An airlock used in space can provide the ability to leave a pressurized volume and enter free space. This is necessary to perform maintenance or make repairs to the pressurized volume or visiting spacecraft, construct or repair structures or devices, tend in-space experiments, etc. The airlock is used to provide the transition between internal pressurized volume, i.e. a shirtsleeve environment, and space. Current state-of-the-art units on the Space Station are rigid systems consisting of massive pressure vessels, hatches, and seals. Past efforts have investigated fabric-based ways of forming the airlock pressure volume, but all have used a more traditional metallic or composite door or hatch, which are heavy and difficult to package into a small volume. The need exists for an airlock, pressure vessel, and opening that are lightweight and can be packaged efficiently.
The innovation described here is a unique structural architecture that enables a linear seal to be used to form a large aperture without experiencing cross loads. The corresponding flexible linear seal provides a way to create an aperture (i.e. opening, hatch, or door) that is lightweight and can be collapsed and folded along with the fabric airlock. The fabric-based aperture is highly scalable and can be used where it is desirable to isolate volumes with different environmental characteristics.
Compared to the state-of-the-art seal systems, the unique structural architecture and aperture seals proposed here are lightweight and can be folded or rolled to package compactly. The seals can be scaled for any size aperture, and can be configured for automatic activation. Redundant seals can be integrated with a small mass and packaging penalty. Because the seals can be formed from the same materials used to form the bladders in inflatable systems, they can be directly integrated with the inflatable materials used to form the airlock or pressure vessel. In this case, the seals do not require interfacing structure traditionally found when inflatable materials are interfaced to metallic or composite components.