A model is presented for sonic region radiation‐heated flow. Sonic combustion provides a direct and efficient heating method and can meet specific impulse and thrust requirements for orbital insertion and escape. The model allows investigation of flow geometry, real gas effects and stability issues using 1, 2 and 3‐dimensional simulations. Concept feasibility, design optimization and trade studies are possible with this model. The paper introduces the concept of end‐to‐end simulation whereby computer modeling is used for all aspects of beamed energy propulsion from source through path to propulsion module. © 2004 American Institute of Physics