1、Lessons Learned Entry: 0333Lesson Info:a71 Lesson Number: 0333a71 Lesson Date: 1993-06-21a71 Submitting Organization: MSFCa71 Submitted by: Baggs, EllisSubject: Evaluation of in-flight anomalies in real or near-real time via rapidly received diagnostics; safing; safemode Description of Driving Event
2、: On the Hubble Space Telescope, the system entered into the Safemode state, and the data to determine why this occurred was not always available in time to evaluate the causes before executing recovery steps. This occurred because the back-up communications for the Safemode Recorder was not designe
3、d for the Low Gain Antenna high/low mode (32 kbps/500bps) transmit capability.Lesson(s) Learned: If data receipt of diagnostic data is delayed because downlink channels are not available, the ability to determine recovery action is severely compromised. This reveals a lack of systems engineering and
4、 application FMEA.Recommendation(s): Provide the capability to rapidly receive diagnostic data when in-flight anomalies occur, especially in regard to automatic shutdown or automatic entry into the safemode state. This may require the provision of backup communications, which can be transmitted on m
5、ore than one telemetry configuration. Implement systems engineering which will require test and c/o verifications and FMEAs to reveal interdiscplinarly activities.Evidence of Recurrence Control Effectiveness: An alternate capability for downlink of diagnostic data increases the likelihood of timely
6、receipt of the data.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Communication Systemsa71 Flight Equipmenta71 Ground Equipmenta71 Safety & Mission Assurancea71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1994-08-17a71 Approval Name: Baggs, Ellisa71 Approval Organization: EL01a71 Approval Phone Number: 205-544-3293Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
