Transcript here - Arizona Space Grant Consortium

PIMA COMMUNITY COLLEGE
ASCEND! 2009
ASGC Symposium
April 18, 2009
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Students:
Team:
Stacy Harrison
Fabrication/Integration
Mike Iuzzolino
Fabrication/Integration
Zack Jarrett
Software
Peter Kozak
Thermodynamics
Chris Miller
Circuits
Kyle Rine
Thermodynamics
Peter Saliba
Circuits
Tarek Touzi
Misc.
Roscoe Vertein
Fabrication/Integration
Faculty:
Position:
Dr. Denise Meeks
Instructor/Dept. Chair
Mike Sampogna
Instructor/Mentor
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
What science can we attach to a balloon that
rises to 90,000 ft. ?
 Measure solar radiation high above the Earth’s
surface where the atmosphere is thin
 Observe necessary heating mechanisms in near
space
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What data should we collect?
What instrument would we use?
How does the “near space” environment affect the
measurements?
 Can the experiment be done within our budget?
 What do we need to learn?
 Stages (Fall 08 launch and Spring 09 launch )
needed to first test the concept and second
complete the experiment.
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Getting started
Heater
Circuits
Software
Fabrication
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
Less than 4 lbs
 Power to weight ratio
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Withstand extreme temperature/pressure
environment found in near space
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Sensor
Head
OA
A/D
Microprocessor
Heater
Data
Stage
Sent
Data
Storage
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LEDs will be used to detect the sun’s
radiation during the flight
Data will be collected, stored, and
transmitted
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Spectrally sensitive
LED will emit light when voltage is applied
but in our case, shine light and a voltage is
created
Direct measure of sun’s intensity
Cost effective
BUT they don’t like low temperatures
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
Responsible for figuring out:
 Heating methods
 Materials best suited

Responsible for construction:
 Mica heater
 Contact with sensors
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Responsible for testing:
 Heat transfer mechanism
 Power requirements
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Efficiency
Adding heat
Removing heat
Convection
Conduction
Radiation
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Thermocouple built into the LED sensor
board
Heating Control
 Measured ambient temp at LEDs
 On – Off control circuit
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Mica heater
Steel Washer
Ceramic Paper
Mica
Steel Washer
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Conduction requires
maximum contact with board
Layers of anti-static plastic
were used to mold heater to
circuit board
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Hours and hours of
testing went into
designing and
developing the
heating system.
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
Heater operation
 Room temp
 Cold temp
 Room temp in vacuum
 Cold temp in vacuum

Completed heater circuit
 Heat up and cool down times
 Understanding heater power requirements
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Sensor
Head
OA
A/D
Microprocessor
Heater
Data
Stage
Sent
Data
Storage
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Tinytrak II
Modem
Radio
triband…
LED
Sensor/
Heating
Board
BX24
Microprocessor
Board
Sensor
Support
Board
Sunfinder
Board
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
Computer
 Netmedia Inc. BX24 Microcontroller

Software
 Programmed using the Basic-X Language, a
subset of Visual Basic
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
4 Functions:
 Gather data from the sensor and sun-finder
platforms
 Toggle the sensor platform heater
 Store the data onboard
 Output the data serially to the radio equipment
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Reads the LED voltage from the
analog/digital converters
Repeats every 30 seconds
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Measure the voltage from the
Zener diode on the sensor
platform
Voltage from thermister is 10
mV to 1 Kelvin conversion
If the temperature is below 11°
C, turn on the heater
When the temperature exceeds
16° C, turn off the heater
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Store the measured data (LED voltages, RC
time constant values, sensor temperature,
and time) in the 32 Kbytes of onboard
EEPROM
Divide the data into 3 packets and transmit
each packet 3 times to the radio transmitter
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
Superstructure of closed-cell
foam (bait box)
 Low weight to volume ratio for
internal space requirement
 Elasticity of material for impact
absorption

Infrastructure of open-cell
foamboard
 Lightweight
 Rigid
 Easy to handle and cut
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A hardpoint is a rigid
connection between
structure and payload; a
firm point is a non-rigid
connection allowing for
a cushion between
internal and external
components.
Circuit boards were
attached via individual
mounting rigs
Nylon machine screws
and nuts fastened rigs
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Open-celled
foamboard
structure
designed
around circuit
sizes and
placement
requirements
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Wrapped in duct tape for fibrous
reinforcement of superstructure
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Current status
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Fabrication technique worked
Data being analyzed
Circuits performed as expected
Heater performed as expected
Conclusion
 2 campuses
 Students 2 – 8
 Many more skills added
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