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How We Nearly Lost the Discovery Shuttle

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Re: How We Nearly Lost the Discovery Shuttle

#31
post #14

A great post, especially since it seeks to get at the truth of something that has implications for future missions, at the risk of the OP's reputation. This part is one of the more disturbing parts though, and a good reminder of why technical persons of all fields, whether rocket scientists or programmers, should not adopt a "Well, we worked hard and we're smart so I'm sure everything's fixed" > What you probably don…

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Re: How We Nearly Lost the Discovery Shuttle

#32
This was one hell of an inspirational post. What I took from it was: we are all human and no matter how smart you are, how many of you are or how much money you have to throw at a problem it's sometimes a mere simple solution or problem that was overlooked. Kind of reminds me of web development.

Re: How We Nearly Lost the Discovery Shuttle

#33
post #13

Earlier quoted context omitted.

In that, the Shuttle was very much like the Concorde: a unique and complex system beyond the edge of knowledge (at its creation), full of flaws and working through a combination of sheer luck and heroic efforts.

Actually the space shuttle is the safest launch vehicle to date. From the ones that have at least 100 launches (in order to be able to properly compute stats for them), here are their failure rates as taken from http://www.ontonix.com/Blog/Outliers_-_understanding_Nature_... : 2% US Space Shuttle 5% R-7 (Russian Soyuz) 5% Ariane 1-4 (European) 6% Tsyklon (Russian) 7% Kosmos (Russian) 10% Thor/Delta/N1/N2/H1 (US) 11%…

Would be better to compare the fatality rate, not the failure rate. I believe Soyuz has had at least one non-fatal failure, for example, while the Shuttle's failures were both fatal. When I recall running the numbers on that, the Shuttle and Soyuz came out similar, although it's been quite a while.

Re: How We Nearly Lost the Discovery Shuttle

#35
post #14

A great post, especially since it seeks to get at the truth of something that has implications for future missions, at the risk of the OP's reputation. This part is one of the more disturbing parts though, and a good reminder of why technical persons of all fields, whether rocket scientists or programmers, should not adopt a "Well, we worked hard and we're smart so I'm sure everything's fixed" > What you probably don…

No, it's about uncertainty. You have a stated problem "the foam that came off didn't come off because of the reasons we thought it did." Now you have no other ideas besides what you've already considered and tested for 26 months. What do you do? Possibly spend another 2 years investigating and find nothing? Or conclude that the risk is small enough to fly while being vigilant about the problem and looking for more da…

I'm not saying that this isn't the case, I was hoping for more clarification. The way that the OP writes it is that this "side note" was included in the final briefing pointing out the flawed hypothesis.

The OP doesn't say how conclusive this "side note" was, or if it was one such note among many others. If it is the latter situation, then yes, it's understandable that it was seen as an acceptable blind spot.

But the situation, as the OP describes it, sounds pretty clear cut: The foam issues could come from poor installation procedures. But testing found that the defective foam "could not have been liberated from an internal installation defect"...

So I'm just interested in knowing the level of conclusiveness in that sidenote.

Re: How We Nearly Lost the Discovery Shuttle

#36

"We informed the foam technicians at our plant in Michoud Louisiana that they were the cause of the loss of Columbia..." That to me is pretty disgusting. In an incident like the loss of Columbia, there is no one, true "root cause". To assign blame to those foam technicians was disingenuous and just another instance of "passing the buck" that seems to happen so often in the post-mortem of NASA failures. NASA knew of e…

I got sick to my stomach when I read that.

Re: How We Nearly Lost the Discovery Shuttle

#37
post #5

Earlier quoted context omitted.

Understand the type of organization NASA is. First, accountability is everything. It's not that there are big internal political struggles (there are), but more importantly accountability is required for high safety. We aren't talking about a 10 person startup where a bad commit to production takes down a site for a few hours. We're talking about people's lives, careers, and the safety of millions of people that coul…

> accountability is required for high safety It's not. That's complete bullshit, and the On-Board Software Group demonstrated it by being as flawless as can be during the whole history of the Shuttle: as far as I know there was no personal accountability in the OSG, the only thing accountable was The Process supported by a strong culture of adversarial testing. Personal accountability in such a system brings politics…

There may not have appeared to have been any personal accountability, but make no mistake if anything had gone wrong with the On-Board Software the EXACT same accountability process would have been initiated to ensure that the same human error did not occur for a second time.

Re: How We Nearly Lost the Discovery Shuttle

#38
post #37

Earlier quoted context omitted.

> accountability is required for high safety It's not. That's complete bullshit, and the On-Board Software Group demonstrated it by being as flawless as can be during the whole history of the Shuttle: as far as I know there was no personal accountability in the OSG, the only thing accountable was The Process supported by a strong culture of adversarial testing. Personal accountability in such a system brings politics…

There may not have appeared to have been any personal accountability, but make no mistake if anything had gone wrong with the On-Board Software the EXACT same accountability process would have been initiated to ensure that the same human error did not occur for a second time.

Very unlikely, unless that had been imposed on the group by an external, blame-oriented entity.

Left to its own devices, the group would most certainly have operated as it did every time it found fault in its output: find out how The Process had allowed for a fault to be introduced and reach output, find out how to make The Process prevent the introduction and/or release of such faults, fix The Process.

So no, the "exact same accountability process" would most definitely not have been initiated within the group, a very different one would have taken place.

Re: How We Nearly Lost the Discovery Shuttle

#39
post #13

Earlier quoted context omitted.

In that, the Shuttle was very much like the Concorde: a unique and complex system beyond the edge of knowledge (at its creation), full of flaws and working through a combination of sheer luck and heroic efforts.

Actually the space shuttle is the safest launch vehicle to date. From the ones that have at least 100 launches (in order to be able to properly compute stats for them), here are their failure rates as taken from http://www.ontonix.com/Blog/Outliers_-_understanding_Nature_... : 2% US Space Shuttle 5% R-7 (Russian Soyuz) 5% Ariane 1-4 (European) 6% Tsyklon (Russian) 7% Kosmos (Russian) 10% Thor/Delta/N1/N2/H1 (US) 11%…

The problem is that in the list there are manned and unmanned rocket mixed. For example, the Ariane rockets are still unmanned, so if they lost one it is only an insurance problem. The Soyuz had manned and unmanned mission. But all the missions of the Shuttle were manned, so each time they had a big problem they had casualties. It would be interesting to see that includes only the manned missions.

Re: How We Nearly Lost the Discovery Shuttle

#40
I posted some days ago an appendix by Feynman in the Challenger report, "Appendix F - Personal observations on the reliability of the Shuttle"[1] for those interested. Also, half of "Why do you care what people think?" is about his experience investigating the safety of the shuttle.

[1] http://news.ycombinator.com/item?id=4371024

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