Abstract: The fuze is armed only if muzzle exit is sensed by a magnetic sensor within a predetermined time after setback is sensed and either one or both of a minimum spin rate is sensed by the magnetic sensor and/or a minimum number of turns are counted.

Abstract: The inventive environment sensor apparatus includes an electrostatic sensor carried by the projectile. The electrostatic sensor has first and second electrical conducting areas separated by a dielectric material to form two plates of a capacitor. The first electrical conducting area is conductively connected to a current-to-voltage converter and the second electrical conducting area is conductively connected to the outside projectile body surface. A time changing electric field surrounding the projectile causes a time changing current to flow within the electrostatic sensor, which is converted to a time changing voltage by the current-to-voltage converter. A threshold detector device is conductively connected to an output of the current-to-voltage converter and provides a voltage signal to the safe and arm mechanism when the time changing voltage signal from the current-to-voltage converter exceeds a predetermined level, to indicate that a change has occurred in the sensed muzzle exit environment.