[wcbtinman]

Don't forget also that the area where the ice forms is inside a low pressure area of the slipstream. Lowered pressure could cause ice to form under otherwise inhibited conditions.

[holden]

Thanks for your interest and comment.

Dependent upon the surface temperatures of the ET, one may need to look upon the entire structure as a moving, condenser-freezer which will inherently and actively generate copious quantities of ice.

Visible moisture is not an absolute requirement in the context of something, the surface temperature of which is far below the moisture-laden environment through which it flies.

I wonder what simulation models NASA has used to insure to itself that such predictable problems not cause its orbiters to be fatally compromised.

HF