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Satellite Charge Monitor

IP.com Disclosure Number: IPCOM000158042D
Publication Date: 2007-Sep-12
Document File: 4 page(s) / 2M

Publishing Venue

The IP.com Prior Art Database

Abstract

The disclosed Satellite Charge Monitor is an instrument for measuring the effects of deep charging on dielectrics used in the construction of satellites. The instrument uses the principle of electrostatic induction to measure the Field Stress, Resistivity and Breakdown of a dielectric material as well as high energy particle fluence within a test dielectric. The instrument monitors the rate and amount of charge deposited on the test dielectric and provides a measure of how close the test dielectric is to a discharge event. This telemetry is provided in real-time and can be used by satellite operators as an early warning measure of a potential electrical discharge. The test dielectric can be prepared in eight possible configurations. These configurations are divided into two distinct groups; the first group consists of samples configured to measure the charge on the dielectric portion of the test sample whereas the second group consists of samples configured to measure the charge on a central metallic disc. The sample configurations from the first group are well suited for reproducing the typical electrical configurations of dielectrics used in satellites. The sample configurations in the second group are well suited for the study of material properties since the configurations are based on a standard method of dielectric resistivity measurement.

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Page 1 of 4

Satellite Charge Monitor

Mark de Payrebrune Elise Lin

DPL Science Inc. Montreal, Canada

Introduction

The disclosed Satellite Charge Monitor is an instrument for measuring the effects of deep charging on dielectrics used in the construction of satellites. The instrument measures the Field Stress, Resistivity and Breakdown of a dielectric material as well as high energy particle fluence within the dielectric.

While in orbit, a satellite is exposed to high-energy particles from the sun. Deep charging occurs when high-energy particles penetrate the satellite surface and deposit charge inside dielectric materials. With the passage of time, the amount of charge accumulated on a dielectric can grow and may lead to a destructive discharge. Several satellites have been severely damaged or destroyed by these discharges. Secondary or less severe effects include the malfunctioning of equipment due to electrical noise caused by said discharges. A method of controlling these effects is of great interest to satellite operators.

The instrument monitors the rate and amount of charge deposited on a test dielectric and provides a measure of how close the test dielectric is to a discharge event. This telemetry is provided in real-time and can be used by satellite operators as an early warning measure of a potential discharge. An early warning of a potential discharge event will allow the satellite operator to initiate corrective actions (turning on heaters1, turning off sensitive electronics, delaying critical operations) to prevent possible damage to the satellite from a destructive discharge.

Theory of Operation

The disclosed Satellite Charge Monitor presents an instrument that measures the charge on a test sample using the principle of electrostatic induction. The Satellite Charge Monitor, shown in Figure 1, consists of a Vibrating Electrode (1), which is actuated by an electro-mechanical actuator (not shown) causing the Vibrating Electrode to move toward and away from the dielectric Sample Under Test (3). Through the principle of electrostatic induction, an alternating current is induced in the Vibrating Electrode which is proportional to the charge on the dielectric Sample Under Test. The induced current is electronically processed to produce a rectified and filtered voltage which is proportional to the charge on the dielectric Sample Under Test. It is this telemetry voltage that is used by satellite operators to assess the threat of a discharge.

                                                            

1 The Arrhenius effect is used to increase charge leak in dielectrics.

© 2007 DPL Science Inc.

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A Calibration Electrode (2), immediately below the Vibrating Electrode, is connected to a variable voltage source. When the voltage of the Calibration Electro...