1、Lessons Learned Entry: 0958Lesson Info:a71 Lesson Number: 0958a71 Lesson Date: 1995-03-27a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Solid Rocket Motor Joint Protection System Description of Driving Event: The Challenger (Space Shuttle Flight #51L) accident trigge
2、red a detailed review of all of the joints in the Solid Rocket Motor. Analyses showed a potential weakness and potential flow paths for hot gasses through the case-to-nozzle joint that could cause a catastrophic event similar to that encountered in Challenger.Lesson(s) Learned: External joint insula
3、tion and sealing, (coupled with the field joint heater) is required to maintain field joint “O“ rings at a 75 F minimum temperature, and to prevent moisture intrusion for both the field joints and the factory joints.Recommendation(s): Cork insulation is applied with an adhesive to protect the field
4、joints from cold temperatures and moisture. Ethylene Propylene Diene Monomer is used as a moisture seal over the factory joints.Evidence of Recurrence Control Effectiveness: Effectiveness: As of this date, eight-six (86) Solid Rocket Motors (RSRM) have flown successfully and ten (10) full-scale RSRM
5、 test motors have been tested successfully since Challenger with no failures and no evidence of joint deterioration or burn-through. This successful record indicates that recurrence control has been successful.Documents Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking pe
6、rmitted without license from IHS-,-,-N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Energetic Materials - Explosive/Propellant/Pyrotechnica71 Launch VehicleAdditional Info: Approval Info: a71 Approval Date: 2001-07-23a71 Approval Name: Eric Raynora71 Approval Organization: QSa71 Approval Phone Number: 202-358-4738Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
