Aerothermodynamics of transatmospheric vehicles

A transatmospheric vehicle (TAV) using air-breathing propulsion requires a long acceleration period within the denser part of the atmosphere to reach orbital speed. The long flight time, coupled with the need for a low-drag configuration, results in the severe heating of parts of the vehicle. The ascent peak stagnation point and wing leading-edge equilibrium wall temperatures are about 3500 and 2600 K respectively, probably requiring some form of mass addition cooling. The corresponding temperatures during entry are 1000 K lower. The vehicle windward centerline temperatures are more moderate, with values peaking around 1300 K during both ascent and entry. Therefore, radiative cooling should be effective over large areas of the vehicle. The windward centerline heat loads during entry are comparable to those for low-acceleration ascent trajectories.