ADVANTAGE ED: Back on February 4th, we asked, "did environmentalism kill Columbia?" and looked at the role the EPA played in requiring NASA to change the formulation of the foam used on its external tank.

Today, Stephen Den Beste writes:

In a conclusion I think few will find surprising, it now appears that Columbia was lost because foam insulation broke loose from its external fuel tank during boost and struck its wing, causing damage to the ceramic tiles on the wing which resulted in catastrophic failure during reentry.

The foam on the fuel tank is sprayed on. In 1997 the formulation used was changed. The new version of the foam seems to be much less satisfactory and has a greater tendency to come off, and this change may end up being the "root cause" of the deaths of 7 good people.

So why was the foam changed? The new foam is "environmentally friendly". The older formulation utilized Freon, the new one doesn't. And the danger from foam fragments was identified five years ago from analysis of the first flight to use the newer foam formulation.

They should have changed back immediately once that had been found. They should change back now.

And way to go Rachel Carson, as well.