Editing Sentinel emitter

{{Status|Canon}}
{{Conjectural title}}
[[File:H3 SentinelLauncher.jpg|thumb|325px|An [[Aggressor Sentinel]] emerging from a Sentinel emitter.]]
'''Sentinel emitters'''{{Ref/File|Id=H2EK|H2EK|tags\objects\solo\sentinelhg\sentinel_emitter\sentinel_emitter.vehicle}} are small armor-covered devices built into the walls of [[Forerunner]] facilities. [[Aggressor Sentinel]]s are sometimes deployed via these devices when reacting to a [[Flood]] outbreak or other situation. They can be found in numerous locations, such as the [[sentinel wall]], the [[Control Room (Installation 04)#Installation 08|control room]], [[Installation 00]]'s [[cartographer]], and the [[Absolute Record]].<ref name="icon">'''Halo 2''', campaign level ''[[Sacred Icon]]''</ref><ref name="ark">'''Halo 3''', campaign level ''[[The Ark]]''</ref><ref name="04B">'''Halo 3''', campaign level ''[[Halo (Halo 3 level)|Halo]]''</ref><ref>'''Halo: Escalation''', ''[[Halo: Escalation Issue 23|Issue #23]]''</ref>

== Overview ==
When hostile entities, such as the [[Flood]], are detected in the immediate area, the sentinel emitters open their covers and dispense [[Aggressor Sentinel]]s. When releasing an Aggressor, the emitter emits a noise that increases in pitch until the Aggressor appears.{{Ref/Reuse|icon}}{{Ref/Reuse|ark}}{{Ref/Reuse|04B}}

A sentinel emitter is at its most vulnerable when its armored cover opens to release an Aggressor. It is the most susceptible to overcharged [[Type-25 plasma pistol|plasma pistol]] shots, [[Anskum-pattern plasma grenade|plasma explosions]], and even [[Melee|physical attacks]]. Upon destruction, a sentinel emitter emits an [[electromagnetic pulse]] to its surroundings.{{Ref/Reuse|icon}}{{Ref/Reuse|ark}}{{Ref/Reuse|04B}}

A sentinel emitter, however, is linked to Sentinel Defense Network on Installation 00. When Voridus disabled the Defense Network, the Sentinels cannot launch from it, resulting in the Flood are able to clog many of emitters due to the network is inoperable. When the Defense Network is reactivated, the Sentinels are once again can be launched to resume their duty.

== Gameplay ==
In ''Halo 2'', sentinel emitters can only be found in the campaign level ''[[Sacred Icon]]'', and consistently release Aggressors to combat [[Flood combat forms]] and [[Thel 'Vadam]].{{Ref/Reuse|icon}}

In ''Halo 3'', sentinel emitters can be found in the campaign levels ''[[The Ark (level)|The Ark]]'' and ''[[Halo (Halo 3 level)|Halo]]''. In addition to being allied with [[John-117]], they are also more durable and release Aggressors at a quicker rate than those in ''Halo 2''. In addition, the hatch closes immediately after the Aggressor is released to prevent weapon fire from getting into the emitter, although this can be bypassed by throwing a grenade before it closes.{{Ref/Reuse|ark}}{{Ref/Reuse|04B}}

In ''Halo Wars 2: Awakening The Nightmare'', Protector Sentinels and Aggressor Sentinels mainly appear from a variant of Sentinel emitter called Launching bays. They can only be disabled temporarily by Voridus' EMP fields and when operating, they come in an endless wave.

In ''Halo Infinite'', sentinel emitters cannot be destroyed, but are more akin to entry corridors and will not generate extra Sentinels beyond the ones that are scripted to appear normally. Emitters can deploy Aggressors, [[Aggressor Sentinel Eliminator|Eliminator]]s and [[Regulator Sentinel|Regulator]]s. Sentinel emitters can be found in the campaign missions ''[[Nexus]]'', ''[[The Command Spire]]'', ''[[Repository (Halo Infinite level)|Repository]]'' and ''[[Silent Auditorium]]''.

==Trivia==
*With the [[M41 SSR MAV/AW|Rocket Launcher]] you can lock onto Sentinel emitters as if they were vehicles. In fact the [[Halo 2 Editing Kit]] reveals that's exactly what they are, and work by having sentinels exit the emitter as if they were exiting a vehicle.{{Ref/Reuse|H2EK}}
*In [[Sacred Icon]], there are many destroyed Sentinel emitters found throughout the level. Despite appearing destroyed, these emitters can be destroyed again (with the armored cover falling out). This is easily seen in the gondola room where, after pressing the holo-panel, all the Sentinel emitters are destroyed, including the ones that are already destroyed.

==Gallery==
===''Halo 2''===
<gallery>
File:H2_ SentinelLauncher.jpg|An inactive sentinel emitter at the sentinel wall.
File:H2_SentinelLauncher_Destroyed.jpg|A destroyed sentinel emitter at the sentinel wall.
</gallery>
===''Halo 3''===
<gallery>
File:H3_ SentinelLauncher_Opening.jpg|A sentinel emitter moments before deploying an Aggressor.
File:H3_ SentinelLauncher_Destroyed.jpg|A destroyed sentinel emitter on Installation 00.
</gallery>
===''Halo Infinite''===
<gallery>
File:HINF SentinelLauncherConcept.jpg|Concept art of a sentinel emitter (right).
File:HINF SentinelLauncher Render 1.jpg|Render of the sentinel emitter.
File:HINF SentinelLauncher Render 2.jpg|Render of the sentinel emitter.
File:HINF SentinelLauncher.jpg|A sentinel emitter without its cover.
File:HINF SentinelLauncher 3.png|A sentinel emitter in a Reformation Spire.
File:HINF SentinelLauncher 2.png|A sentinel emitter deploying an Aggressor.
File:HINF SentinelLauncher 1.png|Four sentinel emitters in the Nexus.
</gallery>

==List of appearances==
*''[[Halo 2]]'' {{1st}}
*''[[Halo 3]]''
*''[[Halo 2: Anniversary]]''
*''[[Halo: Escalation]]''
*''[[Halo Infinite]]''

==Sources==
{{Ref/Sources}}

{{Forerunner|sentinel}}
[[Category:Forerunner technology]]