Airlock Technology

An airlock is a device which allows movement from one kind of environment to another, while maintaining separation between the two. By the time of the New Diasporia airlocks have been in use for hundreds of years. Most spacecraft will have some form of airlock to allow people and objects in the shirtsleeve environment inside the craft to get outside the craft without completely depressurizing it.
The most elementary form of airlock consists of a room with two doors. Each door opens into a different environment. In the case of a spacecraft one will open into the hostile environment outside the ship and the other into the human standard environment inside the ship. Some primitive ships in the Wilds still use this technology.
More modern airlocks use much more sophisticated technology. Modern small craft, especially low tonnage commercial craft use an Airlock Containment Unit. An ACU is a device which is primarily mounted under the deck of a vehicle adjacent to the egress door. The ACU contains the air recovery system and a containment made of smart material. When the unit is in the stowed position it is out of the way and can be walked across like any other section of deck. When deployed the smart material expands to lock into the assembly mounted in the overhead and along the bulkhead. The overhead assembly usually contains a decontamination system. ACUs are available in a number of sizes, with the smallest just big enough for a single person. The ACU has no second door. Its user steps into the delineated square and activates the device which causes the walls to expand and isolate the area. The air is pumped out and the outer door to the vessel opened to allow egress. Most are controlled directly by the vessel's computer, although most also have an emergency power source and manual controls.
A more conventional airlock system for a larger craft consists of a multi-layered airlock system. The typical external airlock door consists of a blast door or safety shutter, which is normally closed during ship operation. Around the external door is typically a docking ring of compressed smart material which can be extruded to create a passage tube between vessels.
Behind the blast door is typically an airlock membrane. Membranes are v-branes which are selectively permeable. That means people and object can pass through them, but atmosphere can't.
A more advanced airlock consists of an opening with a brane which will allow vehicles or individuals to pass through while retaining atmosphere. An airlock planer force field acts as an emergency barrier should the brane fail.
A typical airlock on the most advanced vessels consists of a set of walls which form the airlock each with its portal protected by a brane, with an emergency planer force field and backup blast doors.
While the normal method of airlock control is through the ship's computer most airlocks have control stations located inside the airlock and at each portal. The inner control station typically has a touch panel which will  have controls for both sets of doors and for the planar force field. An interlock will prevent de-energizing both planar force fields at the same time. If a force field goes down the blast doors will close.
The station inside the airlock has controls for both the inner and outer portals. Emergency handles allow the brane to be manually deployed and emergency buttons can activate the force field and shut both sets of blast doors.
The outside control station typically has a communication terminal to allow a visitor to "knock" at the airlock door if the blast door is closed. It is possible to set the brane to keep out anyone not recognized as having authorized access, which is typically established using a wireless transponder or RFID tag.
An atmospheric testing station, which monitors the environment outside the outer door and in the airlock itself is also typically available, usually on the same touch panel as the controls. In normal operation the inside of a modern Tech A airlock is at ship's pressure, even during use. Should the brane fail if the planer force field deploys properly there should be little or no drop in pressure. If the force field should fail the airlock can be cycled in emergency mode from any of the three control stations.
A biofilter field in the brane can selectively keep out dangerous microbes and macropests. Still almost all serious airlock systems include a decontamination system and a dust recovery vacuum system to protect the vessel interior.
Airlocks can also be located between compartments of a ship, but it is much more common for a modern ship to have planer force field projectors installed to allow the ship to be segmented. Men 'O War typically supplement damage control force fields with pressure doors. Each pressure door consists of a pair of heavy sliding hatches with a small compartment between them. brane curtains, which will be activated by falling pressure, even without ships power, provides a final line of defense in preventing catastrophic depressurization. Segmenting barriers always include pressure displays to indicate the pressure on the door's far side.
Closed doors can be remotely overridden using the ship's computer, provided one has the proper access. They can be manually overridden only with the proper tools. If air is rushing past an open door it will automatically re-close unless disabled.