Abstract:
An air barrier having a scuff coating is used in connection with the core of a spacecraft to form an inflatable, or expandable, human habitat module. The air barrier is comprised of a number of segments joined together to form a enclosure that has at least one opening. The joined segments are generally gas impermeable, flexible, and have a scuff coating on both sides of the segments.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air barrier and in particular an air barrier that is used in connection with an expandable, or inflatable, structure suited for space applications or use on extraterrestrial masses. 
     2. Description of Related Art 
     Inflatable, or expandable, spacecraft are known generally in the art as evidenced by U.S. Pat. No. 6,231,010 to Schneider, et al and U.S. Pat. No. 6,547,189 to Raboin, et al. These types of habitable structures have the unique ability to change states from a compressed launch state to an inflated deployed state. In the deployed state, the structure provides an internal volume that is many times greater than the volume found in the launch state. 
     During deployment of the spacecraft an atmosphere suitable to support humans is injected into the structure, or module, to facilitate inflation. When completely inflated environmental systems within the module re-circulates the internal atmosphere to filter out harmful chemicals and recycle carbon dioxide into breathable oxygen. The structure primarily responsible for this operation is the air barrier. 
     A module&#39;s success is therefore heavily dependent upon the reliable operation of an air barrier to retain the environment within the module. However, construction techniques may impart latent defects that could jeopardize the module during operation. These flaws may occur, for example, from people walking on the air barrier during construction or sharp edged items coming into contact with the air barrier during construction on in deployment. What is needed is an air barrier that can withstand such interactions without damaging the air barrier&#39;s gas impermeable characteristic. 
     BRIEF SUMMARY OF THE INVENTION 
     An air barrier system comprised of a plurality of generally gas impermeable and substantially flexible segments having an inner and outer surface where each surface is substantially scuff resistant. The plurality of generally gas impermeable and substantially flexible segments are attached to one another to form an enclosure. The enclosure having at least one edge defining an opening and the edge being securedly disposed between two seal rings. Further, at least one seal ring is securedly attached to a spacecraft bulkhead. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a top view of two segments. 
         FIG. 2  is an end view of two segments being joined. 
         FIG. 3  is a side view of the enclosure. 
         FIG. 4  is an end view of the enclosure showing an opening. 
         FIG. 5  is a cross sectional view of the bulkhead and enclosure. 
         FIG. 6  is a side view of a compressed enclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , two segments  10  are identified. The segments  10  are substantially flexible and generally gas impermeable. Each segment has a first side  12  and a second side  14 . The segment also has a first end  16  and a second end  18 . 
     Turning to  FIG. 2 , two segments  10  are in position for being generally securedly attached to one another. The first side of one segment  12  is brought into the general vicinity of the second side  14  of an adjacent segment  10 .  FIG. 2  shows the sides overlapping. While this is the preferred embodiment, it is also possible to abut the sides together in other embodiments. In this figure, a bonding material  20  is disposed between both segments. The bonding material  20  can be glue designed to bind the segments  10  together, or a material designed to bond the segments  10  when heat is applied. Other types of bonding materials and methods, for example tape overlapping the sides, can be used and are generally know in the art. 
     The segments  10  have a top  22  and bottom  24  surfaces. Each surface has a scuff coat. The scuff coat adds a measure of protection to the segments  10  during construction and deployment against objects coming into contact with the segment  10  that might otherwise damage the segment. For example, the segments  10  might be exposed to foot prints and potential gouging by during the assembly of the segments into an enclosure. Scuff coating materials are known in the art and can be chosen to satisfy mission parameters and environmental requirements of a module being deployed in space or on an extraterrestrial mass. Scuff coatings can also be chosen to further reinforce the segments  10 , or provide yet another layer of a generally gas impermeable surface. Scuff coatings can be an integral part of the segments or applied as a cover to the segments. Further, scuff coats can be designed to accommodate the use of a patch to seal a leak in the segment  10 . 
       FIG. 3  illustrates a number of segments  10  bonded together to form an enclosure  26 . In  FIG. 4 , the enclosure  26  has an opening  30  that is formed by an edge  28 . In this embodiment, the edge  28  is comprised of either the first ends  16  of the segments  10  in  FIG. 2  or the second ends  18  of the segments  10  in  FIG. 2 . 
     The edge  28  is for sealing the enclosure  26  to the structure of a module. The edge  28  may be attached to a variety of structures that would form the solid core of a module.  FIG. 5  is one embodiment for securing the edge  28  in the general vicinity of a bulkhead  34 . The edge  28  is sandwiched between two seal rings  32 . A bonding material  36  is placed on each ring  32  separating the edge  28  from the rings  32 . The bonding material  36  can serve multiple functions. It can serve to secure the edge  28  to the rings  32  and to provide a generally airtight seal between the edge  28  and the rings  32 . The joint structure of the edge  28 , rings  32 , and bonding material  36  can be affixed together by well known means. In the preferred embodiment, the structure is held together by bolts that pass through the edge  28  and bonding material  36  and terminate in the rings  32 . 
     The combination of the edge  28 , rings  32 , and bonding material  36  are held in place securedly to the bulkhead  34 . Again, a bonding material  36  resides between the bulkhead  34  and one of the rings  32 . In the preferred embodiment, the ring  32  and bulkhead  34  are held in place by a bolt that terminates in each structure.  FIG. 5  illustrates one embodiment where the bolts  33  has a head  35  that terminates in ring  32  and the opposite end of the bolt terminates in the bulkhead  34 . 
     Turning to  FIG. 6 , the figure shows a longitudinal axis  38 . The enclosure  26  is compressed along the axis  38 . In this fashion, the enclosure  26  can accommodate modular designs that expand along the longitudinal axis  38  during deployment. 
     There has thus been described a novel air barrier and air barrier system. It is important to note that many configurations can be constructed from the ideas presented. The foregoing disclosure and description of the invention is illustrative and explanatory thereof and thus, nothing in the specification should be imported to limit the scope of the claims. Also, the scope of the invention is not intended to be limited to those embodiments described and includes equivalents thereto. It would be recognized by one skilled in the art the following claims would encompass a number of embodiments of the invention disclosed and claimed herein.