1. SPP FIELDS V5 Antenna Mechanical Peer Review David Glaser, Paul Turin, Jeremy McCauley, John Bonnell, Dennis Seitz SSL UCB 7/17/13

2. Sep. 23, 2012 SPP FIELDS Meeting V5 Overview Thermal Antennas Antenna to PCB PCB Housing Mount to Mag Boom Antenna FEA Analysis Other TBDs Agenda

3. V5 Overview V5 is an electric fields antenna, mounted on the SPP FIELDS Mag Boom, that will provide 3 rd axis measurements complementary to the V1-V4 data. It has only a single Preamp Previous Design ~10 inches inboard Of SCM

4. V5 Overview SC X-axis (RAM Direction) Old Boom Design Shown Here

5. V5 Overview V5 is an electric fields antenna, mounted on the SPP FIELDS Mag Boom, that will provide measurements complementary to the V1-V4 measurements. It has uses a single op amp to cover the LF+MF DC-1MHz frequency range

6. V5 Overview Positronics DD15M0000G Antennas V5 PCB Housing Cover Housing Mass: ~70 g

7. Key Issue: V5 Thermal Minimum expected temperature <<-100°C Occasionally will see the Sun during SC slewing Similar Preamps have been qualified for temperatures in this range Temperature predicts need to be modeled Including heat losses through harness Options for Thermal Control Being Considered: Blanketing Resistive heater on PCB with “clean” power source Heater on exterior of housing Low emissivity coating on housing

8. Antennas 9.73” 4.00” Aluminum wall PEEK Isolators What drives the antenna length? What surface finish for the antennas?

9. Antenna FEA Results 100G Quasi-static Load Load Direction 100G Stress < 10 ksi First Mode Frequency: 493 Hz

10. Antenna to PCB Connection A single photoetched BeCu part makes contact between the two antennas and the PCB

11. V5 PCB Circuit Board Currently 1.41” x 0.85” Layout 1.15” x 0.77” Max Component Height with Headroom: Top 0.34” (8.6mm) Bottom 0.056” (1.4mm)

12. V5 Housing Housing and Cover are aluminum 0.10” wall thickness PCB mounts to Cover with 4X #0-80 screws Mounts to Mag Boom with 2X #4-40 Screws 1.71” 1.09” 1.07”

13. With Backshell Glenair, 557T186

14. V5 PCB to DD15 Connector Want to minimize housing size, but space is tight

15. V5 Mount to Mag Boom TBD

16. FEA Model For Antennas Removed Holes from Box Removed Hex Nut (Interference) Fixed at Mounting Holes

17. Other TBDs Connector to PCB Wires/Connections Harness FEA with Connector & Backshell Qualification Plan

18. Backup Slides

19. PCB Schematic

20. V5 PCB Mech. Drawing

21. PCB Layout Heater resistor is R9 Layout area could be reduced by having an external heater C1, C2 might be reduced or eliminated, but that might lower bandwidth (TBD)

22. V5 SPF Interface