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THEMIS IDPU FSW V4 Mission Profile Tests Peter Harvey Michael Ludlam

Explore objectives, orbit simulations, and operations for the THEMIS mission. Review instrument requirements, simulation results, and conclusions from tests conducted. Understand the significance of magnetospheric observations and collect essential data during orbital maneuvers.

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THEMIS IDPU FSW V4 Mission Profile Tests Peter Harvey Michael Ludlam

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  1. THEMIS • IDPU FSW V4 • Mission Profile Tests • Peter Harvey • Michael Ludlam

  2. Agenda • Agenda • Overview of Science Objectives • MPT Objectives and Method • Typical Orbit Simulations • Instrument Required Operations (FGM to ESA) • Instrument Scripts • Simulation Results • Conclusion

  3. P1 P4 P5 P3 P2 GBO Science Objectives • Science Objectives • Observe Onset and Evolution of Magnetospheric Substorm Instability • Operate 5 Space Probes and 20 Ground Based Observatories • Collect Low Rate (Slow) Survey Data for Full Orbits • Collect High Rate (Fast) Survey during Conjunctions • Identify Substorms and Collect Particle and Wave Burst Data during Conjunctions

  4. Region Crossings & Triggers

  5. TAIL SIMULATION TAIL SEASON (PRIMARY SCIENCE) 42:00: PASS 30:00: P2_SLOW_SURVEY 47:00 MAG_CAL_ON 34:00: 100% COMPRESSED 00:00 01:00 MAG_CAL_OFF 18:00: P2_FAST_SURVEY Orbit Period : 48 hours Fast Survey : 12 hours Compression: 4 hours

  6. CRUISE DAYSIDE SIM DAY SEASON (SECONDARY / LEO ORBIT) 26:00: PASS 20:00: P345_SLOW_SURVEY 27:00 MAG CAL ON 1:00: ECLIPSE ENTRY 24:00: 100% COMPRESSED 26:00: SOLAR WIND EXIT 00:00 2:00: SOLAR WIND ENTRY 01:00 MAG CAL OFF 1:10: ECLIPSE EXIT 8:00: P345_FAST_SURVEY Orbit Period : 28 hours Fast Survey : 12 hours Compression: 4 hours

  7. MPT Objectives • Objectives • SIMULATE THE FOLLOWING ORBITS • P1 Orbit Period 96 hrs • P2 Orbit Period 48 hrs • P345 Orbit Period 24 hrs • VERIFY TELEMETRY STORAGE • Verify Engineering/Survey/Burst Data Rates .v. Data_Rates version G.7.2 • Verify Proper Packet Routing • VERIFY COMPRESSION • Measure Processor Compression Time (<4 hrs) • Verify Compression Ratio > 2.0 • VERIFY PLAYBACK • Test Playback Sequence • Verify All Engineering and Survey Data is played out • Verify Amount of Burst Playback • RUN STORED COMMAND SEQUENCES • Eclipse Entry / Exit • Radiation Belt Entry / Exit • Plasma Pause • Conjunction • Bowshock • MAG Ranging

  8. MPT Method • Method • MPT.CMD • IDPU RESET • IDPU_INIT.CMD – To set Normal Mode, Clear Errors • INST_ON.CMD – Power all Instruments, Configure • Pn_TAIL_SIM.CMD • Loads Script #2,3, or 4 Depending Upon P1,P2 or P345 Simulation • Modify the SSR Routing Map • Command Instrument Data Rates for this Orbit Period • Configure Moment Decimator for this Orbit Period • Execute Slow Survey • Wait • Execute Fast Survey • Wait • Execute Slow Survey • Wait • Start PASS.CMD • Verification • Collection Times (Slow & Fast) are Measured • Playback Time is Measured • GSE Verifies the TM Format and Compression Formats • APID counters are read back from the GSE • Enter APID counts in Spreadsheet to Verify Data Rates and Compression Ratio

  9. FGM TM • Attitude Control / Calibration • Determine Probe Attitude Near Perigee • APID 405 ( 8 Hz x 3 Axes) Enabled at Perigee +/- 1 hour Slow Survey • APID 410 X-Y Sine Wave Least Squares Spin Fits & Z-axis Average Fast Survey • APID 460 3-Axis 16 bit samples at 4 Samples/Second Particle Burst • APID 461 3-Axis 16 bit samples at 128 Samples/Second REM =========================================================== REM MAG_CAL_ON.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX B101 ;FGE ENABLE /ISCMCAL 60 ;SCM CAL ON FOR 1 MINUTE REM =========================================================== REM MAG_CAL_OFF.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX B100 ;FGE DISABLE

  10. FGM RANGING • Magnetometer Ranging • FGM SIGNAL RANGE • RANGE = 0 to 8, Sliding 16-bit Window over 24-bit X,Y,Z Samples • Range 0 : FFFFFFFFFFFFFFFFxxxxxxxx +/- 25000 nT range • Range 3 : xxxFFFFFFFFFFFFFFFFxxxxx +/- 3125 nT range • Range 8 : xxxxxxxxFFFFFFFFFFFFFFFF +/- 97 nT range • OVER RANGE IMPACTS • APID 460/461: • A saturated waveform in the spin plane is relatively recoverable • A saturated signal in the spin-axis is deadly. No way to tell where it really is. • SPIN FITS: • Not recoverable. We lose virtually everything if the signal goes over range. • ON-ORBIT MAG RANGE ADJUSTMENT (ATS) • BELOW 6 Re : Use Range 0 (+/- 25000 nT) • OUTSIDE 6 Re : Use Range 4 (+/- 1563 nT)

  11. SCM TM • SCM Calibrations • Trend Sensor Health each orbit • Calibration Mode for 1 Minute • Slow Survey • APID 440 Filter Bank at ¼ Hz (Note1) • Fast Survey • APID 440 Filter Bank at 4 Hz • APID 444 16 bit samples at 8 Samples/Second Particle Burst • APID 448 16 bit samples at 128 Samples/Second • APID 44D 2 channels 32 freq spectra at 1 spectra/sec (Note1) Wave Burst • APID 44C 16 bit samples at 8192 Samples/Second • APID 44E 2 channels 64 freq spectra at 8 spectra/sec (Note1) • 1. Different from EFI_INIT

  12. EFI TM Slow Survey • APID 410 X-Y Sine Wave Least Squares Spin Fits & Z-axis Average • APID 440 Filter Bank at ¼ Hz (Note1) • Fast Survey • APID 440 Filter Bank at 4 Hz • APID 441 V1-V6 16-bit samples at 4 Samples/Second • APID 443 Ex-z 16-bit samples at 8 Samples/Second Particle Burst • APID 445 V1-V6 16-bit samples at 16 Samples/Second (Note1) • APID 447 Ex-z 16-bit samples at 128 Samples/Second • APID 44D 2 channels 32 freq spectra at 1 spectra/sec (Note1) Wave Burst • APID 449 V1-V6 16-bit samples at 8192 Samples/Second • APID 44B Ex-z 16-bit samples at 8192 Samples/Second • APID 44E 2 channels 64 freq spectra at 8 spectra/sec (Note1) • 1. Different from EFI_INIT

  13. EFI BIASING • EFI BOOM ELECTRONICS MANAGEMENT • As Plasma Conditions Change, EFI Biases Need to be Modified • Four Tables are Executed from the Flight EEPROM as follows: • COMMAND 14F5 EXECUTES TABLE “B0” - EFI Low Density, Sun • COMMAND 14F6 EXECUTES TABLE “B1” - EFI Low Density, Eclipse • COMMAND 14F7 EXECUTES TABLE “B2” - EFI High Density, Sun • COMMAND 14F8 EXECUTES TABLE “B3” - EFI High Density, Eclipse • Src: thm_efi_beb_tables_revC_.doc

  14. SST TM Slow Survey • APID 452 Engineering 1 packet/hour (30 second accum every 4 minutes) • APID 453 Moments every Spin, Decimated in P1 and P2 Orbits (Factor of 8 or 4) • APID 45B Ion Reduced Distributions • APID 45E Electron Reduced Distributions • Fast Survey • APID 452 Engineering 1 packet/hour (30 second accum every 4 minutes) • APID 45B Ion Reduced Distributions Disabled • APID 45E Electron Reduced Distributions Disabled • APID 45A Ion Full Distributions Enabled • APID 45D Electron Full Distributions Enabled Particle Burst • APID 45F Electron Full Distribution Burst Wave Burst • Not Applicable Note1: APID 45C Ion Full Distributions BURST Always Disabled

  15. ESA TM Slow Survey • APID 453 Moments every Spin • Decimated in P1 and P2 Orbits (Factor of 8 or 4, respectively) • APID 455 Ion Reduced Distributions • APID 458 Electron Reduced Distributions • Fast Survey • APID 455 Ion Reduced Distributions Disabled • APID 458 Electron Reduced Distributions Disabled • APID 454 Ion Full Distributions Enabled • APID 457 Electron Full Distributions Enabled Particle Burst • APID 456 Ion Full Distribution Burst • APID 459 Electron Full Distribution Burst Wave Burst • Not Applicable

  16. ECLIPSE REM =========================================================== REM ECLIPSE_ENTRY.CMD REM 9/14/06 REM =========================================================== /IDPURAWHEX 1283 ;EFI -- ECLIPSE, LOW DENSITY CONFIGURATION ; REM =========================================================== REM ECLIPSE_EXIT.CMD REM 9/14/06 REM =========================================================== /IDPURAWHEX 1282 ;EFI -- SUN, LOW DENSITY CONFIGURATION

  17. SOLAR WIND REM =========================================================== REM SOLAR_WIND_ENTRY.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX 14F5 ;EFI -- SUN, HIGH DENSITY CONFIGURATION /IEFICONF F5 ; /IDPURAWHEX 6600 ;ETC -- SOLAR WIND MODE REM =========================================================== REM SOLAR_WIND_EXIT.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX 14F6 ;EFI -- SUN, LOW DENSITY CONFIGURATION /IEFICONF F6 ; /IDPURAWHEX 6600 ;ETC -- MAGNETOSPHERE MODE

  18. RADIATION BELT REM =========================================================== REM RAD_BELT_ENTRY.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX 1251 ;SST FORCED SHUT AND DISABLED REM =========================================================== REM RAD_BELT_EXIT.CMD REM 5/30/06 REM =========================================================== /IDPURAWHEX 1250 ;SST ON AUTOMATIC W/NEW ALLOCATION

  19. TEST RESULTS • GENERAL NOTES • MPT Form : White background on Measured Packet Counts means <10% variance from “Expected” column. Yellow means over 10% variance. • Accelerated tests had issues with very slow packets • Telemetry Segment Packet Minimums interfered with packet counts since we could not read all the packets out of memory (some were still being worked on). • The durations of PB and WB were difficult to verify through this method. Memory capacity drives the amount collected. Estimated time is entered by the test director to check consistency between the PB and WB APIDs. • The Actual Playback time (in seconds) to empty the memory is needed for the test to get all the data out of the SSR. Normally, only half the SSR will be played out. • APID 451 Trigger Rate changed to ½ Hz (was 1 Hz) in last P345 test • APID 452 SST Engineering Data to be 1 packet/Hour (was disabled) in last P345 test

  20. P1 TAIL RESULTS Measure Packet Counts match to within 10% of expectation (white background). Yellow means >10% variance.

  21. P1 TAIL RESULTS

  22. P2 TAIL RESULTS

  23. P2 TAIL RESULTS

  24. P345 TAIL RESULTS

  25. P345 TAIL RESULTS

  26. CONCLUSION • CONCLUSIONS • INSTRUMENT CONTROLS • Orbit Configurations are Complete and Tested • All Instrument Scripts Tested • Script Collections #0002 thru #0004 are Flight Ready • TELEMETRY STORAGE • Survey Collection and Storage Operating per Specification • Burst Collection of 92 MB Understood. • COMPRESSION • Processor Compresses in much less than 4 hours Even While Spin-Fitting • Compression Ratios Between 2.1 and 2.6 • TELEMETRY PLAYBACK • Playback Sequence Tested • All Engineering and Survey Data is played out • Full Burst Playback Pushes Downlink past 375 Mb Allocation (30 min downlink) • Required Burst Playback (<17 MB) plays “best” 2-3 Bursts out of 8 • SPACECRAFT MEMORY • APID 405 (FGM 8 Hz) for 2 Hours/Orbit will Generate 0.439 MB • Needs to be accounted on the BAU memory ledger.

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