LENS II is designed to operate at Mach numbers from 2 to 12 where it duplicates flight velocities from 3,000 to 9000 ft/sec at altitudes down to 3000 ft and became operational in 1998. The large scale of this facility allows CUBRC to test vehicles up to 30 ft in length and can generate Reynolds numbers up to 108. In addition to the reflected shock mode, LENS II can be run as a Ludwieg Tunnel at Mach numbers of 2-4 with a runtime of 1/3 of a second. LENS II played a major role roll in return to flight activities of the Space Shuttle with tests of the integrated launch configuration at duplicated Reynolds number and velocity conditions. Major tests at duplicated flight conditions have been conducted in LENS II to determine the aerothermal loads and the propulsion system performance of a full scale replica of the X-51 Scramjet vehicle, and “Mode Switching” from turbine to ramjet operation with full-scale engine flowpaths has been investigated. Full-scale ground tests at duplicated flight conditions have been conducted to replicate shroud separation from the HyFly Scramjet, and “Hot-Fire” testing has been conducted to examine stage separation of high speed Interceptor launch systems. Fundamental studies of shock wave -turbulent boundary layer interaction have been conducted on flight scale models in high Reynolds Number, high enthalpy flows to provide unique measurements at “flight like” conditions for code development and calibration.