Electromagnetic Manipulation of Plasma Layer for Re-Entry Blackout Mitigation.

Abstract

This thesis uses numerical simulation to study a new communication method for addressing radio blackout during hypersonic flight. The radio blackout problem is an important issue for hypersonic vehicles because of flight safety, catastrophe analysis, and mission success. During the last 50 years, several approaches have been proposed to solve radio blackout. However, from the Apollo reentry capsule to the Space shuttle, vehicles have experienced difficulties in communication and vehicle tracking due to this phenomenon. As a reentry mitigation scheme, this study suggests plasma manipulation methods using an electrostatic sheath and an electromagnetic (ExB) layer. The electrostatic sheath scheme is based on the formation of an electron-depleted sheath with a scale length comparable to the plasma layer. This study suggests two-dimensional shaped electrodes, one U-shaped and the other cylindrical. An electromagnetic, ExB layer mitigation scheme is also studied. The possibility of the scheme is analyzed using two suggested ExB layer models, a one-dimensional and a two-dimensional model. The results of the suggested models are assessed using an analytical solution and experimental results that were obtained at the University of Michigan. The possibility of the ExB layer mitigation scheme is evaluated in a realistic operating condition for a hypersonic flow. The major contributions of this work to the field include: the analysis of two possible blackout mitigation approaches, the electrostatic sheath and the electromagnetic layer mitigation schemes; the development of the one-dimensional and two-dimensional ExB layer models for optimizing the ExB layer configuration; simulations illustrating the effectiveness of the suggested mitigation schemes; the assessment of the suggested ExB layer model using an analytical solution and experimental measurement; and the illustration of the possibility of the ExB layer as a blackout mitigation scheme with the OREX reentry vehicle and the suggestion of a possible ExB layer configuration for L-band and GPS communication during reentry.