May06-17 – StratoLink Spacecraft Bus Design Review StratoLink Spacecraft Bus Senior Design Project...

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


Agenda

Background Information Adam Allison

Lithium Ion Batteries Robert Bond

Battery Charger Hai Duong

GPS Receiver David Johnson

Communications Alan Johnson

Conclusion Adam Allison


Definitions

FAA – Federal Aviation AdministrationHABET – High Altitude Balloon Experiments in TechnologyNMEA – National Marine Electronics AssociationOEM – Original Equipment ManufacturerSSOL – Spacecraft Systems and Operations Laboratory


Background

•Project of Iowa State University SSOL

•Designed to reach near space altitudes

•Provides platform for high altitude experiments

•Highly successful

HABET Project


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


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


System Overview

Note: HOBO Data Logger and digital camera use present design from HABET


Lithium Ion Batteries

•3.7 Volt Each•1200 mAh•Rechargeable•34.2mm x 8.5mm x 48mm•Built in Shutdown Separator•Soldier Tabs included


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


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


Battery Charger

•Auto-off•External from system•Rechargeable•34.2mm x 8.5mm x 48mm•Built in Shutdown Separator•Soldier Tabs included


Battery Charger

•Input: AC 100-240V 50/60Hz•Output: 4.2-16.8VDC•Charging Current: 500mA•Supported Types: Li-Ion larger than 400mAh


Battery Charger


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


TransceiverChoosing a provider

Considerations:•Equipment needed

CostWeightFunctionality

•Subscription/data costs•Communication latency•Reports of usage in the field

ORBCOMM selected as the best solution


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


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


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


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


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


Model: Garmin GA-27C

Technical specifications:

•Connector: MCX Female

•Impedance: 50Ω

•Power gain: 28dB

Cost: $47.14

GPS ReceiverAntenna Selection


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


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

May06-17 – StratoLink Spacecraft Bus Design Review StratoLink Spacecraft Bus Senior Design Project...

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