THEMIS INSTRUMENT SUITE FM2/FM3 PRE-SHIP REVIEW FM4/FM5 PRE-ENVIRONMENTAL REVIEW FGM

1. THEMIS INSTRUMENT SUITE • FM2/FM3 PRE-SHIP REVIEW • FM4/FM5 PRE-ENVIRONMENTAL REVIEW • FGM • Ellen Taylor for FGM Team

2. Overview • Personnel • FGM Flight Hardware Status • FGM Open Items • FGM Backup Slides (presented at FM1 PSR) • Changes since FM1 PER • Environmental Qualification Summary • Performance Testing Summary • MRD Verification Summary

3. FGM Personnel • Personnel • TU Braunschweig and IWF Graz • Wolfgang Baumjohann • Karl-Heinz Glassmeier (Head) • Ulrich Auster (FGM TM) • Werner Magnes (FGM CoTM) • Olaf Hillenmaier • Ronald Kroth • Markus Wiedemann

4. FGM Status • Hardware Status • FGM calibration verified all requirements • 6 Flight Units of FGM Sensor (FGS) and FGM Electronics (FGE) have been delivered to UCB • Design verification through IDPU system occurs periodically during Instrument Suite Comprehensive Performance Tests. FGM sensor is quiet magnetic environment in THEMIS Calibration Unit (TCU) for these tests.

5. FGM Open Items • FM1 Open Item: FGM Sensor Swap • FGM Team would like to replace FM1 Sensor (SN 04) with Flight Spare (SN 12) • Requires 2-3 days to recalibrate through IDPU system • FGM team is currently on-site at UCB to perform re-calibration using Themis Calibration Unit (TCU) and to determine system noise and scale values • Flight Spare sensor will require additional 6 cycles of Thermal Vacuum testing that was missed during Suite testing • FM2/FM3 Open Items: None • FM2 (SN01) and FM3 (SN02) FGM Sensors have been integrated to the Instrument Suite, gone through Suite Environmental Test, and are ready for Integration with the Probe • FM4/FM5 Open Items: None • FM4 (SN03) and FM5 (SN05) FGM Sensors have been integrated to the Instrument Suite and are ready for Suite Environmental Test

6. BACK-UP: • THEMIS FM1 FGM PSR/PER Presentation • Changes since FM1 PER • Environmental Qualification Summary • Performance Testing Summary • MRD Verification Summary

7. FGM Changes since FM1 PER • FGM Part Change • Thermal Vac testing showed the FGM electronics had a temperature dependency of about 10nT/80 degC and that it was noisy at 60 degC • With predicted temperature changes over orbit, temperature dependency affected FGM’s ability to meet MRD requirement IN.FGM-2: The absolute stability of the FGM shall be less than 1nT • AD648 parts were identified as not ideal for temperature stability and were replaced by RH1013 • Re-Work Instructions for exchange and Re-Test Report after exchange are included in FGM EIDP Folder #04 • Replacement of parts improved temperature dependency to about 1nT/80 degC ensuring MRD requirement will be met.

8. FGS qualification • Vibration Specs. • Acceptance performed in Berlin • Sine wave: up to 6.4g @ 50Hz • Random noise: 11.7g RMS • TV-cycle • Performed in Graz • Two cycles between -120°C and 90°C • Parameter check (before, between and after tests) • Resistance of all coils / Sensor output signals • Coil constants and mechanical alignment of feedback coil system

9. Test performed with SN4 • digital functional test • check of board population, FPGA and current sources • Nov. 01. Berlin, THM_FGM_F6StartupTest.doc • analogue adjustment of FGS and FGE • Test of excitation,input filter, phase adjustment, sensitivity and noise • Nov. 05. Berlin, THM_FGM_F4AnalogTest.doc • Parameters vs. electronics temperature • Test of offset, sensitivity, inrush current, phase in dependency on e-temp. • Nov. 06. Braunschweig, THM_FGM_Cal_F4e-temp.doc • Parameters vs. sensor temperature • Test of offset, sensitivity and noise in dependency on sensor temperature • Nov. 14. Graz, THM_FGM_Cal_F4s-temp.doc

10. Test performed with SN4 • test of non-linearity • Test of DAC non linearity and filter characteristics • Nov. 18. Graz, THM_FGM_Cal_F4&F6linearity.doc • Earth field registration • Test of resolution and stability by comparison of F4 and F6 measuring Earth field variations • Nov. 19. Jeserigerhütten, THM_FGM_Cal_F4&F6RegJH.doc • determination of sensor axis direction • Direction of magnetic axis determined with respect to mechanical ref. frame • Nov. 22. Jeserigerhütten, THM_FGM_Cal_F4&F6AlignmentJH.doc • determination of scale value and orthogonality • Scale values and orthogonality check vs. sensor temp. in coil system • Nov. 24 Magnetsrode, THM_FGM_Cal_F4&F6_MR.doc

11. MRD requirements • The absolute stability of the FGM shall be less than 1nT Dependency on sensor temp. 2nT/170°C !!! Dependency on electronics temp. without feedback circuitry: 1nT/80°C with feedback circuitry: 10nT/80°C& (noisy at 60°C) • Action: • AD648 identified as not ideal, replaced by RH1013 • Temperature drift at maximum values of data sheet • noise at 60°C not specified in data sheet

12. FGM Parameter • The relative stability of the FGM shall be less than 0.2nT/12hrs

13. FGM Parameter • The FGM noise level @ 1Hz shall be less than 0.03nT/sqrt(Hz) 0.03nT/Sqrt(Hz) 0.01nT/Sqrt(Hz)

14. FGM Parameter • The FGM digital resolution shall be less than 0.1nT • The FGM science range shall exceed 0-1000nT Test shows Earth field variation with a resolution better 0.1nT @ a back ground field of 12000nT

15. FGM SN4 Test Report • FGE modification and re-tests done in Berkeley • Exchange of amplifiers + Analogue checkout • AD648 replaced by RH1013 • No noise dependency on temperature anymore • Temperature dependency with and without feedback circuitry about 1nT/80°C • Design verification • By SFT before and after each test step • Check of commanding, different modes, noise and scale values • Remaining tasks • Verification of housekeeping values • Spot shielding / removing of test points