THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 1June 1-2, 2004 L&EO and Normal Operations Manfred Bester

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 2June 1-2, 2004 L&EO and Normal Operations Overview Launch Early Orbit Checkout Maneuver Operations Instrument Commissioning Normal Science Operations

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 3June 1-2, 2004 L&EO Operations Launch & Early Orbit Operations Delta II Launch Sequence with Release of Probes Probe A Radiating During Separation, Monitored Via TDRSS Subsequent Round Robin State-of-Health Monitoring Initial Attitude and Orbit Determination Uplink of First Set of Command Loads to Each Probe Change Attitude from Release to Commissioning Attitude Systematic Instrument Power-up and Check-out Decision of Probe Placement − Based on Functional Check-out Orbit Placement Maneuvers Critical Operations Performed Real-time Contact Approval to Proceed via Command Authorization Meetings (CAMs)

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 4June 1-2, 2004 Launch Configuration Third Stage and Probe Carrier Assembly Delta II

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 5June 1-2, 2004 Probe Exterior and Interior View Probe Bus – Exterior View with Magnetometer Booms Stowed Probe Bus – Interior View

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 6June 1-2, 2004 Probe Separation Separation from PCA Monitoring of Separation via TDRSS One Probe Will Be Transmitting (THEMIS A, Top of PCA) All Probes Will Be Recording Data Round-robin Status Polling After Separation Each Probe Will Be Contacted for 5 Minutes Initially

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 7June 1-2, 2004 Dispersion Analysis Post-launch Probe Dispersion Analysis Use Relative Separation Velocities Perform Inter-probe Range Analysis (Not Yet Completed) Relative Separation Velocities X [m/s]Y [m/s]Radial [m/s]Z [m/s] PCA + LV Probe A Probe B Probe C Probe D Probe E

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 8June 1-2, 2004 Mission Profile

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 9June 1-2, 2004 Post-launch Scenario Power Profile Probes Are Power Positive with Minimum Loads Need to Perform Attitude Maneuver to Orient Probe +Z Axis Perpendicular to Probe-sun Line to Allow for Check-out Activities Thermal Profile Worst Case Is Top or Bottom Deck to Sun Communications Coverage Scenario Based on Launch Trajectory Provided by KSC Modeled Probe Antenna Pattern Dynamic Link Margin Calculated for Telemetry Data Rate of kbps

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 10June 1-2, 2004 Launch Scenario

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 11June 1-2, 2004 Launch Scenario

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 12June 1-2, 2004 Launch Scenario

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 13June 1-2, 2004 Launch Scenario

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 14June 1-2, 2004 Probe Antenna Pattern Calculated Probe Antenna Pattern Specification: -3 dB Points at 90° ± 45° Polarization: LHCP Pattern: Toroidal, Centered in X−Y Plane Top Deck of Probe Body Affects Gain Pattern: Blockage at −Z Ripples at +Z

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 15June 1-2, 2004 Launch Scenario Data Rate: kbps

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 16June 1-2, 2004 Launch Scenario Data Rate: kbps

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 17June 1-2, 2004 Launch Scenario Polar Plot of First Two BGS View Periods

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 18June 1-2, 2004 L&EO Timeline

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 19June 1-2, 2004 L&EO Timeline

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 20June 1-2, 2004 L&EO Timeline

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 21June 1-2, 2004 L&EO Timeline

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 22June 1-2, 2004 Maneuver Planning & Execution Maneuver Planning Determine Pre-maneuver State Vector and Attitude with Required Accuracy Perform Maneuver Analysis with Current and Target State Vectors Verify Delta V Budget Perform Contact Schedule and Shadow Analysis Develop Detailed Thruster Firing Sequence Validate Probe Configuration and Maneuver Sequence on Probe Simulator Maneuver Execution Establish Two-way Communications with Probe Ramp Down ESA High-voltage Supply, Place SST into Attenuated Mode Uplink Command Sequence to Perform Reorientation and Orbit Maneuvers Download and Verify Command Buffer and Verify Firing Attitude Monitor Maneuver Execution in Real-time De-configure Probe Systems and Monitor Health and Safety Maneuver Calibration Determine Post-maneuver Orbit and Attitude Calibrate Thrusters and Analyze Overall Maneuver Efficiency and Accuracy Perform Accurate Bookkeeping of Fuel Usage

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 23June 1-2, 2004 Pre-launch Testing & Validation Pre-launch Testing and Validation of Maneuvers Develop Representative Command Profile –Required to Perform End-to-end Tests for All Operational Scenarios for Each Probe Post-test Analysis of Captured VirtualSat Telemetry Data –Validate ACS Flight Software for Thruster Control, On-orbit Attitude Determination and Fault Protection –Validate Ground-based Attitude Determination Software

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 24June 1-2, 2004 Probe Operations Functions Ground Operations Functions Perform Mission Design to Determine Target Probe Orbit and Attitude Perform GMAN Run with Current and Target Orbit and Attitude Formulate Specific Maneuver Events, Attitudes and Durations Generate Discrete Thruster Profile and Pulse Firing Sequence Generate Discrete Stored Command Sequence Via MPS Upload TLM Table, Firing Sequence and Downlink Data Rate Perform Off-line Validation of Entire Stored Command Sequence on Hi-fidelity Probe Simulator Turn On Gyros and Catalyst Bed Heaters (Pre-heat) Downlink On-board CMD Buffer Compare Flight and Ground Reference Image to Verify Load Verify CMD & TLM Link Via BGS, WGS or TDRSS Verify Current Attitude Via Sun Sensor Data Verify Gyro Performance, Catalyst Bed Heater Functionality, Propellant Tank Pressure, Valve and Fuel Line Temperatures and States, and Pre- Maneuver Attitude Turn Off Catalyst Bed Heaters Execute Burn Sequence Monitor Key Temperatures, Tank Pressure, Attitude and State Vector On-board Failure Detection & Correction (FDC) Logic (Gyro Rates, Sun Sensor Attitude Limits, etc.) Aborts Sequence if Anomaly Detected Turn Off Gyros Verify Tank Pressure, General Probe Health and Safety, and Perform Two-way Ranging Turn Off Transmitter Determine New Orbit and Attitude, and Calibrate Maneuver Typical Maneuver Sequence Perform Long-term Calibration of Pulse Timing and Thruster Efficiency

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 25June 1-2, 2004 Maneuver Types Maneuver Type Thrusters Involved Purpose, Requirements and Fuel Efficiency Orbit Position for Maneuver GMAN Compatibility Orbit Maneuver A1 and A2 Continuous Firing Perigee or Apogee Change Preceded and Followed by Attitude Maneuver High Fuel Efficiency Arc Limited Near Perigee to Minimize Cosine Loss Apogee or Perigee Yes Orbit Maneuver A1 and A2 Continuous Firing Inclination Change with or without Arg Per Change Preceded and Followed by Attitude Maneuver High Fuel Efficiency ApogeeYes Orbit Maneuver A1 and A2 Continuous Firing Combined In-plane and Out-of-plane Orbit Change Preceded and Followed by Attitude Maneuver High Fuel Efficiency Arc Limited Near Perigee to Minimize Cosine Loss Apogee or Perigee Yes Orbit Maneuver A1 and A2 Continuous Firing Alternating with T1 and T2 Pulsed Firing In-plane and Out-of-plane Orbit Tweak in Mission Attitude Large Beta Angle Loss Sunlight on Sun Sensor Required Arc Limited Near Perigee to Minimize Cosine Loss Apogee or Perigee Yes Attitude Maneuver A1 and / or A2 Pulsed Firing Attitude Change to or from Mission or Maneuver Attitude High Efficiency Prior to Spin-plane Boom Deploy Low Efficiency after Spin-plane Boom Deploy Sunlight on Sun Sensor Required AnyYes Spin Up or Spin Down T1 or T2 Pulsed Firing Spin Rate Adjustment Sunlight on Sun Sensor Required AnyYes

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 26June 1-2, 2004 Maneuver Sequence Earth Precession Maneuver to Normal Attitude Upload: Thruster Enable Precession Maneuver to Axial Thrust Attitude Attitude Monitoring (MSSS / IRU) Ground-Based Attitude Determination (MSSS / FGM) Upload: Thruster Commands Upload: Thruster Enable Upload: Thruster Enable

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 27June 1-2, 2004 Mission Orbit Placement Mission Orbit Placement for P1 Accelerated Maneuver Sequence Modeled with GMAN –Apogee and Perigee Raises –Inclination Adjustment Goals of Study –Determine Communications Coverage

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 28June 1-2, 2004 Communications Coverage

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 29June 1-2, 2004 Maneuver Details Spin-up and Spin-down Maneuvers Spin Rate Limits: rpm Timing of Pulse Maneuvers Ensure Pulse Frequencies Do Not Coincide with Probes’ Fundamental Frequencies (Nutation, Spin-plane Booms, Axial Booms, Propellant Slosh) Flight Rules Related to Maneuver Operations RCS Configuration Maintain Spin Rate Within Allowable Limits Select Pulse Timing to Avoid Exciting of Resonances

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 30June 1-2, 2004 Real-time Maneuver Support Communications Requirements –Ground Station Contact –TDRSS Contact Real-time Monitoring –Tank Pressure –Thruster Temperatures –Probe Attitude Vector –Doppler Profile Compare Observed Against Predicted Performance –Real-time Trend Plots for Observed Minus Calculated Attitude and Doppler Residuals –Plotting Doppler Residuals Requires Real-time Data from Ground Stations –Plotting Attitude Angle Residuals Requires Data from Probe Telemetry Via ITOS

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 31June 1-2, 2004 Attitude Control Plan Probe Release from Launch Vehicle, Nominally at 15 rpm Optional De-spin to 15 rpm, in Case of Off-nominal Release Attitude Maneuver to Place Spin Axis Perpendicular to Probe-to-sun Line at 15 rpm Deploy of Magnetometer Booms at 15 rpm Spin-up to 20 rpm Attitude and Orbit Maneuvers at 20 rpm Attitude Maneuver to Point Spin Axis Towards Ecliptic South pole at 20 rpm Spin-up to 25 rpm Prior to Spin-plane Boom Deploy Spin-plane Boom Deploy at Variable Spin Rate rpm Spin-up to 20 rpm After Last Spin-plane Boom Deploy Step Axial Boom Deploy at 20 rpm

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 32June 1-2, 2004 Instruments

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 33June 1-2, 2004 IDPU Power Modes ModeIDPU & Instrument StatusPower Consumption Shut Down ModeIDPU Off All Instruments Off 0.0 W Safe ModeIDPU On All Instruments Off 7.8 W Low Power ModeIDPU On FGM On All Other Instruments Off 8.0 W Engineering ModeIDPU On Instrument States Vary Depending on Activity N/A Science ModeIDPU On All Instruments On 11.8 W IDPU Power Modes Launch Configuration: Shut Down Mode FGM Operation: Requires at Least Low Power Mode

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 34June 1-2, 2004 Instrument Commissioning 1.IDPU Turn-on As Soon As Probe Power System Is Stable and Temperature Within Operating Limits, Verification of Nominal Voltages and Currents, Command Communications and DCB Functionality 2.FGM Turn-on, Power Verification and Uplink of Parameter Load for 32 Hz Bx, By and Bz, Verification of Sensitivity Control on Each Axis, Select Sensitivity 3.EFI Turn-on, Power Verification and Configuration for 32 Hz E & B Sample Rates 4.SCM Turn-on, Power Verification and Activation of Calibration Sequence 5.Magnetometer Boom De-spin to <15 rpm and Deployment With FGM at 32 Hz Real-time Science TLM; Cross-calibration of Magnetometers While Probe Separations Are Still Small 6.SST Turn-on After Initial Outgassing Phase, Power Verification, High-voltage Ramp-up and Attenuator Functional Test 7.ESA Turn-on After Initial Outgassing Phase, Power Verification, Cover Release and High-voltage Ramp-up 8.EFI Spin Plane Boom Deployment − Procedure Controlled by IDPU 9.EFI Axial Boom Deployment − Procedure Controlled by IDPU

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 35June 1-2, 2004 EFI Deployment Details EFI Deployment Overview Initial On-orbit Check-out –EFI SOH Determined Using Stowed DC and AC Functional Test Capability Booms Deployed After Completion of Initial Orbit Placement –Attitude Maneuvers with Deployed Booms Too Expensive Deployment Sequence –Spin-plane Boom Deployment –5 to 6 Intermediate Deploy Lengths with Interleaved Spin-up –Axial Boom Deployment –1 Step to Deploy Both Axial Booms Primary Constraints for Deploy and Commissioning –Transmit Time Limited to 30 min –Required Transmitter Cool-down Period of 3.5 h –Desire to Gather Science Data at Intermediate Deploy Lengths and in Different Plasma Regimes

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 36June 1-2, 2004 EFI Deployment Sequence EFI Deployment Sequence Per Probe Deploy SPB-X –Deploy Boom Section –Wait for Transmitter to Cool Down –Run Slow Sweep and Take Diagnostic Mode Data Deploy SPB-Y –Deploy Boom Section –Wait for Transmitter to Cool Down –Run Slow Sweep and Take Diagnostic Mode Data Spin Up to 20 rpm –Prepare for Next Deploy Cycle Slow Sweep Large Parameter Space to Be Explored –4 Braid, 3 Usher, 3 Guard and 32 Bias Settings –1152 Steps, 1 Step / Spin –Sweep Duration Approximately 1 hour

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 37June 1-2, 2004 EFI Deployment Order P3 and P4 Deploy First –2-day, 2-orbit Cycle: –P3 Deploying and P4 Pausing –P4 Deploying and P3 Pausing –Full deploy and commissioning takes 14 days P1 and P2 Deploy Next –P2 on 2-day (1-orbit) Cycle –Deploy on Outbound, Quiescent on Inbound; 14 Days Total –P1 on 4-day (1-orbit) Cycle –Deploy on Outbound, Quiescent on Inbound; 28 Days Total –P1 Deploy Cycle May Be Accelerated –Depends on Experience Gained and Data Gathered During P3 and P4 Deploy and Commissioning P5 Deploys Last –1 or 2-day cycle –Full Deploy and Commissioning Takes 7-14 Days

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 38June 1-2, 2004 EFI Normal Science Operations EFI Instrument Mode –Slow Survey, Fast Survey, Particle Burst, Wave Burst and Diagnostic Mode –Set by ~30 Registers on BEB –Configurable Data Rates Via DFB Mode Commands –Typical Mode Specified with ~200 Commands –Valid Over a Typical One-month Period, Once Deploy and Commissioning Completed Slow Sweeps and Diagnostic Data –Taken Several Times per Year –Upon First Entry into New Plasma Regime –After Long Shadows –Maintain Optimal Bias Settings –Monitor EFI State-of-health EFI Science Operations

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 39June 1-2, 2004 Flight Rules Preliminary Collection for All Subsystems –Power System –Telecommunications Subsystem –Reaction Control System –Attitude Control System –Flight Software –Command & Data Handling –Instruments Detailed List Developed During I&T

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 40June 1-2, 2004 Power System Flight Rules ActivityFlight RulePotential Impact of Violation Subsystem power-onSubsystems must be powered on only when their temperatures are within the specified limits. Damage to flight hardware. Load sheddingBus voltage must be kept within specified operating limits. Load shedding will occur autonomously on-board when under-voltage condition is detected. Battery state-of-charge too low.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 41June 1-2, 2004 Telecom Flight Rules ActivityFlight RulePotential Impact of Violation Transmitter operationTransmitter on-time limited to 30 min. For nominal science operations planning and analyses, transmitter on-time is limited to 30 min per day. Overheating of transmitter. Transmitter operationMinimum transmitter off-time of 3 hours between transmitter on-times. Current thermal analyses show that transmitter needs to be off for 3 hours to cool down completely. Overheating of transmitter. Transmitter operationMinimum period of transmitter off-time prior to entry and after exit of long shadows. Exact times are driven by operational activities and overall power management. Battery state-of-charge too low. Transmitter operationTransmitter on-time during shadows limited to less than 30 min. Allowed transmitter-on times for a given shadow period are driven by overall power management. Battery state-of-charge too low.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 42June 1-2, 2004 RCS Flight Rules ActivityFlight RulePotential Impact of Violation Thruster operationCatalyst bed heaters must be turned on 60 min before thrusting to heat up, and turned off before thrusting. Damage to catalyst beds. Thruster firingThrusters must not be fired unless ESA HV is ramped down and SST attenuators are closed. Damage to ESA and/or SST. Thruster firingManeuvers must not be performed in shadow.Erroneous maneuver execution. Tangential thruster firingTangential thruster T1 (spin-up thruster) must not be fired until SCM boom is deployed. Damage to SCM sensor by thruster plume. Pyro valve operationPyro valve used to repressurize fuel tanks must not be opened until pressure in fuel tanks has dropped to 580 kPa. Bursting of fuel tanks. Destruction of probe. Latch valve operationLatch valves must be configured to allow for equal depletion of fuel tanks in case mass properties are off- nominal. This situation may occur if the spin-plane booms do not deploy symmetrically. Gas migration into fuel lines due to unequal depletion of fuel tanks. Load sheddingBoth RCS heater services must not be turned off simultaneously. Freezing of fuel and bursting of fuel lines. Thruster monitoringLimits for allowable thruster sum current must be set prior to thruster operation. Erroneous limit violations.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 43June 1-2, 2004 RCS Flight Rules - Cont. RCS Flight Rules - Continued ActivityFlight RulePotential Impact of Violation FDC managementMaximum angular rates measured by IRUs must be set according to planned attitude maneuver. Premature or late maneuver abortion. FDC managementMaximum thruster on-time must be configured for expected duration of thruster operation. Premature maneuver termination. Pulsed thruster firingPulsed operation of thrusters must not be performed at pulse rates at or near natural frequencies of nutation, spin-plane booms, axial booms and propellant slosh. Loss of dynamic stability.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 44June 1-2, 2004 ACS Flight Rules ActivityFlight RulePotential Impact of Violation Spin rate controlSpin rate must be maintained within rpm.Loss of dynamic stability. Damage to booms.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 45June 1-2, 2004 FSW / C&DH Flight Rules ActivityFlight RulePotential Impact of Violation RTS operationFDC algorithms and ATS loads must be set up such that not more than two RTSs operate at the same time. Erroneous command execution. FDC managementTurn off Data Monitors when components are turned off. Erroneous limit violations. FDC managementDisable Data Monitors that use delta time before setting the clock. Erroneous limit violations. FDC managementReset time before enabling Data Monitors that use delta time. Erroneous limit violations. Clock adjustmentClock adjustments must not be performed during critical operations such as maneuvers. Erroneous maneuver execution.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 46June 1-2, 2004 Instrument Flight Rules ActivityFlight RulePotential Impact of Violation IDPU power power-onIDPU temperature must be within allowed operational limits prior to powering up. Damage to IDPU electronics. ESA HV power-onESA HV must not be turned on until initial outgassing is completed. Damage to ESA. ESA HV ramp-downESA HV must be ramped down prior to thruster operations. Contamination of ESA. SST HV power-onSST HV must not be turned on until initial outgassing completed. Damage to SST. SST attenuator operation SST attenuators must be closed prior to thruster operations. Damage to SST. Boom deploymentBooms must be deployed only when their temperature is within allowed range. Probe attitude may have to be adjusted to bring temperature into allowed range. Unsuccessful boom deploy. Damage to boom deployment mechanism. Magnetometer boom deployment Magnetometer booms must be deployed at spin rates from 2 to 15 rpm. Damage to magnetometer booms. EFI radial boom deployment EFI radial booms must be deployed at spin rates from 2 to 25 rpm. Unsuccessful boom deploy. Damage to boom deployment mechanism. EFI axial boom deployment EFI axial booms must not be deployed unless spin- plane booms are deployed to their nominal distance. Loss of dynamic stability.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 47June 1-2, 2004 Instrument Flight Rules - Cont. Instrument Flight Rules - Continued ActivityFlight RulePotential Impact of Violation EFI axial boom deployment EFI axial booms must be deployed at spin rates from 2 to 25 rpm. Damage to axial booms.

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 48June 1-2, 2004 Normal Science Operations Mission Planning Pass Schedule and Command Load Generation Probe Command and Control Probe Health and Safety Monitoring Recovery of Science and Engineering Data Command Load Uplink Twice Per Week Probe Clock Adjustments Instrument Configuration and Data Trending Orbit and Attitude Determination Routinely Performed Multiple Times per Week Maneuver Planning and Execution Orbits of P1 and P2 Adjusted Few Times Per Year to Optimize Conjunctions and Annually to Avoid Shadows Orbit of P5 Adjusted for First Year Dayside and Second Year Tail and Dayside Seasons

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 49June 1-2, 2004 Weekly Operations Schedule Week Operations Schedule for the Constellation MonTueWedThuFriSatSun 5 Pass Supports FOT On Console 5 Pass Supports FOT On Console 5 Pass Supports FOT On Console 5 Pass Supports FOT On Console 5 Pass Supports FOT On Console 5 Pass Supports Lights-out Operation 5 Pass Supports Lights-out Operation Generation and Uplink of ATS Loads Pass Scheduling Uplink of Table Loads (If Required) Pass Scheduling Generation and Uplink of ATS Loads Telemetry Recovery Data Trending and Limit Checking Tracking Data Pre-processing Attitude Validation Maneuver Calibration Tracking Data Pre-processing Attitude Validation Orbit Determination Attitude Determination Maneuver Planning Orbit Determination Attitude Determination Ephemeris and Product Generation Delivery of IIRVs and PSATs

THEMIS FDMO CDR Peer Review − L&EO and Normal Operations 50June 1-2, 2004 Probe Safing Operations Power System –Automatic Load Shedding Attitude Control System –Spinning Platform Reaction Control System Shutdown –Various Fault Detection Mechanisms –Time-out for Thrusting –Rate Monitoring Via IRUs Instrument Safing –HV Ramped Down and Attenuators Moved into FOV for Thruster Operations