# How much lower is max q if launching from high altitude (i.e. mountain top)?

I looked at very simple max q formula: q=1/2 ρv^2 (https://en.wikipedia.org/wiki/Max_q). As air density is lower with altitude, the max q should be lower as well, and also should occur at higher altitude. using this formula, I estimated for Falcon 9 that Mount Everest should reduce max q by 16 times, compared to sea level launch and max-Q altitude increases about from 7km to 11 km.

But then I saw this post: Is it possible to calculate Max-Q without having to input an altitude, which basically says "it's complicated". Is it possible to significantly reduce real max q by launching of high altitude? And by how much?

• Hmmm.. somewhere in there you have to posit an acceleration profile so you know the speed as a func of time and therefore as a func of altitude. I"m guessing you expect the same profile, in which case graphing $\rho*v^2$ vs. time is easy; but if you start at higher altitude, drag is less, so the accel profile for the same thrust profile will differ. Jan 15 at 12:53
• Hopefully someone with a simulation will run this. Interesting. Jan 15 at 15:36