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The soccer ball that survived the Challenger explosion

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Re: The soccer ball that survived the Challenger explosion

#51

Post by hluska »

rmason wrote: post #23

I was visiting farmers reviewing plans for the next crop year. I'd just arrived and the farmer says do you mind if we watch the Challenger launch before starting? It's got that teacher going up in space. I told him that my high school government teacher had been one of the ten finalists so I took a pretty keen interest myself. I can remember the numbness I felt in his living room as we watched the Challenger explode.…

I was in the third grade when this happened. My elementary school was (un)fortunate enough to carry the launch live, so I watched it happen with a room full of my 8 and 9 year old peers.

Like you, I can remember the numbness I felt in the classroom as we watched the explosion. And, I will never forget the look on my teacher's face as she shut off the television.

Re: The soccer ball that survived the Challenger explosion

#52

Post by nerdponx »

0xffff2 wrote: post #36
oh_sigh wrote: post #31

Earlier quoted context omitted.

And if the politicians didn't vote to build the SRBs in Utah, then maybe there would be no SRB at all, which is a good method to prevent deaths from SRBs.

Okay... how is that relevant to my comment at all?

I think this was meant to be a comment on the OP.

Re: The soccer ball that survived the Challenger explosion

#53

Post by blahedo »

jedberg wrote: post #6

> You may not know it, but you carry some of his words with you in your own earthly exploration, printed in every U.S. passport. This whole article was fantastic, but this was the coolest part for me. To learn that his quote is on every passport. I've never read the quotes on my passport before, but now I have.

I agree. It's on the biometric passports but not the previous generation, on p28 (and is abbreviated from the full quote printed in the article):

"Every generation has the obligation to free men's minds for a look at new worlds ... to look out from a higher plateau than the last generation." --Ellison S. Onizuka

The background on that page is a palm tree and a silhouette that might be Diamond Head, but the facing page is a space scene (not to scale) with an earthrise over the moon and a satellite.

Re: The soccer ball that survived the Challenger explosion

#55

Post by InclinedPlane »

nashashmi wrote: post #50
InclinedPlane wrote: post #47

Earlier quoted context omitted.

It was a specific warning about the vulnerability of the O-ring seals in low temperatures (precisely the mechanism of failure that doomed the Challenger). It was an unusual, specific, and high profile warning which was effectively overruled by NASA management. The guidance was to avoid launching in such low temperatures, the response was: "My God, Thiokol. When do you want me to launch? Next April?" That from Lawrenc…

Maybe it wasn't warning fatigue then. It might be overthinking fatigue. I guess missions have gotten delayed before for so many reasons and this time they just got tired of "doing it again."

This is a well studied problem, it wasn't overthinking, it was "go fever", specifically in the form of "Normalization of Deviance" [1].

Morton-Thiokol and NASA set criteria for safety margins on the Shuttle system. And the Shuttle kept on violating those safety margins again and again. Instead of grounding the fleet or studying the problem further or attempting to ameliorate the problem the safety margins were loosened, deviance was normalized, unsafe operations were normalized. And those who called out the legitimate safety problems with the Shuttle were harassed and derided because their views differed from the orthodoxy (that a Shuttle loss was a 1 in 100,000 probability) and got in the way of their goals (the high flight rate of dozens of launches per year that were necessary for the Shuttle system to meet its promises).

Later analysis of the Shuttle system [2] has indicated several other potential key failure modes that could have caused a loss of vehicle and crew, especially during the early flights. Not just the SRBs and the thermal protection system (the weaknesses which doomed Challenger and Columbia) but other systems such as the APUs, SSMEs, flight software, etc. led to a risk of catastrophic loss as high as 1 in 10 during the first several years of flights, 1 in 20 around the Challenger disaster period, 1 in 50 during the return to flight period after Challenger, and about 1.1-1.3% during the post-Columbia period.

1: https://en.wikibooks.org/wiki/Professionalism/Diane_Vaughan_...

2: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201100...

Re: The soccer ball that survived the Challenger explosion

#56

Post by T-hawk »

InclinedPlane wrote: post #47
T-hawk wrote: post #32

Earlier quoted context omitted.

One important piece of data to correlate with that: how many times previously had engineers issued similar warnings for launches that then proceeded fine? Warning fatigue is a thing and reasonable to wonder whether that happened at all here.

It was a specific warning about the vulnerability of the O-ring seals in low temperatures (precisely the mechanism of failure that doomed the Challenger). It was an unusual, specific, and high profile warning which was effectively overruled by NASA management. The guidance was to avoid launching in such low temperatures, the response was: "My God, Thiokol. When do you want me to launch? Next April?" That from Lawrenc…

The question isn't whether O-rings had ever been warned about before; it's whether and how often there were ever any warnings of equal specificity and high profile to this one. "Go fever" accumulates from overriding previous warnings that didn't materialize as a threat.

Re: The soccer ball that survived the Challenger explosion

#57

Post by tigeba »

rmason wrote: post #23

I was visiting farmers reviewing plans for the next crop year. I'd just arrived and the farmer says do you mind if we watch the Challenger launch before starting? It's got that teacher going up in space. I told him that my high school government teacher had been one of the ten finalists so I took a pretty keen interest myself. I can remember the numbness I felt in his living room as we watched the Challenger explode.…

If you listen to the NPR story above you will want to know that about a month later they ran a followup story.

https://www.npr.org/sections/thetwo-way/2016/02/25/466555217...

Re: The soccer ball that survived the Challenger explosion

#59

Post by ridgeguy »

On Challenger's last day, I had met very early that morning with a couple of angel investors who signed a funding commitment for my first company. Went home, watched Challenger explode. An hour later, angel investors called to say "never mind".

Watching Challenger blow up hurt worse. Especially in following months when failure analysis showed it could have been avoided by launching within the allowable temperature window.

Some days you really remember.

Re: The soccer ball that survived the Challenger explosion

#60

Post by oska »

jedberg wrote: post #6

> You may not know it, but you carry some of his words with you in your own earthly exploration, printed in every U.S. passport. This whole article was fantastic, but this was the coolest part for me. To learn that his quote is on every passport. I've never read the quotes on my passport before, but now I have.

> This whole article was fantastic

I personally found the writing somewhat overwrought, despite thinking it's a story worth telling and feeling respect for the astronaut involved and sympathy for his family. I wouldn't call it good writing. But I'm not a US American, so maybe it's a cultural difference.

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