Electromagnetic shielding of thermal protection system for hypersonic vehicles M. Albano a , D. Micheli a , G. Gradoni b , R.B. Morles a , M. Marchetti a , F. Moglie c,n , V. Mariani Primiani c a Sapienza Universit  a di Roma, Dipartimento di Ingegneria Astronautica Elettrica ed Energetica, Area Ingegneria Astronautica, Via Salaria 851, 00138 Roma, Italy b Department of Physics, University of Maryland, Paint Branch Drive, College Park, MD 20742, USA c Universit  a Politecnica delle Marche, Dipartimento di Ingegneria dell’Informazione, Via Brecce Bianche 12, 60131 Ancona, Italy article info Article history: Received 24 November 2012 Received in revised form 30 January 2013 Accepted 4 February 2013 Available online 11 February 2013 Keywords: Electromagnetic shielding effectiveness Carbon foam Carbon/carbon Carbon silicon carbide Reverberation chamber Space re-entry vehicle Thermal protection system Numerical simulation abstract The numerical simulation and the measurement of electromagnetic shielding at micro- wave frequencies of thermal protection system for hypersonic vehicles is presented using nested reverberation chamber. An example of a possible thermal protection system for a re-entry vehicle is presented. This system based on carbon material is electro- magnetically characterized. The characterization takes into account not only the materials but also the final assembly configuration of the thermal protection system. The frequency range is 2–8 GHz. The results of measurements and simulations show that the microwave shielding effectiveness of carbon materials is above 60 dB for a single tile and that the tile inter-distance is able to downgrade the shielding effectiveness on the average to about 40 dB. & 2013 IAA. Published by Elsevier Ltd. All rights reserved. 1. Introduction Heat shields development started with ATLAS in 1950. Although big results and improvements have been done, the aim of today’s research is to develop a light and reusable thermal protection system (TPS), here presented. In the physics of flows, the hypersonic regime is defined as the realm of speed where aerodynamic heating is dominating. This heating is far more intense than at speeds that are merely supersonic [1, 2]. Typically the hypersonic vehicle reaches the highest altitudes on board of a launcher such as ‘‘Vega launcher’’ for the future ‘‘Intermediate eXperimental Vehicle’’ (IXV) [3]. Then the vehicle leaves the launcher and starts its real mission. In Fig. 1 a simple schematic of the mission profile for a hypersonic vehicle is shown. For this reason the hypersonic condition is far one of the most critical for a space structure life. Resistance of materials is hard tested by fast chemical reactions so that sublimation and ablation easily can take place. Nowadays limitation of costs is pushing to the necessity to develop a lightweight and reusable thermal protection system. Many international programs, such as IXV (ESA) [4], X-vehicles (US) [5], HYFLEX (JP) [6], and ASA (IT) [7] are developing materials and structures which can be reused. In particular, IXV is the European program whose aim is to demonstrate hypersonic un-powered maneuvering re- entry flight of a lifting configuration. This is a test vehicle to qualify during the flight several key re-entry systems and technologies necessary for multiple space applications Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/actaastro Acta Astronautica 0094-5765/$ - see front matter & 2013 IAA. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.actaastro.2013.02.003 n Corresponding author. Tel.: þ39 071 2204445; fax: þ39 071 2204224. E-mail address: f.moglie@univpm.it (F. Moglie). Acta Astronautica 87 (2013) 30–39