Editing Semi-Powered Infiltration armor

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{{Armor Infobox

|testsite=[[Currahee Special Assembly Plant 2]]<ref name="HM"/>

The '''Semi-Powered Infiltration armor''' ('''SPI armor''') is a [[UNSC]] combat [[armor]] system designed with an emphasis on stealth through the use of [[photoreactive panel|special photoreactive panels]].<ref name="goo14">'''[[Halo: Ghosts of Onyx]]''', ''page 14''</ref> Although early versions of the SPI system were tested by [[Orbital Drop Shock Troopers]],<ref name="g164">'''Halo: Ghosts of Onyx''', ''page 164''</ref> the armor was most prominently issued to the [[Spartan-III]] supersoldiers.<ref name="goo14"/> With over 2,000 units of SPI armor manufactured during the [[Human-Covenant War]],<ref name="HM"/> the SPI armor had been mostly phased out of use by Spartan-IIIs by [[2558]]. However, select Spartan-IIIs (such as [[SPARTAN-G059]]) continue to field the suit,<ref>'''[[Halo: Tales from Slipspace]]''', ''[[Knight Takes Bishop]]''</ref> and the photoreactive plating technology has seen limited but successful use in several special operations ODST units.<ref>[https://www.halowaypoint.com/en-us/community/blog-posts/canon-fodder-fifty-caliber '''Halo Waypoint''' - ''Cannon Fodder: Fifty Caliber'']</ref> The SPI armor was developed by the [[Watershed Division]], with [[Ruk Ariaustin]] as design lead.<ref name="HM"/>

Described as "part legionnaire mail, part tactical body armor, and part chameleon", the SPI armor features [[photoreactive panel]]s that mimic the surrounding textures, effectively being the UNSC equivalent to the [[Covenant]]'s [[active camouflage]] systems.<ref>'''Halo: Ghosts of Onyx''', ''page 16''</ref> The SPI armor features a full body armor with an enclosed helmet and [[heads-up display]]. The undersuit is equipped with a cushioning layer of liquid nanocrystal that provides more ballistic protection than three centimeters of [[wikipedia:Kevlar|Kevlar]] diamond weave, without the bulk.<ref name="goo171">'''Halo: Ghosts of Onyx''', ''page 171''</ref> The hardened armor plates, though advanced compared to standard UNSC infantry armor, can take only a few glancing blows before failing.<ref name="goo14"/>

Though more advanced than the [[Orbital Drop Shock Troopers]]' [[ODST armor|body armor]], the SPI armor is less powerful than the [[Mjolnir armor]] originally issued to the [[Spartan-II]]s.<ref>'''[[Halo: Glasslands]]''', ''page 207''</ref> Its main benefit is that it is drastically cheaper to produce than Mjolnir.<ref name="goo46">'''Halo: Ghosts of Onyx''', ''page 46''</ref> Although the SPI suit provides modest enhancements to the wearer's strength and mobility,<ref name="HM"/> this amplification is not as drastic as that afforded by the Mjolnir.<ref>'''Halo: Last Light''', ''page 33'' (Google Play edition)</ref> Consequently, the SPI armor can be worn by any individual and does not require special neurological, skeletal or muscular [[Biological augmentation|augmentation]]; for example, the unaugmented instructors for the Spartan-IIIs often wore SPI armor.<ref>'''Halo: Ghosts of Onyx''', ''pages 89, 94''</ref><ref name="g164"/> The SPI armor is not as bulky or as heavy as the Mjolnir armor,<ref>'''Halo: Glasslands''', ''page 40''</ref> although the plating material is also less durable: [[Kelly-087]] dented a Spartan-III's chest plate with her fist when first encountering the Spartan-IIIs.<ref name="goo168">'''Halo: Ghosts of Onyx''', ''pages 168-169''</ref>

The Mark I was the first, experimental iteration of the SPI system used by the Spartan-IIIs of [[SPARTAN-III Alpha Company|Alpha Company]]. The featured photoreactive panels gave the Spartans of Alpha Company a rough equivalent to active camouflage. The camouflage patterns, however, shifted irregularly and imperfectly, which made the photoreactive panels inferior compared to the [[Covenant]]'s active camouflage technologies.<ref>'''Halo: Ghosts of Onyx''', ''page 85''</ref>

The Mark II was an improvement of the SPI Mark I, first used by the drill instructors of [[SPARTAN-III Beta Company|Beta Company]], and then by the Spartans of Beta and Gamma Companies.<ref name="goo89">'''Halo: Ghosts of Onyx''', ''page 89''</ref> The armor sports new photoreactive coating to boost its camouflaging properties. Although the new photoreactive coating can mimic a wide range of electromagnetic radiation, it is still sensitive to overload, making the wearer vulnerable for several seconds after a [[flashbang]] or [[plasma]] hit while the panels reset.<ref name="goo113">'''Halo: Ghosts of Onyx''', ''page 113''</ref>

The armor was proposed by [[Kurt Ambrose]] in [[2537]] for Alpha Company, but the request was denied because the armor was over budget.<ref>'''Halo: Ghosts of Onyx''', ''page 80''</ref> After Alpha Company's Pyrrhic victory in [[Operation: PROMETHEUS]], the Mark II was approved for mass production. After the augmentation of [[SPARTAN-III Gamma Company|Gamma Company]], small adjustments were installed into the Mark II SPI armor,<ref name="goo99"/> including experimental refits to the ballistic gel layers, upgraded software suites, and other functions, slated to be introduced to the systems prior to Gamma Company's deployment in [[2552]].<ref name="goo99">'''Halo: Ghosts of Onyx''', ''page 99''</ref> One improvement is that the armor is now hermetically sealed and contains an internal [[oxygen]] supply.<ref name="g251">'''Halo: Ghosts of Onyx''', ''page 251''</ref>

==Armor components==

;Mirage-class helmet<ref name="mythos">'''[[Halo Mythos]]''', ''page 77''</ref>: The default headgear of the SPI armor, the Mirage-class helmet features a large, bulbous faceplate somewhat similar to that of the [[MJOLNIR Powered Assault Armor/V variant|Mjolnir EVA variant]]. The visor is normally gold-mirrored in color<ref name="goo115">'''Halo: Ghosts of Onyx''', ''page 115''</ref> and can be depolarized.<ref name="goo168"/> The helmet supports a [[heads-up display]] with features similar to that of the MJOLNIR system, including TACMAP, TEAMBIO, and [[COM|TEAMCOM]] interfaces; a [[motion tracker]];<ref>'''Halo: Last Light''', ''page 146'' (Google Play edition)</ref> as well as team status lights.<ref>'''Halo: Ghosts of Onyx''', ''pages 17, 22''</ref><ref name="g114">'''Halo: Ghosts of Onyx''', ''page 114''</ref> The visor suite features an automatic magnification and image enhancement system controlled by the wearer's eye movements. For example, if the wearer squints while looking at a particular spot the system will automatically zoom in.<ref>'''Halo: Ghosts of Onyx''', ''page 19''</ref> Both the image enhancement and the visor's internal polarization can also be controlled manually.<ref>'''Halo: Ghosts of Onyx''', ''page 268''</ref><ref>'''Halo: Ghosts of Onyx''', ''page 345''</ref> The helmet possesses tactical lights<ref>'''Halo: Ghosts of Onyx''', ''page 273''</ref> and a defogging vent to remove internal moisture.<ref>'''Halo: Ghosts of Onyx''', ''page 316''</ref>

;Techsuit: The bodysuit of the SPI system is composed of a layered mesh of ballistic liquid nanocrystal that is significantly more effective than traditional body armor materials such as Kevlar while being less bulky.<ref name="goo171"/><ref name="g114"/><ref>'''Halo: Ghosts of Onyx''', ''page 360''</ref> The techsuit's leggings<ref name="g141">'''Halo: Ghosts of Onyx''', ''page 141''</ref> and sleeves can be removed independently.<ref>'''Halo: Last Light''', ''page 125'' (Google Play edition)</ref>

;Photoreactive panels: The outer shell of the SPI armor comprises a series of lightweight laminate plates with a photoreactive coating.<ref name="HM"/> The photoreactive panels act as [[active camouflage]] when active,<ref>'''Halo: Ghosts of Onyx''', ''page 165''</ref> effectively blending the wearer with their environment.<ref name="goo14"/> The coating also renders the wearer nearly invisible to infrared and passive light-gathering systems.<ref>'''Halo: Last Light''', ''page 95'' (Google Play edition)</ref> Since the photoreactive plates take time to recover after explosions such as a [[flashbang grenade]] and [[Plasma weaponry|plasma]] hits, the wearer is visible until the plates recover.<ref name="goo113"/> With the exception of the [[Headhunters]]' suits, the SPI armor does not feature energy field-based active camouflage systems like those of the Covenant.<ref name="head212"/> When inert, the plating is matte gray<ref name="g141"/><ref name="mythos"/> or green, though some SPI suits have been known to use different colors such as red.<ref>'''Headhunters''' ''motion comic''</ref><ref>'''Halo Mythos''', ''page 135''</ref>

;Rift-class gauntlets: The SPI suit is equipped with shock-resistant and force-amplifying gauntlets.<ref name="HM"/>

;Tactile bracers: The bracer armor pieces around the boots grant slight improvements to speed and dexterity with negligible shielding reduction.<ref name="HM"/>

;Environmental controls: The suit possesses rudimentary environmental regulation system to maintain a comfortable temperature for the wearer.<ref>'''Halo: Ghosts of Onyx''', ''page 22''</ref> However, the system is not designed for extended use and it will become increasingly uncomfortable to wear if used continuously over long periods of time.<ref>'''Halo: Ghosts of Onyx''', ''page 254''</ref> As of 2552, the Mark II SPI armor is also fully sealed and contains an internal oxygen supply.<ref name="g251"/> The armor also has an efficient cooling system and is significantly difficult to detect even with thermal scanners.<ref name="goo89"/>

;Power cell: The armor is powered by a low-profile, shielded BA-55901/PLMD battery cell.<ref name="mythos"/>

In addition to the standard model, several variants of the SPI armor exist.<ref group="note">Similar to the somewhat differing depictions of [[Mjolnir armor]], the exact design details of the "default" SPI armor vary between different sources of ''Halo'' canon, sometimes within a single source. Since it is difficult to determine which of these examples constitute officially-defined variants of the suit rather than artistic license, only the versions that overtly deviate from the standard pattern are listed below, while the gallery section provides examples of less pronounced variety between SPI suits.</ref>

===Operator-like===

This variant has a [[STALKER-class Mjolnir|Stalker]]-like suit, with a helmet that is similar to design to [[OPERATOR-class Mjolnir|Operator]]. It was utilized by [[Roland (Spartan-III)|Roland]].

File:Roland SPI 2.png|Operator-like.

This variant has a helmet design that is similar to [[GRENADIER-class Mjolnir|Grenadier]]. [[Mark-G313]] wore this suit during [[Operation: JOVIAN WHISTLE]].<ref group="note">In [[:File:Halo Last Light cover.jpg|the cover]] of ''Halo: Last Light'', Mark (who is seen in the background of the image) is depicted as wearing a standard set of SPI armor.</ref>

File:SpartanIII.jpg|A Spartan wearing SPI armor.

File:Headhunters.png|Two Headhunters, [[Roland (Spartan-III)|Roland]] and [[Jonah]], wearing SPI armor. The former is wearing an unknown variant.

File:Headhunter SPI Armor.jpg|[[Jonah]] wearing his SPI armor.

File:HLL cover-Olivia full.png|[[Olivia-G291]] in SPI armor with her helmet removed.

File:HM-SIIIs.png|Mirage-class helmet with an eagle emblem on the visor.

File:TfS - SPARTAN-G059.png|[[SPARTAN-G059]] clad in SPI armor.

File:Veta SPI.png|[[Veta Lopis]] equipped with SPI armor.

<references group="note"/>

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{{Armor}}