I can't recall where I read that the foam insulation was installed to replace some type of freon coolant system.
That under pressure from enviromental wacko's, NASA designed an 'earth-friendly' alternative to the freon system.
Anyone else know of this?
It wasn't a freon coolant system. Freon was used as in an aerosol form to apply the "old" foam insulation onto the Booster. When "ozone depleting substances" (ODS's) were outlawed a few years back, a different method was developed that did not use freon - this new method was not as efficient as the freon method and often led to debonding of the insulation from the skin of the booster.