Hypothetical Altitude question

[Kirk G]

I know that cold air is more dense than warm air. We know this because cold/cool canyon winds flow downhill..."cold air drainage".

And I believe that moist air, containing more "lighter" water molecules, tends to be less dense than dry air.

This leads me to the question, would a given rocket fly higher (all things equal) on a cool day or a warm day...and on a warm moist day or a warm drier day?

Would we see higher flights on a day when it was about to rain? Or on cold dry winter days?

 

[Rex R]

for max speed/altitude you want the lowest density air you can get...the eye of a hurricane would likely give the best results .
Rex

 

[JMZawodny]

The answer all depends upon how fast the rocket is going to fly. If is transonic or slightly supersonic, you want a warm day where the speed of sound is faster. Generally, I'd think a warm humid day with low pressure sounds good - go with the eye of the hurricane suggestion.

 

[bobkrech]

Drag is proportional to density. Altitude causes the greatest reduction in density that you can choose, so pick a launch side with a base altitude over 4150' so you don't have to find a cyclone with a minimum pressure equal to Typhoon Tip. Hot air is also less dense, but you can't always pick your temperature.

A high plains desert environment like Black Rock, or in Colorado, New Mexico or Wyoming on a hot summer day will get you the highest altitude.

Bob