The “missing” damage-temperature relationship in the Challenger Incident

Communication is a major part of an engineer´s work at all levels, and should be considered a fundamental part of total quality management in any industrial process. The communication´s failures encountered in the Challenger Incident (flight 51-L, January, 1986) can be generalized to show how to examine critical features in engineering design and service. Since the publication of the Report of the Rogers Commission on the Challenger Incident, there has been a widespread consensus on the conclusion that the engineers failed to demonstrate what they felt, i.e., that temperature was a critical factor in the rubber O-rings´ performance. Based on experimental data concerning the “severity-weighted” total number of incidents of O-ring erosion, heating and blow-by proposed by Tufte on the 22 flights before flight 51-L, the paper shows that a power-law function would have been a good estimate of the damage-temperature relationship. The formula agrees qualitatively and quantitatively with physical theory applied to the critical element of the shuttle, the boosters O-rings. For flight 51-L, it would have predicted an average damage well beyond the engineering safety “factor of three”. The formula has been obtained in a rational and objective way and it is based on experimental data: it should have convinced NASA officials to delay the launch, and avoided the last and fatal communication failure in a long sequence