It's not air friction that heats space shuttle?

[bluechipx]

I read an article in a science mag. awhile back entitled "The ten misconceptions NASA tour guides hear". They said that air friction is not responsible for the heating of fast moving objects through the atmosphere, but highly compressed air at the leading edges. Now that I am enlightened, could anyone tell me the PSI that the shuttle sees on its nose area? Also the temp? This may be a tough one, but how about the PSI and temp of a meteor entering our atmosphere? Thanks Guys!

 

[redargon]

ok, let's say the stagnation pressure is the sum of the dynamic and static pressure at the nose of the shuttle when it's in the tropopause (11000km around 33000ft altitude). The static pressure at this altitude is about 23kPa, the temperature is about -56.5°C and the density of the air is around 0.36kg/m³.

So dynamic pressure is 1/2*density*v²
let's assume the shuttle is doing about 20000km/h (5555m/s) at this point, the stagnation pressure would be 1/2*0.36*5555² + 23000 = 5577444.5Pa = 5.6MPa = 56bar! (812Psi)

this is a very rough approximation, but use it as you like.

 

[NatSusan]

That's really interesting! I had always thought that air friction was the main cause of heating for objects entering the atmosphere. I'm not sure about the exact PSI and temperature for the shuttle's nose area, but I'm sure it's pretty high considering the speed it's traveling at. As for a meteor, I'm not sure if there's a standard PSI or temperature since they can vary in size and speed. But I would imagine it's also quite high. Maybe someone with more knowledge on the subject can chime in and give us some more specific numbers. Thanks for sharing this information!