Viewing a single comment thread. View all comments

Epcplayer t1_ivy9fxc wrote

I was going off just last week, when he was the NASA director… but yeah, Space Shuttle Columbia as well.

Columbia Accident Investigation Board

> It was the seventh known instance of a piece of foam, from this particular area of the external tank, breaking free during launch.

> The problem of debris shedding from the external tank was well known and had caused shuttle damage on every prior shuttle flight. The damage was usually, but not always, minor. Over time, management gained confidence that it was an acceptable risk.

15

gaunt79 t1_ivycyaj wrote

Columbia University sociologist Diane Vaughan wrote The Challenger Launch Decision to illustrate the theory of "normalization of deviation", in which accepting small deviations from requirements leads to a slippery slope and eventually places a project in an extreme state of nonconformance. She added a section on Columbia in the second edition to show that NASA hadn't actually learned anything from earlier disasters.

12

fjzappa t1_ivym90j wrote

And the reason they used that particular foam was because "more environmentally friendly." Apparently not "astronaut friendly."

2

invaderzim257 t1_ivz31cx wrote

…is that relevant to why it came off of the shuttle? or is it just a point that people can hang on and direct criticism at?

2

fjzappa t1_iw0267j wrote

Yes it's relevant. The foam was a different composition than the original. Original composition foam did not flake off in flight. But it had some pretty strong solvents that were emitted to the air as it cured.

Sauce

> In July 2005, NASA reported that they changed the foam insulation a decade earlier, switching from a foam-blowing agent that used an environmentally damaging chlorofluorocarbon (CFC) to one using a more benign hydrofluorocarbon (HFC) blowing agent. The newer HFC-blown foam insulation is a significant change since it is reported to be more brittle than the originally specified insulation material.

3