Impact of range safety requirements on electronic S and A (Safe and Arming Device) design

The use of a tactical Safe and Arming Device (S and A) as a flight termination system for range safety creates some conflicting requirements on the design of the unit. The purpose for a flight termination system (FTS) is to detonate the weapon under any unforeseen set of circumstances, while the purpose of a tactical S and A Device is to prevent weapon detonation for all but the intended flight profile. With the advent of the all-electronic S and A, the ramifications of the dual requirements on the design of the system should be examined. As viewed from the S and A design vantage point, the issue of range safety is really a reliability issue and not a safety issue. The purpose of the range safety policies is to ensure that the unit used to terminate the flight of a missile will function under any expected or unforeseen set of circumstances which the missile might encounter during its flight. This calls for a flight termination system which must function with ultra-high reliability and with special design features which allow it to operate even under flight environments beyond the tactical requirements. Henceforth, when the issue of range safety is discussed, itmore » will be done so under the guise of the reliability of the flight termination unit, be it the tactical S and A or not.« less