stream of superplastically deformed metal formed from trumpet-shaped metallic liners. The result is a narrow high velocity particle stream that can penetrate armor. The Javelin counters the advent of explosive reactive armor (ERA). ERA boxes or tiles lying over a vehicle's main armor explode when struck by a warhead. This explosion does not harm the vehicle's main armor, but causes steel panels to fly across the path of a HEAT round's narrow particle stream, disrupting its focus and leaving it unable to cut through the main armor. The Javelin uses two shaped-charge warheads in tandem. The weak, smaller diameter HEAT precursor charge detonates the ERA, clearing the way for the much larger diameter HEAT warhead, which then penetrates the target's primary armor. A two-layered molybdenum liner is used for the precursor and a copper liner for the main warhead. To protect the main charge from the explosive blast, shock, and debris caused by the impact of the missile's nose and the detonation of the precursor charge, a blast shield is used between the two charges. This was the first composite material blast shield and the first that had a hole through the middle to provide a jet that is less diffuse. A newer main charge liner produces a higher velocity jet. While making the warhead smaller, this change makes it more effective, leaving more room for propellant for the main rocket motor, and thus increasing the missile's range. Electronic arming and fusing, called Electronic Safe Arming and Fire (ESAF), is present on the Javelin. The ESAF system enables the firing and arming process to proceed, while imposing a series of safety checks on the missile. ESAF cues the launch motor after the trigger is pulled. When the missile reaches a key acceleration point (indicating that it has cleared the launch tube), the ESAF initiates a second arming signal to fire the flight motor. After another check on missile conditions (target lock check), ESAF initiates final arming to enable the warheads for detonation upon target impact. When the missile strikes the target, ESAF enables the tandem warhead function (provide appropriate time between the detonation of the precursor charge and the detonation of the main charge). Though the Javelin's tandem HEAT warhead has proven efficient at destroying tanks, most threats it was employed against in Iraq and Afghanistan were weapon crews and teams, buildings, and lightly armored and unarmored vehicles. To make