Numerical Analysis Approach to Aid in Launch Vehicle Lightning Effects Protection Design

Lightning is a critical safety issue for all aerospace vehicles. Commercial aircraft are protected from the effects of lightning strikes per the FAA regulation. Some launch vehicles rely on lightning launch criteria rules to avoid lightning. That launch vehicles can and do get struck by lightning has been recently demonstrated by the Soyuz rocket during a satellite launch on May 27, 2019, through which the rocket persevered and went on to complete its mission successfully (it is unclear what kind of lightning protection design was implemented). In this work we discuss how numerical analysis provides an in-depth understanding of the effects of a lightning strike on a launch vehicle by simulating lightning coupling processes and obtaining transient levels throughout the vehicle on bonds, harnesses, and at box interfaces. This understanding aids in the vehicle lightning protection design and reduces elements of an expensive test program. We accomplish this through a simulation example of a notional launch vehicle.