Abstract: An active IR signature target simulation system which includes: a platform having a known temperature profile and a preplanned flight trajectory; a heat source carried onboard the platform, capable of producing heat following a controlled heating plan; and a control unit connected to the heat source and configured for initiating the heat source, thereby modifying the known temperature profile and generating a desired temperature profile required for sensing a simulated target IR signature during a simulation time window at a desired line of sight from the platform to an observing sensor, wherein the platform is an exo-atmospheric missile which includes an inner shell and a perforated outer shell, and wherein the heat source is a thermally active material disposed between at least a part of the inner shell and a part of the outer shell.