New approach for EMC Assurance of Noise Propagation Effects on Spacecraft Unit

Abstract

In orbit satellite, it is major source of unit malfunction that spacecraft material discharging. The two major reason of malfunction are, 1: Low voltage threshold material/process for creeping discharge, and 2: Weak unit for noise. If the switching unit is affected by noise, critical failure occurs due to the hot-switching. In addition, it is susceptible to noise by using the newest components/COTS.In the through of previous satellite development, we decided that satellite manufacturer selected discharge hardened material, but not enough to evaluate knowledge for effects of noise propagation caused by material discharge. There are two possible propagation paths for the discharge noise: space propagation and panel propagation.Well known as that some unit cannot find problems with existing test methods. The major perspective of current standard test method (from MIL/ESA) are space propagation for coupling of cable. It is not enough to evaporate the influence of panel propagation. The test method that is currently the world's standard is focused on applying noise to cables by spatial propagation. It is not sufficient as a method for evaluating the noise that propagates through the panel and the effects other than the cable.In this paper, we propose the test method to evaluate the effect on the unit for noise propagation on the structure panel, based on our test results performed by the gun generator.First of all, we got Dielectric Surface Breakdowns Voltage of some materials by ELECTRON-BEAM RESISTIVITY TEST that are basic characteristics. After that, the unit was mounted on a satellite model panel (modeling the satellite structure: it is Al honeycomb core/Al skin), and the noise injection test was performed. Measured the threshold at which the device malfunctioned.A simple evaluation model (using Al metal panel) and a satellite model panel were compared, and the same evaluation result as the satellite model panel result was obtained.Therefore, we propose a simple test method using an Al flat panel and a noise source as an evaluation method for the noise propagating through the satellite structure panel.We also introduce our activity to implement our findings into EMC technical standards not only Japanese standard document, but also international standard such as ISO.