What are the unique aerodynamic challenges in hypersonic flight regime?

Hypersonic flight (M > 5) presents unique challenges: Thin shock layers with strong viscous interaction require combined inviscid-viscous analysis; High temperature effects including real gas chemistry, dissociation, and ionization change flow properties; Extreme aerodynamic heating requires thermal protection and affects structural design; Low lift-to-drag ratios (typically 3-5) limit range and maneuverability; Boundary layer transition at high temperatures affects heating predictions. Analysis requires specialized CFD with high-temperature thermochemistry, non-equilibrium models, and radiation coupling. Design examples include X-15, Space Shuttle (blunt body for heating management), and hypersonic vehicles like X-43 (scramjet integration).