Abstract: A hybrid active cooling system for hypersonic vehicle nosecaps and leading edges integrates a forced convection cooling system with a transpiration cooling system. A pair of concentric shells, hemispherical for a nosecap and cylindrical for a leading edge, are separated by pin fins to form a first manifold for passage of a convection coolant. A second manifold for a transpirant coolant is located behind the first manifold. The pin fins comprise a nonporous structural outer shell surrounding a porous core. The porous cores are open to the inside of the second manifold and to the outside of the first manifold. The outside of the first manifold forms part of the outer surface of the nosecap or leading edge. Convection coolant is pumped through the first manifold to provide forced convection cooling. Transpirant coolant pumped into the second manifold travels through the porous cores of the pin fins to be injected into the atmosphere to provide transpiration cooling.