Undergraduate Space Research Symposium
University of Colorado Boulder
Presenters:
Caleb Lipscomb and Jon Sobol
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Supported by the NASA
Balloon Program Office (BPO),
run by LSU
Max Altitude: approx. 36km
15 to 20 hours of flight time
11 million cubic foot helium
Balloon
12 Student Payloads
◦ 8 small 3 kg payloads
◦ 4 large 20 kg payload
HELIOS II, Large payload
University of Colorado Boulder
2
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Orbital Platforms
◦ Expensive to develop and launch into space, cost
limits access.
◦ Advanced Composition Explorer (ACE) – $106.8
Million
◦ Solar and Hemispheric Observatory (SOHO) - $1.05
Billion
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Ground Based
◦ Face interference from the atmosphere, lowering the
quality of the images
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High Altitude Balloons
◦ Low Cost
◦ Ascended above 99.5% of atmosphere
University of Colorado Boulder
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Mission Objectives:
1. Observe and capture images of the Sun in
Hydrogen Alpha wavelength and to identify sun
spots in those images.
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Design and implement a system to locate the Sun
in the sky and orient cameras towards the sun.
Prove the viability of high altitude balloon solar
observation during a Colorado Space Grant
Consortium (COSGC) sponsored HASP flight.
University of Colorado Boulder
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Sun Spots
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656.28 nm
◦ In visible light range
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Mid Chromosphere
of the Sun
Average Sunspots:
10,000 km to 50,000
km in diameter
Solar Cycle max
University of Colorado Boulder
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Attitude
Determination and
Control System
(ADCS)
Solar Wavelength
Imaging System
(SWIS)
Electronic Power
System (EPS)
Command and Data
Handling (C&DH)
Structure and
Thermal
University of Colorado Boulder
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2 cameras
◦ Science Camera - Identify Sun Spots
◦ ADCS Camera - Characterize performance of
Attitude Determination and Control System (ADCS)
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Imaging Source “51”Series CCD Cameras
◦ 1600 x 1200 pixel CCD chip
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Hydrogen Alpha filtration system
University of Colorado Boulder
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2 Lenses
Fov:
 Vertical ϕ Axis: 1.56° or 1° 33’ 30.1”
 Horizontal θ Axis: 2.08° or 2° 4’ 40.1”
University of Colorado Boulder
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1 Lens
Fov:
 Vertical ϕ Axis: 15.5°
 Horizontal θ Axis: 20.1°
University of Colorado Boulder
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Filtration System
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400 nm Dichroic Longpass Filter (UV filter)
Hot Mirror (IR filter)
Neutral Density Filters
Narrow Bandpass Filter (Hydrogen Alpha)
◦ 656 nm, 10 nm bandwidth
University of Colorado Boulder
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Picture: 1600 px by 1200 px
University of Colorado Boulder
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University of Colorado Boulder
Sun: approx 417px
in diameter
10,000 km: 3 px in
diameter
50,000 km: 15 px in
diameter
1 px: approx. 3333
km
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Photodiodes
ADCS
SWIS
Electrical
and
Computing
Housing
Aluminum
Frame
Mounting
Plate
Triangular Trusses
University of Colorado Boulder
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14.
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University of Colorado Boulder
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Motor drivers and CPU to be heat sinked to
outer aluminum structure
Entire platform to be painted white
◦ Higher emissivity
◦ No reflective interference
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Excess aluminum to be used in the electrical
and computer housing structure to dissipate
heat
University of Colorado Boulder
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Power Provided by HASP Platform
◦ EDAC 512 connector
◦ 30 Volts at 2.5 Amps
Converts HASP power to power required by payload
systems
Arduino Due
◦ Monitor current and voltage
◦ MOSFETs
University of Colorado Boulder
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Circuit Diagram
University of Colorado Boulder
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Main Computer – Pandaboard
Communication between
subsystems
Store images
◦ Solid State Drive
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Environmental Sensors:
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Accelerometer
Pressure Sensor
Thermocouples
Signal relay: MUX
Analog to digital converter
Discrete Commands:
Command
Action
Power ON
Activates power to
HELIOS II payload
Power OFF
Terminates power to
HELIOS II payload
Reset ADCS
Restarts the ADCS
command algorithm,
used to trouble shoot
in flight ADCS issues
Health and Status Downlink
University of Colorado Boulder
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Communication
Digital signal to
Pandaboard confirming
orientation
ADCS
Digital signal to ADCS
to start orienting
HASP
Platform
Temperature
sensors
Pandaboard
Ground
Station
Digital signal to SWIS
to take picture
SWIS
Picture sent to
Pandaboard thereby
informing it to
signal ADCS to start
orienting
University of Colorado Boulder
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2 Motors
Arduino DUE
2 Photodiode Arrays
◦ Theta (Θ) Array
◦ Phi (Φ) Array
Theta (Θ) Array
Phi (Φ) Array
Phi Motor
Theta Motor
Theta (𝜃) Photo Diode Array
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Phi (Φ) Photo Diode Array
3D Printed at ITLL
Made out of Nylon/Acrylic Composite
Theta sensor has 14 photodiodes and Phi Sensor has 6.
Designed for modularity and ease of access
University of Colorado Boulder
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University of Colorado Boulder
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1. C&DH sends ADCS command to reorient.
2. ADCS collects Theta Plane photodiode
readings
3. ADCS centers to highest intensity source
4. ADCS collects phi plane photodiode
readings.
5. ADCS centers to highest intensity source
on phi plane
6. ADCS retakes theta plane readings and
reorients.
7. ADCS initiates Symmetry Test
8. ADCS sends command to C&DH that
orientation has been completed.
9. C&DH sends command to SWIS to capture
an image
University of Colorado Boulder
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Day Float
Altitude
36 km
Night Float
Ascent
Descent
Launch
Landing
Flight Timeline
T 0 hrs
LaunchSystem
powered
off
T 2 hrs
T 2.5 hrs
Float AltitudeBegin
Power on and
Mission
check H+S of Operations
all systems
T 10 hrs
Power off
Payload
T 20
Begin Descent
University of Colorado Boulder
T 22 hrs
HASP
Platform
Lands
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System Initialization
Procedures
1. Discrete Cmd
given by ground
station to power on
HELIOS II
2. EPS activates
power to
Pandaboard.
Pandaboard reports
initial health and
status to ground
4. Discrete
command ADCS to
begin operations
3. EPS powers on
ADCS, ADCS
reports H+S to
Pandaboard
5. Run mission
operations: track
sun & capture
images
University of Colorado Boulder
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Current Flight date: August 26
Identify at least one sun spot
◦ Observe same sun spot in 3 separate pictures
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ADCS success:
◦ Observe sun in 10% of Science camera images
◦ Exact performance characterized by ADCS camera
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Prove viability of high altitude balloon
observatories
University of Colorado Boulder
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University of Colorado Boulder
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