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THEMIS RRConstellation Operations − 1UCB, June 28, 2007 THEMIS Constellation Operations Manfred Bester THEMIS Mission Operations Manager University of California at Berkeley
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THEMIS RRConstellation Operations − 2UCB, 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
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THEMIS RRConstellation Operations − 3UCB, June 28, 2007 Mission Profile Update
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THEMIS RRConstellation Operations − 4UCB, June 28, 2007 Mission Readiness Testing Extensive Mission Readiness Test Program –See MRT Spreadsheet for Details Training & Simulation Sessions –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-2007MD0 Simulation – MOC with UCB/Swales Team 19-Jan-2007MD1 Simulation – MOC with UCB/Swales Team 02-Feb-2007MD0 Simulation – MOC with UCB/Swales Team, UCB@KSC 03-Feb-2007MD1 Simulation – MOC with UCB/Swales Team, UCB@KSC 05-Feb-2007MD0 Simulation – MOC, KSC, NOM, GN/SN 09-Feb-2007MD0 Simulation – MOC, KSC, NOM, GN/SN, UCB@KSC 13-Feb-2007MD0 Simulation – Launch Countdown with KSC, Boeing 16-Feb-2007MD0 Countdown to L−4 min Scrub
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THEMIS RRConstellation Operations − 5UCB, June 28, 2007 THEMIS Mission Data Flows JPL I&T Facility Berkeley Mission Operations Center White Sands Complex Compatibility Test Van GSFC NMC Wallops Ground Station Different Routes for End-to-end Data Flows Between Probes and GS Elements Berkeley Ground Station THEMIS Probe Secure Intranet TDRS Secure VPN Tunnel via Open Internet Notes: Open (1), Restricted (2) or Closed (3) IONet Open IONet Hartebeesthoek Ground Station Dial-up ISDN Line Santiago Ground Station Merritt Island Ground Station KSC & Astrotech UCB I&T Facility (3) (1) (2) (3)
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THEMIS RRConstellation Operations − 6UCB, June 28, 2007 MOC Console Assignments
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THEMIS RRConstellation Operations − 7UCB, June 28, 2007 Launch & Early Orbit Campaign
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THEMIS RRConstellation Operations − 8UCB, 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 –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
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THEMIS RRConstellation Operations − 9UCB, June 28, 2007 Launch Campaign THEMIS Launch Launch Site:CCAFS SLC-17B Launch Vehicle:Delta II 7925-10 Lift-off Time:17-Feb-2007 23:01:00.384 UTC (at Opening of 19-min Launch Window) Target Orbit:435.0 × 91845.2 km at 16.0 deg
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THEMIS RRConstellation Operations − 10UCB, June 28, 2007 Launch from MOC Perspective FOT in Action T−00:00:01 and Lift-off! Post-launch Briefing First BGS Contact
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THEMIS RRConstellation Operations − 11UCB, June 28, 2007 Flight Profile
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THEMIS RRConstellation Operations − 12UCB, 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
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THEMIS RRConstellation Operations − 13UCB, June 28, 2007 Launch & Separation Trends Filtered IRU X and Y Output Separation Event THEMIS A & B Launch and Separation Trend Plots SA Panel 1 Temp (C) SA Top Temp (C) S-band Antenna Temp © Transmitter Temp (C) Lift-off Partial Lunar Shadow
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THEMIS RRConstellation Operations − 14UCB, 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
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THEMIS RRConstellation Operations − 15UCB, 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 4K 01:00:00 – 13:00:00 MET
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THEMIS RRConstellation Operations − 16UCB, 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
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THEMIS RRConstellation Operations − 17UCB, 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
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THEMIS RRConstellation Operations − 18UCB, June 28, 2007 Vector Delivery 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)
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THEMIS RRConstellation Operations − 19UCB, June 28, 2007 Insertion Orbit Successful Initial Set of Round-robin State-of-health Checks via BGS
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THEMIS RRConstellation Operations − 20UCB, June 28, 2007 Insertion Orbit First Negative Acquisition at Apogee via HBK
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THEMIS RRConstellation Operations − 21UCB, June 28, 2007 Insertion Orbit Difference Between Predictive and Definitive Insertion Orbits
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THEMIS RRConstellation Operations − 22UCB, 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
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THEMIS RRConstellation Operations − 23UCB, June 28, 2007 Insertion Orbit Successful Reacquisition via HBK Based on GSFC/FDF’s First OD Solution
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THEMIS RRConstellation Operations − 24UCB, June 28, 2007 First Orbit Solution Post-launch Orbit Configuration – Dispersed at L + 6.5 d
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THEMIS RRConstellation Operations − 25UCB, June 28, 2007 Flight Systems Performance
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THEMIS RRConstellation Operations − 26UCB, June 28, 2007 Power Subsystem 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
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THEMIS RRConstellation Operations − 27UCB, June 28, 2007 Thermal Subsystem 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:Spin Axis to Sun Angle of 135 deg (Sun at -45 deg w.r.t. Spin Plane) Not Yet Seen On Orbit –Cold Case:Top Deck Towards Sun ± Offset S-band Antenna Temperature Too High (> 70 C) When Sun Above Spin Plane by 45-50 deg (Launch Attitude)
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THEMIS RRConstellation Operations − 28UCB, June 28, 2007 Long Term Trend Plots Long Term Trends of: Battery Voltage Battery Temperature Tank 1&2 Liquid Temperatures Probe: THEMIS A Coverage: 130 Days (100 Orbits − DOY 49−179) Tank Liquid Temperatures Show Heater Cycles with Periods of 7−8 Days Battery Voltage Battery Temperature Tank 1 & 2 Liquid Temperatures
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THEMIS RRConstellation Operations − 29UCB, June 28, 2007 Telecom Subsystem 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 4K – 64K Data Rates Antennas –Seem to Have Lower Gain Than Expected –Overall Drop by 1.0 dB –Ripple of Up to 4.0 dB pp Degraded Telemetry Link Budget –THEMIS B:-3.0 dB –THEMIS A, C, D:-4.0 dB –THEMIS E:-5.0 dB
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THEMIS RRConstellation Operations − 30UCB, June 28, 2007 Telecom Subsystem – Cont. Qual Antenna (AL350) 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
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THEMIS RRConstellation Operations − 31UCB, 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
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THEMIS RRConstellation Operations − 32UCB, June 28, 2007 Additional Telecom Issues Problems Encountered on Ground Network Side –BGS 11m –Supports Passes at Apogee with Data Rates of 64K for THEMIS B and 32K for All Other Probes Using Direct Carrier Modulation –Improved Station Performance and Procured Additional Receivers –Station Has Best G/T (25.0 dB/K) and Optimal Receiver Performance –WGS 11m –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 9m1/2 and AGO 9m –Station Locks on RF and Data at Apogee with 8K and Subcarrier Modulation –Near Perigee Passes at High Data Rates Are Nominal –HBK 10m and 12m/6m –Station Works Nominally when Configured Correctly –Used 12m Receive and 6m Transmit Antennas for Most Supports
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THEMIS RRConstellation Operations − 33UCB, June 28, 2007 Updated GN Link Analysis THEMIS E Downlink to BGS at 512K Frequency2282.5 MHz ModulationBPSK Probe Antenna Gain-7.0 dBic Probe EIRP-1.3 dBW Range21,500 km Path Loss186.3 dB Polarization and Pointing Losses1.0 dB Ground Station G/T (BGS)25.0 dB/K Data Rate (BSPK)524.288 kbps Bandwidth1048.576 kHz Coding Gain RS + Rate-1/2 Conv.8.0 dB BER10 -6 Required Eb/No2.5 dB Predicted Eb/No7.9 dB Implementation Loss2.3 dB Link Margin3.1 dB THEMIS B Downlink to BGS at 4K Frequency2282.5 MHz ModulationBPSK Probe Antenna Gain-8.6 dBic Probe EIRP-2.9 dBW Range200,000 km Path Loss205.6 dB Polarization and Pointing Losses1.0 dB Ground Station G/T (BGS)25.0 dB/K Data Rate (BPSK)4.096 kbps Bandwidth8.192 kHz Coding Gain RS + Rate-1/2 Conv.8.0 dB BER10 -6 Required Eb/No2.5 dB Predicted Eb/No8.0 dB Implementation Loss2.3 dB Link Margin3.2 dB Updated Ground Network Link Analysis Takes Into Account Lower Spacecraft Antenna Gains & Ripple Usage of BPSK with Low Data Rates
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THEMIS RRConstellation Operations − 34UCB, June 28, 2007 SN Link Analysis TDRSS SSA Return Link at 1K Frequency2282.5 MHz Modulation (Mod. Index: 1.6 rad)PCM/PSK/PM Probe Antenna Gain-3.0 dBic Probe EIRP2.9 dBW Range43,500 km Path Loss192.4 dB Polarization and RFI Loss0.8 dB TDRS G/T10.5 dB/K Data Rate1.024 kbps Channel Power Split Loss4.9 dB Coding Gain RS + Rate-1/2 Conv.8.0 dB BER10 -6 Implementation Loss2.6 dB Required Eb/No2.6 dB Predicted Eb/No11.7 dB Link Margin9.1 dB TDRSS SSA Forward Link Frequency2101.8 MHz Modulation (Mod. Index: 1.0 rad)PCM/PSK/PM TDRS Antenna Gain 37.5 dBic TDRS EIRP (High-power Mode)48.5 dBW Range43,500 km Path Loss191.7 dB Polarization Loss0.1 dB Probe G/T-31.6 dB/K Data Rate1.0 kbps Modulation Loss4.1 dB Coding Gain0.0 dB BER10 -6 TDRS Transponder Loss4.4 dB Required Eb/No10.5 dB Predicted Eb/No15.1 dB Link Margin 4.6 dB Space Network Link Analysis Originally Performed by GSFC Code 450 – No Change Available Telemetry Data Rates: 1K, 4K and 8K
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THEMIS RRConstellation Operations − 35UCB, 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 (A1 and A2 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
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THEMIS RRConstellation Operations − 36UCB, June 28, 2007 Attitude & Delta V Maneuvers First Attitude Precession and First Delta V Maneuver Attitude Precession Towards Sun Normal Using Thruster A1 Perigee Raise Maneuver Using Thrusters T1 & T2
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THEMIS RRConstellation Operations − 37UCB, June 28, 2007 Maneuver Summary Delta V and Propellant Summary ParameterTHEMIS ATHEMIS BTHEMIS CTHEMIS DTHEMIS E Initial Fuel Load [kg]48.80048.78048.810 48.820 Expended Fuel [kg]2.0461.2722.8552.4642.103 Remaining Fuel [kg]46.75447.50845.95546.34646.717 Total Delta V [m/s]26.92819.94452.91348.27339.000 Total Number of Maneuvers 11 191314 Note: Total Delta V includes targeted delta V maneuvers plus contributions imparted by attitude precession and spin rate change maneuvers.
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THEMIS RRConstellation Operations − 38UCB, June 28, 2007 C&DH 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
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THEMIS RRConstellation Operations − 39UCB, June 28, 2007 BAU FSW BAU Flight Software Performance All Probes Currently Use FSW Version 0x3191 –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)
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THEMIS RRConstellation Operations − 40UCB, June 28, 2007 Instrument Commissioning
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THEMIS RRConstellation Operations − 41UCB, June 28, 2007 Instrument Suite All Booms Stowed Deployed Configuration
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THEMIS RRConstellation Operations − 42UCB, June 28, 2007 Instrument Commissioning Instrument Commissioning Activities and Schedule – First Two Weeks On-orbit ProbeActivityDescriptionConstraints A −EIDPU Power On and Checkout IDPU CMD/TLM links, Power On and Initialize, Go to Normal Mode, Verify IDPU SOH. Probe Power System Stable and Temp within Operating Limits A −EFGM Power On and Checkout Turn on FGM, Go to Standard Mode, Run Functional (Step Function, Find Phase), Dump Quicklook Data A −EEFI/SCM Power On and Checkout Turn on EFI Floaters and Boards, Turn on SCM, Run EFI Functional (Noise, AC, DC), Run SCM Calibration, Run EFI/SCM Filters Test, Dump Quicklook Data A −EMagnetometer Boom Deploy Turn on Actuator Supply, Enable Deploy (Eng. Mode, Arm), Deploy Mag Boom, Verify Post-deploy Conditions (Spin Rate), Turn Off Actuator Supply Temp/Voltage Constraints A −ESST Power On and Checkout Turn On SST, Run SST Functional (Bias Ramp, Threshold), Open/Close SST Attenuators, Dump Quicklook Data A −EESA Cover OpenTurn on Actuator Supply, Enable Deploy (Engineering Mode, Arm), Open ESA Cover, Verify Cover Read-back, Turn Off SC Actuator Supply Temp/Voltage Constraints Outgassing > 1 Week A −EESA Power On and Checkout Turn on ESA, Run ESA Functional (Noise, Mask, Pulser), Dump Quicklook Data A −EESA High Voltage Ramp Up and Checkout Enable and Turn On ESA High Voltage, Ramp Up MCP Supply, Ramp Up Sweep Supply, Exercise Sweep at 1/4, 1/2, and Full Scale, Dump IDPU Quicklook Data Outgassing > 1 Day with ESA Cover Open
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THEMIS RRConstellation Operations − 43UCB, June 28, 2007 Critical Instrument Operations ActivityNominal OperationVerification of SuccessRisk Mitigation FGM and SCM Boom Deployment Simultaneous release of primary FGM and SCM Frangibolts Verify expected change in spin rate Redundant frangibolts; Actuation length can be increased ESA Cover OpenActuation of primary SMA wire for cover release Verify cover monitor readbackRedundant SMAs Actuation length can be increased ESA High Voltage Turn-on Ramp up Ions/Electrons High Voltage Supplies in 2 real-time passes Verify expected current readback on MCPs Real-time scientist feedback on ESA health during ramp-up EFI SPB Doors OpenSimultaneous release of X pair then Y pair EFI doors Verify expected actuation current, change in science data Actuation length can be increased EFI Spin Plane Boom Deployment Release of X pair and Y pair wires in 5 m increments Verify expected motor current, turns count verification, expected change in spin rate Passive stability with one failed wire boom EFI Axial Boom Deployment Release of primary +Z, then –Z AXB frangibolts Verify expected actuation current, change in science data Redundant frangibolts (Secondary deploys ±Z AXB simultaneously); Actuation length can be increased
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THEMIS RRConstellation Operations − 44UCB, June 28, 2007 Instrument Performance IDPU –Flight Software Version 0x46 (THEMIS C) and 0x45 (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
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THEMIS RRConstellation Operations − 45UCB, June 28, 2007 Instrument Requirements Matrix Probe Bus and Instrument Requirements Matrix Probe ID Probe Bus FGMSCMESASSTEFI P1XX(X) P2XXOXX(X) P3XXOX(X)O P4XXOX(X)O P5OOOO(O)O X = Function Required for Minimum Mission (1 Year, 94 h of P1-P4 Conjunctions in One Tail Season) O = Additional Function Required for Baseline Mission (2 Years, 188 h of P1-P4 Conjunctions per Tail Season, Including 94 h of P1-P5 Conjunctions per Tail Season) () = Only Partial Function Required (1 SST Head, 1 Pair of EFI Spin-plane Booms)
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THEMIS RRConstellation Operations − 46UCB, June 28, 2007 Probe Placement Decision Assigned Constellation IDs (P1−P5) to Probe Buses THEMIS A −> P5 THEMIS B −> P1 THEMIS C −> P2 THEMIS D −> P3 THEMIS E −> P4 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
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THEMIS RRConstellation Operations − 47UCB, June 28, 2007 Probe Identification Matrix THEMIS Probe Identification Matrix Probe Bus / Simulator Name Probe Bus ID Instrument Suite ID CCSDS V1 TLM/CMD SCID NASA Support ID Code UCB Satellite Catalog Number NORAD Satellite Catalog Number International Designator Constellation ID FlatSat West——0x150————— THEMIS AF1FM10x153045199001305802007-004AP5 THEMIS BF2FM20x151045299002305812007-004BP1 THEMIS CF3FM30x155045399003305822007-004CP2 THEMIS DF4FM40x154045499004307972007-004DP3 THEMIS EF5FM50x152045599005307982007-004EP4 THEMIS Spare ——0x156————— FlatSat East——0x157—————
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THEMIS RRConstellation Operations − 48UCB, June 28, 2007 EFI Deployment THEMIS C (P2) 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 (P3) & E (P4) 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
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THEMIS RRConstellation Operations − 49UCB, June 28, 2007 EFI Deployment THEMIS C EFI Deploy Steps 3 & 6 Using Dual Pulse Thrusting of T1 First Spin-up with Wire Booms Out by 5m in X and Y Unfurling of Fine Wires in X and Y Spin-up to 15 rpmSpin-up to 26 rpm
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THEMIS RRConstellation Operations − 50UCB, June 28, 2007 Coast Phase
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THEMIS RRConstellation Operations − 51UCB, 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
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THEMIS RRConstellation Operations − 52UCB, June 28, 2007 Coast Phase Orbit Placement Intermediate Orbits Towards Coast Phase Alignment
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THEMIS RRConstellation Operations − 53UCB, June 28, 2007 Ground Systems Performance
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THEMIS RRConstellation Operations − 54UCB, 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
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THEMIS RRConstellation Operations − 55UCB, 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 –T1 Line to GSFC Had No Issues Since Launch –Dial-up IDSN Line to HBK Works Well
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THEMIS RRConstellation Operations − 56UCB, June 28, 2007 Telemetry Recovery Plan
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THEMIS RRConstellation Operations − 57UCB, 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 13m), to Alleviate Scheduling Conflicts (USNHI 13m) and to Provide Long Range Coverage (White Sands)
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THEMIS RRConstellation Operations − 58UCB, 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
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THEMIS RRConstellation Operations − 59UCB, June 28, 2007 Data Quality Metrics Conjunction Science –Tail and Dayside Seasons Nominally Defined as WD ± 2 Months –Tail Season 1 (T1) Winter of 2006/2007 (Skipped) –Day Season 1(D1)Summer of 2007 –Tail Season 2 (T2)Winter of 2007/2008 –Day Season 2 (D2)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
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THEMIS RRConstellation Operations − 60UCB, June 28, 2007 Anomalies
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THEMIS RRConstellation Operations − 61UCB, 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)
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THEMIS RRConstellation Operations − 62UCB, June 28, 2007 Anomaly Tracking List IDDateAnomaly TitleDescription and Status of AnomalyClosure 12/20/2007Weak Signals with Space-to-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 22/18/2007False 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 32/18/2007Potential 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 42/28/2007Spin Rate Drop or RiseOccasional 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 FlatSat 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 53/8/2007Corrupted 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
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THEMIS RRConstellation Operations − 63UCB, June 28, 2007 Anomaly Tracking List – Cont. Anomaly Tracking List - Continued IDDateAnomaly TitleDescription and Status of AnomalyClosure 63/14/2007Instrument 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 FlatSat are ongoing. Affected probes: Likely all, except that problem has not been seen on THEMIS E. Closed 6/14/2007 73/26/2007Instrument 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 FlatSat. Affected probes: All Closed 4/27/2007 84/1/2007IDPU Data CompressionIDPU resets and instrument turn-off occurred on three probes shortly after science data compression was started. IDPU FSW patch version 0x45 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 94/4/2007BAU 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 104/5/2007BAU 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
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THEMIS RRConstellation Operations − 64UCB, June 28, 2007 Anomaly Tracking List – Cont. Anomaly Tracking List - Continued IDDateAnomaly TitleDescription and Status of AnomalyClosure 114/17/2007BAU Experienced Cold Reset 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
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THEMIS RRConstellation Operations − 65UCB, June 28, 2007 Known Instrument Issues Instrument Issues Known Prior to Launch PFR # Probe / Instrument IssueOperational Work-Around PFR 030All 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 075All Probes ESA 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 164All Probes ESA Unloaded ESA supply causes IDPU current oscillation at narrow temperature range around 10 C. Oscillation would only be seen if ESA was off over narrow temperature range. FOT alerted that condition can be expected and causes no damage. PFR 183Probe C EFI Lower AXB (V6) 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 206Probe D EFI F4 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 F4 AXB temp sensor noted by FOT to avoid alarm over condition.
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THEMIS RRConstellation Operations − 66UCB, June 28, 2007 Constellation Status Summary
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THEMIS RRConstellation Operations − 67UCB, 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
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THEMIS RRConstellation Operations − 68UCB, June 28, 2007 Constellation Status Page
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THEMIS RRConstellation Operations − 69UCB, June 28, 2007 Critical Operations Completed Critical Operations RCS Operations –Completed 68 Thrust Maneuvers for Orbit and Attitude Control –Fired All Thrusters (A1 and A2 in Pulsed Mode Only) Instrument Operations –Magnetometer Booms Deployed on All Probes –EFI Boom Deployment Completed on THEMIS C (P2), D (P3) & E (P4) –ESA Covers Are Open and HV Turned On Remaining Critical Operations Mission Orbit Placement –Beginning in September and Completed in December 2007 Fuel Tank Repressurization –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 B (P1) and THEMIS A (P5) –Following Mission Orbit Placement
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THEMIS RRConstellation Operations − 70UCB, June 28, 2007 Configuration Management Application of Configuration Management –Workspaces –Operational Software & Databases –Configuration Files –Hardware Configurations –Network Configurations –Procedure Documents Configuration Freezes –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
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THEMIS RRConstellation Operations − 71UCB, 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 FlatSat Testing –Performed by FOT, Flight Dynamics Team, Instrument Team –All STOL Procs Tested and Verified on FlatSat –All Maneuvers Simulated on FlatSat/VirtualSat Sustaining Engineering –UCB Subsystems Engineers –Available and Called as Needed –Spacecraft Bus and FSW Subsystems Engineers –Contracts for Field Support
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THEMIS RRConstellation Operations − 72UCB, June 28, 2007 Back-up Slides
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THEMIS RRConstellation Operations − 73UCB, June 28, 2007 Updated Flight Rules
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THEMIS RRConstellation Operations − 74UCB, June 28, 2007 Power System Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Subsystem power-onSubsystems must be powered on only when their temperatures are within ITOS green limits. Damage to flight hardware. Monitor subsystem temperatures. Load sheddingBus voltage must be kept within ITOS green limits. Load shedding will occur autonomously on- board when under-voltage condition is detected. Battery state-of- charge too low. Power down of instrument bus and/or selected probe bus components. Monitor battery state- of-charge and overall power budget.
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THEMIS RRConstellation Operations − 75UCB, June 28, 2007 Telecom Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Transmitter operationTransmitter 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. Overheating of transmitter and damage of power amplifier. Set on-board FDC parameter to turn off transmitter after 60 min. Monitor transmitter-on time on the ground and alert FOT to turn off transmitter. Schedule passes and build ATS loads with transmitter-on times of 60 min or less. Transmitter operationMinimum transmitter off-time of 3 hours between transmitter on-times is required only if transmitter reached maximum allowable temperature during pass. Current thermal analyses show that transmitter needs to be off for 3 hours to cool down completely from maximum temp. Overheating of transmitter and damage of power amplifier. Monitor transmitter temperature. Schedule passes and build ATS loads with transmitter-on times of 60 min or less.
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THEMIS RRConstellation Operations − 76UCB, June 28, 2007 Telecom Flight Rules – Cont. Telecom Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation 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. Include check for long shadow periods in pass planning activities. 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. Include check for shadow constraints in pass planning activities. Transmitter operationNo transmission during launch vehicle thrust phases. Damage to probe transmitter due to corona effects. Check LV ascent profile. Embed checks into ascent procs and procedures. Transmitter operationCycle transmitter power using FET in power module only while leaving transmitter-on relay always in on-position. Excessive wear of relay contacts with 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.
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THEMIS RRConstellation Operations − 77UCB, June 28, 2007 RCS Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Thruster operationCatalyst 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 firingThrusters 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 firingManeuvers must not be performed in shadow. Erroneous maneuver execution. Check shadow constraints as part of maneuver planning. Tangential thruster firing Tangential thruster T1 (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 operationBefore 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 operationThe pyro valve shall not be opened until enough fuel is consumed so that the fuel tank pressure will be 400 psia or less at any expected temperature in the re-pressurized state. Bursting of fuel tanks. Destruction of probe. Verify tank pressure in valve operations procedure.
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THEMIS RRConstellation Operations − 78UCB, June 28, 2007 RCS Flight Rules – Cont. RCS Flight Rules Continued ActivityFlight 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 be opened against high pressure differential. Partial loss of mission. Verify isolation valve open status in pyro actuation procedure. Pyro/Isolation valve operation After pyro is blown, isolation valve must be opened 3 min later. Isolation valve cannot be opened against high pressure differential. Verify isolation valve operation in pyro actuation procedure. Isolation Valve operation Isolation valve shall not be held open more than 4 min at any time. Temperature exceedance. Include checks in flight procedures and procs that controls isolation valve. Load sheddingTwo of three RCS heater services shall be on at all times. Freezing and bursting of fuel lines. Include checks in flight procedures and procs that control heaters. Load sheddingRCS heater service #2 shall never be turned off. Freezing and bursting of fuel lines. Include checks in flight procedures and procs that control heaters.
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THEMIS RRConstellation Operations − 79UCB, June 28, 2007 RCS Flight Rules – Cont. RCS Flight Rules Continued ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Pulsed thruster firingPulsed operation of thrusters must not be performed at pulse rates at or near natural predicted frequencies of nutation, spin- plane booms, axial booms and propellant slosh. Loss of dynamic stability. Keep pulse durations short to avoid resonance frequencies. Pulsed thruster firingThe 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 thrusting is 30deg unless tank fill is between 68% and 58% or 39% and 29% where half width should be reduced to 20deg. Excessive near resonant slosh. Dynamics review of pulse thrusting proc. Pulsed thruster firingPulsed side and axial thrusting shall not be combined. Loss of dynamic stability. Dynamics review of pulse thrusting proc. Thruster firingA Critical Stop command shall be sent prior to issuing any thrust commands. Improper maneuver execution. Include checks in flight procedures and procs that control thruster operations.
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THEMIS RRConstellation Operations − 80UCB, June 28, 2007 ACS Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Spin rate controlSpin 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 controlProbe 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.
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THEMIS RRConstellation Operations − 81UCB, June 28, 2007 FSW / C&DH Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation RTS operationNo combination of ATS, RTS, and real-time commands shall be sent to exceed the maximum command rate per task as stated in the FSW Users Guide. Erroneous command execution. Configuration control of FDC. Verify ATS loads and check for violations. Clock adjustmentClock adjustments must not be performed during critical operations such as maneuvers. Erroneous maneuver execution. Place verification steps into procs that execute clock adjust. Clock adjustmentDo not command large clock jumps during RTS execution. Commands skipped over will execute. Place verification steps into procs that execute clock adjust.
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THEMIS RRConstellation Operations − 82UCB, June 28, 2007 Instrument Flight Rules ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation IDPU power-onIDPU temperature must be within allowed operational limits prior to powering up Unclean start-up likelyVerify IDPU temperature in procedure EFI power-onEFI 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-onESA HV must not be turned on until initial outgassing is completed Damage to ESADisable HV turn-on procedure until L+7 days ESA HV power-onESA HV must not be turned on until at least 60 min after a thrust maneuver is completed Damage to ESAVerify time since last maneuver in HV turn- on procedure ESA HV ramp-downESA HV must be ramped down prior to thruster operation Contamination of ESACheck status prior to enabling Prop Bus for maneuver SST attenuator operation SST attenuators must be closed prior to thruster operation Possible performance degradation (calibration change) Check status prior to enabling Prop Bus for maneuver
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THEMIS RRConstellation Operations − 83UCB, June 28, 2007 Instrument Flight Rules – Cont. Instrument Flight Rules − Continued ActivityFlight Rule Potential Impact of Violation Action to Prevent Violation Boom deploymentAll 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. Unsuccessful boom deployment; Overheating of boom frangibolts causing contamination Include temperature/ voltage check in procedure Magnetometer boom deployment Magnetometer booms must be deployed at 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
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