CliveL
Is the R = rankine?
As for the second diagram regarding temperatures of an object at Mach 25... how the hell did such a blunt object get up to 6,000 K? That's 10,340 F -- blunt objects generally achieve lower skin temperatures than do sharp objects which is why they're used. IIRC, the space shuttle on reentry reached something like 1,650 to 1,750 C