MCGRATH%OZ.AI.MIT.EDU@XX.LCS.MIT.EDU ("Jim McGrath") (03/11/86)
Apparently the Morton-Thiokol engineers did tests on scale models of the SRBs for a very wide range of conditions (including those present at the fatal shuttle launch). However, they had done full scale testing for a much narrower range of conditions (most important, only for temperatures above 50 F). Previous shuttle launches showed that real performance had a greater than expected deviation from the predictions based on the scale model tests. Thus the cause of their uncertainty. (Information from CNN/C-SPAN) However much we like to bash administrators, the primary fault appears to lie with the engineers. The faults in their model were known to them months before the fatal shuttle launch. So there was plenty of time to do the necessary full scale tests. Only an absolute idiot would feel comfortable with bad test data for an environment range (near freezing temperatures) which they KNEW they would shortly encounter. If the engineers did not voice strong concerns during the months before the launch, then I cannot really blame the NASA people for downgrading the reliability of their warnings. If there really was a problem, then the engineers were incompetent for not bringing it up sooner - in which case you can't really believe their "expert" opinion when, at the 11th hour, they say that you might have a problem. The managers (especially those in the company) share blame for not overseeing their engineers adequately. But I think they are spared the lion's share UNLESS the engineers did, during the months before, forcefully request additional full scale testing and this was denied. In that case the budget officials (who ultimately decide resource allocation) are ultimately responsible (anyone know if this happened?). This brings up an interesting point. If funds for testing and associated activities are in a separate line of the NASA budget, then Congress shares a lot of the blame. I can easily see a Congress fighting a deficit by cutting back a bit too much on those "invisible" expenses, such as post production testing (they do similar things with the defense budget all the time). Alternately, high NASA administrators may have made the fatal budget decisions. Jim -------