mmm@cup.portal.com (Mark Robert Thorson) (02/04/91)
The following letter appeared in the Feb. 2 issue of the San Jose Mercury-News. Who is AbuTaha and why should we believe him? ----------------------------------------------------------------- The fifth anniversary of the Challenger accident was Monday and, although the O-ring has become a modern colloquialism, not many people were aware of the extensive work of Ali AbuTaha, a space and structural engineer from Herndon, Va. AbuTaha's independent investigation of the accident included analysis of computer-enhancement-of-flight videos, review of structural specifications and study of the pre-explosion flight deck transcript. His analyses show strong evidence that the crew was well aware of significant problems prior to the actual explosion. AbuTaha's findings also clearly show confusion on the part of NASA and the Rogers Commission concerning just how much bending load should be expected on the solid rocket boosters just prior to their ignition. His extensive analysis of the lower aft joint shows the impossibility of either O-ring failure in the manner reported or even the production of flames from the joint if there were no O-ring at all. Is it possible that the accident was the result of the following combined culprits? -- The over-compression of the aft-center booster section beyond pre-established limits when the chell was re-assembled, and -- At least some of the booster and peripheral components designed to withstand only half the actual load that they should have been. Wouldn't that have initiated a crack and thus a major leak at the joint? More important, and at the expense of sounding facetious, who cares? NASA doesn't seem to. Neither does Congress nor the American press. There are a handful of engineers, however, who wince at how AbuTaha and his work have been treated. It is time we found the legitimate cause of the accident. Not only does the future success of our space program rest on this but so does the integrity of the engineering profession. James Intrater Vice-President, R&D Advanced Technology, Inc.
yetmank@merrimack.edu (02/04/91)
In article <38828@cup.portal.com>, mmm@cup.portal.com (Mark Robert Thorson) writes: > The following letter appeared in the Feb. 2 issue of the San Jose > Mercury-News. Who is AbuTaha and why should we believe him? > > ----------------------------------------------------------------- > > The fifth anniversary of the Challenger accident was Monday and, > although the O-ring has become a modern colloquialism, not many > people were aware of the extensive work of Ali AbuTaha, a space > and structural engineer from Herndon, Va. > > AbuTaha's independent investigation of the accident included > analysis of computer-enhancement-of-flight videos, review of > structural specifications and study of the pre-explosion flight > deck transcript. His analyses show strong evidence that the crew > was well aware of significant problems prior to the actual > explosion. > > AbuTaha's findings also clearly show confusion on the part of > NASA and the Rogers Commission concerning just how much bending > load should be expected on the solid rocket boosters just prior > to their ignition. His extensive analysis of the lower aft joint > shows the impossibility of either O-ring failure in the manner > reported or even the production of flames from the joint if > there were no O-ring at all. > > Is it possible that the accident was the result of the following > combined culprits? > > -- The over-compression of the aft-center booster section beyond > pre-established limits when the chell was re-assembled, and > > -- At least some of the booster and peripheral components designed > to withstand only half the actual load that they should have been. > Wouldn't that have initiated a crack and thus a major leak at the > joint? > > More important, and at the expense of sounding facetious, who cares? > NASA doesn't seem to. Neither does Congress nor the American press. > > There are a handful of engineers, however, who wince at how AbuTaha > and his work have been treated. It is time we found the legitimate > cause of the accident. Not only does the future success of our space > program rest on this but so does the integrity of the engineering > profession. > > James Intrater > Vice-President, R&D > Advanced Technology, Inc. I think the problem was at NASA myself (Sorry guys, I know you do a great job, but this was one where you dropped the ball). Published reports I've read have stated on previous missions before the shuttle tragedy, there were unacceptable levels of blowby (the hot gases blowing by the O-rings.). Every time they flew a mission, they had to override this restriction, and allow the shuttle to go even with the blowby. I still think that the blowby caused the brackets that held the SRB to the fuel tank to weaken. Eventually, the bracket broke. That would have caused extreme instability, which some at NASA have said that the pilot noticed. It could well have been that the exhaust end of the SRB hit the tank, puncturing it, and causing the blast. The first thing people are going to ask is why couldn't we see the puncture of the tank on the video. I think the shuttle was too high up for us to see it. The shuttle was 10 nautical miles up when it blew up. I really don't think we could have seen the booster move much from ten miles down. Again let me say that I am no rocket scientist (no pun intended), but this is what I think caused the blast. Anyway, what's it matter what caused it? The fact is that it happened, and there is nothing we can do to change that. Kevin E-mail MIGHT reach me at: yetmank@merrimack.edu "You can still Rock in America" - Night Ranger
henry@zoo.toronto.edu (Henry Spencer) (02/06/91)
In article <38828@cup.portal.com> mmm@cup.portal.com (Mark Robert Thorson) writes: >... Who is AbuTaha and why should we believe him? Ali AbuTaha is a semi-crank who's come up with a steady stream of, uh, interesting theories about the cause of the Challenger disaster. Some of them had enough merit, or simply attracted enough attention, for NASA to spend some effort checking them out. For example, his claim that Challenger's SRB had been overstressed by centrifugal force as the crawler went around the bend in the crawlerway to pad 39B [!] was decisively refuted by strain-gage measurements during the Atlantis rollout in the post-Challenger hiatus. Every now and then the media rediscovers him and his latest theory. -- "Maybe we should tell the truth?" | Henry Spencer at U of Toronto Zoology "Surely we aren't that desperate yet." | henry@zoo.toronto.edu utzoo!henry
mears@hpindda.cup.hp.com (David Mears) (02/06/91)
> / yetmank@merrimack.edu / 6:34 am Feb 4, 1991 / > > Anyway, what's it matter what caused it? The fact is that it happened, > and there is nothing we can do to change that. > > Kevin ``What's it matter what caused it?'' you say. The point is, that although it is too late to change what happened with Challenger, it's not too late to change what could otherwise happen with another shuttle. That's why it's important to know the truth. If (I said IF) the O-Rings were not the cause, and the real cause has not been addressed, then another catastrophe could happen. It may very well anyway, even if we know what went wrong and have fixed it adequately. David B. Mears Hewlett-Packard Cupertino CA hplabs!hpda!mears mears@hpinddf.cup.hp.com