Abstract: A firing mechanism for portable rocket launchers that includes a percussion activated thermal battery to supply electrical power for arming the warhead and igniting the motor of the rocket contained within the launcher. The energy to activate the thermal battery is not available until a firing pin spring is compressed by the opening of the firing mechanism cover preparatory to firing, and the output of the battery is isolated from the rocket by a normally open electrical switch that is not closed until the trigger mechanism moves to initiate the activation sequence. A safety plate physically blocks movement of the battery firing pin and trigger until positioned by the operator. The trigger and safety plate are arranged for single handed operation while at the same time maintaining a firm grip on the firing mechanism in aiming and firing the rocket launcher.