The Nammo Space Safe and Arm Device has been developed and qualified for use on the Ariane 5 and Vega launchers. It has also been used on the VLS and KSLV launch vehicles.
The primary function of the Nammo safe and arm device is to prevent accidental transmission of the main detonation command prior to the arming command, and to allow detonation signal transfer once the device is armed. This is an electromechanical device. The unit is remotely controlled, and the change between the two stable positions is performed by the electrical motor in the device. The safe and arm device can be assembled and disassembled without the use of special tooling.
The device contains a status indicator that shows the position of the barrier, in either the safe or armed positions. The Nammo safe and arm device is shock and vibration resistant, signifying that the barrier will not to inadvertently change position from the set positions. The Nammo safe and arm device is used in mission critical applications where reliability is essential. The actuator uses an electrical DC brush motor as the active element. The power supply and electrical signals are transferred through three connectors defining the electrical system interface.
Actuation of the motor is initiated by the safe/arm command from the system. The motor operates the barrier and four micro switches for passive electrical status indication. The speed of the motor is adapted to the arming time requirement by using of a reduction gear.