'Robot Cars Can't Count on Us in an Emergency'

General Discussion
121

They just feel left out. Why should the guys on the other side have all the fun?

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Sorry, Shadowfax, but that is NOT correct.

The SRBs for the STS had a defined “performance envelope.” Specifically mentioned in said envelope was a “minimum temperature for takeoff.” NASA brass explicitly decided to launch OUTSIDE of the performance envelope, to the disgust of Morton-Thiokol, the manufacturer of the SRBs. M-T went so far as to send a letter on company letterhead explicitly stating they did NOT consider the SRBs “airworthy” given the launch conditions.

NASA’s response was to “play ostrich,” and silence internal dissent by saying “take off your ‘safety hat’ and put on your ‘management hat.’”

It is a smirch on our nation that somebody in NASA management didn’t serve a decade-plus behind bars for the wholly preventable loss of life. The SRBs had, and continue to have, a 100% safety and reliability record, when operated within their design performance envelope, and I won’t let you besmirch Morton-Thiokol’s EXCELLENT design as a result of HUMAN ERROR secondary to a DYSFUNCTIONAL management style that existed (and IMHO, still exists) at NASA.

This stuff would have NEVER happened under Wehrner VonBraun: VonBraun was a “astronauts-first” leader, and he made certain their safety and health was looked after, even when engineered-in redundancy led to cost overruns
better “make it back alive” than “make it back under budget.” He was NASA’s “moral compass,” and the organization has never truly filled his shoes. (And yes, I’m aware of the inherent irony of Wehrner VonBraun, of all people, being a “moral compass,” but facts are facts.)

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123

Everything you said about NASA’s safety culture and management style is true, but it was also a flawed design because even when operated within its performance envelope, on several occasions burnthrough of the O-rings was observed. This was because the joint would flex under load, and the rubber couldn’t always react quickly enough to seal the joint.

In fact this was a known design flaw since before Columbia’s first flight, as a 1977 water pressure test showed that the joint could separate and allow burnthrough. SRB project manager George Hardy received numerous memos to that effect during development, but declined to forward them up the chain and so the design was approved despite known flaws.

Even after STS 41-D in 1984, when burnthrough was very clearly observed including soot being found on the outside of the rocket, NASA chose to ignore the design flaw and instead essentially say “we got away with it this time, and therefore we will get away with it every time” - this was the crux of Feynman’s appendix in the Rogers Commission report - the safety goalposts kept getting moved in order to continue launching despite complete knowledge of the design flaw.

True the design flaw was greatly exacerbated by launching in low temperatures, but it was there nonetheless.

Put another way, if it wasn’t a design flaw, why did they redesign the booster after Challenger? If it was only caused by operating outside of design parameters, they wouldn’t have bothered. There have been several aviation accidents in which pilots crashed a plane because they tried to take off with too much weight at too high an altitude. No one demands that Cessna redesign the airplane when that happens - they demand that pilots stop screwing around with their performance envelope.