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STARDUST 20 Nov 2003CERR - Charles Love1 of 7 STARDUST Project CRITICAL EVENTS READINESS REVIEW COMET P/WILD 2 ENCOUNTER ISA Status Charles Love JPL: 303-411.

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Presentation on theme: "STARDUST 20 Nov 2003CERR - Charles Love1 of 7 STARDUST Project CRITICAL EVENTS READINESS REVIEW COMET P/WILD 2 ENCOUNTER ISA Status Charles Love JPL: 303-411."— Presentation transcript:

1 STARDUST 20 Nov 2003CERR - Charles Love1 of 7 STARDUST Project CRITICAL EVENTS READINESS REVIEW COMET P/WILD 2 ENCOUNTER ISA Status Charles Love JPL: 303-411 AM / 301-427 PM LMA:MSA +1 818 354-1275 08:00 AM - 05:00 PM PST 20 Nov 2003

2 STARDUST 20 Nov 2003CERR - Charles Love2 of 7 Total ISA’s 196 –Crit 1: Represents High Effect on Achieving Full Mission Success. 5 Total - All Closed, None Impact Successful Encounter –FSW Corrections Identified for 4 to Preclude Recurrence of Issue –1 Documents NAVCAM Contamination Issue –Crit 2: Represents Significant Effect on Achieving Full Mission Success. 56 Total - 55 Closed, None Impact Successful Encounter Z82232, Safe Mode Entry on 10/22/03 –Spacecraft Successfully Recovered per SM Recovery Procedure –Cause Investigation Continuing –Rapid SM Recovery Possible Up To E–17 Hours –Crit 3 & 4: Represents No Significant or No Effect on Achieving Full Mission Success. 135 Total - 134 Closed, None Impact Successful Encounter Z82341, NAVCAM Cal Lamp Inoperable –No Impact to Mission Objectives –Shutter Operation Verified –Cause Investigation Continuing ISA SUMMARY

3 STARDUST 20 Nov 2003CERR - Charles Love3 of 7 ISA’s With Possible Wild 2 Encounter Ramifications –SSPA 3dB Power Drop (Z70033, Z50509, Z50525) Data Rates Adjusted to Account for Power Decrease Sufficient Link Margin Exists for Comm Through MGA and No Additional Degradation in SSPA Performance Noted. (Trending Continues) –PACI Resets (Z69809) FSW Patch Installed to Monitor & Account for Internal Resets Temperature Range of Concern will not be Breeched During Encounter –Safe Mode Entry November 2000 (Z70478) Most Likely Caused by a Large Solar Flare Resulting in a Star Camera Outage or SEU Solar Flare Contingency Plan Previously Considered, However, Risk of Plan Action (Due to an Imminent Solar Flare Hit) Potentially Greater than Doing Nothing –LGA 2 Antenna Pattern Dead Zone (Z51876, Z51353) Represents a 3dB to 6dB Loss in Performance Sufficient Uplink Margin Exists and No Additional Degradation in Performance Noted ISA SUMMARY (Continued)

4 STARDUST 20 Nov 2003CERR - Charles Love4 of 7 ISA’s with Possible Wild 2 Encounter Ramifications (Continued) –Limited Dust Flux Monitor Operation Time (Z50845) Most Likely Cause Attributed to Internal Power Circuitry Planned Operation at Encounter Limited to ~33 Minutes –Unexpected NAVCAM Mirror Offset (Z78279) Caused by Large Attitude Knowledge Errors Due to Rate Biases Mitigation Technique (Enabling Star Camera Processing Post Slew) not Possible at Encounter Risk of Losing Closest Approach Images Accepted by Project Since No Other Workarounds are Possible –Stuck Filter Wheel (Z71028) Cause is Unknown Commanding Suspended Since Filter is Stuck in a Favorable Position –LOS LOCK Errors Result in Uplinks Not Being Received (Z78164, Z71700, Z70268, Z71803, Z71942, Z75486) Operational Workaround In Place (NOOP is Sent Prior to Every Uplink Session) FSW Patch to Correct this Nuisance was Rejected Since STL Verification of Patch Performance is not Possible ISA SUMMARY (Continued)

5 STARDUST 20 Nov 2003CERR - Charles Love5 of 7 OTHER ANOMALIES Red Flag Problem/Failure Reports (6 of 69 Total P/FRs) –All Resolved Pre-Launch (Reworked, Replaced or Repaired) –No Recurrences of Any Related Failures In Flight Unverified Failures (5 Total UVFs) –All Resolved Pre-Launch (Replaced or Designated Non-Critical to Mission) –No Recurrences of Any Related Failures In Flight EEPROM Single Bit Failures on Genesis Spacecraft C&DH –Has Occurred Twice on Genesis but Never on Stardust –Cause Attributed to “Weak Cells” Due to Process-Induced Defective Cells or Poorly Programmed Cells –Genesis Implemented Contingency Process to Maintain Side-A Reboot Capability (Overwriting EEPROM via FSW Patch) –Similar Process Could be Applied to Stardust Should it Occur –Stardust EEPROM Image Monitored Each Week

6 STARDUST 20 Nov 2003CERR - Charles Love6 of 7 SINGLE POINT FAILURES & WAIVERS All Approved Pre-Launch No Failures Nor Degradation of Performance Detected During 4.7 Years of Flight Single Point Failures Include: –“Standard” Structure, Cables, Connectors, Passive RF, Prop Tanks and Lines, Thermal Blankets –Coax Transfer Switch Failure at “In Between” Position Unlikely Due to Heritage Experience –Single Prop Filter Order of Magnitude Design Margin –Single Battery Single Cell Short Failure Tolerant Extensive Flight and Test Data Indicates Minimal Risk of Cell Open Failure –Pyro Initiation Unit FPGA Low Risk Due to Radiation Tolerance vs. Total Dose Fifty (50) Total Waivers –18 Major (Class 1) Waivers Against Contract Requirements Documents, ICDs, Etc. –32 Minor (Class 2) Waivers Against Internal LMA or Stardust Derived Documents No Single Point Failure Items or Waivers Impact Successful Encounter

7 STARDUST 20 Nov 2003CERR - Charles Love7 of 7 READINESS ASSESSMENT Stardust Encounter is Ready to Proceed –Risks have been Identified, Evaluated, Mitigated and Accepted –All ISAs Are Sufficiently Understood and/or Mitigated –All Red Flag PFRs Are Closed –All UVFs Are Closed –All Single Point Failures have been Identified, Evaluated and Accepted –All Waivers have been Identified, Evaluated and Accepted –No Waivers to Flight Rules and Constraints for Encounter –Encounter Test Program and Anomalies Well Documented and Completion On Track


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