REG NASA-LLIS-0954-1995 Lessons Learned Solid Rocket Motor Case-to-Case Field Joint Added Joint Heater.pdf

1、Lessons Learned Entry: 0954Lesson Info:a71 Lesson Number: 0954a71 Lesson Date: 1995-03-27a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Solid Rocket Motor Case-to-Case Field Joint: Added Joint Heater 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 the case-to-nozzle joint that could cause a catastrophic event similar to that encountered in Challenger.Lesson(s) Learned:

3、“O“ rings become inflexible and do not properly seal at low temperatures. A heater is needed to raise the “O“ ring temperature above that which would cause improper sealing.Recommendation(s): Provide a joint heater for all field joints to maintain resiliency of the “O“ rings.Evidence of Recurrence C

4、ontrol Effectiveness: As of this date, eight-six (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 t

5、hat recurrence control has been successful.Documents Related to Lesson: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Mission 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-,-,-