So I was reading about the challenger disaster and came across this report: http://history.nasa.gov/rogersrep/v1ch3.htm Both the Shuttle main engines and the solid rockets operated at reduced thrust approaching and passing through the area of maximum dynamic pressure of 720 pounds per square foot. I listed to rocket launches & they all seem to mention MaxQ but have never seen a value. From the report, 720 pounds per square foot = exactly 5psi. A typical car tyre is 30psi, so the maximum pressure on the space shuttle is about 1/6 of that of a car tyre. That seems low to me so why mention it at all? The recent SpaceX was near Max Q so was that part of the problem, is was vibration the problem? What is Max Q for an airplane?