I’m not a rocket scientist, so I can’t opine on the technique whereby they load fuel and then attach solid rocket booster segments to each other. But the whole idea of solid rocket boosters in the first place was to save cost: the cost of boosting the Orbiter into low earth orbit on liquid fueled motors alone was deemed unacceptable. When you consider that a solid rocket booster (SRB) is essentially a giant firecracker, in that once it’s lit it runs until it burns out, and nothing on earth can control it, then you see that compromises with respect to the safety of a fully controllable liquid rocket motor (as installed on the Orbiter itself) were taken from the very inception of the design.
This is not a criticism at all; it is a simple recognition that cost vs. risk tradeoffs are part of the very fabric of any manned space program, or any product development for that matter. I remain convinced, absent any deathbed confessions, that the managers who signed off on launching the Challenger that January in 1986 felt they were simply assuming one more risk, and one that did not significantly increase the overall risk of the mission. Obviously the decision was incorrect, and they had been warned, but as I noted earlier, it was one more warning amongst the myriad over the life of the program, and it was “lost in the noise”, they had no way of discerning that this warning was real, as opposed to the many that had been received and properly disposed of during the previous decade of development and spaceflight. Ken Javor Phone: (256) 650-5261 ________________________________ From: "Price, Edward" <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Sat, 19 Dec 2009 09:29:13 -0800 To: <[email protected]> Conversation: [PSES] Emissions (now the STS O-ring debate) Subject: RE: [PSES] Emissions (now the STS O-ring debate) While it was fascinating to learn of the compromises and bad assumptions that led to this disaster, I think you can say that the players were locked into their positions by some nasty political horse-trading. We talk about the seals, saying that rubber O-rings sealing a rocket motor case doesn’t sound too bright. But they had to seal the seams somehow, because there were seams. OK, now why were the booster rockets built out of multiple linked cylindrical sections? Was this decision based on good rocket-building guidelines, or maybe because they needed to ship the rockets a long way from where they were built to where they were used? I don’t think I have heard any discussion about why the boosters were designed this way. Perhaps it was because the boosters were required to be re-usable, or perhaps it was just a quick answer to how to ship them easily, once a vendor had already been selected (based on the time-honored process of distributing the jobs to the right Congressional districts). Usual disclaimers; my suspicious private opinions only. Ed Price [email protected] <blocked::mailto:[email protected]> WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Friday, December 18, 2009 1:34 PM > To: [email protected] > Subject: Re: [PSES] Emissions from Computer power supplies - update > > Wikipedia: > "Roger Boisjoly, the engineer who had warned about the effect of cold > weather on the O-rings, left his job at Morton Thiokol and became a > speaker on workplace ethics.[46] He argues that the caucus called by > Morton Thiokol managers, which resulted in a recommendation to launch, > "constituted the unethical decision-making forum resulting from intense > customer intimidation."[47] For his honesty and integrity leading up to > and directly following the shuttle disaster, Roger Boisjoly was awarded > the Prize for Scientific Freedom and Responsibility from the American > Association for the Advancement of Science." > > MacDonald had an engineering background, but at the time he was a > Thiokol manager at the launch center and later wrote a book about the > disaster. To his credit, he followed his technical instincts once > given the facts, but he is not mentioned in the Wikipedia article. > Boisjoly was the engineer inside Thiokol who ran the numbers and raised > the alarm, then held his position against management pressure even at > the threat of losing his job. > > Orin Laney - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
