Ah, I found an oblique reference in the New York Times: "NASA engineers had already seen how fixes can break things. After they made a minor change in the foam application process in the late 1990's to comply with environmental rules, small divots of foam rained off of the tank during ascent. The phenomenon, called popcorning, was caused by trapped bubbles; NASA solved the problem by venting the foam with tiny holes, but it was a reminder, if any was needed, that seemingly small changes could have profound effects." This come from: http://nytimes.com/2005/07/31/science/space/31foam.html? hp&ex=1122782400&en=f35a8f54ae5625aa&ei=5094&partner=homepage (Access to this link may require you to register with NYTimes.com...) So it would appear that they did have a problem born of the CFC elimination, and subsequently solved. Still, I want to know more... Jim On Jul 29, 2005, at 7:43 PM, Jim Cobb:
I've been waiting for some mention of the possible role the CFC, ozone hole, scare may have played in the destruction of Columbia and NASA's subsequent problems.