Thermal Stress Management of Infrared (IR) Windows

"One of the major challenges in the development of high velocity interceptor missiles is the need to provide a method of keeping the infrared window cool enough to allow target tracking. Several active window cooling techniques are under investigation,however, these must address the twin challenges of increased weight and added system failure mechanisms. We have recently invented a technique for passive cooling of interceptor windows. Our modeling has shown that this innovative approach can satisfysystem needs without adding any moving parts or significant mass to the system. The passive cooling material can also be employed as a window frame material mitigating thermal stress effects for standard IR windows. The material is effective undersupersonic and hypersonic heating conditions. In Phase I we propose to experimentally demonstrate the cooling capacity of our window concept under moderate heating conditions. In Phase II we will design, develop, and evaluate a prototype window. A newpassive-cooling IR sensor window material is directly applicable to missile defense interceptor programs sponsored by the Ballistic Missile Defense Organization, the U.S. Army, and U.S. Navy. It is particularly relevant to the atmospheric interceptorprograms being conducted by the Navy. The commercial benefits of these concepts are to organizations involved in the design and fabrication of vehicles performing sensing and tracking operations at