1、Lessons Learned Entry: 0206Lesson Info:a71 Lesson Number: 0206a71 Lesson Date: 1992-11-12a71 Submitting Organization: KSCa71 Submitted by: Lisa L. MusgraveSubject: Inertial Upper Stage (IUS) Propellant Tank Assemblies (PTAs) Description of Driving Event: Inertial Upper Stage/Tracking and Data Relay
2、Satellite (IUS/TDRS) instrumentation design allows active monitoring of only one of two Propellant Tank Assemblies (PTAs) during the countdown phase. The PTAs are isolated from each other until activated after IUS deployment. Therefore, the status of all PTAs can not be determined by monitoring one
3、PTA. Pre-launch preparation procedures permit adequate determination of pre-flight PTA leakage status; pyrotechnic system design adequately protects against inadvertently commanded loss of PTA isolation; and structural design safety factors are adequate. However, no indicator is available to detect
4、a flight-induced anomaly, thereby making the IUS status uncertain.Lesson(s) Learned: With no PTA indicator to detect flight hardware anomalies, the IUS status will be uncertain and may result in undetected propellant leaks.Recommendation(s): Provide individual pressure and temperature monitoring of
5、the IUS reaction control system PTAs to detect potential propellant leakage failures.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AMission Directorate(s): N/AAdditiona
6、l Key Phrase(s): a71 Energetic Materials - Explosive/Propellant/PyrotechnicAdditional Info: Approval Info: a71 Approval Date: 1994-06-08a71 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-,-,-
