Composite and PCB Based Implementations of a Solar Panel Design for SwampSat

Transcription

1 Composite and PCB Based Implementations of a Solar Panel Design for SwampSat 24th Annual AIAA/USU Conference on Small Satellites August 9 12, 2010 Utah State University Logan, Utah USA Sharan Asundi, Matthew Mahin, Vivek Nagabhushan, Tzu Yu Lin, Norman G. Fitz-Coy 08/10/ /10/10 1

2 SwampSat Mission Rapid Retargeting and Precision Pointing Precision 3-axis attitude control Validate Rapid Retargeting and Precision Pointing Attitude Determination System (ADS) Command and Data Handling System (CDH) Telemetry, Tracking and Command (TT&C) Electrical Power System (EPS) 08/10/10 2

3 SwampSat Subsystem Assembly 1. CMG Based ACS 2. Electrical Power System 3. SwampSat Transceiver 4. SwampSat Flight Computer 5. Solar Panels 6. Solar Cells 7. Sun Sensor 8. Sun Sensor Filter 9. Motor Driver Board 10.Structure 11.Receive Antenna Module 12.Transmit Antenna Module 08/10/10 3 SwampSat Subsystem Assembly

4 SwampSat Solar Panel Design Motivation and Requirements Satisfy requirements across subsystems Adhere to CubeSat form factor Surface suitable for mounting solar cells Embed magnetic coils for angular momentum management Provision for mounting Sun sensors, temperature sensors, diodes, etc Structural members and debris abatement Interface peripheral components with the respective subsystem boards Accommodate Delrin plate design and enable access to connectors through them 08/10/10 4

5 Solar Panel Design Sun sensor TEMT6000 Temperature Sensor LM135/335 Bypass diode BAS40-04 Connector for solar cells and temperature sensor Connector for magnetic coils Connector for Sun sensor 08/10/10 5 Solar Panel Design

6 Carbon Fiber Composite Solar Panel Magnetic coils prepared from enamel coated 30 AWG copper core wire and EPO-TEX epoxy Two metal plates with a spacer sandwiched between are held together by a nut and bolt Metal rods used for guiding the path of copper wire Layers of magnetic coils secured together in place by the epoxy and cured for 10 minutes at C or 30 minutes at 80 0 C Magnetic Coil Fabrication Fixture and Finished Coil 08/10/10 6

7 Carbon Fiber Composite Solar Panel Wet lay up technique using a carbon fiber fabric is chosen for implementing the composite Composite preparation vacuum bagged on cured for 3-4 hours at room temperature EPO-TEK conductive epoxy from Epoxy Technology, conductive pen and metal foil tape used for laying electrical traces CV-2566 CV Silicone elastomer used for mounting solar cells A Composite Panel Under Development 08/10/10 7

8 Printed Circuit Board (PCB) Solar Panel 6-layer 1mm thick PCB with FR-4 cores 5-layers have electrical traces as magnetic coils 2oz per square foot copper traces Dual side solder mask with fully insulated vias Immersion gold over electroplated nickel finish Each panel accommodates ~71 turns of coil 08/10/10 8 A Multifunctional PCB Solar Panel

9 Composite vs PCB Panel Composite solar panels Solar panel epoxy can lead to outgassing Heat dissipation is not an issue Electrical traces and pads are manually laid Wet layup technique can lead to outgassing Panel thickness ~2.5 mm (with coils) PCB solar panels Suited for solder paste or epoxy Heat dissipation might be an issue Electrical traces and pads are machined PCB boards are machine fabricated Panel thickness ~1 mm Composite Solar Panel 08/10/10 9 PCB Solar Panel

10 Tests and Results Basis Composite coil has more turns PCB coil has more area Magnetic moment is assumed to be equal Composite and PCB Panel Evaluation 08/10/10 10 u = nia u magnetic moment n - # of turns I current A vector area of each loop

11 Tests and Results (cont d ) 08/10/10 11 PCB Solar Panel Vibration Test Setup and Profile (Ref. PSD table in the Cubesat to PPOD ICD)

12 Conclusion PCB panels are selected for SwampSat mission for reliability and compact packaging CubeSat form factor and SwampSat mission limit the thickness to be under ~1mm PCB panel address the requirements of EPS subsystem ACS subsystem ADS subsystem Structural and cabling requirement Facilitate TT&C subsystem PCB panels are well designed within the limits Copper pads for solar cells, sensors and pheripherals Connectors for interfacing with subsystem boards SwampSat power budget is designed to accommodate the power requirement of the embedded coils 08/10/10 12

13 Future Work Precisely determine the magnetic field output by the embedded magnetic coils Perform thermal analysis and evaluate heat dissipation capability PCB panels can accommodate additional turns to accommodate future missions Capability of the embedded magnetic coils to manage SwampSat s angular momentum Accommodate different orientations of solar cells, alternate PCB material, solar cell mounting technique 08/10/10 13

14 Acknowledgements SwampSat development team Everything and more!! Vijay Jagdale, Dr. Ifu and Dr. Shankar Composite fabrication facility and assistance Timco Engineering Vibration testing facility Peggy Evanich Everything and much more!! 08/10/10 14

15 Thank You!! Questions? Sharan Asundi Space Systems University of Florida 08/10/10 15