Hull breach
From Halopedia, the Halo wiki
A Hull Breach occurs when the outer layer, or hull, of a starship armor plating is somehow damaged or destroyed, rendering the interior of the ship exposed to vacuum (space).[1] Hull breaches typically result in violent explosions of the atmosphere within the vessel venting into the vacuum of space, known as "explosive decompression". This can also happen to smaller ships, such as Pelican Dropships or Longsword starfighters.
References
- ^ Halo: Contact Harvest, page 27