Accurate numerical modeling of the aerothermal environment around an ablation-cooled hypersonic re-entry vehicle requires high-fidelity models for processes such as non-equilibrium surface themochemistry, non-equilibrium pyrolysis chemistry, multi-scale radiation, spallation and charring. It is expected that, these models when utilized in a coupled manner will be able to accurately capture the possible nonlinear interactions between various phenomena in a computationally efficient manner. Development of a coupled radiative solver is currently being carried out as part of a joint effort between CFDRC, University of Michigan and University of Kentucky to develop a fully coupled method of simulating atmospheric entry flows and response of the thermal protection system. A key aspect of the project is development of a modular radiative transfer equation (RTE) solver which can be used in a tightly coupled manner with any hypersonic flow code. The code will be coupled with latest spectral property databases allowing almost line-by-line accuracy for radiative heat-fluxes on the spacecraft surface while still utilizing a multidimensional RTE formulation. The presentation will focus on architecture of the RTE solver, radiative property models that can be used in the solver and its interfacing with LeMANS aerothermal code for a simple demonstration case. The infrastructure to couple the solver with other codes of interest will be outlined