Exopacks on! Remember people, you lose that mask, you’re unconscious in 20 seconds, and you’re dead in four minutes.The Venture Star Crew Chief to new recruits as they exit the Valkyrie shuttle.
The exopack is a lightweight atmosphere filtration system developed from civilian rebreather technology that allows humans to survive on Pandora with a minimum amount of equipment.
Purpose[]
An emergency exopack in case there is an unexpected breach.
Pandora's toxic atmosphere is unbreathable by humans due to the presence of high concentrations of carbon dioxide (>18%) and hydrogen sulfide (<1%). Pandora's other main atmospheric constituents; nitrogen, oxygen, and xenon, are also present in Earth's atmosphere. Fortunately, Pandora's atmospheric oxygen content and its partial pressure (pO2) are suitable to support human life. So in order for a human to breathe it is only necessary to filter or "scrub" out the toxic components, which is the exopack's purpose.
Without the exopack, the potent mix of high concentrations of carbon dioxide and especially hydrogen sulfide will cause a variety of unpleasant or deadly reactions; including choking and burning of mucous membranes, followed by unconsciousness within twenty seconds and death within minutes due to cellular oxygen deprivation.[1]
Carbon dioxide binds to human red blood cells as part of normal human metabolism in Earth's atmosphere (.036% carbon dioxide). However, high concentrations of atmospheric carbon dioxide (exceeding 4%) will decrease the amount of oxygen that is bound onto red blood cells, which leads to oxygen deprivation and asphyxiation.[2]
Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body but affecting the nervous system most severely. The toxicity of hydrogen sulfide is comparable with hydrogen cyanide in that it is a strong hemotoxin and will destroy red blood cells by irreversibly forming a complex bond with the iron in the red blood cells. This permanently destroys the blood cells ability to bind to and transport oxygen throughout the body which leads to cellular oxygen deprivation and ultimately death. [3]
The exopack utitilizes a full-face, transparent, perspex faceplate with a polymer static seal, which is connected by a hose to a small pack containing the filters and a power supply. There is a high-flow valve at the bottom of the mask, allowing the user taking deep breaths rapidly if necessary, especially if they were exposed to Pandora's atmosphere for a period of time.
The filters function for two weeks before accumulated soot clogs the filter pores. The filter pads can be regenerated by gentle washing with running water and last indefinitely with proper care.
Multiple different versions of the exopack exist. Some versions allow the wearer to breathe underwater for a limited time and have an integrated HUD to display the system's status.
For emergencies there are several devices with the same purpose as the exopack, such as the emergency oxygen supply and the standby rebreather.
Older versions of the mask had to be refilled at oxygen pods.[4]
Source[]
Gallery[]
References[]
- ↑ It is very possible to hold your breath, and thus survive the Pandoran atmosphere for much longer. For instance, Miles Quaritch endured for 38 seconds without a mask and 54 seconds without eye protection.
- ↑ http://en.wikipedia.org/wiki/Carbon_dioxide
- ↑ http://en.wikipedia.org/w/index.php?title=Hydrogen_sulfide&oldid=348033922 retrieved on March 10th, 2010 at 06:30 UTC
- ↑ Avatar: The Game NDS, ingame pandorapedia for "Oxygen Pod". The game is set prior to 2152.