SpaceWire

SpaceWire is a point-to-point bit shipping protocol for high-speed data communication links and networks providing equipment compatibility and seamless component reusability. It has found great application in many space missions reducing the development cost, offering architectural flexibility and improving reliability. This chapter delves into the standard describing the SpaceWire, focusing on the lower levels that play a key role in the electromagnetic behavior of the system and concern cable assemblies, shielding, bonding, and grounding. Findings regarding emissions affecting spacecraft components are presented as well as other EMC issues that have an impact on the system performance. Recent developments and upcoming updates to the standard are also presented and discussed.

Magnetic Sensors for Space Applications

This chapter is composed of three parts. The first is an introductory part, providing general information about magnetism and related phenomena. Magnetic materials are also discussed and presented. Afterwards, the magnetic field and various measurement techniques are discussed. In the second part, different magnetic sensors used in a laboratory or space are presented. Magnetic sensors that are discussed include anisotropic magneto-resistance (AMR), giant magneto-resistance (GMR), giant magneto-impedance (GMI), flux-gate and superconducting quantum interference device (SQUID). Although some of them may be outdated and well known, they are widespread and they still pose an excellent choice for certain applications. Magnetic cleanliness is an important factor both in calibration and in normal operation of a system; in the third part, current techniques to isolate a system from the external magnetic field providing cleanliness are discussed.

Transient Electromagnetic Phenomena–Standardization and EMC Requirements–Mitigation Techniques

In this chapter, the spacecraft charging effects that lead to ESD events, as well as the associated immunity testing required, are presented in detail and compared to the human-induced discharges, mainly simulated by most commercial ESD generators. Additionally, design guidelines for mitigating the effects of these ESD occurrences, essential for every space application designer, are discussed. Finally, the measurement requirements, as well as the test setups, regarding the immunity testing to power leads transients are described thoroughly. This chapter aims at reviewing the current international standards and the recent bibliography, summarizing and commenting on the EMC requirements, regarding the transient phenomena, pinpointing the differentiations of these standards and their effects on the design procedure and testing creditability.

Electromagnetic Compatibility for Space Applications

In a space system or equipment, electromagnetic compatibility is a critical aspect affecting its operation, function, and performance. In the beginning of this chapter, an overview of the electromagnetic compatibility main considerations is provided. Then the main electromagnetic compatibility standards and relative useful handbooks for space applications are briefly presented. Testing methods and procedures to assess electromagnetic compatibility of space systems and units are discussed briefly covering all kinds of measurements. Moreover, information regarding the instrumentation and the testing facilities is also provided. Mission testing requirements and limits are also presented as examples for every electromagnetic compatibility test. Recent developments in test methods are also discussed where applicable.

Magnetic Dipole Modeling for DC and Low Frequency AC Magnetic Fields in Space Missions

In this chapter, modeling methods of static and slowly varying magnetic field emissions that are generated by spacecraft equipment are analyzed and discussed. In particular, specific issues on the established methods for multiple magnetic dipole modeling (MDM) are investigated and validated via near field measurements of well-behaved magnetic sources. Moreover, a software-based calibration technique for measuring facilities, dedicated to magnetic characterization of spacecraft units, is described and implemented on a configuration consisting of 12 sensors. Due to increasingly strict magnetic cleanliness demands, the modeling of units' induced DC magnetic behavior has become a necessary requirement for various space missions. Therefore, a baseline methodology regarding the measurements and modeling of induced magnetic fields is presented. Finally, DC methods are complemented to cover AC magnetic cleanliness requirements for on-ground verification of low-frequency magnetic fields, including AC induced magnetization effects.

Progress in Advanced Materials Used in Electromagnetic Interference Shielding for Space Applications

Aerospace applications experience electromagnetic interference produced by the space environment and by the materials, devices, and systems used in satellites, space shuttles, the international space station, and airplanes. The advanced materials represent a technological possibility to develop coatings that are able to offer a better shielding effectiveness against electromagnetic interference due to the possibility of controlling its electrical and magnetic properties as well as to that the size of the materials is very similar to the electromagnetic waves that it receives. In this chapter, an analysis of progress over advanced materials is presented with the aim of diffusing the role that nanomaterials have had, have and will have to increase the shielding to electromagnetic interference. Nanomaterials will protect aerospace components in the range of Hz to THz, but the huge advantage is that the range of protection can be optimized according to the technical requirements with a considerable weight reduction.

Extremely Low Frequency Electric Field Emissions for Space Applications

This chapter focuses on understanding the behavior of the extremely low frequency (ELF) electric field emissions of EUTs from spacecraft subsystems and on reviewing reliable equivalent models combining measurement techniques in order to acquire a complete system electromagnetic cleanliness. More precise time variations of the electric fields produced by spacecraft equipment have to be characterized, measured, and modeled. The proposed methodology is employing equivalent dipole modeling (EDM) to describe the ELF electric field spectral dependency. Each spectral component of the measured field is considered isolated and produced by one electric dipole. In order to validate the accuracy of the proposed methodology, various ELF signals in different distances are studied. In addition, since the validation of the proposed methodology would require “on ground” measurements and due to the low-frequency range, test facilities decoupling techniques are discussed. Moreover, early considerations including contributing phenomena for the complete spacecraft system modeling are reviewed.

Numerical Assessment in Aeronautics for Electromagnetic Environmental Effects

Electrical and electronic systems on board air vehicles are susceptible to electromagnetic interference (EMI). This has made the topic of electromagnetic compatibility (EMC), a major concern for aircraft safety. The use of composite materials worsens this situation, for their poor shielding and low conductive capabilities. Some of the main experimental E3 certification scenarios used in aeronautics are revisited in this chapter. Guidelines to achieve simple, yet accurate, numerical models of them are provided, with appropriate tradeoffs between computational simplicity and accuracy. The numerical method, endowed with extended capabilities, has been chosen for this task for its ability and efficiency to deal with complex problems of arbitrary materials. The feature selective validation (FSV) IEEE standard procedure, commonly used to quantify the comparison of data in electromagnetic problems, is also revisited. The simulation of three different air vehicles in several certification scenarios is finally described and the numerical results compared to experimental data.