1. AMSAT Fox-1 Overview AMSAT Engineering Team 2011 Space Symposium

2. 2 Fox-1 Introduction AO-51 replacement 1-Unit CubeSat (4" x 4" x 4") Target orbit 650 km Magnetically stabilized FM transponder IHU for telemetry and command Science experiment

3. 3 Fox-1 Operational Modes Transponder Mode –FM repeater –Telemetry data sent as low-speed FSK in sub-audible band Command Mode –Transmitter dedicated for data downlink –High-speed FSK –More power available for running experiment

4. 4 Special "ZombieSat" Features Designed to extend usable life FM Transponder will operate with dead cpu FM Transponder will operate without ground station intervention FM Transponder will operate while in sunlight even with dead (shorted) battery

5. 5 Fox-1 Systems Power System Internal Housekeeping Unit (IHU) RF System Antennas Science Experiment

6. 6 Fox-1 System Diagram RF System Battery Solar Cells IHU Power System Sensors Science Experiment Power bus 70 cm Antenna 2 m Antenna

7. 7 Power System - Solar Panels 6 solar panels 2 cells per panel Spectrolab Ultra Triple Junction Space-rated, high radiation tolerance 28% conversion efficiency

8. 8 Solar Cell Characteristics Spectrolab UTJ, 27cm 2, Full Sun, 28C

9. 9 Maximum Power Point Tracking 

10. 10 Generated Solar Power

11. 11 MPPT Operation Switching Supply Solar Panel Power Bus Pulse Width Control Tracking Algorithm Max-voltage Sense

12. 12 Power System - Block Diagram MPPT MPPT (x2) MPPT Battery Protection Battery 3 x NiCd +Z Panel -Z Panel X,Y Panels Power Bus PIC I2C Interface SPV1040

13. 13 Power System - Battery 3 x NiCad cells 3.6 V nominal 10 watt-hours 10% depth of discharge Charge: 0 to +45 C Discharge: -20 to +60 C

14. 14 DC Power Available 1.9 watts min in sunlight (no battery) 2.2 watts average (max eclipse) 2.8 watts average (no eclipse) 10 watts peak power

15. 15 Internal Housekeeping Unit Collects telemetry information Supports science experiment Sends telemetry as low speed FSK w/FEC in transponder mode High speed FSK w/FEC in command mode Executes commands from ground control

16. 16 IHU Block Diagram

17. 17 IHU Microcontroller STMicroelectronics STM32L151VBT6 ARM3 Cortex CPU (32-bit) Up to 33 MIPS @32 MHz Designed for "ultra" low power consumption 128K FLASH program memory 16K RAM On board RTC, D/A, A/D

18. 18 IHU Non-volatile FRAM Memory

19. 19 RF System 70 cm FM receiver (uplink) 2 m FM Transmitter (downlink) Transponder mode provides FM repeater Command mode for running experiment

20. 20 Transponder Mode FM Transmitter CTCSS Decoder FM Receiver 70 cm Antenna 2 m Antenna IHU 2-minute Timer Audio PTT Low Speed FSKCommands

21. 21 Command Mode FM Transmitter FM Receiver 70 cm Antenna 2 m Antenna IHU FSK Experiment Commands

22. 22 RF System Design

23. 23 RF Power Amp

24. 24 Antennas 2 meter whip 70 cm whip

25. 25 VHF Antenna Pattern

26. 26 VHF Antenna SWR 1.0 1.1 1.5 2.0 SWR

27. 27 UHF Antenna Pattern

28. 28 UHF Antenna SWR 1.0 1.1 1.5 2.0 SWR

29. 29 Science Experiment Penn State University - senior design project 3-axis MEMs gyro sensor Measures satellite spin rate, spin direction and wobble about the magnetic axis in orbit May include GPS receiver

30. 30 Fox-1 Team Developers Advisors Logo by Steve Kenwolf

31. 31 Sound Like Fun? AMSAT is always hiring! Engineering: mechanical, electrical, systems, software, project management Satellite construction: PCB layout, parts procurement, surface mount construction, parts machining, testing Contact Tony Monteiro, aa2tx@amsat.org

32. Any Questions? AMSAT Engineering Team 2011 Space Symposium