|
Major findings The board found both the immediate physical cause of the accident and also what it called organizational causes. Immediate cause of the accident 82 seconds after launch a large piece of foam insulating material from the external tank broke free and struck the leading edge of the shuttle's left wing, damaging the protective carbon heat shielding panels. This damage allowed super-heated gases to enter the wing structure during re-entry into the earth's atmosphere and caused the destruction of the Columbia. Organizational cause of the accident. The problem of debris shedding from the external tank was well known and had caused shuttle damage on every prior shuttle flight. The damage was usually, but not always, minor. Over time ,management gained confidence that it was an acceptable risk. The board found that this should not have happened. The shuttle organization is very large, and decision makers cannot embody all information. Organizational mechanisms are responsible for properly informing and guiding decision makers. The report placed equal weight on organizational failings as the cause of the accident. Echoes of Space Shuttle Challenger disaster|Challenger One board member, Dr. Sally Ride, served on both the CAIB panel and Rogers Commission and noted remarkable similarities between the two tragedies; why was the shuttle allowed to continue to fly with known problems that were, eventually, catastrophic. Since no machine is perfect, the problem comes down to identifying which known problems are an acceptable risk and which are not. In these two examples, shedding foam and failing o-rings, the organization failed to predict the seriousness of the problem. To illustrate the organizational problems of safety awareness, Richard Feynman attached a personal appendix to the Rogers Commission Report. It is equally relevant to the CAIB report. In it he says; "It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management. What are the causes and consequences of this lack of agreement? … we could properly ask "What is the cause of management's fantastic faith in the machinery?" The CAIB report found these same differences of perception, and that they contributed to the accident. Both reports also examined the ability of schedule pressures to influence safety related design decisions. Board recommendations The board made 29 specific recommendations to NASA to improve the safety of future shuttle flights. These recommendations include: Board members Chairman of the board Board members Board support Partial list of additional investigators and CAIB support staff | |||||||||
|
| ||||||||||
 |
|
| |