|This article may not meet Halo Nation's standards. You can help by cleaning this article.|
Technically, an airlock is a device which permits the passage of people and objects between a pressure vessel and its surroundings while minimizing the change of pressure in the vessel and loss of air from it. The lock consists of a small chamber with two airtight doors in series which do not open simultaneously. Also, some airlocks on ground prevent compression, such as underwater excursions akin to the space compressions.
An airlock may also be used for passage between environments of different gases rather than different pressures, to minimize or prevent the gases from mixing.
Airlocks are used in UNSC spacecraft to prevent pressure loss from exposure to vacuum either due to a hull breach or the deployment of a lifepod or HEV. Halcyon-class light cruiser in particular, employ them as redundancy features for survivability during combat with Covenant warships. The UNSC Hopeful also had an airlock large enough to cycle a fleet of dropships simultaneously.
Covenant airlocks feature a force field similar to Kig-Yar Shield Gauntlets that have to be deactivated to allow anything through. It is impervious to any Human projectiles.