A hypersonic aircraft includes one or more leading edge assemblies that are designed to cool the leading edge of certain portions of the hypersonic aircraft that are exposed to high thermal loads, such as extremely high temperatures and/or thermal gradients. Specifically, the leading edge assemblies may include an outer wall tapered to a leading edge or stagnation point. A coolant supply provides a flow of cooling fluid to a porous tip that is joined to the forward end of the outer wall and defines variable porosity and/or internal barriers to direct a flow of cooling fluid to the regions of the leading edge experiencing the highest thermal loading.