Electromagnetic Transients: EMC Testing and Mitigation Methodologies – Recent Trends

Introduction

Spacecraft in synchronous or lower orbits often experience charge build-up on exposed and internal material as a result of geomagnetic storms. The resulting large potential differences can cause incidents of insulation breakdown and electrostatic discharge reaching peak values of several kilovolts. The induced electric current is, in turn, coupled to the terminals of electronic devices, disrupting sensitive digital and analog electronics with possible catastrophic consequences and potential system failure. In the past few decades, various ESD mitigation methods (selection of specific surface materials, grounding techniques, etc.) are being applied by aerospace engineers to modern spacecraft. Nevertheless, equipment-level immunity testing to ESD remains the most reliable method of preventing system failure. International standardization provides test specifications that simulate the flight The ESD phenomena taking place during a flight are reproduced as precisely as possible within the test procedures specified in the international standards.

Apart from the above ESD testing methods, later in this chapter, power bus transients caused by switching loads on and off on the bus will be analyzed. The proposed measurements and immunity test methods of the associated standards are presented and commented on. Some of the Standards presented in this chapter are the Military standard MIL-STD-461 and its latest version (G), the ISO 14302 standard, which specifies the Electromagnetic Compatibility requirements for Space Systems, and the ECSS-E-ST-20-07C European Standard on Electromagnetic Compatibility for space technology of the European Cooperation for Space Standardization. In summary, this chapter aims to present the types and sources of transient electromagnetic phenomena in the space environment, to review and comment on the recent standardization efforts of the various associated bodies, and to propose sufficient protective measures for a robust and electromagnetically compatible space system design.

More specifically, in the “BACKGROUND” section the electromagnetic phenomena expected to occur in the space environment and affect the aerospace systems, as well as their causes are described. The “INTERNATIONAL STANDARDS: TESTING AND MEASUREMENT PROCEDURES” section presents earlier and current testing methods according to different International Standards trying to establish the most accurate simulation and testing of the aforementioned phenomena. Differentiation points as well as the authors’ comments on the preferable methods are presented herein. Finally, the “SOLUTIONS AND RECOMMENDATIONS” section includes design guidelines and mitigation techniques against those types of electromagnetic disturbances crucial during the design process of every aerospace system.