High-speed boundary layer turbulence is the primary driver for thermal loads on high-speed vehicles. Much research has been conducted to study when, why and how the boundary layer transitions from laminar to turbulent. However, we lack a physics-based understanding of high-speed turbulent boundary layers. Therefore, the Boundary Layer Turbulence (BOLT II), in Memory of Dr. Mike Holden, specifically addresses this lack of understanding through synergistic ground testing, high-fidelity simulations and a flight experiment. Additionally, three approaches to characterizing the stratosphere, in ways that directly affect the boundary layer, contributed to the project to intertwine the boundary layer behavior with the atmosphere.