May06-17 – StratoLink Spacecraft Bus Design Review

1. StratoLink Spacecraft Bus Senior Design Project May06-17 Adam Allison Robert Bond Hai Duong Alan Johnson David Johnson Client: Spacecraft Systems and Operations Lab Faculty Advisor: Prof. Mani Mina May06-17 – StratoLink Spacecraft Bus Design Review

2. Agenda Background Information Adam Allison Lithium Ion Batteries Robert Bond Battery Charger Hai Duong GPS Receiver David Johnson Communications Alan Johnson Conclusion Adam Allison May06-17 – StratoLink Spacecraft Bus Design Review

3. Definitions FAA – Federal Aviation Administration HABET – High Altitude Balloon Experiments in Technology NMEA – National Marine Electronics Association OEM – Original Equipment Manufacturer SSOL – Spacecraft Systems and Operations Laboratory May06-17 – StratoLink Spacecraft Bus Design Review

4. Background HABET Project • Project of Iowa State University SSOL • Designed to reach near space altitudes • Provides platform for high altitude experiments • Highly successful May06-17 – StratoLink Spacecraft Bus Design Review

5. Background StratoLink Project • Created as a variation of HABET • Designed for informal educational groups and institutions • Will collect temperature, position, and visual data • Stores data on pre-existing data logger from HABET program • Provides opportunity for students to learn about the flight procedures of a basic spacecraft • More restrictive design constraints What needs to be changed to accommodate those needs? May06-17 – StratoLink Spacecraft Bus Design Review

6. Background HABETStratoLink Uses amateur radio comm.  Satellite-based comm. Requires amateur radio licenseCapable of transmission after landing Payload limited by balloon restraints  Payload limited to 4 lbs FAA regulation Highest Altitude recorded ≈ 100,000 ft Approx. up to 120,000 ft May06-17 – StratoLink Spacecraft Bus Design Review

7. System Overview Note: HOBO Data Logger and digital camera use present design from HABET May06-17 – StratoLink Spacecraft Bus Design Review

8. Lithium Ion Batteries • 3.7 Volt Each • 1200 mAh • Rechargeable • 34.2mm x 8.5mm x 48mm • Built in Shutdown • Separator • Soldier Tabs included May06-17 – StratoLink Spacecraft Bus Design Review

9. Technical Specs • Operating voltage: 2.8-4.2V • Individual Weight: 38g per battery • 4V cell weight: 152g +1g for soldier tabs • Max Discharge Rate: 2.0A • Rec. discharge voltage: 2.8-3.1V (avoid discharge below 2.5V) • Recommended Temp: –20-60ºC May06-17 – StratoLink Spacecraft Bus Design Review

10. Charging info for Batteries • Max Charge Current: 2.0A • Charge time: 80% cap. in 1h • 100% cap. in 2h • Charge at const. voltage of 4.2V with current limited to 0.5-1.0 A • Rec. charging temp: 0-40ºC May06-17 – StratoLink Spacecraft Bus Design Review

11. Battery Charger • Auto-off • External from system • Rechargeable • 34.2mm x 8.5mm x 48mm • Built in Shutdown • Separator • Soldier Tabs included May06-17 – StratoLink Spacecraft Bus Design Review

12. Battery Charger • Input: AC 100-240V 50/60Hz • Output: 4.2-16.8VDC • Charging Current: 500mA • Supported Types: Li-Ion larger than 400mAh May06-17 – StratoLink Spacecraft Bus Design Review

13. Battery Charger May06-17 – StratoLink Spacecraft Bus Design Review

14. Transceiver Overview • Purpose: • Communicate with base without using amateurradio • Services considered: • Iridium • Global satellite network • Used for voice communication • ORBCOMM • US coverage • Used for low data-rate data communications May06-17 – StratoLink Spacecraft Bus Design Review

15. Transceiver Choosing a provider • Considerations: • Equipment needed • Cost • Weight • Functionality • Subscription/data costs • Communication latency • Reports of usage in the field • ORBCOMM selected as the best solution May06-17 – StratoLink Spacecraft Bus Design Review

16. Transceiver Selected Transceiver • Model: Stellar ST2500 • Bought without case to reduce weight • GPS Receiver – Garmin GPS-15H • Antennas for each • Tasks to be done: • Program ST2500 • Devise a shielding system for ST2500 May06-17 – StratoLink Spacecraft Bus Design Review

17. Transceiver Technical Details • System will be controlled by the ST2500’s onboard processor • ST2500 will periodically take readings from the GPS and send data to the satellite • ORBCOMM will forward the information via e-mail May06-17 – StratoLink Spacecraft Bus Design Review

18. GPS Receiver Overview Purpose: To capture position from GPS satellites and relay it to spacecraft bus. • Design requirements: • Lightweight • Low Cost • Functionality at 120,000 Ft. • Operability at -85°C May06-17 – StratoLink Spacecraft Bus Design Review

19. GPS Receiver Receiver Selection Researched Garmin, Thales, and Magellan OEM units • Models considered: Input (VDC) Weight (g) • Garmin GPS-15H 8-40 15.0 • Garmin GPS-15L 3.3-5.4 14.1 • Garmin GPS-18PC 8-30 184.6 • Garmin GPS-18LVC 4-5.5 110.6 May06-17 – StratoLink Spacecraft Bus Design Review

20. Garmin GPS-15H Receiver (courtesy Garmin International) GPS Receiver Receiver Selection Model: Garmin GPS-15H Cost: $45.75 • Technical Specifications: • 12 Channel GPS Receiver • Power Usage: 396mW @ 12VDC • Input 8-40 VDC • Output: RS232 • NMEA 0183 and ASCII • Antenna Connector: MCX Male May06-17 – StratoLink Spacecraft Bus Design Review

21. GPS Receiver Antenna Selection Model: Garmin GA-27C Cost: $47.14 • Technical specifications: • Connector: MCX Female • Impedance: 50Ω • Power gain: 28dB May06-17 – StratoLink Spacecraft Bus Design Review

22. Current issues and risks • Issues • Communication with transceiver provider • Finding proper antenna • Risks • Satellite transceiver may not be effective without shielding provided by the case • Transceiver may not work at peak altitude • ORBCOMM may not be reliable or quick enough to provide timely communication • Temperature related equipment failure May06-17 – StratoLink Spacecraft Bus Design Review

23. Summary What we changed to meet the new Requirements HABETStratoLink Uses Radio Communication  New Satellite Package Amateur Radio licenseGPS, ORBCOMM Payload limited by balloon restrains  Payload limited to 4 lbs New Batteries requiring Charger May06-17 – StratoLink Spacecraft Bus Design Review