Editing Energy barrier

{{Era|UNSC|HCW}}
<center>''Were you looking for [[Shield door]]s?''</center>
[[File:Energy_barrier.jpg|thumb|250px|An energy barrier in the hangar bay of a [[Covenant corvette]].]]
'''Energy barriers''', sometimes referred to as '''energy fields''', are a type of visible energy field used to separate a pressurized environment from the vacuum of space.<ref>'''[[Halo: Contact Harvest]]''', ''page 98''</ref><ref>'''Halo: Contact Harvest''', ''page 309''</ref> Energy barriers are useful because they allow solid matter through, but not gases, such as [[oxygen]] and neon. However, before matter passes through, the pressure on both sides must be equalized, to minimize the risk of explosive decompression.

The Covenant use energy barriers as hangar doors, in [[airlock]]s and for [[boarding|boarding parties]] to board enemy ships. Energy barriers are present on [[Covenant boarding craft]], on the end of the craft's penetration tip.<ref>'''[[Halo 2]]''', level ''[[Cairo Station (level)|Cairo Station]]''</ref> Energy barriers are also used as exterior doors in [[hangar bay]]s on Covenant starships.<ref>'''[[Halo: Combat Evolved]]''', campaign level, ''[[The Truth and Reconciliation]]''</ref> The barriers can also be configured to block all vehicles or personnel or allow them to pass through when required.<ref>'''[[Halo: Reach]]''', campaign level, ''[[Long Night of Solace (level)|Long Night of Solace]]''</ref> It is interesting to note that [[Covenant]] [[signal unit]]s work through Covenant energy barriers, while human [[COM]] units do not.<ref name="ch99">'''Halo: Contact Harvest''', ''page 99''</ref><ref>'''Halo: Contact Harvest''', ''page 132''</ref>

By [[2552]], the UNSC had also begun to employ energy barrier technology in their space installations and ships in a fashion similar to the Covenant. Examples of human energy barriers include the [[UNSC Sabre engineering facility|Sabre engineering facility]] on the [[Refit station|orbital dockyard]] ''[[Anchor 9]]'',<ref>'''[[Halo: Reach]]''', multiplayer map, ''[[Anchor 9 (level)|Anchor 9]]''</ref> and the windows of the {{Class|Charon|light frigate}} {{UNSCShip|Forward Unto Dawn}}.<ref>'''[[Halo 4]]''', campaign level ''[[Dawn (level)|Dawn]]''</ref> As the most advanced warship in the [[UNSC Navy|Fleet]], the hangar bays of the {{UNSCShip|Infinity}} are also equipped with energy barriers.<ref>'''[[Spartan Ops]]''': [[S1/Exodus|S1E10 ''Exodus'']]</ref>

==Gameplay==
In the ''Halo'' games, energy barriers are typically encountered in levels featuring a Covenant ship. 

In ''[[Halo: Combat Evolved]]'', it is possible to operate the shuttle bay doors of the ''[[Truth and Reconciliation]]''. On the level [[The Truth and Reconciliation]], the player is able to access the doors by heading to the third floor of the shuttle bay and pressing '''X''' on the control panel. This is required to complete the mission, so the player can escape in a [[Type-28 Troop Carrier|Spirit]] with [[Jacob Keyes|Keyes]].

In ''[[Halo: Reach]]'', on the [[Covenant corvette]] ''[[Ardent Prayer]]'' in the level ''[[Long Night of Solace (level)|Long Night of Solace]]'', the shields operate in a different fashion: after [[SPARTAN-B312|Noble Six]] presses a button, the shields still remain in place over the bay, but ships can now go in and out of them. Presumably they are simply lowered to a point things could travel through them while remaining in place to hold the atmosphere in the bay as the ship is in space.<ref>'''[[Halo: Reach]]''', campaign level ''[[Long Night of Solace (level)|Long Night of Solace]]''</ref>

==List of appearances==
*''[[Halo: Combat Evolved]]'' {{1st}}
*''[[Halo 2]]''
*''[[Halo 3]]''
*''[[Halo: Reach]]''
*''[[Halo: First Strike]]''
*''[[Halo: Contact Harvest]]''
*''[[Halo Legends]]''
**''[[The Package]]''

==Sources==
<references/>
[[Category:Security technology]]