# Presentation: 532996

## STARDUST Project

-  ***CRITICAL EVENTS READINESS REVIEW***
***COMET P/WILD 2 ENCOUNTER***
***Spacecraft/Testing/FP Status***
***Allan Cheuvront***

- 12 Dec 01

## Overview

**Spacecraft Status**
**Encounter Requirements**
**Encounter Commanding**
**First Time Events**
**Fault Protection**
**Encounter Test Program**
**Contingencies**
**Staffing**
**Readiness Assessment**

- 12 Dec 01

## Spacecraft Status

**Configuration**
**AACS**
**All Stellar Mode**
**Transition to Gyro Based Mode for OPNAV**
**Power**
**Solar Arrays Strings Are Parallel**
**Battery Voltage Ranges 30-32**
**Telecom**
**All Components Powered On Until After Encounter**
**Power Cycle Once/Week to Prevent Trapped Charge **
**FSW is Operating at 20 MHz**
**Thermal is Nominal**
**Instruments**
**CIDA is Operating**
**DFM is Powered Off**
**SRC is Stowed**
**NAVCAM is On for OPNAV**

- 12 Dec 01

## Spacecraft Status (Cont’d)

**Performance Margins**
**Fuel = 9 Kg (81 m/s)**
**Tank Pressure = 18 psi (100 psi Minimum Required)**
**IMU = 60 Days (Worst Case)**
**Power = 100 Watts**
**No Concerns for Telecom, Thermal, and FSW**
**Spacecraft Trends**
**All Subsystem’s Performances are Nominal**
**Power Output is Slowly Decreasing Since Spacecraft is Moving Away From Sun**
**Thermally the Spacecraft is Also Slowly Cooling**
**PACI Temp Keep Out Zone Not an Issue**
**SSPA Is On**

- 12 Dec 01

## Encounter Requirements

- 12 Dec 01

## Encounter Requirements (Cont’d)

- 12 Dec 01

## Encounter Approach Activities

- 12 Dec 01

## Close Encounter Activities

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |

**E-6h**

**E-5h**

**E-4h**

**E-3h**

- - Sequence Start
- -Disable SCAM Track Mode
- -Start APID 27
- -Config File Initialization
- (E-5.5h)

- -ACS Mode-Encounter Absolute
- -Reallocate Heap
- -NAVCAM to Encounter Mode
- -CIDA to Encounter Mode
- -Start sending CIDA data

**E-2h**

- -Disable SCAM
-  Processing
- (E-2.5h)

- -Take  1 Image
- And Downlink

- -Take 1
-  Image

**E-1h**

**E-0**

- -Start APID 28
- -Nav Mirror to
- Auto Track

- -Images Every 30 Seconds

**E-30m**

- -DFM On,
- Send Data

- -Start APID 30
- (E-13.5m)

**E-15m**

- -Switch to
- MGA
- -Carrier Only
- (E-6.5m)

- -Roll
- Mnvr
- (E-6m)

- -Images
- Every 10 Seconds
-  (E-6m)

- -Stop DFM & CIDA Data (E-7m)

- 12 Dec 01

## Close Encounter Activities (Cont’d)

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |

- -Stop APID 30 (E+13m)

- -Take Last Image
-  (E+8m)
- -NAVCAM Off

- -Begin Playback
- -DFM Off

- -Stop APID 28

**E+6h**

**E+15m**

**E+30m**

**E+1h**

**E+2h**

**E+3h**

**E+4h**

**E+5h**

**E+0**

- -Roll Back
- (E+6m)

- -Switch to HGA
-  (E+7m)

- -Enable SCAM Processing
- (E+2.5h)

- -ACS Mode- AutoRef Earth Point
- -Stop APID 27

- -CIDA to Cruise Mode
- -CIDA Off
- -Sequence End
- (E+5.5h)

- 12 Dec 01

## Encounter Commanding

**Command Encounter Mission Phase After TCM 12**
**Encounter Sequence**
**Testing Flight Versions of All Products**
**All Configuration Files Have Been Reviewed**
**Late Updated Files Have Been Identified and Update Process Tested**
**Critical Commanding**
**TCM 12 – E-48 Hours**
**Finalizes Flyby Distance**
**3 Hours of Margin in Schedule For Uplink**
**Encounter Sequence**
**Loaded Spacecraft at E-40 Hours**
**Not Time Critical**
**NAVCAM Image Priority FSW Patch**
**Plays Back 5 Closest Approach Images First**
**Patch Products Incorporated in All Encounter Testing**
**Will Be Installed on S/C by December 15**

- 12 Dec 01

## Encounter Commanding (Cont’d)

**Significant Commanding**
**Mission Phase to Encounter (Post TCM 12)**
**Open Latch Valve 2 (Post TCM 12)**
**Disable FP (Post TCM 13 or E-17 Hours)**
**Command Cruise 2 Mission Phase When All Science Data Has Been Played-Back And Greater Than E+4 Days**

- 12 Dec 01

## Encounter Uplink Schedule

- 12 Dec 01

## First Time Events

**First Time Events Performed at Annefrank**
**Disable S/W Fault Protection Entries Except**
**Attitude Control Fault Remained Enabled**
**Battery State of Charge Fault Remained Enabled**
**Critical Event Fault Protection Will Be Enabled**
**Attitude Commanded to Encounter Absolute Mode and Encounter Relative Mode**
**Reallocation of HEAP Space To Encounter Configuration**
**Command AACS To Encounter Mode**
**Command CIDA To Encounter Mode**
**Command NAVCAM to Encounter Mode**
**Nucleus Tracking**
**Reallocation of HEAP Space To Cruise Configuration (Post Annefrank)**

- 12 Dec 01

## First Time Events (Cont’d)

**Remaining First Time Events**
**Autonomous Roll Maneuver**
**Tested and Verified in STL**
**Cannot Be Performed on Spacecraft**
**Execute the “Bang” Part of the “Bang-Bang” Controller**
**Demo on S/C Scheduled for Early December**
**Tested and Verified in STL**

- 12 Dec 01

## Fault Protection Analysis 

**Wild 2 Encounter Fault Tree Analysis Performed Prior to Annefrank and Revisited in October 2003**
**237 Potential Faults Identified**
**11 Major Fault Areas**
**Fail to Collect 1000 Particles (61 Faults)**
**Encounter Velocity > 6.5 km/s (2 Faults)**
**Spacecraft Survivability (128 Faults)**
**Do Not Take > 65 Images (15 Faults)**
**Images Resolution > 67 mrad/pixel (1 Fault)**
**Images Taken > 2000 km (3 Duplicates)**
**CIDA Fails (5 Faults)**
**Failure to Collect Comet Coma Molecules (2 Duplicates)**
**Failure to Perform Dynamic Science (8 Faults)**
**DFM Fails (4 Faults)**
**Sequence/Command Errors**** **** (13 Faults)**
**Utilized STARDUST and Non-STARDUST Personnel**

- 12 Dec 01

## Fault Protection Analysis (Cont’d)

**No Show Stoppers Were Identified**
**Original Review Exposed Subsystem Personnel Not Present During Design to Their Subsystem Performance Expectations**
**Modeling Prop Slosh Was An Item Identified For Additional Analysis**
**Completed**
**Simulations in Progress**
**All Faults Identified Were Able To Say YES to Accepted Risk**
**Review of All Fault Protection Configuration Files Scheduled For December 4 **
**Disable FP Entries Into Safe Mode After TCM 13 (E-18 Hours)**
**Re-Enable FP Post Encounter From The Ground**
**Verify No Time Bombs**
**Spacecraft is Safe**

- 12 Dec 01

## Fault Protection Enables/Disables

- 12 Dec 01

## Encounter Test Program

**Purpose**
**Verify S/C Can Survive Safe Mode/Re-Boot In Order To Obtain Primary Science (Dust Collection)**
**Test Encounter Sequence That Will Obtain Secondary and Tertiary Science (Images, CIDA, DFM, Dynamic)**
**“****Test As You Fly”**
**17 Tests Have Been Identified in Test Plan**
**Nominal 300 Km Flyby**
**Stacked Errors – 2 Cases**
**1000 Km Stacked Error**
**3 Sigma Dust**
**Specified Torques**
**Fault Protection – 5 Cases**
**Risk Reduction – 6 Cases**
**13 Cases Have Been Completed, Remaining Cases On-Schedule**
**Additional Cases Will Be Performed As Time Permits**

- 12 Dec 01

## Encounter Test Program Results

**Minor Changes to Encounter Sequence**
**Identified Y-Axis Controller Improvement**
**IMU Failed Test**
**IMU Failed Off**
**No Attitude Knowledge/Control**
**Re-Examining Allowing IMU Swap**
**Test Anomaly Sheets**
**Documents Test Anomalies, Set-up, etc**
**Status**
**72 Opened**
**53 Closed**
**46 Related to STL Issues**
**ENC-1-037**
**SM Entry During Nominal Flyby**
**Experts Have Reviewed All Available Data But Cause Remains Unknown**
**Has Not Been Duplicated**
**No Constraint on Testing**

- 12 Dec 01

## Contingencies

**No Waivers To Flight Rules and Constraints**
**Streamline Existing Safe Mode and LOS Plans for Rapid Recovery**
**Power Contingency Plan**
**Requires 4 Solar Array String Failures**
**Ground Commands to Power Off All Non-Essential Components (Instruments, Catbed Heaters to Non-Op Set –Point)**
**Telecom Data Rates**
**In Case Signal Strength Is Lower Than Expected**
**Commands Exist For Safe Mode Recovery**
**RCS Thruster Swap**
**FP Strategy Disable Swap to Secondary RCS Thruster**
**FP Test Has Verified Current Strategy Will Provide Necessary Attitude Control, TCM Thrusters Keeping S/C Behind Whipple Shield**
**Ground Will Swap RCS Thruster When Appropriate to Minimize Propellant Usage**

- 12 Dec 01

## Staffing

**ACE Coverage **
**Prime Shift December 23 – December 30**
**24/7 December 30 – January 3, 2004**
**Prime Shift January 4 – January 8, 2004**
**SCT Staff Capable Of Supporting 24/7 Operations **
**Draw on Existing Operations Team (GNS, ODY, MGS), S/S Designers On-Call**
**Event Related Coverage Prior to January 1 (Primarily Prime Shift)**
**Everyone On-Call Starting December 23 (After TCM 11) Until January 8, 2004.**
**24/7 Coverage January 1 – 2, 2004**
**ORT**
**TCM 12 and Encounter Sequence Performed on Nov 5**
**TCM 13 and 14 Scheduled for Dec 9-10**

- 12 Dec 01

## READINESS ASSESSMENT

**STL Testing Has Sufficient Margin**
**Spacecraft Is Operationally Ready**
**Personnel Resources Are Available**

- 12 Dec 01