1、Lessons Learned Entry: 0950Lesson Info:a71 Lesson Number: 0950a71 Lesson Date: 2001-03-27a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Solid Rocket Motor Case-to-Nozzle Joint: Addition of Radial Bolts Description of Driving Event: The Challenger (Space Shuttle Fligh
2、t #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:
3、 Radial bolts, as well as longitudinal bolts, are required to ensure an impenetrable seal between the nozzle and case metal parts. (In the SRM Application, one hundred Radial Bolts were added.) (Nozzle-to case joint deflections at the primary seal are reduced in the Space Shuttle SRM from 0.053 inch
4、es in 0.008 inches.)Recommendation(s): Provide radial bolts alternating with the axial bolts that attach the nozzle, to ensure an effective seal between the case and nozzle metal parts.Evidence of Recurrence Control Effectiveness: As of this date, eight-six (86) Solid Rocket Motors (RSRM) have flown
5、 successfully 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
6、for ResaleNo 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-,-,-
