Airlock

UNSC airlock floor sign

An airlock is a device which allows passage between two areas of drastically different pressures and/or atmospheric composition, while preventing the exchange of gases and pressure. An airlock consists of a small chamber with two airtight doors in series, which do not open simultaneously. They are most commonly used on spacecraft, where they allow safe passage between the pressurized interior of the ship and the vacuum of space, though they can also be found in enclosed habitats on worlds with toxic atmospheres, for example.

On UNSC spacecraft, hangar bays, lifepod or drop pod launch areas are typically equipped with airlocks, used to prevent pressure loss from exposure to vacuum either due to a hull breach or the deployment of a lifepod or HEV. Halcyon-class cruisers, in particular, employ them as redundancy features for survivability during combat with Covenant warships. The UNSC Hopeful had an airlock large enough to cycle a fleet of dropships simultaneously.

The Covenant typically employs energy barriers in place of physical airlocks. Certain UNSC facilities also employ energy barriers for this purpose, presumably having reverse-engineered Covenant or Forerunner versions.

Identified airlocks

• Airlocks on the Pillar of Autumn
• Cairo Station umbilical locks

Gallery

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  An external airlock/docking collar on the side of a UNSC frigate's bridge.

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  An external airlock on the UNSC Pillar of Autumn.

List of appearances

• Halo: The Fall of Reach (First appearance)
• Halo: Combat Evolved
• Halo: The Flood
• Halo 2
• Halo: Ghosts of Onyx
• Halo: Uprising
• Halo: Glasslands
• Halo: Combat Evolved Anniversary
• Halo 4
• Halo 2: Anniversary
• Halo 5: Guardians
• Halo: Fractures
  • Breaking Strain (Mentioned only)
  • A Necessary Truth (Mentioned only)
  • Into the Fire