1、Lessons Learned Entry: 0962Lesson Info:a71 Lesson Number: 0962a71 Lesson Date: 1995-05-15a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Space Shuttle Main Engine (SSME): Computer Models of Transient Performance Description of Driving Event: Fuel or oxidizer starvatio
2、n will cause hazardous conditions due to off-nominal mixture ratios in liquid propellant rocket engines. A safe and repeatable start sequence was developed by making maximum use of the engine mounted computer to control propellant valve positions. The report stated that “Without the precise timing a
3、nd positioning (of valves) allowed by the Main Engine controller (MEC), it is doubtful that a satisfactory start could have been deveLesson(s) Learned: The use of computer models to depict transient behavior helps to characterize critical startup and operational parameters.Recommendation(s): Make ma
4、ximum use of computer modeling techniques to characterize the start-up and shut-down transient performance of liquid propellant rocket engines.Evidence of Recurrence Control Effectiveness: The Space shuttle Main Engines have operated successfully in over 68 flights. Although many minor changes have
5、been made to improve performance and reliability, this lesson learned or feature described has continued to sustain reliable performance in over 200 flight performances of individual engines.Documents Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking permitted without lic
6、ense from IHS-,-,-N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Configuration 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-,-,-
