Beyond pure academic research, a number of application elds raise a challenge. In activities such as planetary exploration, undersea servicing, wo r k i n n uclear plants, or disaster intervention , the dynamics of the environment and the strong constraints on data transmissions call for advanced robot autonomy. In this paper we propose a cooperative robot control system architecture based on a reaction planner. We d e v elop our representation for action and event operators and present a simple algorithm for building robust plans. Finally, w e discuss plan execution and give hints of possible future developments.