51–60 of 63 posts
"There is a saying that a wise old program manager once passed along to me: “Great engineers, given unlimited resources and time will achieve exactly . . . . nothing” Think about it."
This is an outstanding post that shows first hand what life as an engineer is like. It is often very hard to truly come to a conclusion that is 100% correct, even given what seems like infinite resources to do testing and analysis. The big take away from this is what it means to be a good engineer: to be able to bow your head, and admit you were wrong despite all prior evidence. outstanding!
This reminded me of the problem of unit testing vs integration testing. Sometimes, no matter how much code coverage you have, the unit tests don't find that critical bug that takes everything down. Just like testing the 2 square feet of foam didn't find the problem. You also need integration testing.
Earlier quoted context omitted.
I was involved in a similar discussion a couple of weeks ago. I was looking at the same figures you were and complimented the space shuttle because of it. I was wrong, and you're making the mistake that I did. Namely confusing reliability and safety. A reliable rocket is one that successfully does what it is supposed to. A safe rocket is one that doesn't kill people. The US space shuttle has proven to be more reliabl…
The video of T-10-1 is stunning: http://www.youtube.com/watch?v=UyFF4cpMVag That the people on that rocket escaped with "bruises" is amazing.
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
Earlier quoted context omitted.
The video of T-10-1 is stunning: http://www.youtube.com/watch?v=UyFF4cpMVag That the people on that rocket escaped with "bruises" is amazing.
So, this is why you top-load the crew compartment, and not side-load like the shuttle. There's no eject-system that could have saved a space shuttle in a situation like that since it would be engulfed by flames together with the rocket itself. This is also how SpaceX are doing it and for exactly this reason iirc.
The Challenger explosion could have hypothetically been survivable though. In fact, the explosion itself was survived, likely by all of the crew. The crew cabin (http://upload.wikimedia.org/wikipedia/en/thumb/4/42/Challeng...) remained intact and possibly pressurized after vehicle breakup. The crew were almost certainly alive (and if the cabin remained pressurized, could have been concious as well) for nearly 3 minutes until it hit the ocean at over 200 miles per hour.
At some point during those 3 minutes, I don't know if the SR-71 ejection seats used for the first few Shuttle launches could have improved their chances of survival, but it seems at least somewhat possible that it could have. A parachute system for the crew cabin probably wouldn't work for the same reason the launch abort system on the proposed Ares was flawed (flying burning solid fuel going everywhere in the air is bad for parachutes)... nevertheless I think it is conceivable that you could build a Shuttle that would allow the crew to survive an accident like that.
But really, just stick the people on top. It makes way more sense. I know it is hard to compare the two accidents (though from what I understand, as far as solid fuel rocket failures go Challenger was pretty tame), but the contrast between Challenger and T-10-1 is something that lessons should be taken from.
"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…
As additional color here is what he posted in a reply to a reply of his blog entry: Perhaps I was a little too brief in my writeup. Nobody that I know (certainly not me) went to MAF and downdressed any of the workers. What happened was that the conclusion was reached in engineering and management meetings and the word filtered out to the workers that poor workmanship was the proximate cause of the loss of Columbia –…
Until we can say we got this getting to space thing, spacecraft should be considered research vehicles and information on every single aspect of their operation has to be gathered. When the Columbia was lost, I was appalled nobody ever inspected the heatshield for damage occurred during lift-off after more than 100 flights. Even if you consider it dangerous (or too much work) to have an astronaut visually inspect it, this could have been done from the Mir space station.
Many spacecraft were lost to arrogance, to the false certainty we know what we are doing when, in fact, we are still learning.
THAT'S THE PROBLEM WITH NASA!
In any other situation, when faced with such a dangerous close call, there would have been emotion and strong language used. But in NASAworld, that's all considered verboten. As Mr. Hale points out in his post, these people were his friends. He knew their families well. They weren't just employees. They dodged a bullet, and all he could call it was "unsatisfactory."
I'm not asking NASA to be full of raving loons. But show some goddamn emotion from time to time! One of the most wonderful things about Curiosity was not just the amazing landing, but the sheer jubilation the JPL team went through once they realized their little rover had safely survived the "7 minutes of terror" and landed. For 10 minutes, they hugged, shouted, and cheered. For crying out loud, the flight director had a mohawk! I have no doubt that by showing themselves as fully human, these amazing people just created a whole new generation of kids who will dream of sending probes to faraway places like Europa, Titan, and beyond.
Bottom line: I admire Mr. Hale's honesty in hindsight. But his bland non-emotionalism is one of the reasons people just don't care about space anymore. Make it exciting and demonstrate emotion, and people will care. Act all Spock-like 100% of the time and people will think you DON'T care (so why should they?)
This is an outstanding post that shows first hand what life as an engineer is like. It is often very hard to truly come to a conclusion that is 100% correct, even given what seems like infinite resources to do testing and analysis. The big take away from this is what it means to be a good engineer: to be able to bow your head, and admit you were wrong despite all prior evidence. outstanding!
My favorite story along those lines: http://www.duke.edu/~hpgavin/ce131/citicorp1.htm
