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1
STARDUST Project CRITICAL EVENTS READINESS
REVIEW COMET P/WILD 2 ENCOUNTER READINESS
PREPARATION T. Duxbury
JPL 303-411 AM / 301-427 PM LMA MSA 1 818
354-1275 0800 AM - 0500 PM PST 20 Nov 2003
2
Total Workforce  
Operations, Science, E/PO and Management at JPL
and LMA
3
SCOPE OF READINESS PREPARATION

• Used the Flyby of Main Belt Asteroid Annefrank to
  Test Wild 2 Approach Operations, Timelines,
  Interfaces and Encounter Sequence
• DRR and CERR Held before Event
• Wild 2 E-3d to E1d Timeline
• Approach Geometry Significantly More Severe than
  Wild 2Approach
• Annefrank 30 deg from Sun, Required Large
  Attitude Turns and Performed on Batteries with
  Flyby Speed 7.4 km vrs 6.1 km/s at Wild 2
• Annefrank Too Dim to See Before Flyby
• All Operations Performed Within Timelines
• All Interfaces, Peer Reviews, Command Products
  Implemented/Validated
• Survived Loss of 1 1/2 DSN Passes - Forced
  Quick Turn Around of Sequences
• Radio/Optical Nav Performed w/ Encounter
  Annefrank/Star Images
• Encounter Sequence Completely Successful
• Collector Deployed, CIDA and DFMI on and Nucleus
  Tracking Captured All 72 Flyby Images
• Nav too Accurate, Bank Turn Computed but too
  Small to Implement
• Operations Would Have Succeeded at Wild 2

4
SCOPE OF READINESS PREPARATION

• Produced New Wild 2 Dust Production Model
• 10 Times Less Collectable Dust w/ Ten Times More
  Hazardous Dust
• Peer Reviewed w/ 15 International Comet
  Scientists
• James Rose Chaired Review
• Current Model Viewed as Worst Case/Upper Limit to
  Large Dust
• Recommended Earth-based Observations for
  Additional Validation
• Produced New Wild 2 Ephemerides
• Accuracy of Time of Encounter Degraded from 30
  seconds to 180 seconds (1,100 km 1s)
• Reviewed by Navigation Advisory Group (NAG)
• Validated New Model
• Recommended Earth-based Observations for
  Additional Validation

5
SCOPE OF READINESS PREPARATION

• Reviewed Science Requirements and Spacecraft
  Safety
• Moved Flyby from 150 km to 300 km for S/C Safety
• Response to New Dust Model
• Reduced Collection from 1,000 Particles gt 15 mm
  to 500
• Effect of New Dust Model
• Reduced Images Within 2,000 km from 65 to 30
• Effect of Degraded Time of Encounter Uncertainty
• New Mission Success Criteria in Approval Cycle at
  NASA HQ
• Changes to Level 1 Requirements Need OSS
  Associate Administer Approval
• Is a Given for This Review

6
SCOPE OF READINESS PREPARATION

• Conducted Readiness Reviews of Key Operational
  Elements
• Nav Readiness Review by Navigation Advisory Group
  (NAG)
• Deep Space Mission Systems (DSMS) Readiness
  Review
• Multi Mission Office (MMO) Ground Data System
  Readiness Review
• Planetary Data System (PDS) Review of Data
  Archive Formats and Contents - Used for
  Operations as Well
• Meetings with JPL Office of Communications and
  Education Continuing
• 20 Full Tests of Encounter Sequence with
  Expected Range in Variables Plus Anomalies
  Nearing Completion in the Spacecraft Test
  Laboratory
• Conducting Operational Readiness Testing (ORTs)
• Radio Opt Nav for E-2d TCM Completed
• E-2d to E-6h ORT Remaining
• Science ORT Remaining
• E/PO ORT Remaining
• Camera Cleanup Performed / Opt Nav Images Started
• Compliant w/ Flight Project Practices

7
SCOPE OF READINESS PREPARATION
8
READINESS

• Simple Flyby Trajectory at Encounter
• Straight Line Motion Past a Massless Body
• Moved from Previous Planned Flyby of 150 km to
  300 km
• Reduced Spacecraft Risk at Flyby by a Factor of 2
• Reduced Delivery Performance by Nav by a Factor
  of 2
• Successful Flyby Totally Dependent on OpNav
• Needs DS1 Level of Sensitivity and Geometric
  Accuracy
• Op Nav Already Detected Wild 2 - Will
  Significantly Ease Encounter Operations
• Deleted Many Contingency Plans if Detection was
  Late
• No Need to Take Lots of Pictures and Co-Add on
  the Ground for Detection as Planned
• Can Implement Leisurely Trajectory Correction
  Maneuver Schedule and Miss a Few if Needed
• The Remaining Presentations will Demonstrate
• Relative Ease of Remaining Operations
• Excellent Preparation and Qualifications of
  Flight Team
• Robust Timeline w/ Excellent Margin and
  Contingency Strategies
• The STARDUST Project is Ready for Wild 2