1、Lessons Learned Entry: 0952Lesson Info:a71 Lesson Number: 0952a71 Lesson Date: 1995-03-27a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Solid Rocket Motor Case-to-Nozzle Joint: Added Capture Feature Description of Driving Event: The Challenger (Space Shuttle Flight #
2、51L) accident triggered 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 he case-to-nozzle joint that could cause a catastrophic event similar to that encountered in Challenger.Lesson(s) Learned: A
3、capture feature is required on case-to-case solid rocket motor field joints to prevent joint rotation and subsequent deactivation of primary and secondary sealing “O“ rings.Recommendation(s): Provide an additional “tang“ on the field joint, which is an interference fit with the clevis on the mating
4、segment. This tang contains an additional “O“ ring groove and “O“ ring which provides a thermal barrier to prevent hot combustion gasses from escaping from the field joint.Evidence of Recurrence Control Effectiveness: As of this date, eight-six (86) Revised Solid Rocket Motors (RSRM) have flown succ
5、essfully and ten (10) full-scale RSRM 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 R
6、esaleNo reproduction or networking permitted 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-,-,-
