1、Lessons Learned Entry: 0387Lesson Info:a71 Lesson Number: 0387a71 Lesson Date: 1995-02-21a71 Submitting Organization: JPLa71 Submitted by: R.J. ZenoneSubject: NOAA-13 Satellite Solar Array Bus Short to Ground Abstract: When all contact with a weather satellite was lost, it was surmised that thermal
2、cycling had caused one or more mounting bolts to protrude through a heat sink and short the solar array output to ground. Review packaging designs, assure ease of manufacturing and inspection, provide for adequate temperature margins, and consider the mission thermal cycle profile in design and test
3、Description of Driving Event: The National Oceanic and Atmospheric Administration (NOAA) weather satellite NOAA-I (NOAA-13 after launch), was launched on 9 August 1993 from Vandenberg Air Force Base. No anomalies were encountered during flight until 21 August 1993 at which time it was determined fr
4、om telemetry data that while in full sun, the solar array was inoperative and that the spacecraft was being powered by the batteries. Within six orbits after observance of the anomaly, communication with the spacecraft was found not to be possible and no downlink signal from the spacecraft was there
5、after detected.Upon closer examination of recorded spacecraft telemetry data, it was ascertained that the solar array was putting out electrical power, but that no power was being provided to the battery charging unit, and the batteries were not receiving a charge.Cause of the failure surmised by th
6、e cognizant operations crew and concluded by the Goddard Space Flight Center (GSFC) NOAA-13 Failure Review Board, was that the solar array bus had shorted to spacecraft ground. Specifically, constant thermal expansion and contraction in excess of previous flights was thought to have caused one or mo
7、re mounting bolts protruding through the heat sink contained in the battery charging unit to penetrate isolation material and short the solar array output to ground. It is believed that a rise in temperature and resultant increase in temperature excursion Provided by IHSNot for ResaleNo reproduction
8、 or networking permitted without license from IHS-,-,-were due to greater electrical power required to operate additional instruments added to the spacecraft.Reference(s): NOAA-13 Failure Report, dated August, 1994 by Goddard Space Flight CenterLesson(s) Learned: 1. Poor packaging design and an inad
9、equate insulation scheme allows numerous places for electrical shorts.2. Poor processing and insufficient inspection were major contributors to the failure.3. In-flight temperature extremes experienced by NOAA-13, due to increased power requirements imposed by flying additional instruments, were gre
10、ater than experienced by previous NOAA satellites of this series and were near qualification temperature limits.Recommendation(s): 1. Packaging designs, whether new or inherited, need to be reviewed for adequacy; especially when electrical power and thermal aspects of a design can be affected by spa
11、cecraft system configuration changes.2. Manufacturing processes need to encompass ease of manufacturing and inspection aspects. Inspection must be performed by Quality Assurance instead of by an assembler.3. Adequate temperature margins between qualification temperatures and expected in-flight opera
12、ting temperatures need to be assured.4. Consider mission thermal cycle profile in mission design and test.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Environmenta71 Safety & Mission AssuranceProvided by IHS
13、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-a71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1995-03-02a71 Approval Name: Carol Dumaina71 Approval Organization: 125-204a71 Approval Phone Number: 818-354-8242Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
