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Assured Space Sensor Operation in Harsh Electromagnetic/RF Environment

Description:

OBJECTIVE: Develop an electromagnetically-tailored material for assured sensor operation on SATCOM and/or space-based ISR systems against various electromagnetic environments. DESCRIPTION: Satellite communications (SATCOM) and space-based Intelligence, Surveillance, and Reconnaissance (ISR) systems in Low-Earth Orbit (LEO) are susceptible to a challenging mixture of electromagnetic (EM) environments, both natural and manmade. These systems receive information, process it, and then retransmit it, all by electronic circuits. Both prompt and enduring radiation effects could corrupt these processes in systems that lack electronic protection (EP). Radiation hardening can protect electronics from many scenarios, but integrating this capability adds significant complexity and cost to the satellite program. So much so that the 2008"Report of the Commission to Assess the Threat to the United States from EMP Attack"recommends that a cost-effective approach to EP should not be just rad-hardening, but also a balance of mitigation options. What is needed is an innovative approach to develop these mitigation options for EP on SATCOM and/or space-based ISR systems. A new, expansive field of engineered materials are emerging that offer a means to control the electromagnetic properties of a wave that permeates its structure, through tailoring its reflectivity, transmittivity, and/or absorptivity. Materials that include, but are not limited to, metamaterials, metasurfaces, and carbon nanotubes. These materials open up the possibility to use as an EP technology, and warrants further investigation. Any material that can interact with EM waves will affect sensor performance. However, as an EP function, the key requirement is that the solution must maintain or improve the performance of the sensor while in the presence of evolving EM environment. It is also required that the solution work symbiotically with the system for quicker integrationfor example, as a thin-film surface or as part of the sensor itself. This innovative approach to design will provide the community with an EP technology that can be optimized for mission specific SATCOM/ISR applications without having to consider the complexities of an add-on EP technology. Proof of scalability in the frequency of operation is a must, as this would give rise to a modular toolkit for satellite developers. Low-power active tunability is of interest. Component or system level solutions will be accepted, but a pervasive technology that could apply to numerous components or systems is highly desired. Finally, the solution must prove to be more cost-effective than just rad-hardening. Primary challenges are the characterization, fabrication and survivability issues of an engineered material. In particular, consider the harsh launch and operating environments that LEO satellite systems undergo. Heavy modeling and simulation for initial investigation of design approaches is highly encouraged. PHASE I: Identify concepts and preliminary assessment of EP performance, fabrication and space-worthiness. Threshold for protection will be 80dB attenuation at 1 GHz (from Mil-Std-188-12). Simulate performance of solution in high-threat environment, both in isolation and while integrated with a sensor system. PHASE II: Refine concept based on Phase I. Validate the proposed EP design approach through development, fabrication and test of a prototype article that meets design and technical objectives. Demonstrate maintained or improved sensor performance during simulation of appropriate environment. Provide AFRL with working hardware and samples. PHASE III: Military App: Any space-based DoD application that requires a cost-effective, readily-integratable EP solution. Commercial App: In addition to EP for commercial space systems, unintentional signals--such as co-site interference--could be mitigated in many communications or sensing systems. REFERENCES: 1. Graham, William, R., et al,"The Commission to Assess the Threat to the United States from EMP Attack: Critical National Infrastructures Report."Undated. Available: http://empcommission.org/. 2. Rowe, Neil C.,"Electronic Protection,"U.S. Naval Postgraduate School, 2006. Available: http://faculty.nps.edu/ncrowe/eprotect_final.htm. 3. Department of the Army,"Grounding and Bonding in Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities,"Army Publication TM 5-690, February 2002. 4. Lovat, G., Burghignoli, P.,"Shielding Effectiveness of a Metamaterial Slab,"IEEE International Symposium on Electromagnetic Compatibility, pp 1-5, July 2007.
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