OBJECTIVE: Develop a tool to enable modeling and simulation and, in turn, design of antennas in a re-entry environment. Specifically, the goal is for a tool that provides the coupled prediction of the antenna performance in a plasma sheath. DESCRIPTION: The Missile Defense Agency flies a variety of ballistic missile targets for all elements of the Ballistic Missile Defense System. Depending on the individual test objectives, it may be necessary to fly a missile into the endo-atmosphere where the plasma environments can impede TM&GPS communication. Plasma sheaths envelop portions or the entirety of the vehicle and effectively shield the antennas from proper operation. A variety of solution techniques exist for the development of antennas which perform in the plasma environment. These techniques vary from antenna placement to matching scenarios, etc. In the BMDS target development arena, expensive testing to characterize plasma environments and subsequent design loops for antennas is not possible. It is instead desirable to develop an antenna design tool that can predict the plasma environment and the antennas operation in it. The goal is a coupled Computational Electro-Magnetic / Computational Fluid Dynamics (CEM/CFD) tool that predicts the plasma environment and the antenna (including the impact of the antenna and associated transmit power on the plasma environment). The tool must provide detailed antenna modeling for generic antenna designs on the re-entry body. The end result tool could then be coupled with traditional or advanced antenna techniques to design antennas which would then be able to support maintaining data link throughout re-entry. Alternatively, it could enable the selection of ground telemetry asset locations as to minimize impact of the plasma sheath of telemetry coverage. PHASE I: Demonstrate in simulation the ability to develop a coupled CEM/CFD tool that can provide CEM predictions of both antenna performance in a plasma sheath for a simple scenario of the proposer"s choosing. PHASE II: Expand the tool to be able to model re-entry bodies along general trajectories with general antennas. Anchor the tool against known test data. PHASE III: Apply the tool to support MDA or other agencies in predicting re-entry antenna performance or designing antennas. COMMERCIALIZATION: A variety of commercial space projects are now under way. These systems would provide enhanced safety and/or failure analysis should this tool enable antennas that operate all the way through the re-entry environment with fewer to no drop-outs.