Research is the area of fluid mechanics, specifically laminar- turbulent transition. The focus is on two critical issues: boundary-layer receptivity and the stability of supersonic/hypersonic boundary-layers. The following features of high-speed flight must be addressed and their effects on transition determined: nonequilibrium chemistry and the sweep of the wings. This research will combine the effects of chemistry and sweep and, in the process, determine appropriate shock boundary conditions for the disturbances as well as include the effects of leading-edge bluntness and nonparallelism. The research will consist of both a linear stability analysis and a Parabolized Navier-Stokes (theoretical/numerical) treatment.