Programme Element: ARTES 5.1
Reference nr.: 13.1TT.09
Planned Tender Issue: quarter 3, 2013
The objective of this activity is to develop a process that withstands in-orbit ageing and is able to enhance the overall electrical conductivity of widely used materials in order to prevent charging and differential charging.
Targeted Improvements: Reduce ESD and secondary arcing risks on walls and solar arrays, enhance sustainability and availability.
Spacecraft in geostationary or MEO orbits are subjected to electrical charging and can reach highly negative potentials. Dielectrics situated in the external areas of the spacecraft are directly exposed to the space environment, and due to their properties (secondary electron emission, electrical conductivity) they reach differential potential with respect to the satellite. This can result in electrostatic discharges (ESD) and destructive discharges when such events occur near available power. While some solutions to reduce ESD risks have been proposed, further improvement is still needed.
As coverglass and OSR are one of the most used dielectrics for external applications on telecommunication satellites, the focus of this study will be on these two dielectrics. In this case the new process shall not diminish the overall functional optical properties in the EOL and BOL cases and this process have to be able to sustain the ageing tests (radiation and thermal cycles under vacuum).
Task 1: Critical review of the requirements for charging properties and optical functional properties.
Task 2: Review of the state of the art technologies and processes for the candidate materials.
Task 3: Identification and analysis of the materials that could be used to satisfy the requirements established in Task 1.
Task 4: (as required) development of a new material.
Task 5: Manufacturing and/or procurement of samples
Task 6: Tests on samples of the different techniques in order to select the most appropriate technique.
Tests shall include optical properties measurements and detailed electrical properties characterisation: Surface and bulk electrical conductivity, radiation induced conductivity under electron beam irradiation.
Characterisation of the critical properties in the End Of Life case is particularly important: representative ageing tests have to be done with an emphasis on synergistic effects. Vacuum thermal cycles, protons and electron irradiation with a representative dose profile, UV irradiation shall be performed to fully characterise the process.