1、Lessons Learned Entry: 0955Lesson Info:a71 Lesson Number: 0955a71 Lesson Date: 1995-03-27a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Solid Rocket Motor Case-to-Case Field Joint: Addition of a Pressurizing “J“ slot in the Case Insulation Description of Driving Even
2、t: The Challenger (Space Shuttle Flight #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 the case-to-nozzle joint that could cause a catastrophic event similar to that encou
3、ntered in Challenger.Lesson(s) Learned: An interference fit between the case insulation of adjacent field segments, coupled with a pressurizing “J“ slot in the male side of the joint will prevent hot combustion gasses from reaching the sealing “O“ rings.Recommendation(s): Cast or machine the joining
4、 insulation surfaces for an interference fit, and provide a “J“ shaped circumferential groove in the insulation on the male side of the joint to allow chamber pressure to help ensure impenetrable sealing of the insulation joint.Evidence of Recurrence Control Effectiveness: As of this date, eight-six
5、 (86) Solid Rocket Motors (RSRM) have flown 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.Provi
6、ded by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: 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-,-,-
