1、Lessons Learned Entry: 1009Lesson Info:a71 Lesson Number: 1009a71 Lesson Date: 1997-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: Space Shuttle Program/Reusable Solid Rocket Motor (RSRM)/Manufacturing & Process Control and Certification Testing Description of Driving
2、 Event: Environmental Regulations Resulting in Material Changes for RSRMLesson(s) Learned: A substantial program effort is under way to eliminate the asbestos used in RSRM manufacture and replace it with more environmentally acceptable (i.e., “asbestos-free“) materials. Although some of the material
3、s tested to date meet specifications, they do not provide as high structural and thermal margins as the asbestos-containing materials.Recommendation(s): To maintain flight safety, NASA should not eliminate the use of asbestos in RSRM manufacture. An environmental waiver should be obtained to continu
4、e its use in RSRM insulation, liners, inhibitors, and other motor parts in the event of future regulatory threat to the asbestos supplier.Evidence of Recurrence Control Effectiveness: NASA currently has no plan to introduce nonasbestos-based replacements for asbestos-based components in RSRM product
5、ion. The RSRM production and flight history are baselined with asbestos-based materials, primarily NBR rubber. Asbestos is also a constituent of liner and adhesives. The production, handling, and disposal processes for these materials are performed in compliance with strict state, Federal, and local
6、 controls and regulations regarding asbestos material. There are no currently identified regulations to ban production or use of asbestos materials in the RSRM supply chain. Because there is no existing or pending regulation, pursuit of waivers or Provided by IHSNot for ResaleNo reproduction or netw
7、orking permitted without license from IHS-,-,-exemptions is not applicable at this time.NASA considers it prudent to continue low-level development of possible alternative nonasbestos materials. This reflects NASAs sensitivity to the environment, worker safety and health issues, and the fact that th
8、e shelf life of these materials precludes the option to stockpile. This development effort is being carried out to provide limited contingency development at a routine pace. The recommendations by both the ASAP and the RSRM initiatives to find alternative materials are consistent with program policy
9、 documented in SSP letter MS 96-071, dated September 16, 1996. The policy seeks to balance flight safety and environmental protection goals.Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panel
10、a71 Environmenta71 Ground Operationsa71 Hazardous/Toxic Waste/Materialsa71 Policy & Planninga71 Safety & Mission AssuranceAdditional Info: Approval Info: a71 Approval Date: 2001-11-01a71 Approval Name: Bill Loewya71 Approval Organization: QSa71 Approval Phone Number: 202-358-0528Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
