Safe and Arm Device

Product Description

An Electronic Safe and Arm Device (ESAD) provides safety critical energetic systems initiation on command, when commanded for flight termination, solid rocket motors, warheads etc. Designed for applications where a reliable arming and firing sequence with precise timing events is vital. Used for flight termination systems and rocket motor ignition, our ESADs meet the stringent requirements of RCC-319 and MIL-STD-1901A.

Utilized with our Bulk Destruct Charge or Linear Shaped Charge, our fully electronic device interfaces with a flight termination receiver, or mission controller, through a customizable input connector. This device outputs a high voltage firing current to initiate single or dual Low Energy Exploding Foil Initiators (LEEFIs). Our ESADs can be integral with the LEEFI energetic output or can initiate the LEEFIs through a high voltage flex tip. Also referred to as a high-energy electronic initiator firing unit, this device meets safety board requirements by incorporating two unique inhibits that must be satisfied prior to firing. Both “armed on the ground” and “armed after safe separation” approved variants are available.

Product Description

The Electro-mechanical Safe and Arm Device purpose is to prevent catastrophic damage from accidental arming of a device, during shipping, handling and storage, by initiating an explosive train only when needed.  At the same time, the device arms the ordnance at the proper time when all of a set of predetermined conditions have been met. The safe and arm device will only initiate when it senses it has either hit or is in close proximity to the target.

The main function is to mitigate the hazards associated with the initiation of explosives by preventing inadvertent initiation while at the same time assuring the ordnance will detonate on command and only when commanded.

They are used in mission critical applications where a reliable initiation device that is intrinsically safe from inadvertent firing is required. Typical applications needing these mission critical attributes include rocket or missile motor ignition, stage separation, and flight termination. Our Electro-mechanical Safe & Arm Device (ESAD) designs are qualified and extensively used on a multitude of launch vehicle and missile platforms, including Atlas, Delta, and Antares to name a few. The design principles of safety and arming devices can be found outlined here.

The Electro-Mechanical Safe and Arm still uses a low voltage bridgewire initiator, however the initiator is integrated internally to the SAD and a mechanical device physically moves or rotates the initiator to a state where even if inadvertent initiation occurred, no pyrotechnic event transfers out of the SAD device. An internal initiator is physically rotated out of line inside the safe and arm from the output pyrotechnics, hence they are referred to as “Out-of-line” Safe and Arms.

If the low voltage initiator were to inadvertently initiate, it will not transfer any energy to the next device in the pyrotechnic chain. To be armed, the internal initiator must be mechanically rotated from an out of line state to an inline state prior to firing and it is only in that state that the initiator would reliably transfer energy to the next pyrotechnic in the chain.

•  If a low voltage initiator is needed it can be coupled with an electromechanical SAD and still use a low voltage bridgewire type initiator.
• Arming an electromechanical safe and arm requires mechanical rotation of the initiator from an out-of-line state to an in-line-state prior to firing.