True Airspeed (TAS) is the vehicle speed relative to the surrounding air. My assumption is that if I am in orbit say at 120 km altitude with an instantaneous velocity of 8 km/s my TAS would be fairly close to 8 km/s even though my Indicated Airspeed (IAS) shows zero.
Assuming the above holds true, the "ram rise" (RR) formulas I find are all based on Mach (which, in turn, is based on TAS) or TAS directly. They do not appear to take into account the static pressure or atmospheric composition, only the adiabatic index. Therefore, my TAT (OAT plus ram rise) is in the thousands of degrees Kelvin ... which makes no sense because there are practically no molecules of air to hit!
So are these RR=TAS²/87 formulas assuming to be used below a specific altitude? I can't find anything for orbit or reentry. I also can't find any space shuttle telemetry to corroborate the TAS assumptions I made above. I am aware there is also a Mach-based RR formula and it has the same problem.
Your help is sure appreciated!