''[[Under The Dark]]''</ref> Prior to the launch of [[Installation 09]], the security protocols was heightened to finalize the preparation for the launch to its original site and as the part of protocol, the Sentinels release [[Retriever Sentinel]] to cleanse the Installation from the threat, including the UNSC and the Banished.<ref>'''[[Halo Wars 2]]''', campaign level ''[[The Halo]]''</ref> During [[Operation: SPEARBREAKER|an operation]] led by Major Vaughan, a Controller Sentinel attacked anyone it deemed a threat, even the UNSC, due to constant abuse of the teleportation network before the ''Spirit of Fire''{{'}}s arrival.<ref>''[[Halo Wars 2: Operation: SPEARBREAKER]]''</ref> [[Voridus]] managed to shut down the Sentinel defense network around [[High Charity]]'s crash site, but at the price of the [[Flood]] being released from the ruined city after he breached the [[containment shield]] with a [[Barukaza Workshop Scarab]]. When the network was reactivated, the Sentinels resumed their duties and aided the Banished in defeating the Flood, enabling them to enact the containment protocol once again.{{Ref/Reuse|Awakening the Nightmare}}

===Slipspace portals===
A major aspect of Installation 00 was its ability to send and receive objects via [[slipspace portal]]s. Late in the [[Forerunner-Flood war]], the rebuilt Halo array was dispersed throughout the galaxy through the use of these portals.<ref>'''Halo Legends''': ''Origins''</ref>

In order to ensure the safety of [[human]]ity, the [[Librarian]] established a [[Portal at Voi|portal-generating structure]] near Mount Kilimanjaro on the human homeworld of Erde-Tyrene.<ref>'''[[Halo: Silentium]]'''</ref> During the [[Human-Covenant War]] on November 17, 2552, the Covenant forces under the command of the Prophet of Truth utilized this portal, sparking the [[Battle of Installation 00]]. The portal was damaged by the firing of [[Installation 08]] and shut down while the {{UNSCShip|Forward Unto Dawn}} was still in transit.{{Ref/Reuse|The Ark}}{{Ref/Reuse|Floodgate}} The portal was eventually repaired and used again in 2555 by Tragic Solitude, though he could not activate its doorway to Earth from the Ark's end due to the firing of Installation 08 severing his control over it. Tragic Solitude managed to increase the power to the portal exponentially, causing travel between Earth and the Ark to be almost instant.{{Ref/Reuse|Hunters}} After the start of the [[Created conflict]], the Ark's failsafe measures closed it again to keep the Ark out of [[Cortana]]'s hands.{{Ref/Reuse|Mythos202}} Professor [[Ellen Anders]] was unable to figure out how to reactivate it from the Ark, necessitating the launch of [[Installation 09]] in an effort to make contact with the UNSC.<ref name="Hold the Line">'''[[Halo Wars 2]]''', campaign level ''[[Hold the Line]]''</ref> Following the departure of Anders and the Halo ring, Captain [[James Cutter]] felt that the portal should remain closed until the ''Spirit of Fire'' could fully evaluate the Banished threat to it. Cutter ordered [[Isabel]] to start investigating the portal's controls in case they needed to open or close it again.<ref>'''[[Halo Wars 2]]''' - ''[[Phoenix Logs]]'' - ''Beyond the Edge''</ref>

An unknown entity at the Ark generated a portal to transport the {{UNSCShip|Spirit of Fire}}, which had drifted in interstellar space for 28 years, to the installation in 2559.<ref name="The Signal">'''[[Halo Wars 2]]''', campaign level ''[[The Signal]]''</ref>

After hijacking the {{UNSCShip|Rubicon}}, [[343 Guilty Spark]] used one of the Ark's remaining active portals to return the ship to the galaxy in an effort to find the [[Librarian]]. However, after its return to the Milky Way, the ''Rubicon'' crashed on [[Geranos-a]].<ref>'''[[Halo: Renegades]]'''</ref>

There is [[Menachite portal complex|another slipspace portal]] on [[Reach]] similar to the [[Portal at Voi]] that the [[Keepers of the One Freedom]] and some of the Banished were able to access in [[2559#October|October 2559]] when combined with Atriox using the shards of the [[Menachite Forerunner crystal]] on the Ark's end.{{Ref/Reuse|Sacrifice}} However, this portal only remained open as long as the local charge remained rather than remaining continuously open like the Portal at Voi. It closed within a fairly short period of time, but remained open long enough for a [[Banished Lich]] to make a two-way trip through the slipspace portal, making it to Reach and the Ark respectively.{{Ref/Novel|Id=Chapter 21|HSoR|Chapter=21}}{{Ref/Novel|Id=Epilogue|HSoR|Chapter=Epilogue}}

==Trivia==
===Production notes===
{{Other languages
|fr={{Tooltip|''L'Arche''|The Ark}} and {{Tooltip|''Installation 00''|(Same as English)}} in almost every media.<br>
{{Tooltip|''La petite Arche''|The little Ark}} in ''Halo: Silentium''.
|es={{Tooltip|''El Arca''|The Ark}} and {{Tooltip|''Instalación 00''|Installation 00}} in almost every media.<br>
|de={{Tooltip|''Die Arche''|The Ark}} and {{Tooltip|''Installation 00''|(Same as English)}}
}}
{{Linkbox|gallery=yes}}
*The Ark was known as "Waypoint" during the production of ''Halo 3''.<ref>[http://www.isaachannaford.com/2011/01/rapid-environment-work-2-6-hours-piece.html '''Isaac Hannaford''': ''rapid environment work 2-6 hours a piece'']</ref><ref>[http://carnage.bungie.org/haloforum/halo.forum.pl?read=1047186 '''halo.bungie.org''': ''Re: Halo Concept Art'']</ref> This name was later rendered canonical by the Halo Waypoint forum administrator {{Plain|[https://forums.halowaypoint.com/yaf_profile601146.aspx Catalog]}} (posing as the Forerunner entity of [[Catalog|the same name]]).{{Ref/Reuse|CatalogWaypoint}}
*In early conceptual stages, artist [[Paul Russel]] did not want to make the Ark significantly larger than a Halo ring. One of his early concepts of the Ark design incorporated a cradle for a Halo installation in the center, with four sleek arms on one side of the ring, along with several beams leading to a central hub structure situated on the other side.<ref>[https://picasaweb.google.com/114253662089061571624/Halo3TheLostCity#5573889897215738578 '''Picasa''': ''Paul Russel > Halo 3: The Lost City 16/16'']</ref>
*In ''Origins'', the Ark and the Halos are depicted without land on their surfaces during the activation of the Halo Array. This is likely due to [[Cortana]]'s interpretation, or an instance of artistic license, as both ''Halo: Silentium'' and the terminals in ''Halo: Combat Evolved Anniversary'' show that the Ark and the Halos had fully terraformed surfaces prior to the activation of the Array.
*The Ark as a concept has existed since the development of ''Halo: Combat Evolved''.<ref>[[:File:HCE Ark Concept.jpg|Halo: Combat Evolved concept art]]</ref><ref>[https://twitter.com/game_fabricator/status/1088274744456159232 Marcus Lehto on Twitter].</ref> Bungie artist [[Marcus Lehto]] produced several sketches of structures for the Ark concept, that would later go on to be refined and considered during the development of ''Halo 2''.<ref>[[:File:H2 Ark Concept.jpg|Halo: 2 concept art]]</ref> These concept images both depict the Ark as a structure within the ground, a concept later instead used for the design of the [[Portal at Voi]] in ''Halo 3''.
*One of the early concepts for the Ark produced in ''Halo 3'', depicting a Forerunner circular structure encasing a regular planet, was later reused in ''[[Halo: Escalation Issue 23]]'' for the design of an as-yet unnamed Forerunner installation.

===References===
*The history and name of the Ark are a [[List of references to religion in Halo|reference]] to the Biblical story of Noah, who was instructed by God to build an Ark to save specimens of every animal on Earth from a great flood. The name may also be a reference to [[Wikipedia:Ark of the Covenant|Ark of the Covenant]], which, according to the Jewish Torah and the Biblical Old Testament, contains the stone tablets of the ten commandments. It is the holiest object of the Jewish faith.
*The Ark has some similarity to the concept of an [[wikipedia:Alderson disk|Alderson disk]]. However, an Alderson disk is much larger and has a star in the center.

==Gallery==
===Concept art===
<gallery>
File:H3_Ark_Planetoid_Concept.jpg|Early concept art depicting a planetoidal Ark.
File:HE-23-ArtiPlanet.png|The prior concept, reused for the design of a structure in ''Halo: Escalation''.
File:H3_Ark_Concept_1.jpg|Early concept art of Waypoint, former name of the Ark.
File:H3_Ark_Concept_2.jpg|More concept art for Waypoint. The structure in this version of the concept was designed to not have many elements bigger than the Halo it was constructing.
File:H3 Ark Dynamic Concept.jpg|Concept art of the Ark from the surface.
File:H3 Ark Dynamic Night Concept.jpg|View of this version at night.
File:H3_Ark_Desert_Concept.jpg|Concept art of a desert on the installation.
File:H3_Ark_Structure_Concept.jpg|Concept art of a structure on the installation.
File:H3 Concept ArkSpokedStructure.jpg|Concept art of a large structure on the installation.
File:H3 Ark Warthog Concept.jpg|Concept art of Warthogs on their way to a Forerunner building after Installation 08's reveal in ''[[Halo 3]]''.
File:H3 - Ark and 04B.jpg|Concept art depicting the Ark and Installation 08 in ''Halo 3''.
File:HW2 Installation00 Environment Concept 1.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 2.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 3.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 4.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 5.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 6.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 7.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 8.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 9.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 10.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 11.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 12.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 13.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 14.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 15.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 16.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 17.jpg|Concept art of the installation, for ''Halo Wars 2''.
File:HW2 Installation00 Environment Concept 18.jpg|Concept art of the installation, for ''Halo Wars 2''.
</gallery>

===Screenshots and renders===
<gallery>
File:H3_Installation00_Full.jpg|The Ark in ''Halo 3''.
File:ARK2.jpg|The size of the Ark compared to that of Earth and a Halo installation.
File:Arklandscape.JPG|The desert near the Ark's Cartographer facility.
File:Ark.JPG|A [[Holography|holographic]] representation of the Ark.
File:Sheltered Valley.jpg|A small mountain clearing near the Citadel.
File:Narrows01.jpg|A view of one of Installation 00's cooling systems.
File:H3 Ark Sky.png|The Ark as seen from Installation 08.
File:Ark_light_source.jpg|The Ark's artificial sun.
File:Ark_4.jpg|A view of most of Installation 00's surface.
File:TerminalArkArray.jpg|The Ark along with the Halo installations prior to their activation.
File:HOSFM Installation 00 forerunner symbol.png|The [[Forerunner symbols|symbol]] representing Installation 00.
File:HW2 CoverArt Scarab.jpg|Banished and ''Spirit of Fire'' forces clash on the Ark.
File:HM - SOF and Ark.jpg|Installation 00 in ''[[Halo Mythos]]''.
File:HW2B-Arkholo.gif|A hologram of the Ark in ''[[Halo Wars 2]]''.
</gallery>

==List of appearances==
{{col-begin}}
{{col-2}}
*''[[Halo: First Strike]]''
**''[[Petra]]'' {{Mo}}
*''[[Halo 2]]'' {{Fm}}
*''[[Halo Graphic Novel]]''
**''[[Second Sunrise Over New Mombasa]]'' {{Mo}}
*''[[Iris]]'' {{Mo}}
*''[[Halo 3]]'' {{1st}}
*''[[Halo: Legends]]''
**''[[Origins]]''
**''[[Homecoming]]''
*''[[Halo: Cryptum]]''
*''[[Halo: Combat Evolved Anniversary]]''
**''[[Terminal (Halo: Combat Evolved Anniversary)|Terminals]]''
*''[[Halo: Primordium]]''
*''[[Halo: The Thursday War]]'' {{Mo}}
*''[[Halo 4]]'' {{Mo}}
**''[[Terminal (Halo 4)|Terminals]]''
*''[[Halo: Silentium]]''
*''[[Rebirth]]''
{{col-2}}
*''[[Halo: Broken Circle]]'' {{Mo}}
*''[[Halo 2: Anniversary]]'' {{Mo}}
**''[[Terminal (Halo 2: Anniversary)|Terminals]]'' {{C|Hologram only}}
*''[[Halo: New Blood]]'' {{Mo}}
*''[[Halo: Spartan Strike]]'' {{Mo}}
*''[[Halo: Hunters in the Dark]]''
*''[[Halo 5: Guardians]]'' {{Mo}}
**''[[Halo 5: Guardians Limited Edition dossiers|Limited Edition dossiers]]'' {{Mo}}
*''[[Know Your Enemy]]''
*''[[Halo Mythos]]''
*''[[Halo: Fractures]]''
**''[[Promises to Keep]]''
*''[[Halo: Tales from Slipspace]]''
**''[[Dominion Splinter]]'' {{C|Flashback only}}
*''[[Halo Wars 2]]''
*''[[Halo: Envoy]]'' {{Mo}}
*''[[Halo: Official Spartan Field Manual]]''
*''[[Halo: Renegades]]'' {{Mo}}
*''[[Halo: Shadows of Reach]]'' {{Mo}}
**''[[Sacrifice]]'' 
*''[[Halo: Point of Light]]'' {{Mo}}
*''[[Halo: Divine Wind]]''
*''[[Halo Infinite]]'' {{Mo}}
*''[[Halo: Outcasts]]'' {{Mo}}
*''[[Halo: Epitaph]]'' {{Mo}}
{{col-end}}

==Notes==
{{Ref/Notes}}

==Sources==
{{Ref/Sources|2}}
{{Forerunner|array|category=no}}

[[Category:Installation 00 locations| ]]
[[Category:Halo Array]]