Abstract : The results of a preliminary investigation of the combustion of hydrogen fuel at hypersonic flow conditions are provided. The tests were performed in a generic, constant-area combustor model with test gas supplied by a free-piston-driven reflected-shock tunnel. Static pressure measurements along the combustor wall indicated that burning did occur for combustor inlet conditions of P(sub static) = approx. 19kPa, T(sub static) = approx. 1080K and velocity = approx. 3630 m/s with a fuel equivalence ratio = approx. 0.9. These inlet conditions were obtained by operating the tunnel with stagnation enthalpy H sub s 8.1 M J/kg , stagnation pressure P sub s = approx. 52MPa and a contoured nozzle with a nominal exit Mach number of 5.5.