may06-17 – stratolink spacecraft bus design review stratolink spacecraft bus senior design project...
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May06-17 – StratoLink Spacecraft Bus Design Review
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
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
Definitions
FAA – Federal Aviation AdministrationHABET – High Altitude Balloon Experiments in TechnologyNMEA – National Marine Electronics AssociationOEM – Original Equipment ManufacturerSSOL – Spacecraft Systems and Operations Laboratory
May06-17 – StratoLink Spacecraft Bus Design Review
Background
•Project of Iowa State University SSOL
•Designed to reach near space altitudes
•Provides platform for high altitude experiments
•Highly successful
HABET Project
May06-17 – StratoLink Spacecraft Bus Design Review
Background
What needs to be changed to accommodate those needs?
•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
StratoLink Project
May06-17 – StratoLink Spacecraft Bus Design Review
Background
HABET
StratoLink
Uses amateur radio comm. Satellite-based comm.Requires amateur radio license Capable 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
System Overview
Note: HOBO Data Logger and digital camera use present design from HABET
May06-17 – StratoLink Spacecraft Bus Design Review
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
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
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
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
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
Battery Charger
May06-17 – StratoLink Spacecraft Bus Design Review
Transceiver
Purpose:Communicate with base without using
amateur radio
Services considered:Iridium•Global satellite network•Used for voice communicationORBCOMM•US coverage•Used for low data-rate data communications
Overview
May06-17 – StratoLink Spacecraft Bus Design Review
TransceiverChoosing a provider
Considerations:•Equipment needed
CostWeightFunctionality
•Subscription/data costs•Communication latency•Reports of usage in the field
ORBCOMM selected as the best solution
May06-17 – StratoLink Spacecraft Bus Design Review
TransceiverSelected Transceiver
Model: Stellar ST2500Bought without case to reduce weight
GPS Receiver – Garmin GPS-15HAntennas for each
Tasks to be done:Program ST2500Devise a shielding system for ST2500
May06-17 – StratoLink Spacecraft Bus Design Review
TransceiverTechnical 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
GPS Receiver
Design requirements:
•Lightweight
•Low Cost
•Functionality at 120,000 Ft.
•Operability at -85°C
Purpose:
To capture position from GPS satellites and relay it to spacecraft bus.
Overview
May06-17 – StratoLink Spacecraft Bus Design Review
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
Researched Garmin, Thales, and Magellan OEM units
GPS ReceiverReceiver Selection
May06-17 – StratoLink Spacecraft Bus Design Review
Garmin GPS-15H Receiver (courtesy Garmin International)
Model: Garmin GPS-15H
Technical Specifications:•12 Channel GPS Receiver
•Power Usage: 396mW @ 12VDC
•Input 8-40 VDC
•Output: RS232
• NMEA 0183 and ASCII
•Antenna Connector: MCX Male
Cost: $45.75
GPS ReceiverReceiver Selection
May06-17 – StratoLink Spacecraft Bus Design Review
Model: Garmin GA-27C
Technical specifications:
•Connector: MCX Female
•Impedance: 50Ω
•Power gain: 28dB
Cost: $47.14
GPS ReceiverAntenna Selection
May06-17 – StratoLink Spacecraft Bus Design Review
Current issues and risks
IssuesCommunication with transceiver providerFinding proper antenna
RisksSatellite transceiver may not be effective without shielding provided by the caseTransceiver may not work at peak altitudeORBCOMM may not be reliable or quick enough to provide timely communicationTemperature related equipment failure
May06-17 – StratoLink Spacecraft Bus Design Review
SummaryWhat we changed to meet the new Requirements
HABET
StratoLink
Uses Radio Communication New Satellite Package
Amateur Radio license GPS, ORBCOMM
Payload limited by balloon restrains Payload limited to 4 lbs New Batteries requiring Charger