Use of Modeling to Design Lightning Protection on Launch Vehicle 2001-01-2900
This paper focuses on advanced electromagnetic computational tools used for designing protection against the indirect lightning effects on launch vehicles.
The launcher design has to integrate lightning requirements determined by a lightning risk and risk coupling analysis.
Lightning currents couple with the launcher avionics mainly through cables running externally along the booster stages where they are the most exposed. These cables are generally protected by ducts which are made either of conductive or dielectric material. In the last case,. If the duct is dielectric, the cable bundles have to be protected by braided overshielding. When it is made of aluminium alloy, it is obviously attempting to use the duct itself as overshielding.
A cable duct is a complex mechanical assembly. Its electromagnetic attenuation is more difficult to control than that of a braided overshielding.
In order to provide quick reliable advice, electromagnetic coupling of the cable duct bundles is calculated and the duct’s electromagnetic efficiency is quickly characterised.
To conclude the analysis, the cable duct definition is corrected in accordance with modeling results.
This avoids late hardware changes and thereby cost overshoots and schedule delays.