1. Solar Probe Plus – FIELDS Main Electronics Package
Instrument Pre-Environmental Review
EMC
Keith Goetz
University of Minnesota
10 April 2017

2. SPP/FIELDS MEP Two Sides Each has a Spacecraft I/F
Each has a Magnetometer
Each has Antenna Biasing
Each has a Power Supply
FIELDS1 also has
Data Controller Board
Radio Frequency Spectrometer
Digital Fields Board
SCM Calibration Control
Absolute Time Sequencer
TDS I/F
FIELDS2 also has
Time Domain Sampler
DCB I/F
SWEAP I/F
MEP

3. SPP/FIELDS Unchanged from CDR Five voltage sensors
V2 electric antenna
Unchanged from CDR
Five voltage sensors
Two Fluxgate magnetometers
One Search-Coil Magnetometer
Main Electronics Package
V3 electric antenna
MAGi, MAGo
MEP
V4 electric antenna
V5, SCM
V1 electric antenna

4. MEP – Buttoned Up

5. Environmental Testing
EMC
Here’s trouble – 10 February 2017
As part of conducted susceptibility testing (CS01)
Test calls for a 1 Vpp sine wave atop the S/C power bus (32VDC)
We inadvertently applied a much larger sine wave – tests suggest 70 Vpp
LNPS1 operational power supply failed instantly – no current
Slice was returned to UMN
First stage 12V buck-coil converter was replaced – unit returned to full functionality
~20 EEE parts identified as possibly affected by the voltage extreme – replaced
Conformalled and inspected (via photography)
Temperature testing (in air)
Fully functional – all supply voltages matched previous calibrations
Failed part is out for DPA
Slice was returned to UCB and MEP
BB converter tested with a variety of torture
Part worked normally up to 70V but failed abruptly at 80V
Monitors on the 12V inner stage showed no trace of voltages above 12V
Further CS testing to be done on high fidelity EM

6. Magnetic Sniff Materials all clean Flight hardware verified as clean
A286 on boom verified as non-magnetic
Flight hardware verified as clean

7. Isolation All greater than 1 MΩ FIELDS1 power interfaces
Operational
Heater
FIELDS2 power interfaces
All greater than 1 MΩ

8. Bonding MEP to copper plate – 1.6 mΩ V1234 EM enclosures ~4mΩ
Not flight-like

9. Transients
In-rush current measured high
Waiver in place

10. CE01/CE03 Performed on EM MEP, EM V1234, EM V5, EM SCM, FM MAGo
Performed on FM MEP, EM V1234, EM V5, EM SCM, FM MAGo, FM MAGi
Very similar results
150 kHz picket fences

11. CE07 Performed on EM MEP, EM V1234, EM V5, EM SCM, EM MAGo
Performed in lab (not screen room)
150kHz spikes

12. CS01
A dangerous test
Performed on FM MEP, EM V1234, EM V5, EM SCM, FM MAGo, FM MAGi
Resulted in overvoltage damage on MEP LNPS1
Resumed with EM MEP
Performed on EM MEP, EM V1234, EM V5, EM SCM, EM MAGo
Performed in lab (not screen room)
No issues

13. CS02 Another dangerous test CS02 requires running from 50kHz to 400MHz
Waiver to run only to 30MHz (test equipment limit)
Deviation previously granted another instrument
Performed on EM MEP, EM V1234, EM V5, EM SCM, EM MAGo
Performed in lab (not screen room)
No issues

14. CS06 Another slightly dangerous test
Performed on EM MEP, EM V1234, EM V5, EM SCM, EM MAGo
Performed in lab (not screen room)
Rented pulse generator failed to make pulses
To be continued in late April on EM

15. RE01 Emission lines generally at 150kHz picket fence Magnetic
Performed on FM MEP, EM V1234, EM V5, EM SCM, FM MAGo, FM MAGi
EM harnessing
In UCB screen room
Emission lines generally at 150kHz picket fence

16. RE01 - setup

17. RE01 – MEP side

18. RE01 – from above

19. RE01 – V1234

20. RE01 - MAGs

21. RE02 Emission lines generally at 150kHz picket fence Electric
Performed on FM MEP, EM V1234, EM V5, EM SCM, FM MAGo, FM MAGi
V1234 whip simulators
EM harnessing
In UCB screen room
Emission lines generally at 150kHz picket fence

22. RE02 – Whip Simulators

23. RE02 - Monopole

24. RE02 - Biconic

25. RE02 - MF

26. RE02 - HF

27. RS03
Done on FM at APL
Operational and Non-operational radiated susceptibility
No problems