THEMIS Constellation Operations Manfred Bester THEMIS Mission Operations

THEMIS Constellation Operations Manfred Bester THEMIS Mission Operations Manager University of California at Berkeley THEMIS RR Constellation Operations − 1 UCB, June 28, 2007

Agenda • • • • Mission Profile Update Mission Readiness Testing Launch & Early Orbit Campaign Flight Systems Performance & Status Instrument Deployment & Commissioning Coast Phase Ground Systems Performance & Status Telemetry Data Recovery & Processing Anomalies Constellation Status Summary Configuration Management Staffing & Engineering Support Updated Flight Rules THEMIS RR Constellation Operations − 2 UCB, June 28, 2007

Mission Profile Update THEMIS RR Constellation Operations − 3 UCB, June 28, 2007

Mission Readiness Testing • Extensive Mission Readiness Test Program – • Training & Simulation Sessions – – • See MRT Spreadsheet for Details Many Training and Simulation Sessions Including Greencard Exercises to Prepare the UCB Operations Team Conducted by Contractors (B. Stroozas, C. Deyarmin) Mission Simulations & Dress Rehearsals 18 -Jan-2007 19 -Jan-2007 02 -Feb-2007 UCB@KSC 03 -Feb-2007 UCB@KSC 05 -Feb-2007 09 -Feb-2007 13 -Feb-2007 16 -Feb-2007 THEMIS RR MD 0 Simulation – MOC with UCB/Swales Team MD 1 Simulation – MOC with UCB/Swales Team MD 0 Simulation – MOC with UCB/Swales Team, MD 1 Simulation – MOC with UCB/Swales Team, MD 0 Simulation – MOC, KSC, NOM, GN/SN, UCB@KSC MD 0 Simulation – Launch Countdown with KSC, Boeing MD 0 Countdown to L− 4 min Scrub Constellation Operations − 4 UCB, June 28, 2007

THEMIS Mission Data Flows THEMIS Probe TDRS Berkeley Ground Station KSC & Astrotech (1) UCB I&T Facility Secure Intranet JPL I&T Facility Compatibility White Sands (3) Test Van Complex Merritt Island Ground Station (3) Santiago Ground Station Secure VPN Tunnel via Open Internet (2) Open IONet Berkeley Mission Operations Center (3) Wallops Ground Station GSFC NMC Dial-up ISDN Line Notes: Open (1), Restricted (2) or Closed (3) IONet Hartebeesthoek Ground Station Different Routes for End-to-end Data Flows Between Probes and GS Elements THEMIS RR Constellation Operations − 5 UCB, June 28, 2007

MOC Console Assignments THEMIS RR Constellation Operations − 6 UCB, June 28, 2007

Launch & Early Orbit Campaign THEMIS RR Constellation Operations − 7 UCB, June 28, 2007

Launch Campaign • Launch Team Located at KSC and UCB – UCB, Swales, Hammers and GSFC Team Members – Communications via 3 Voice Loops • Pre-launch Data Flows – – – • Launch Pad and GN/SN to MOC Activities Started at L-9: 30 Data Flow Tests with GN/SN Probes Powered On at L-7: 00 Blockhouse Cleared at L-4: 30 Go/No-Go Polls – First Go/No-Go Poll at L-4: 00 – Final Go/No-Go Poll at L-0: 20 – THEMIS Configured for Launch at L-0: 05 • Real-time Data Flows from All Probes to MOC Until Lift-off THEMIS RR Constellation Operations − 8 UCB, June 28, 2007

Launch Campaign THEMIS Launch • • • Launch Site: CCAFS SLC-17 B Launch Vehicle: Delta II 7925 -10 Lift-off Time: 17 -Feb-2007 23: 01: 00. 384 UTC (at Opening of 19 -min Launch Window) • THEMIS RR Target Orbit: 435. 0 × 91845. 2 km at 16. 0 deg Constellation Operations − 9 UCB, June 28, 2007

Launch from MOC Perspective T− 00: 01 and Lift-off! Post-launch Briefing FOT in Action THEMIS RR Constellation Operations − 10 First BGS Contact UCB, June 28, 2007

Flight Profile THEMIS RR Constellation Operations − 11 UCB, June 28, 2007

Probe Separation Confirmation of Probe A Separation via TDRS West: 2007/049 00: 14: 00 UTC First TDRS Contact via Blind Acquisition Forward Link: 1. 000 kbps Return Link: 1. 024 kbps THEMIS RR Constellation Operations − 12 UCB, June 28, 2007

Launch & Separation Trends Partial Lunar Shadow SA Panel 1 Temp (C) SA Top Temp (C) S-band Antenna Temp © Transmitter Temp (C) Separation Event Filtered IRU X and Y Output Lift-off THEMIS A & B Launch and Separation Trend Plots THEMIS RR Constellation Operations − 13 UCB, June 28, 2007

Initial Acquisition via GN Initial Acquisition via Ground Network • Insertion Attitude Was Difficult for Ground Network Coverage – Probes Were Oriented with Antennas Pointing Away from Ground Stations (Known Before Launch) • All Telemetry Links Appeared Weaker Than Expected – Initial Concerns of Continuing Degradation Were Dispersed Later – Overall Drop in Signal Level Plus Variations with Spin Phase • Causes for Lower Than Expected Performance – RF Power Dissipation Within Antenna (20% instead of 10%) – Ripple in Antenna Patterns as Function of Antenna Look Angles – Spin Phase and Elevation Angle Relative to Spin Plane – Magnitude of Ripple Determined by Characterizing Telemetry Link Performance as Function of Probe Attitude and Range • Ground Stations Had Difficulties to Lock on Weak Signals – Equipment Characteristics and Configuration Does Not Match Assumptions Used to Develop Telemetry Link Budgets THEMIS RR Constellation Operations − 14 UCB, June 28, 2007

Initial Acquisition – Cont. Predicted Spacecraft Antenna Aspect Angle (Top Panel) and Resulting Telemetry Link Margin (Bottom Panel) Based on Nominal Insertion Attitude Initial BGS View Period Data Rate 4 K 01: 00 – 13: 00 MET THEMIS RR Constellation Operations − 15 UCB, June 28, 2007

Initial Acquisition – Cont. Recorded Signal Strength from Initial BGS Passes with THEMIS B, C, D, E, A Intermittent RF and Data Lock on THEMIS B Only Recorded Signal Strength from Second BGS Pass with THEMIS A Solid RF and Data Lock THEMIS RR Constellation Operations − 16 UCB, June 28, 2007

Power & Thermal Issues • Insertion Attitude Caused Concerns – Spin Axis to Sun Angle: 45 - 50 deg – Solar Panels Generate More Power Than Expected – Shunts in Power System Cannot Dissipate Energy When Top Solar Panel Illuminated – Turned on Catalyst Bed Heaters for Mitigation Prior to IDPU Power-on – Battery Overvoltage Protection (OVP) Trips – Detected OVP Trip First on THEMIS A during Separation Event Pass – Team Was Concerned that Battery Overcharging Might Occur – OVP Trips Turn All Digital Shunts On, Removing Power from Solar Array Strings 1, 2 and 3 Until Battery Voltage Drops to 32. 2 V – High Antenna Temperature (>70 C) When Transmitter Turned On • Transmitter Operations – Limited Due to Antenna Heating Up, Especially Near Perigee THEMIS RR Constellation Operations − 17 UCB, June 28, 2007

Vector Delivery from Boeing • UCB Received Post-launch AAM Vector – Based on Measured Performance of LV Second Stage and Predicted Performance of Third Stage – Very Close Agreement with Pre-launch Predicts – USSPACECOM Provided TLEs that Appeared to Match the AAM • Orbital Period – Expected Orbital Period Was 1999 ± 180 min (3 -σ) – Achieved Orbital Period Was 1884 min (1999 - 115 min) (OD Solution Provided by GSFC/FDF on 20 -Feb-2007) THEMIS RR Constellation Operations − 18 UCB, June 28, 2007

Insertion Orbit Successful Initial Set of Round-robin State-of-health Checks via BGS THEMIS RR Constellation Operations − 19 UCB, June 28, 2007

Insertion Orbit First Negative Acquisition at Apogee via HBK THEMIS RR Constellation Operations − 20 UCB, June 28, 2007

Insertion Orbit Difference Between Predictive and Definitive Insertion Orbits THEMIS RR Constellation Operations − 21 UCB, June 28, 2007

Spacecraft Emergency Declared Spacecraft Emergency • Declared Spacecraft Emergency at 2007/050 03: 30: 00 UTC – No Communications with Any Probe for 17 hours – Concerns with Power and Thermal Issues in Insertion Attitude • Additional Assets Brought Online – GSFC/FDF Generated Acquisition Vectors for DSN Stations • GSFC/FDF Generated First Valid OD Solution – Initial Two-way Doppler Tracking Data Were Sparse Since Both BGS and WGS Had Difficulties to Lock onto Weak Signals – Used Crude Angle Data from WGS to Enhance Tracking Data Set • Probes Reacquired via HBK After 28 Hours – Confirmed Good State of Health of All Five Probes • Continued to Shadow Track with DSN Stations for Another Day – DSS 46 (Madrid), DSS 66 (Canberra) and DSS 27 (Goldstone) • Emergency Terminated at 2007/051 11: 45: 00 UTC THEMIS RR Constellation Operations − 22 UCB, June 28, 2007

Insertion Orbit Successful Reacquisition via HBK Based on GSFC/FDF’s First OD Solution THEMIS RR Constellation Operations − 23 UCB, June 28, 2007

First Orbit Solution Post-launch Orbit Configuration – Dispersed at L + 6. 5 d THEMIS RR Constellation Operations − 24 UCB, June 28, 2007

Flight Systems Performance THEMIS RR Constellation Operations − 25 UCB, June 28, 2007

Power Subsystem Performance • Power Generation Much Better Than Expected – Shunts Cannot Dissipate Enough Power When Instruments Are Turned Off – Used Catalyst Bed Heaters Initially to Dissipate Excess Power – Battery State of Charge Typically Maintained Above 90% (Full Capacity 11. 8 Ah) • Overvoltage Protection Trips Turned Out to Be False Alarms – Initially Thought to Be Related to Transmitter Power-on Events – Later Shown to Be Related to RTS Execution – Reason Unknown THEMIS RR Constellation Operations − 26 UCB, June 28, 2007

Thermal Subsystem Performance • • All Probes Behave Thermally as Designed One Exception – RCS Service Valve on THEMIS E Colder Than on Other Probes – Protected Against Freezing with Secondary Heater • Attitude Dependent Thermal Profile – Hot Case: – Cold Case: • Spin Axis to Sun Angle of 135 deg (Sun at -45 deg w. r. t. Spin Plane) Not Yet Seen On Orbit Top Deck Towards Sun ± Offset S-band Antenna Temperature Too High (> 70 C) When Sun Above Spin Plane by 45 -50 deg (Launch Attitude) THEMIS RR Constellation Operations − 27 UCB, June 28, 2007

Long Term Trend Plots Battery Voltage Long Term Trends of: • Battery Voltage • Battery Temperature • Tank 1&2 Liquid Temperatures Probe: THEMIS A Battery Temperature Coverage: 130 Days (100 Orbits − DOY 49− 179) Tank Liquid Temperatures Show Heater Cycles with Periods of 7− 8 Days Tank 1 & 2 Liquid Temperatures THEMIS RR Constellation Operations − 28 UCB, June 28, 2007

Telecom Subsystem Performance • Transponders Work Very Well – Receivers Are Very Sensitive – Lock on BGS Uplink Signals of Typically 50 W Out to 92, 000 km – Transmitters Work Well – No Problems With Any Modes of Operation – Discovered Direct Modulation Can Be Used at 4 K – 64 K Data Rates • Antennas – Seem to Have Lower Gain Than Expected – Overall Drop by 1. 0 d. B – Ripple of Up to 4. 0 d. B pp • Degraded Telemetry Link Budget – THEMIS B: – THEMIS A, C, D: – THEMIS E: THEMIS RR -3. 0 d. B -4. 0 d. B -5. 0 d. B Constellation Operations − 29 UCB, June 28, 2007

Telecom Subsystem – Cont. Qual Antenna (AL 350) Receive Pattern at 2101. 1 MHz (Left) and Transmit Pattern at 2282. 5 MHz (Right) Antenna Was Mounted Over Mock-up Probe Body and Measured at GAAMS Facility (GSFC Code 567) Contours Are Great Circle Cuts in Azimuth Steps of 5 deg with +Z Axis Pointing to the Right Side THEMIS RR Constellation Operations − 30 UCB, June 28, 2007

Telecom Subsystem – Cont. Processed Operational Antenna Patterns Used to Perform Dynamic Link Margin Predictions and Corresponding Selection of Data Rates for Pass Scheduling THEMIS RR Constellation Operations − 31 UCB, June 28, 2007

Additional Telecom Issues • Problems Encountered on Ground Network Side – BGS 11 m – Supports Passes at Apogee with Data Rates of 64 K for THEMIS B and 32 K for All Other Probes Using Direct Carrier Modulation – Improved Station Performance and Procured Additional Receivers – Station Has Best G/T (25. 0 d. B/K) and Optimal Receiver Performance – WGS 11 m – Station Can Still Not Lock on Telemetry Signal at Current Apogee – Near Perigee Passes at High Data Rates Are Nominal Now – Occasional Problems with Acquisition Vector Processing – MILA 9 m 1/2 and AGO 9 m – Station Locks on RF and Data at Apogee with 8 K and Subcarrier Modulation – Near Perigee Passes at High Data Rates Are Nominal – HBK 10 m and 12 m/6 m – Station Works Nominally when Configured Correctly – Used 12 m Receive and 6 m Transmit Antennas for Most Supports THEMIS RR Constellation Operations − 32 UCB, June 28, 2007

Updated GN Link Analysis Updated Ground Network Link Analysis • • Takes Into Account Lower Spacecraft Antenna Gains & Ripple Usage of BPSK with Low Data Rates THEMIS E Downlink to BGS at 512 K THEMIS B Downlink to BGS at 4 K Frequency 2282. 5 MHz Modulation BPSK Probe Antenna Gain -7. 0 d. Bic Probe Antenna Gain -8. 6 d. Bic Probe EIRP -1. 3 d. BW Probe EIRP -2. 9 d. BW Range 21, 500 km Range Path Loss Polarization and Pointing Losses Ground Station G/T (BGS) 186. 3 d. B 1. 0 d. B 25. 0 d. B/K 200, 000 km Path Loss 205. 6 d. B Polarization and Pointing Losses 1. 0 d. B Ground Station G/T (BGS) 25. 0 d. B/K Data Rate (BSPK) 524. 288 kbps Data Rate (BPSK) 4. 096 kbps Bandwidth 1048. 576 k. Hz Bandwidth 8. 192 k. Hz Coding Gain RS + Rate-1/2 Conv. BER 8. 0 d. B 10 -6 Required Eb/No 2. 5 d. B Predicted Eb/No 7. 9 d. B Predicted Eb/No 8. 0 d. B Implementation Loss Link Margin 2. 3 d. B 3. 1 d. B Implementation Loss Link Margin 2. 3 d. B 3. 2 d. B THEMIS RR Constellation Operations − 33 UCB, June 28, 2007

SN Link Analysis Space Network Link Analysis • • Originally Performed by GSFC Code 450 – No Change Available Telemetry Data Rates: 1 K, 4 K and 8 K TDRSS SSA Return Link at 1 K Frequency Modulation (Mod. Index: 1. 6 rad) 2282. 5 MHz PCM/PSK/PM TDRSS SSA Forward Link Frequency 2101. 8 MHz Modulation (Mod. Index: 1. 0 rad) PCM/PSK/PM Probe Antenna Gain -3. 0 d. Bic TDRS Antenna Gain 37. 5 d. Bic Probe EIRP 2. 9 d. BW TDRS EIRP (High-power Mode) 48. 5 d. BW Range 43, 500 km Range Path Loss Polarization and RFI Loss 43, 500 km 192. 4 d. B 0. 8 d. B Path Loss Polarization Loss 191. 7 d. B 0. 1 d. B TDRS G/T 10. 5 d. B/K Probe G/T -31. 6 d. B/K Data Rate 1. 024 kbps Data Rate 1. 0 kbps Channel Power Split Loss 4. 9 d. B Modulation Loss 4. 1 d. B Coding Gain RS + Rate-1/2 Conv. 8. 0 d. B Coding Gain 0. 0 d. B BER 10 -6 Implementation Loss 2. 6 d. B TDRS Transponder Loss 4. 4 d. B Required Eb/No 2. 6 d. B Required Eb/No 10. 5 d. B Predicted Eb/No Link Margin 11. 7 d. B 9. 1 d. B Predicted Eb/No Link Margin 15. 1 d. B 4. 6 d. B THEMIS RR Constellation Operations − 34 UCB, June 28, 2007

RCS and ACS RCS Performance • • Each Probe Carried 48. 8 kg of Hydrazine at Launch Pressurizing Tank with He Latch Valves and Position Indicators Work Nominally All Axial and Tangential Thrusters Exercised (A 1 and A 2 in Pulsed Mode Only) Thruster Control Modes Function Nominally Thruster Temperatures Behave as Expected No Fuel Leaks Observed – Latch Valves Open Since MD 4 Solenoid and Pyro Valves Not Yet Actuated ACS Performance • All Sun Sensors and IRUs Function Nominally THEMIS RR Constellation Operations − 35 UCB, June 28, 2007

Attitude & Delta V Maneuvers Attitude Precession Towards Sun Normal Using Thruster A 1 Perigee Raise Maneuver Using Thrusters T 1 & T 2 First Attitude Precession and First Delta V Maneuver THEMIS RR Constellation Operations − 36 UCB, June 28, 2007

Maneuver Summary Delta V and Propellant Summary Parameter THEMIS A THEMIS B THEMIS C THEMIS D THEMIS E Initial Fuel Load [kg] 48. 800 48. 780 48. 810 48. 820 Expended Fuel [kg] 2. 046 1. 272 2. 855 2. 464 2. 103 Remaining Fuel [kg] 46. 754 47. 508 45. 955 46. 346 46. 717 Total Delta V [m/s] 26. 928 19. 944 52. 913 48. 273 39. 000 11 11 19 13 14 Total Number of Maneuvers Note: Total Delta V includes targeted delta V maneuvers plus contributions imparted by attitude precession and spin rate change maneuvers. THEMIS RR Constellation Operations − 37 UCB, June 28, 2007

C&DH Performance • • C&DH Systems Generally Work Well Encountered Two Anomalies – THEMIS B: Generation of Most BAU Housekeeping Packets Stopped on DOY 094 Processor Was Commanded to Perform “Cold Reboot Without Clear” to Restore Proper Functionality on DOY 095 Cause Unknown – Likely Due to SEU – THEMIS D: Experienced Cold Restart on DOY 107 FOR Ran Cold Restart Recovery Procedure No Issues Observed Since Cause Unknown – Post-event Analysis Failed to Show Cause THEMIS RR Constellation Operations − 38 UCB, June 28, 2007

BAU FSW BAU Flight Software Performance • All Probes Currently Use FSW Version 0 x 3191 – Loaded Into EEPROM Prior to Launch – FSW Works Very Well in General • Three Issues Related to Spin Rate Calculation 1. Small Increase in Spin Rate Each Time Raw Latched Sun Pulse Time Rolls Over at Subseconds (Magnitude ~ 0. 003 rpm) 2. FSW Skips Processing Interrupts from Sun Crossing Events and Results in a Low Spin Rate Calculation for the Next 5 Averaged Points (Magnitude ~3 rpm at Spin Rate of 20 rpm) 3. FSW Receives Extra Interrupt from Hardware and Resulting in Calculated High Spin Rate (Magnitude ~5 rpm at Spin Rate of 20 rpm) THEMIS RR Constellation Operations − 39 UCB, June 28, 2007

Instrument Commissioning THEMIS RR Constellation Operations − 40 UCB, June 28, 2007

Instrument Suite All Booms Stowed Deployed Configuration THEMIS RR Constellation Operations − 41 UCB, June 28, 2007

Instrument Commissioning Activities and Schedule – First Two Weeks On-orbit Probe Activity Description Constraints A −E IDPU Power On and Checkout IDPU CMD/TLM links, Power On and Initialize, Go to Normal Mode, Verify IDPU SOH. A −E FGM Power On and Checkout Turn on FGM, Go to Standard Mode, Run Functional (Step Function, Find Phase), Dump Quicklook Data A −E EFI/SCM Power Turn on EFI Floaters and Boards, Turn on SCM, Run EFI On and Checkout Functional (Noise, AC, DC), Run SCM Calibration, Run EFI/SCM Filters Test, Dump Quicklook Data A −E Magnetometer Boom Deploy Turn on Actuator Supply, Enable Deploy (Eng. Mode, Arm), Deploy Mag Boom, Verify Post-deploy Conditions (Spin Rate), Turn Off Actuator Supply A −E SST Power On and Checkout Turn On SST, Run SST Functional (Bias Ramp, Threshold), Open/Close SST Attenuators, Dump Quicklook Data A −E ESA Cover Open Turn on Actuator Supply, Enable Deploy (Engineering Mode, Arm), Open ESA Cover, Verify Cover Read-back, Turn Off SC Actuator Supply A −E ESA Power On and Checkout A −E ESA High Enable and Turn On ESA High Voltage, Ramp Up MCP Outgassing > 1 Day with Voltage Ramp Up Supply, Ramp Up Sweep Supply, Exercise Sweep at 1/4, ESA Cover Open and Checkout 1/2, and Full Scale, Dump IDPU Quicklook Data THEMIS RR Probe Power System Stable and Temp within Operating Limits Temp/Voltage Constraints Outgassing > 1 Week Turn on ESA, Run ESA Functional (Noise, Mask, Pulser), Dump Quicklook Data Constellation Operations − 42 UCB, June 28, 2007

Critical Instrument Operations Activity Nominal Operation Verification of Success Risk Mitigation FGM and SCM Boom Simultaneous release of Deployment primary FGM and SCM Frangibolts Verify expected change in spin rate ESA Cover Open Actuation of primary SMA wire for cover release Verify cover monitor readback Redundant SMAs Actuation length can be increased ESA High Voltage Turn-on Ramp up Ions/Electrons High Verify expected current Voltage Supplies in 2 real-time readback on MCPs passes EFI SPB Doors Open Simultaneous release of X pair Verify expected actuation then Y pair EFI doors current, change in science data EFI Spin Plane Boom Release of X pair and Y pair Deployment wires in 5 m increments EFI Axial Boom Deployment THEMIS RR Redundant frangibolts; Actuation length can be increased Real-time scientist feedback on ESA health during ramp-up Actuation length can be increased Verify expected motor current, Passive stability with one turns count verification, failed wire boom expected change in spin rate Release of primary +Z, then –Z Verify expected actuation AXB frangibolts current, change in science data Constellation Operations − 43 Redundant frangibolts (Secondary deploys ±Z AXB simultaneously); Actuation length can be increased UCB, June 28, 2007

Instrument Performance • IDPU – Flight Software Version 0 x 46 (THEMIS C) and 0 x 45 (All Others) – Nominal Operation and Performance, ETC Kicker Functional • FGM – Nominal Operation and Performance • SCM – Nominal Operation and Performance • ESA – Nominal Operation and Performance • SST – Nominal Operation and Performance • EFI – Three EFIs Completely Deployed (THEMIS C, D, E) – Nominal Operation and Performance THEMIS RR Constellation Operations − 44 UCB, June 28, 2007

Instrument Requirements Matrix Probe Bus and Instrument Requirements Matrix Probe ID Probe Bus FGM P 1 X X P 2 X X O P 3 X X P 4 X P 5 O SCM ESA SST EFI (X) X X (X) O X O X (X) O O (O) O X = Function Required for Minimum Mission (1 Year, 94 h of P 1 -P 4 Conjunctions in One Tail Season) O = Additional Function Required for Baseline Mission (2 Years, 188 h of P 1 -P 4 Conjunctions per Tail Season, Including 94 h of P 1 -P 5 Conjunctions per Tail Season) () = Only Partial Function Required (1 SST Head, 1 Pair of EFI Spin-plane Booms) THEMIS RR Constellation Operations − 45 UCB, June 28, 2007

Probe Placement Decision • Assigned Constellation IDs (P 1−P 5) to Probe Buses THEMIS A THEMIS B THEMIS C THEMIS D THEMIS E • −> −> −> P 5 P 1 P 2 P 3 P 4 Decision Based on Probe Bus and Instrument Performance – Also Included Performance Details Found During Ground Testing – Only Differences Noted Are in Telecom System • Team Members Involved in Probe Placement Decision – PI, PM, MSE, MOM, MDL, Swales Probe Bus Systems Lead, Instrument Scientists, GSFC Program Manager and GSFC Project Scientist • Coast Phase Orbit Set-up (THEMIS A−E) Interleaved with EFI Deploy (THEMIS C−E) Followed Probe Placement Decision THEMIS RR Constellation Operations − 46 UCB, June 28, 2007

Probe Identification Matrix THEMIS Probe Identification Matrix NASA Support ID Code UCB Satellite Catalog Number NORAD Satellite Catalog Number 0 x 150 — — — FM 1 0 x 153 0451 99001 30580 2007 -004 A P 5 F 2 FM 2 0 x 151 0452 99002 30581 2007 -004 B P 1 THEMIS C F 3 FM 3 0 x 155 0453 99003 30582 2007 -004 C P 2 THEMIS D F 4 FM 4 0 x 154 0454 99004 30797 2007 -004 D P 3 THEMIS E F 5 FM 5 0 x 152 0455 99005 30798 2007 -004 E P 4 THEMIS Spare — — 0 x 156 — — — Flat. Sat East — — 0 x 157 — — — Probe Bus / Simulator Name Probe Bus ID Flat. Sat West — — THEMIS A F 1 THEMIS B THEMIS RR CCSDS V 1 Instrument TLM/CMD Suite ID SCID Constellation Operations − 47 International Constellation Designator ID UCB, June 28, 2007

EFI Deployment • THEMIS C (P 2) Was Trail Blazer – 13 Deployment Steps Plus Initial Spin-up to 20 rpm – Fortunately No Restrictions on Transmitter-on Times – Four Sets of Alternating Operations – Wire Boom Spool-out on X and Y Axes in 5 -m Steps – Spin-up Maneuvers – Sensor Diagnostic Tests – Last Step Is Release of +Z and −Z Axial Booms – All Completed in 7 Working Days • THEMIS D (P 3) & E (P 4) Followed 3 Weeks Later – Performed Interleaved with Back-to-back Operations – Optimized On-console Staffing – Instrument and Mechanical Engineers for Boom Deploy Operations – Propulsion and Flight Dynamics Teams for Spin-up Operations – All Completed in 5 Working Days THEMIS RR Constellation Operations − 48 UCB, June 28, 2007

EFI Deployment Spin-up to 15 rpm Spin-up to 26 rpm First Spin-up with Wire Booms Out by 5 m in X and Y Unfurling of Fine Wires in X and Y THEMIS C EFI Deploy Steps 3 & 6 Using Dual Pulse Thrusting of T 1 THEMIS RR Constellation Operations − 49 UCB, June 28, 2007

Coast Phase THEMIS RR Constellation Operations − 50 UCB, June 28, 2007

Coast Phase Operations • Purpose of Coast Phase – Additional Mission Phase Inserted to Control Orbital Dispersions Prior to Mission Orbit Placement in Fall of 2007 – Dayside Science Campaign • Instrument Characterization and Tuning – SST Attenuator Operations – EFI Bias Currents, Usher and Guard Voltages, Sensor Diagnostic Tests (SDTs) • Science Data Acquisition – Tuning of Science Trigger Algorithms – Usage of Predicted Magnetospheric Regions of Interest – Optimization of Acquisition and Recovery of Science Data Volumes • Orbit Placement for Coast Phase – See Mission Design Presentation THEMIS RR Constellation Operations − 51 UCB, June 28, 2007

Coast Phase Orbit Placement Intermediate Orbits Towards Coast Phase Alignment THEMIS RR Constellation Operations − 52 UCB, June 28, 2007

Ground Systems Performance THEMIS RR Constellation Operations − 53 UCB, June 28, 2007

Ground System Block Diagram Ground System Elements • • • Ground Stations Space Network Mission Operations Center Science Operations Center Flight Dynamics Center Interfaces • Secure Real-time TCP/IP Socket Connections • File Transfer via Secure Network and Open Internet THEMIS RR Constellation Operations − 54 UCB, June 28, 2007

Ground Systems Status • Mission Operations Center – All Hardware and Software Systems Performed Essentially Flawlessly Since Prior to Launch • Flight Dynamics Center – Two-way Doppler Tracking Data Processed by GTDS for OD – Attitude Determination via MSASS – Integrated Mission Design Tool and GMAN Work Well • Berkeley Ground Station – Supported Almost 900 Pass with THEMIS Probes – Receiver Upgrade in Progress to Improve Data Recovery • IT Network Systems – Servers and Workstations Work Nominally – T 1 Line to GSFC Had No Issues Since Launch – Dial-up IDSN Line to HBK Works Well THEMIS RR Constellation Operations − 55 UCB, June 28, 2007

Telemetry Recovery Plan THEMIS RR Constellation Operations − 56 UCB, June 28, 2007

Telemetry Recovery Plan • Instrument Data – – – Each Probe Accumulates Up to 750 Mbits of Instrument Data per Orbit Data Compressed by Factor of 1. 5 -2. 0 Prior to Transmission to the Ground Apply 12% Overhead for CCSDS Formatting, 14% for RS Code Symbols, 5% for Replay Resulting Science Telemetry Data Volume Is 503 -670 Mbits / Orbit / Probe Required Downlink Time 16 -22 min Orbit / Probe at Data Rate of 524. 288 kbps • Engineering Data – – Each Probe Bus Accumulates Up to 87 Mbits of Engineering Data per Orbit Apply 12% Overhead for CCSDS Formatting, 14% for RS Code Symbols, 5% for Replay Resulting Engineering Telemetry Data Volume Is 111 Mbits / Orbit / Probe Required Downlink Time 4 min / Orbit / Probe at Data Rate of 524. 288 kbps • Ground Stations – Primary Ground Station (BGS) Supports 1360 Passes / Year for Telemetry Recovery (Original Plan) – Secondary Ground Stations (WGS, MILA, AGO and HBK) Support 190 Passes / Year Combined for Telemetry Recovery – Additional Tracking Passes Scheduled for Special Operations and Probe Monitoring – Additional Stations Are Considered to Fill Coverage Gaps (USNAU 13 m), to Alleviate Scheduling Conflicts (USNHI 13 m) and to Provide Long Range Coverage (White Sands) THEMIS RR Constellation Operations − 57 UCB, June 28, 2007

Probe Science Data Acquisition • Science Mode Selected by ATS and / or On-board Triggers – – Slow Survey (SS) Fast Survey (FS) Particle Burst (PB) Wave Burst (WB) On-board Data Compression • Selectively Enabled / Disabled – Huffman, Delta Modulation, Decimation – Applied Prior to Downlink • Compression Factor of 2. 0 Seems to Be Achievable – Efficiency Depends on Instrument Data Type • Solid-state Recorder Sized at 256 MBytes – 100 MBytes Available for Storage of Science Data THEMIS RR Constellation Operations − 58 UCB, June 28, 2007

Data Quality Metrics • Conjunction Science – Tail and Dayside Seasons Months – – Tail Season 1 Day Season 1 Tail Season 2 Day Season 2 Nominally Defined as WD ± 2 (T 1) (D 1) (T 2) (D 2) Winter of 2006/2007 (Skipped) Summer of 2007 Winter of 2007/2008 Summer of 2008 – 750 Mbits Uncompressed per Orbit per Probe Corresponds to 100% • Radiation Belt Crossings – Slow Survey Mode – Secondary Science Goal – 40 Mbits Uncompressed per Orbit per Probe Corresponds to 100% • Engineering Data – Recorded Throughout Orbit at Various Cadences – Total Recorded Data Volume Corresponds to 100% • Statistics Generated Against Above Metrics – Recovery Requirement for All Science and Engineering Data Is 95% – Included in Weekly Status Reports to SSMO Project Office THEMIS RR Constellation Operations − 59 UCB, June 28, 2007

Anomalies THEMIS RR Constellation Operations − 60 UCB, June 28, 2007

Anomaly Resolution Flight & Ground Systems Anomaly Resolution • Tiger Teams Assigned – Investigate Cause of Anomaly – Recommend Solutions, Work-arounds and/or Mitigations • Anomaly Tracking List – Items Closed Out When Anomaly Report Written and Recommended Actions Were Performed – Currently Tracking 11 Items (9 Closed Already) THEMIS RR Constellation Operations − 61 UCB, June 28, 2007

Anomaly Tracking List ID Date Anomaly Title 1 2/20/2007 Weak Signals with Spaceto-ground Communications Telemetry signals on all five probes appear to be appreciably weaker than predicted prior to launch. Mitigations are currently developed and tested. Affected probes: All NET 6/30/2007 2 2/18/2007 False Over-voltage Protection Trips False over-voltage protection trips occur when the battery is fully charged, and are apparently caused by transients when the transmitter is configured and/or turned on/off via relays inside the transponder. Operational work-arounds are in place. Affected probes: All NET 6/30/2007 3 2/18/2007 Potential Over-charge of the Battery Solar panels generate appreciably more power than expected, and the power control system cannot dissipate excess power at certain attitudes. As mitigation, additional loads are turned on (catalyst bed heaters and IRUs) to dissipate power as necessary. As additional protection, new tables with improved limit monitors will be uploaded to EEPROM. Affected probes: All Closed 4/6/2007 4 2/28/2007 Spin Rate Drop or Rise Occasional errors in the on-board spin rate calculations were observed on all probes and occur on average a few times per day. The spin rate drops were reproduced on Flat. Sat and a FSW patch was developed. Operational work-arounds are in place. The spin rate rises are under investigation. Affected probes: All (Spin rate rise seen only once on THEMIS C) Closed 6/28/2007 5 3/8/2007 Corrupted Level Zero Science Data Processing Ground processing software did not correctly process packets spanning frame boundaries when frames were missing. The software was fixed and all science data were successfully reprocessed. Affected probes: None Closed 3/20/2007 THEMIS RR Description and Status of Anomaly Constellation Operations − 62 Closure UCB, June 28, 2007

Anomaly Tracking List – Cont. Anomaly Tracking List - Continued ID Date 6 3/14/2007 7 Description and Status of Anomaly Closure Instrument ETC Packet Generation Halted Every few weeks the packet data generation from the ESA and SST instruments that is controlled via the ETC FPGA halts. A FSW patch was developed to detect these conditions on orbit and to restart the packet data acquisition. Tests on Flat. Sat are ongoing. Affected probes: Likely all, except that problem has not been seen on THEMIS E. Closed 6/14/2007 3/26/2007 Instrument ETC Table Loads Unreliable Problem is caused by conflicting processes accessing ETC memory while tables are loaded from IDPU EEPROM to this memory. Work-around successfully tested on Flat. Sat. Affected probes: All Closed 4/27/2007 8 4/1/2007 IDPU Data Compression IDPU resets and instrument turn-off occurred on three probes shortly after science data compression was started. IDPU FSW patch version 0 x 45 uploaded to all probes. Affected probes: Likely all, although compression was only used on three probes, and these experienced the resets (THEMIS A, B and D). Closed 6/14/2007 9 4/4/2007 BAU PCM Packet Generation Halted Generation of BAU power and thermal engineering packets read from the PCM card halted. Resetting the PCM card and warm resetting the BAU did not restore operational status. Cold reset without clear did restore the packet generation. Likely cause was a Single Event Upset (SEU). A report is currently written. Affected probes: Seen only once on THEMIS B. Closed 6/28/2007 10 4/5/2007 BAU Generates Inaccurate Sun Pulse Time Stamps BAU generates time tags for sun pulses that are occasionally off by a few milliseconds. Possible work-around is to fix the time stamps in ground processing. Affected probes: All Closed 6/14/2007 THEMIS RR Anomaly Title Constellation Operations − 63 UCB, June 28, 2007

Anomaly Tracking List – Cont. Anomaly Tracking List - Continued ID Date 11 4/17/2007 THEMIS RR Anomaly Title BAU Experienced Cold Reset Description and Status of Anomaly Closure A cold reset was experienced without any recognizable cause. As a result of the reset, the IDPU and instruments were turned off. BAU mode logs were downloaded and are currently analyzed. Affected probes: Seen only once on THEMIS D. Closed 6/28/2007 Constellation Operations − 64 UCB, June 28, 2007

Known Instrument Issues Known Prior to Launch PFR # Probe / Instrument Issue Operational Work-Around PFR 030 All Probes Actuators PCB FPGA accepts actuator commands only if actuator voltage is present. If SC actuator supply trips off during actuation, PCB will not turn off actuator switch. Thus, actuator will be active when actuator supply voltage is re-enabled. In the event that the SC Actuator supply trips off during an actuation, the ground must enter a SAFE command prior to re-enabling supply. (SAFE command has IPCB_ACTREST which resets all instruments and states). PFR 075 All Probes ESA High Voltage tripped off during Suite Thermal Vacuum testing due to in-rush. PCB supplies must be forced on during Low Voltage, High Voltage and HV level adjustment. Current trip should be re-enabled after during normal operations. PFR 164 All Probes ESA Unloaded ESA supply causes IDPU current Oscillation would only be seen if ESA was off oscillation at narrow temperature range over narrow temperature range. FOT alerted around 10 C. that condition can be expected and causes no damage. PFR 183 Probe C EFI Lower AXB (V 6) EFI channel responded anomalously during EFI Functional Test (DC excitation higher amplitude and noisier, AC excitation high-pass filtered). Not an issue after AXB deploy. Unit still provides sufficient SOH (through anomalous, but consistent DC response) information to make probe assignment decision. PFR 206 Probe D EFI F 4 AXB temperature sensor reads incorrectly (1052 C). Performance of associated EFI channel not affected. Temp sensor not critical for operation of the EFI. Failed state of the F 4 AXB temp sensor noted by FOT to avoid alarm over condition. THEMIS RR Constellation Operations − 65 UCB, June 28, 2007

Constellation Status Summary THEMIS RR Constellation Operations − 66 UCB, June 28, 2007

Constellation Status Summary • • • Mission Completed 100 Orbits on Mission Day 130 (Today) All Five Probes Are Very Healthy Orbits and Attitudes Are Stable and Safe Subsystems Performance Nominal All Instruments Are Powered On and Function Nominally EFI Booms Are Completely Deployed on THEMIS C, D and E Ground Systems Are Functioning Well Flight Dynamics Operations Are Almost Routine Operations Team Has Everything Under Control Constellation Status Online and Updated with Each Pass http: //soleil. ssl. berkeley. edu/ground_systems/themis_constellation_status. html • Planning Schedule Available Online http: //soleil. ssl. berkeley. edu/ground_systems/request_planning. themis. txt THEMIS RR Constellation Operations − 67 UCB, June 28, 2007

Constellation Status Page THEMIS RR Constellation Operations − 68 UCB, June 28, 2007

Critical Operations Completed Critical Operations • RCS Operations – – • Completed 68 Thrust Maneuvers for Orbit and Attitude Control Fired All Thrusters (A 1 and A 2 in Pulsed Mode Only) Instrument Operations – – – Magnetometer Booms Deployed on All Probes EFI Boom Deployment Completed on THEMIS C (P 2), D (P 3) & E (P 4) ESA Covers Are Open and HV Turned On Remaining Critical Operations • Mission Orbit Placement – • Fuel Tank Repressurization – – – • Beginning in September and Completed in December 2007 Need to Expend Fuel Mass – Min and Max Limits Driven by RCS System Required Tank Pressure Range 75 – 400 psia Repressurization Will Be Interspersed with Mission Orbit Placement EFI Boom Deployment – – THEMIS RR THEMIS B (P 1) and THEMIS A (P 5) Following Mission Orbit Placement Constellation Operations − 69 UCB, June 28, 2007

Configuration Management • Application of Configuration Management – – – • Configuration Freezes – – • Workspaces Operational Software & Databases Configuration Files Hardware Configurations Network Configurations Procedure Documents Current Status: Soft Freeze Regression Testing Completed Changes Allowed for Software and Hardware Upgrades Prior Approval Required by Local CCB: PM (as required), MOM, DMOM, MSE (as required), ITM (as required) Instrument Configuration Change Requests – Approved by PI, Tohban, MSE, Instrument Scientist, ISE, MOM THEMIS RR Constellation Operations − 70 UCB, June 28, 2007

Staffing & Engineering Support • Flight Operations – All Flight Procedures Executed by Certified Flight Controllers – All Special Operations Require Presence of Cognizant Subsystems Engineers and/or Instrument Scientists On Console at MOC or via Remote ITOS Displays – RCS Operations (Commissioning, Maneuvers, Pyro Valve Opening) – Instrument Commissioning & Configuration, Boom Deployment • Flat. Sat Testing – Performed by FOT, Flight Dynamics Team, Instrument Team – All STOL Procs Tested and Verified on Flat. Sat – All Maneuvers Simulated on Flat. Sat/Virtual. Sat • Sustaining Engineering – UCB Subsystems Engineers – Available and Called as Needed – Spacecraft Bus and FSW Subsystems Engineers – Contracts for Field Support THEMIS RR Constellation Operations − 71 UCB, June 28, 2007

Back-up Slides THEMIS RR Constellation Operations − 72 UCB, June 28, 2007

Updated Flight Rules THEMIS RR Constellation Operations − 73 UCB, June 28, 2007

Power System Flight Rules Activity Flight Rule Potential Impact of Violation Subsystem power-on Subsystems must be powered on only when Damage to flight their temperatures are within ITOS green hardware. limits. Load shedding THEMIS RR Bus voltage must be kept within ITOS green limits. Load shedding will occur autonomously onboard when under-voltage condition is detected. Action to Prevent Violation Monitor subsystem temperatures. Battery state-of. Monitor battery statecharge too low. of-charge and overall power budget. Power down of instrument bus and/or selected probe bus components. Constellation Operations − 74 UCB, June 28, 2007

Telecom Flight Rules Activity Flight Rule Transmitter operation Transmitter on-time limited by transmitter temperature staying within ITOS green limits. For nominal science operations planning and analyses, transmitter on-time is limited to 60 min per day. Potential Impact of Violation Overheating of transmitter and damage of power amplifier. Action to Prevent Violation Set on-board FDC parameter to turn off transmitter after 60 min. Monitor transmitter-on time on the ground alert FOT to turn off transmitter. Schedule passes and build ATS loads with transmitter-on times of 60 min or less. Transmitter operation Minimum transmitter off-time of 3 hours between transmitter on-times is required only if transmitter reached maximum allowable temperature during pass. Overheating of transmitter and damage of power amplifier. Current thermal analyses show that transmitter needs to be off for 3 hours to cool down completely from maximum temp. THEMIS RR Constellation Operations − 75 Monitor transmitter temperature. Schedule passes and build ATS loads with transmitter-on times of 60 min or less. UCB, June 28, 2007

Telecom Flight Rules – Cont. Telecom Flight Rules Activity Flight Rule Potential Impact of Violation Action to Prevent Violation Transmitter operation Minimum 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-ofcharge too low. Include check for long shadow periods in pass planning activities. Transmitter operation Transmitter 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-ofcharge too low. Include check for shadow constraints in pass planning activities. Transmitter operation No transmission during launch vehicle thrust Damage to probe phases. transmitter due to corona effects. Check LV ascent profile. Embed checks into ascent procs and procedures. Transmitter operation Cycle transmitter power using FET in power Excessive wear of module only while leaving transmitter-on relay contacts with relay always in on-position. potential for inability to turn transmitter on. Configure blind acquisition procs and RTS loads to turn relay and FET on (in this order), but only FET off. THEMIS RR Constellation Operations − 76 UCB, June 28, 2007

RCS Flight Rules Activity Flight Rule Potential Impact of Violation Action to Prevent Violation Thruster operation Catalyst bed heaters must be turned on 30 min (nominal) or 20 min (contingency) before thrusting to heat up, and are turned off at the end of thrusting. Damage to catalyst beds. Verify catalyst bed current prior to enabling thrust sequence. Thruster firing Thrusters must not be fired unless ESA HV is ramped down and SST attenuators are closed. Damage to ESA and/or SST. Verify HV and SST attenuator status prior to maneuver execution. Thruster firing Maneuvers must not be performed in shadow. Erroneous maneuver execution. Check shadow constraints as part of maneuver planning. Tangential thruster firing Tangential thruster T 1 (spin-up thruster) must not be fired until SCM boom is deployed. Damage to SCM sensor by thruster plume. Include deployment check in early maneuver sequences. Pyro valve operation Before re-pressurization, thrusters shall be fired only when the pressure in the propellant tank is 75 psia or higher. Operation outside qualification pressure limits. Verify tank pressure in valve operations procedure. Pyro valve operation The pyro valve shall not be opened until Bursting of fuel tanks. Verify tank pressure in enough fuel is consumed so that the fuel Destruction of probe. valve operations tank pressure will be 400 psia or less at any procedure. expected temperature in the re-pressurized state. THEMIS RR Constellation Operations − 77 UCB, June 28, 2007

RCS Flight Rules – Cont. RCS Flight Rules Continued Activity Flight Rule Potential Impact of Violation Action to Prevent Violation Pyro/Isolation valve operation Pyro valve must be opened only when isolation solenoid valve is open. Isolation valve cannot Verify isolation valve be opened against open status in pyro high pressure actuation procedure. differential. Partial loss of mission. Pyro/Isolation valve operation After pyro is blown, isolation valve must be opened 3 min later. Isolation valve cannot Verify isolation valve be opened against operation in pyro high pressure actuation procedure. differential. Isolation Valve operation Isolation valve shall not be held open more than 4 min at any time. Temperature exceedance. Load shedding Two of three RCS heater services shall be on at all times. Freezing and bursting Include checks in of fuel lines. flight procedures and procs that control heaters. Load shedding RCS heater service #2 shall never be turned off. Freezing and bursting Include checks in of fuel lines. flight procedures and procs that control heaters. THEMIS RR Constellation Operations − 78 Include checks in flight procedures and procs that controls isolation valve. UCB, June 28, 2007

RCS Flight Rules – Cont. RCS Flight Rules Continued Activity Flight Rule Potential Impact of Violation Action to Prevent Violation Pulsed thruster firing Pulsed operation of thrusters must not be performed at pulse rates at or near natural predicted frequencies of nutation, spinplane booms, axial booms and propellant slosh. Loss of dynamic stability. Keep pulse durations short to avoid resonance frequencies. Pulsed thruster firing The thruster pulse repetition rate shall be synchronized at once per probe rotation. Loss of dynamic stability. Dynamics review of pulse thrusting proc. Axial pulsed thruster firing The preferred pulse half width for axial thrusting is 12 degrees for all tank levels. Excessive near resonant slosh. Dynamics review of pulse thrusting proc. Side pulsed thruster firing The preferred pulse half width for side Excessive near thrusting is 30 deg unless tank fill is between resonant slosh. 68% and 58% or 39% and 29% where half width should be reduced to 20 deg. Dynamics review of pulse thrusting proc. Pulsed thruster firing Pulsed side and axial thrusting shall not be combined. Loss of dynamic stability. Dynamics review of pulse thrusting proc. Thruster firing A Critical Stop command shall be sent prior Improper maneuver to issuing any thrust commands. execution. Include checks in flight procedures and procs that control thruster operations. THEMIS RR Constellation Operations − 79 UCB, June 28, 2007

ACS Flight Rules Activity Flight Rule Potential Impact of Violation Action to Prevent Violation Spin rate control Spin rate must be maintained within range of 5 -26 rpm. Loss of dynamic stability. Damage to booms. Monitor spin rate and set into safe regime prior to boom deployment. Monitor spin rate during side thrusting maneuvers. Attitude control Probe attitude (spin axis) must be maintained such that the Sun is kept out of the exclusion zone of 15 deg with respect to the surface normal of the top and bottom decks. Thermal problems with probe bus in general and deployed axial booms in particular. Monitor attitude and take flight rule into account for planning attitude precession maneuvers. THEMIS RR Constellation Operations − 80 UCB, June 28, 2007

FSW / C&DH Flight Rules Potential Impact of Violation Action to Prevent Violation RTS operation No combination of ATS, RTS, and real-time Erroneous commands shall be sent to exceed the execution. maximum command rate per task as stated in the FSW Users Guide. Configuration control of FDC. Verify ATS loads and check for violations. Clock adjustments must not be performed during critical operations such as maneuvers. Erroneous maneuver execution. Place verification steps into procs that execute clock adjust. Clock adjustment Do not command large clock jumps during RTS execution. Commands skipped over will execute. Place verification steps into procs that execute clock adjust. Activity THEMIS RR Flight Rule Constellation Operations − 81 UCB, June 28, 2007

Instrument Flight Rules Activity Flight Rule Potential Impact of Violation Action to Prevent Violation IDPU power-on IDPU temperature must be within allowed operational limits prior to powering up Unclean start-up likely Verify IDPU temperature in procedure EFI power-on EFI Floater voltages must be powered on prior to (~10 s) to EFI Board Prevents EFI BIAS drivers from latching at a ± 100 V rail EFI_ON. proc with correct sequence used whenever EFI is powered on ESA HV power-on ESA HV must not be turned on until initial outgassing is completed Damage to ESA Disable HV turn-on procedure until L+7 days ESA HV power-on ESA HV must not be turned on until at least Damage to ESA 60 min after a thrust maneuver is completed ESA HV ramp-down ESA HV must be ramped down prior to thruster operation Contamination of ESA Check status prior to enabling Prop Bus for maneuver SST attenuator operation SST attenuators must be closed prior to thruster operation Possible performance Check status prior to degradation enabling Prop Bus for (calibration change) maneuver THEMIS RR Constellation Operations − 82 Verify time since last maneuver in HV turnon procedure UCB, June 28, 2007

Instrument Flight Rules – Cont. Instrument Flight Rules − Continued Potential Impact of Violation Action to Prevent Violation Unsuccessful boom deployment; Overheating of boom frangibolts causing contamination Include temperature/ voltage check in procedure Magnetometer booms must be deployed at deployment spin rates from 2 to 12 rpm. Unsuccessful boom deployment; Damage to magnetometer booms Include spin rate checks in deployment procedure EFI radial boom deployment EFI radial booms must be deployed at spin rates detailed in SPB Boom Deploy. xls spreadsheet. (Too High) Damage to boom deployment mechanism at high cable root tension; (Too low) Excessive spin down Include spin rate check in deployment procedure; Predict cable root tension for deployments 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 Verify spin-plane boom deployment status in procedure Activity Boom deployment THEMIS RR Flight Rule All booms must be deployed only when their temperature is within the allowed range. Minimum deployment temperature for magnetometer booms is -17 C. Probe attitude may have to be adjusted to bring temperature into allowed range. Constellation Operations − 83 UCB, June 28, 2007