Phase I shall determine if the phenomena and material performances being observed in MLBC ground tests simulating Extended Range trajectories envisioned for TSVs are representative of actual flight. In this effort, preliminary thermal-ablation models will be developed for the class of C-C currently showing great promise in TSV missions. The Catalytic Wall analytical techniques developed for NASA reentry TPS shall be applied to these thermal-ablation models and recent MLBC ground tests. From these correlations, the analyses will determine the Catalytic Wall and Kinetic coefficients of the selected materials. These coefficients and analyses shall be applied to representative points on a TSV flight trajectory to determine the importance of Catalytic Wall and Chemical Kinetics in flight. These results shall determine if the ground tests are simulating flight and if not, then what needs to be done to improve the ground test evaluation methods