PRACTICEPRACTICE NO.NO. PD-ED-1231PD-ED-1231
PREFERREDPREFERRED
RELIABILITYRELIABILITY
PRACTICESPRACTICES
PAGEPAGE 11OFOF 77
DESIGNDESIGN CONSIDERATIONSCONSIDERATIONS FORFOR
LIGHTNINGLIGHTNING STRIKESTRIKE
SURVIVABILITYSURVIVABILITY
Practice:
LEWIS
RESEARCH
CENTER
Implement lightning survivability in the design of launch vehicles to avoid lightning induced
failures.
Benefits:
Experience learned from the Atlas/Centaur and Space Shuttle flights serve to emphasize the
importance of the implementation of the proper protection/design enhancements to avoid and
survive natural or triggered lightning for all launches.
Programs Which Certified Usage:
Saturn, Atlas/Centaur, Titan, Space Shuttle
Center to Contact for More Information:
Lewis Research Center, Kennedy Space Center, Marshall Space Flight Center
Implementation Method:
Due to the lightning strike incident on Apollo 12, the AC-67 failure, and the numerous
lightning strikes to the shuttle launch complex at 39-B, significant changes were made to
improve electromagnetic compatibility (EMC) of launch vehicles and ground support
equipment. The EMC approach is essentially the same for all of these vehicles with special
considerations given to specific payload and launch requirements. The Atlas/Centaur and the
Shuttle protection design are described in Reference 2.
The major areas that a designer needs to address for lightning and transient hardening are:
proper grounding of vehicle and ground support equipment, bonding requirements, and circuit
protection. This is accomplished primarily through wire shielding and secondarily through
transient limiters. Following the detailed requirements will limit the damage inflicted by
lightning or high current transients.
Ground Support Equipment
The Launch System Fixed Service Structure (FSS) stands considerably
taller than the airborne vehicle, creating a 45
o
"cone of protection" relative
Downloaded from http://www.everyspec.com
