Abstract:
A projectile system for impeding vessel movement is provided. The system includes a projectile device that contains a superoxide material for generating an exothermic reaction when exposed to water. At termination of flight, the projectile releases the superoxide material into the surrounding water. A delay can be set to enable the projectile to release its payload underneath the water surface, creating both a disturbance in the water and large gas bubbles to affect the trajectory of the target surface vessel.

Description:
STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein was made in the performance of official duties by one or more employees of the Department of the Navy, and the invention herein may be manufactured, practiced, used, and/or licensed by or for the Government of the United States of America without payment of any royalties thereon or therefor. 
    
    
     BACKGROUND 
     The invention relates generally to projectiles, and more particularly to a projectile system and method for impeding vessel movement on a water&#39;s surface. 
     Conventional methods and devices for impeding the movement of small surface vessels include deployable nets designed to foul the propeller mechanism of a vessel, fences, and fixed barriers. While generally effective at stopping small surface vessels, all are limited in terms of flexibility due to their small area of effect. 
     Accordingly Stationary barriers take time to set up and restrict both desirable and undesirable maritime traffic, and are passive defenses. Deployable nets, either shot from some launching apparatus or dropped into the water by a boat or aircraft, have limited range, cover a limited area, and require the target vessel to collide with the nets in order to be effective. Without any of these nonlethal options, lethal force can be used, but is much more prone to uncertainty. Moreover, net systems have negligible effect on surface vessels powered by jet propulsion systems. 
     SUMMARY OF THE INVENTION 
     Accordingly, various exemplary embodiments provide a method and a system that can be used to effectively and non-lethally impede movement of a vessel on the surface of water. Other objects and advantages of various exemplary embodiments will become more obvious hereinafter in the specification and drawings. 
     In accordance with the various exemplary embodiments, a projectile system and method are provided for impeding vessel movement. The projectile system includes a superoxide material for generating an exothermic reaction when exposed to water. A device contains the superoxide material during a projectile flight thereof. The device also supports release of the superoxide material into a surrounding environment upon completion of the projectile flight. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein: 
         FIG. 1  is a cross-sectional view of a projectile system for impeding vessel movement in accordance with an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view of a projectile system for impeding vessel movement in accordance with another embodiment of the present invention; 
         FIG. 3  is a schematic view of a projectile system for impeding vessel movement in accordance with yet another embodiment of the present invention; and 
         FIG. 4  depicts an operational scenario of the method for impeding vessel movement in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Referring now to the drawings and more particularly to  FIG. 1 , a projectile system that can be used to impede movement of a surface or floating vessel (not shown) is illustrated and is referenced generally by numeral  10 . As used herein, the term “floating vessel” refers generally to relatively small (i.e., generally on the order of 40 feet or less in length) boats that can be manned or unmanned. Further, the phrase “impede movement” as used herein contemplates a variety of non-lethal outcomes ranging from simple course disruption to capsizing of the vessel. However, it is to be understood that both the size of the floating vessel and the type of movement impediments generated by embodiments of the projectile system are not limitations of the present invention. 
     Projectile system  10  includes a casing  12  that is at least partially filled with a superoxide material  14 . As is known in the art, superoxide materials (e.g., potassium superoxide (KO 2 ), sodium superoxide (NaO 2 )) are a class of materials that exothermally react with both fresh and salt water environments. More specifically, the exothermic reaction is very fast and generates heat and gas such that a gas bubble(s) are readily generated as a result of the reaction. Control of the reaction rate can be achieved via particle size, packing density, and the rate that superoxide material  14  is dispersed in the water environment. In the illustrated embodiment, superoxide material  14  is in a particle or powder form to maximize reaction surface area when dispersed from casing  12 . 
     Casing  12  is generally shaped to be aerodynamically stable in a ballistic sense. That is, casing  12  is generally shaped as a projectile that can be fixed or launched from a barrel or launcher, and then fly through the air in an aero-dynamically stable fashion for delivery to a specified/aimed location as will be explained further below. In addition, casing  12  will generally be made completely or partially from a material that will fracture when receiving an impact force (e.g., when casing  12  strikes a target, when something within casing  12  generates a pressure wave pushing out on casing  12 , etc.). For example, casing  12  can be made completely or partially from a frangible material (e.g., plastic) that readily fractures when casing  12  is subject to an impact force. 
     The projectile system of the present invention is not limited to using a powdered superoxide material  14 . For example,  FIG. 2  illustrates another projectile system  20  in which casing  12  is completely or partially filled with pellets  24  of superoxide material. Pellets  24  might be used to generate a slower but longer-lasting reaction when casing  12  fractures/ruptures thereby dispersing pellets  24  into a surrounding environment. 
     As mentioned above, the projectile system of the present invention can be configured to generate its own casing rupturing force that will also function to disperse the superoxide material contained therein. Accordingly,  FIG. 3  illustrates another projectile system  30  in which casing  12  encases both super-oxide material  34  (e.g., in powdered form, pelletized form, etc.) and a device  36  designed to expel/disperse superoxide material  34  from casing  12 . For example, device  36  could be configured similar to an automobile airbag initiator that generates a rapid pressure wave that will cause casing  12  to fracture while also dispersing superoxide material  34  into a surrounding environment. 
     A method of using the projectile system of the present invention to impede movement of a vessel will now be explained with the aid of  FIG. 4 . For simplicity,  FIG. 4  illustrates the use of a single projectile system (e.g., projectile system  10 ). However, it is to be understood that a plurality of projectile system  10  can be utilized in an operational scenario without departing from the scope of the present invention. In  FIG. 4 , a vessel  100  is shown floating at the surface  202  of a body of water  200 . Vessel  100  can be traveling in the direction indicated by arrow  102 . 
     In accordance with the present invention, projectile system  10  is launched or otherwise propelled to a location  300  that can be just forward of vessel  100  or a location  302  that targets vessel  100  at or near the waterline  104  thereof. Obviously, if more than one projectile system  10  is being used, both location  300  and location  302  could be selected or targeted. Once reaching its selected or targeted location, the casing of projectile system  10  fractures as described above to thereby disperse superoxide material  14  in water  200  around locations  300  and/or  302 . (For sake of clarity, the fractured pieces of the casing are not illustrated in  FIG. 4 .) The dispersed superoxide material  14  reacts with water  200  to quickly generate heat and gas that causes a gas bubble  400  to form in water  200 . The presence of gas bubble  400  impedes the movement of vessel  100  by, for example, disrupting its course, rocking vessel  100 , or capsizing vessel  100 . 
     The advantages of the present invention are numerous. The non-lethal projectile system can be used to specifically target suspicious vessels traveling along the surface of the water. The number of projectile systems used can be selected predicated on the suspected threat level. Since the exothermic reaction provided by the superoxide materials is rapid, the effectiveness of the present invention can be readily gauged so that a more lethal deterrent can be employed if necessary. 
     Although the invention has been described relative to specific embodiments thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.