Was the Space Shuttle Columbia Downed by Greens?

I don't usually listen to Rush Limbaugh. Nothing against Rush, but the local station runs his show from 1 to 3 in the afternoon, and I'm usually doing other things. But today I happened to be driving down to Target to get some new golf spikes, the better to tread on the faces of the proletariat like a good capitalist pig.

Roger Hedgecock was filling in for Rush and he said something so outrageous that I thought he must be joking. Hedgecock claimed that the problems with the insulating foam on the Space Shuttles only cropped up after Freon was replaced with other materials due to environmental concerns. It doesn't get much press, but apparently Hedgecock was right.

From Richard Bennett's Mossback Culture (February 2, 2003):

So concerns about the effects of freon on the ozone layer lead directly to the crash of the Shuttle, apparently. You'd think NASA would be able to get some kind of a waiver on this stuff.

Bennett quotes from a Mercury News article:

As recently as last September, a retired engineering manager for Lockheed Martin, the contractor that assembles the tanks, told a conference in New Orleans that developing a new foam to meet environmental standards had "been much more difficult than anticipated."
The retired Lockheed engineer, who helped design the thermal protection system, said the switch from a foam based on Freon - also known as CFC-11 - has "resulted in unanticipated program impacts, such as foam loss during flight."

Unfortunately, the article is no longer available online. Of course, you only find this out after filling out the nosy registration form and being solicited for a couple hundred spammers - thanks, Mercury.

NASA officially blames foam loss during flight on hand spraying techniques that leave voids in the foam in this document, but this News Max story lays the blame squarely on the Freon substitute:

As recently as last month, NASA had been warned that foam insulation on the space shuttle's external fuel tank could sheer off as it did in the 2003 Columbia disaster - a problem that has plagued space shuttle flights since NASA switched to a non-Freon-based type of foam insulation to comply with Clinton administration Environmental Protection Agency regulations.

The thought that the Columbia astronauts died in the name of political correctness is awful. Surely the amount of Freon used in the Space Shuttle program couldn't have had any measurable effect on the environment.