OUR PROPOSED EXPERIMENTAL AND THEORETICAL RESEARCH WILL MAKE A.LASTING CONTRIBUTION TO THE COMPLEX PROBLEM OF PREDICTING THERMOCHEMICAL AND RADIATIVE.ENVIRONMENTS ASSOCIATED WITH HYPERSONIC ATMOSPHERIC ENTRY THROUGH A CHEMISTRY-FOCUSED.APPROACH. UNDERSTANDING AND PREDICTING THE RADIATIVE HEAT FLUX TO THE VEHICLE SURFACE IS A.CONSIDERABLE CHALLENGE AND REMAINS ONE OF THE MOST UNCERTAIN ASPECTS OF THERMAL PROTECTION SYSTEM (TPS) DESIGN. AS DISCUSSED IN THE CALL FOR PROPOSALS UNDERSTANDING THE RADIATIVE HEAT FLUX TO THE VEHICLE BACKSHELL HAS BEEN AN ONGOING CHALLENGE. MORE IMPORTANTLY PERHAPS NEW NASA MISSIONS SUCH AS MARS SAMPLE RETURN INVOLVE EXTREME RE-ENTRY CONDITIONS AND WILL REQUIRE AN.UNPRECEDENTED LEVEL OF CERTAINTY IN A MINISCULE CHANCE OF TPS FAILURE. THE RADIATION PROBLEM.COMBINES FLUID DYNAMICS HIGH-TEMPERATURE GAS-PHASE AND GAS-SURFACE CHEMISTRY MATERIAL.RESPONSE AND ABSORPTION AND EMISSION OF RADIATION WHERE ALL PROCESSES OCCUR UNDER.NONEQUILIBRIUM CONDITIONS. THE PARTICULAR PROBLEM WE PROPOSE TO STUDY IS THE INTERACTION OF TPS.ABLATION PRODUCTS AND DISSOCIATED AIR SPECIES IN THE BOUNDARY LAYER OF A CARBON-BASED ABLATOR WHERE GAS-PHASE REACTIONS RESULT IN THE FORMATION OF HIGHLY INTERNALLY EXCITED PRODUCTS WHICH RADIATE STRONGLY AND MAY ALSO ADSORB RADIATION THEREBY DICTATING THE RADIATIVE HEAT FLUX.