- It is a kind of Ship Equipment.
An airlock is a compartment with its own isolated environmental systems and parallel sets of doors. It permits movement between areas at different pressures or experiencing different environmental conditions.
Airlocks are typically designed to hold one or more individual sophonts and usually allow for additional bulk, such as Environment Suits or Vacc Suits and any associated equipment such as PLSS gear. Larger races such as K'kree or Virushi utilize correspondingly larger airlocks.
- A standard human-sized airlock has a volume of 7m³ (0.5 Tons), including any associated stowed docking tube.
- Airlocks may have hatches or doors or may utilize iris valves.
- some airlocks may contain three or more sets of doors, typically to give a staged progress and thus allow hazards, contaminants or pathogens to be eliminated.
Starships and bigcraft usually have at least one airlock. Large vessels frequently have multiple airlocks. Smallcraft are assumed by default not to have an airlock, though certain designs are fitted with one.
All spacecraft airlocks include docking tubes that allow passengers to cross from one ship to another. Docking tubes are designed to link airlocks together. Most are constructed from plastics and similar materials and are flexible. Vessels such as Passenger Liners sometimes utilize rigid, articulated docking tubes that include grav plates to facilitate the ease and comfort of guests.
- A docking tube may be rapidly released in an emergency.
Military spacecraft may have a breaching tube. This apparatus functions similarly to a docking tube but it is substantially more bulky, typically occupying around 40m³ (approximately 3 Tons). The tube's docking collar has powerful attachment mechanisms capable of latching onto a variety of surfaces and contains inherent plasma cutters. Breaching tubes are generally armored.
- If a breaching tube attaches to an airlock it may rapidly cut an opening. If it attaches to an exterior area of the hull it may still cut through, but the process takes longer.
- A breaching tube may be rapidly released if required.
Early designs of airlock are most commonly found aboard watercraft and submersibles or used in environmental applications such as building entrances. Lower tech designs tend to be heavily constructed, requiring bulky machinery to open and close. More sophisticated designs, generally made of lighter materials, are occasionally used aboard aircraft.
Airlocks may also be used in Environmental Tanks such as hyperbaric chambers or medical quarantine facilities. They may also be used to enter clean rooms, typically within industrial plants where particulate material or trace contaminants could affect delicate manufacturing processes.