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1
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 0800 AM - 0500 PM PST 20 Nov 2003
2
ISA SUMMARY

• Total ISAs 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 E17 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

3
ISA SUMMARY (Continued)

• ISAs 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

4
ISA SUMMARY (Continued)

• ISAs 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

5
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
  CDH
• 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
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
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