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Team DSRO
Critical Design Review
Taylor Boe
Andrew Buckner
Andrew Gilbert
Emily Howard
Grace Harsha
Bobby Stillwell
October 14, 2008
Mission Overview
• The primary mission of Operation H.A.L.O. is to find the
optimal altitude at which one can take quality
telescopic images of celestial bodies from a high
altitude observatory. By taking light readings of
ambient light intensity (all wavelengths) at various
altitudes up to 30,000 meters using a photometer, and
comparing this to past data we shall achieve an
understanding of where ambient light remains
constant above our stratosphere, no longer interfering
with telescopic imagery, so that future missions can
attempt to obtain quality images of celestial bodies at
a lower cost compared to current ground based or
orbiting telescopes.
Requirement Flow Down
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1.0 Mission requirements:
The H.A.L.O. payload shall provide evidence that it is feasible to capture high quality
images of celestial bodies from a near space environment. The payload will be
functioning no later than November 15, 2008 and will follow all proposal requirements
concerning the weight (1000g) and price ($150) budgets.
2.0 Objective Requirements:
2.1 Operation H.A.L.O. will take light intensity readings throughout the ascent to an
altitude of 30 km.
2.2 The payload will be logging the internal and external temperature for the duration of
the flight as well as humidity to ensure that the environment is not to extreme for a high
altitude observatory.
3.0 System Requirements:
3.1 The payload will gather light intensity readings through a photometer, and store the
voltage data onboard the payload via a microcontroller.
3.2 The photometer shall be calibrated and tested prior to November 15, 2008, to ensure
its proper functionality.
3.3 We shall use an internal heating device to keep our power source at an optimum
level.
3.4 A “cold finger” will be implemented into our photometer design to conduct heat
away from our photometer circuit to ensure that the photodiode stays cool and does not
record false data due to excess energy in the form of heat.
How
• We plan to build a photometer to take light
readings, via a photodiode, that shall provide
data about sky brightness at different altitudes up
to 30 kilometers.
• The data shall be stored on a microcontroller.
• The photometer is Kyle Kemble’s design which is
based upon the design of Dr. Yorke Brown.
• The altitude, at which we took our readings, shall
be obtained using math and our understanding of
the rate of ascent after the balloon flight.
Given Parts
• Camera
• HOBO Data Logger
• Temp Probes
• 9V Batteries x 3
• Heater
• Tube
• Foam Core
• Aluminum Tape
• Switches x 3
• American Flag
Photometer Parts
• Microcontroller
(Arduino Pro Mini, • Lens
Logomatic v2 Serial • Lens
SD Datalogger, FTDI • Black Felt
Basic Breakout)
• 1.25 inch PVC Pipe
• 1 inch PVC pipe
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Photodiode
Photodiode
Op-Amps
Reed Relay
Capacitor (1000 pf)
Voltage Divider
Decoupling
Capacitors (.1 uf)
910 Ohm Resistor
750 Ohm Resistor
LED
Circuit Board
12V Batteries x 2
Photometer Schematic
Mass Contingency
Item
Camera
HOBO Data Logger
Temp Probes
9V Batteries x 3
Heater
Tube
Foam Core
Aluminum Tape
Switches x 3
American Flag
Photometer
Item Mass (grams)
220
29
30
135
32.5
50
155
30
21
1
200
Mass Remaining (grams)
780
751
721
586
553.5
503.5
348.5
318.5
297.5
296.5
96.5
Price Budget
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Item
Camera
HOBO Data Logger
Temp Probes
9V Batteries x 3
Heater
Tube
Foam Core
Aluminum Tape
Switches x 3
American Flag
Photometer
• Total:
Price (in Dollars)
0
0
0
0
0
0
0
0
0
0
100.35
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100.35
Functional Block Diagram
2 12V Battery
Switch
Circuit Board
Photodiode
External Temperature
Internal 3V
Lithium Battery
Hobo Data
Logger
Internal Temperature
Humidity
3 9V Batteries
Switch
Heater
Internal Lithium
Battery
Switch
Camera
Internal SD Memory Card
Microcontroller/
Memory
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Schedule
October 1: Start work on the first test shell of the satellite.
October 4: First test of Satellite shell (drop test, whip test, and stair test).
October 13: Start Work on our photometer.
October 20: Start construction of final satellite shell.
October 22: Final shell of satellite shall be finished.
October 25: First cold test of working components in test box with heater.
October 29- November 8: Component Testing (photometer tests and
more cold tests).
November 4: In class mission simulation.
November 6: In class mission simulation.
November 12: Design shall be finished. All tests shall have been
performed.
November 15: Launch Day
November 17: Gather raw flight data. Begin work of final presentation.
November 18: In-Class Launch Recap
November 19- 29: Repair satellite.
November 29: Team Video shall be finished.
December 2: Final team Presentation
Testing
• Drop test
• Stair test
• Whip test
• Cold Test of basic electronics
• Cold/Light test of Photometer
• Functionality tests
• Memory/Data test
• Capacitor/Electronics test (final)
• Imaging test
Expected Results
• We expect to prove that there is in fact an
altitude above which ambient light (light from
the atmosphere) stabilizes enough to image
stars.
• The data collected will provide evidence that it
is possible to take high quality telescopic
images of celestial bodies from near space.
Biggest Worries
• Photometer working
• Photometer pointing at the sun
• Thermal
• Time