Department of the Air Force Report, 1996

This final report, dated September 10, 1996, was prepared by the Research Triangle Institute for the Department of the Air Force's 45th and 30th Space Wing safety offices. Titled Modeling Unlikely Space-Booster Failures in Risk Calculations, it shows how rare Mode-5 failures, in which a rocket veers well off its intended flight line, are modeled in the DAMP risk-analysis program. An appendix lists Atlas, Delta, Titan and Thor launch and failure histories through August 1996.

From the source: Release of 2026-05-08 Incident: 9/10/96, N/A. This report describes the Modeling of Unlikely Space-Booster Failures in Risk Calculations, documenting historical launch failure modes and recommending corrective actions to address them using novel modelling techniques.

It is obvious from the response-mode definitions in Appendix A that none of the described
vehicle failures can be considered as a Mode 1, 2, or 3 response, or a Mode-4 on-trajectory
failure.• Except possibly for (2), it also seems apparent that none can be modeled as either a
rapid tumble or a slow tum.
• Although prompt destruct action during any of the described flights might have resulted in a Mode-4
classification, the safety officer typically needs several seconds to evaluate data after a malfunction.
Quick action is contrary to safety philosophy if impact limit lines are not threatened and the destruct •
system is not at risk, since additional flight time enhances the user's opportunity to pinpoint the
nature of the problem.
9/10/96 5 RTI