1、Lessons Learned Entry: 0967Lesson Info:a71 Lesson Number: 0967a71 Lesson Date: 1995-05-15a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Space Shuttle Main Engine (SSME): Instrumented Safety Checks During Engine Startup Description of Driving Event: Turbine speed must
2、 be high enough at the time of main combustion chamber priming to be able to pump hydrogen through the downstream system against the back pressure rise created by the chamber priming, or an engine burnout will occur due to the oxygen rich combustion.Lesson(s) Learned: Instrumented “safety checks“ at
3、 critical points in the startup and operational procedures ensure proper engine system priming.Recommendation(s): A safety check of turbopump speed is made at 1.25 seconds in the startup sequence to ensure that the high pressure fuel turbopump speed is high enough to safely proceed through the primi
4、ng sequence.Evidence of Recurrence Control Effectiveness: The Space Shuttle Main Engines have operated successfully in over 68 flights. Although many minor changes have been made to improve performance and reliability, this lesson learned or feature described has continued to sustain reliable perfor
5、mance in over 200 flight performances of individual engines.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 Configuration
6、 Managementa71 Cryogenic Systemsa71 Ground Equipmenta71 Hardwarea71 Launch Vehiclea71 Parts Materials & Processesa71 Safety & Mission Assurancea71 Spacecrafta71 Test Articlea71 Test FacilityAdditional 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-,-,-
