1、Lessons Learned Entry: 0963Lesson Info:a71 Lesson Number: 0963a71 Lesson Date: 1995-05-15a71 Submitting Organization: MSFCa71 Submitted by: Billy Cole / RetiredSubject: Space Shuttle Main Engine (SSME): Start Sequence Investigations Description of Driving Event: Computer mathematical models had show
2、n the engine to be sensitive to small changes in propellant conditions, and that timing relative to opening the propellant valves was critical. Expecting difficulties, a cautious step-by-step plan was followed to explore the start sequence in small time increments. It took 35 weeks and a series of 3
3、7 test, including 13 turbopump replacements to extend reliable performance form the 2-second startup transient to main power level.Lesson(s) Learned: Exploration of engine start sequences in small time increments provides reliable start cycles.Recommendation(s): Explore engine start sequences in sma
4、ll time increments.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
5、 performance 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 Config
6、uration 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-,-,-
