Hull breach
From Halopedia, the Halo wiki
A Hull Breach occurs when the outer layer, or hull, of a starship's 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 star fighters. In these smaller cases, "explosive decompression" can be fatal, making the pilot lose control, or perhaps die himself from vacuum.
References
- ^ Halo: Contact Harvest, page 27