1、Lessons Learned Entry: 0034Lesson Info:a71 Lesson Number: 0034a71 Lesson Date: 1992-09-17a71 Submitting Organization: KSCa71 Submitted by: Lisa L.MusgraveSubject: Cryogenic Loading/Draining of the Main Propulsion System (MPS) Description of Driving Event: The main propulsion systems (MPS) LH2 system
2、 operations include the transfer of LH2 from the pad storage tank to the orbiter and pressurization of the external tank during drain operations. A leak/fire during cryogenic loading or draining operations may result in loss of vehicle and/or life. This risk remains active until shuttle liftoff from
3、 the fixed service structure, for a flight readiness firing, or for a countdown demonstration test. LH2 leaks may occur via structure/component failure, purge loss due to flow restriction (clogs, regulator/valve fails closed), or flow diversion (relief valve fails open, flexhose ruptures).Lesson(s)
4、Learned: Cryogenic loading/draining operations may produce a leak/fire, resulting in loss of shuttle vehicle and/or loss of personnel life.Recommendation(s): Minimize leakage by utilizing welded connections, pneumatic systems for controlling cryogenic valves, and purging system for valves flowing LH
5、2.Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Cryogenic Systemsa71 E
6、nergetic Materials - Explosive/Propellant/Pyrotechnica71 Facilitiesa71 Flight Equipmenta71 Ground Operationsa71 Ground Equipmenta71 Hardwarea71 Hazardous/Toxic Waste/Materialsa71 Launch Processa71 Launch Vehiclea71 Parts Materials & Processesa71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1994-06-01a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
