The present invention is directed to missile training systems, especially to those relating to the provision of a mechanism that allows missiles and similar devices to be fired at a target in a realistic, but safe, manner. The use of live fire exercises, in which army or other armed forces personnel use fully functioning weapons systems is well established. Live fire exercises can be used to provide realistic training scenarios, but also present obvious dangers. The present invention provides a module for attachment to an object (such as a missile), the object being adapted to be directed towards a target (such as a ship), the module comprising a control system providing an output signal indicative of whether or not said object is to be destroyed.