Grounding Schemes for Small Satellite Systems

Grounding is very essential part of any electrical and electronic system design. Spacecraft is a complex system consisting of multiple complex subsystems electrically connected to each other. Most operations in satellites take place autonomously based on measurements; improper measurements may lead to unintended operation. Spurious triggering of switches and relays due to EMI is also very dangerous in satellites as it consists pyros and propulsion. Spacecraft charging will cause arcing in satellite which may lead to failure of subsystems. These situations sometimes lead to loss of whole satellite and make it irretrievable. Proper grounding is very essential to avoid these kinds of problems. The associated costs of any failure of on orbit satellite are very huge; hence, minute care shall be taken from the design phase to avoid any such problems. The objective of grounding is to ensure the proper operation of the spacecraft and reduction in electromagnetic interference. A good grounding design critically looks into these aspects and tries to minimize such occurrences and henceforth helps in reducing the noise coupling. This paper briefly presents the spacecraft grounding requirements, design approaches, grounding scheme philosophy at satellite level and discusses the different types of grounding schemes in small satellites. This paper also deals with advantages and disadvantages of different grounding schemes in small satellites.