Preliminary Design Review
Michael Stephens, Eric Robinson, Alex Antonacci, Andrew Hellquist, Joe Backstrom, Bryan Overcast,
Jeffrey Watters, Jonathan Melton, Marshall Moore, Matthew Lehmitz, Tal Wammen, Colin Lucas
October 27, 2011
1
Mission Overview
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10/27/2011
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Scientific Mission Overview
o Characterize the performance of electrically active heat
shielding
o Proposed method of reentry:
o
10/27/2011
Electromagnetic Heat Shield
Presenter: Tal Wammen
3
Engineering Mission Overview
o Develop a standardized probe and deployment system.
o Develop a reliable and reusable standard electronic
system.
10/27/2011
Presenter: Tal Wammen
4
Theory and Concepts
o To design and build a standardized probe deployment
system to test an advanced, electrically shielded reentry
system.
o These concepts, as well as a standardized delivery
mechanism, will provide a foundation to build future
experiments.
10/27/2011
Presenter: Tal Wammen
5
Theory and Concepts
o Research based from several papers regarding preventing
radio black out.
o A strong magnet should repel
charged particles.
o Particles striking the payload
impart energy on the probe
causing heat.
10/27/2011
Presenter: Tal Wammen
6
Concept of Operations
t ≈ 1.7 min
Shedding of Skin
t ≈ 2.8 min
Apogee
t ≈ 4.0 min
Probe Deployment
End of Terrier
Malamute Burn
t ≈ 8.2 min
Chute Deploys
t ≈ 0 min
Launch
10/27/2011
Presenter: Tal Wammen
t ≈ 15 min
Splash Down
7
Success Criteria
o Reduce heat on reentry of a probe.
o Confirm results with control.
o Create a standardized probe deployment platform
enabling future progression in the field.
10/27/2011
Presenter: Tal Wammen
8
System Overview
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Payload
AHHS
Subsystem Definitions
System
Abbreviation
Description
Electromagnet
EM
Generates a strong magnet force to reduce heat during reentry
Power
POW
Supplies power to the electromagnet and various sub systems.
Sensors
SENS
Provides data for temperature and other environment variables.
Wireless
Control
WR
CTRL
Provides wireless uplink to the rocket for safe data storage.
Controls all major functions of the probe.
Recovery
REC
Slows descent so that radio uplink can be maintained.
Airframe
AF
Provides safe heat resistant housing for all components
Wallops Power
WP
Power provided by wallops during flight will control our systems.
Wallops Telemetry
WT
Telemetry provided by wallops during flight will allow us to transmit sensor data.
Sensors
SENS
Provide data for temperature as well as other environmental variables.
Wireless
WR
Provides the capability for the probe to transmit data for later recovery.
Payload Electrical System
PES
Provides necessary control, refines wallops interfaces, back up wallops interfaces.
Onboard Power
POW
Provides additional power as well as backup power after reentry.
Ejection System
Wallops Deck
ES
WD
Provides the capability to retain probe safely as well as eject it freely.
Provides firm mounting of components.
10/27/2011
Presenter: Tal Wammen
10
Subsystem Overview
MN/POW
SENS/CTRL
CTRL/POW
10/27/2011
Presenter: Tal Wammen
Recovery
Control
Wireless
Sensors
Power
Magnet
Air Frame
WR/CTRL
CTRL/REC
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Subsystem Overview
llop
a
W
r
we
o
sP
Wa
llop
Nasa Deck
sT
ele
m
Ejection System
WT/PES
WP/PES
Sensors
SENS/PES
ES/PES
PES
Wireless
WR/PES
POW/PES
Onboard Power
10/27/2011
Presenter: Tal Wammen
12
Abbreviation
Breif description
Possible solution
The magnet will have to have a direct high
capacity route to the battery if an
MN/POW
electromagnet is used.
High current wires at the same guage of the battery will need to be used.
The control sytem will need to not only
supply but also control the power system to
CTRL/POW
boot the probe up and shut it down.
Power mosfets may be able to couple these systems together safely.
The control system will need to be able to
SENS/CTRL
read data from the sensors.
This can be accomplished with either an ADC system or digital bus.
The wireless system will need to carry data
from the ctrl system to the rocket base
WR/CTRL
station.
This will be done typically via a UART port.
The control system will need to be activated Power mosfets or relays could activate the control surfaces to release the power
CTRL/REC
at the proper time.
chute.
All sub systems within the probe will need to The probe body will need mounting holes at various places to keep electronics
*/AHHS
be mounted securely and safely.
mounted firmly.
The AHHS prove will need to be mounted to
the payload firmly during ascent and allow Several options are being reviewed. One possible solution is a nylon cover over
AHHS/Payload the probe to be ejected safely and reliably. the probes that is released by burning attachments with nicrome wire.
Power provided through wallops will need to
be routed to the PES system for safe
WP/PES
distribution.
Poly fuses and mosfets will be used to manage the power supply from wallops.
The PES system will need to get data from
SENS/PES
the sensor subsystem.
This can be accomplished with either an ADC system or digital bus.
The ejection system will need to get control
signals from the PES at the right time to
This can be accomplshed with power mostfets or relays to activate the release
ES/PES
release the probe.
mechanism.
The wireless system will need to receive
signals from the probes and relay the data
WR/PES
back to wallops.
This will be done typically via a UART port.
The backup power system will need to be
connected to the PES to supply power in the
POW/PES
event of a power failure.
This will be done with standard battery connectors.
The wallops telemetry system will need to
communicate with the PES to transmit data
WT/PES
from the probes and onboard sensors.
This will be accomplished via the telemetry connector.
10/27/2011
Presenter: Tal Wammen
All systems will need to be firmly mounted
*/Payload
to the payload during ascent.
This will be accomplished in variouse ways depending on the sub system.
Payload
AHHS
Critical Interfaces
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System/Project Level
Requirement Verification Plan
Requirement
Produce a 1 Tesla Magnetic Field
The payload structure will survive 50G
forces with minimal deflections during
launch.
Probe Should Eject From the Payload
Safely and Cleanly
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Verification
Method
Simulation
and
Testing
Description
Use an iron core with copper windings to
produce an electromagnet. A Gauss meter to
measure the magnetic field.
Analysis
SolidWorks will be used to subject our payload
structure to a 50G uniform acceleration to
measure deflections.
Demonstration
Probe will be against a spring, secured with a
Wallops ribbon which is melted, releasing the
probe.
Presenter: Tal Wammen
14
User Guide Compliance
Type
Quantitative Constraint
Physical Envelope
Cylindrical
Diameter: 12 inches
Height: 6 inches
Weight
15 lbf ± 0.5 lbf
Center of Gravity (COG)
±0.5in from axial center of RockSat-X plate
Power and Telemetry
10x 0-5V 16-bit A/D Lines
1 parallel line
One asynchronous line
One redundant power line (28V)
3 non-redundant power lines
1 GSE power line (28V)
1 Ah capacity
High Voltage
No high voltage lines required.
10/27/2011
Presenter: Tal Wammen
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Sharing Logistics
o Who are we sharing with?
o
University of Northern Colorado
o
The possibility of a communication system between the AstroX
payload and the UNC payload is being considered.
o Plan for collaboration?
10/27/2011
o
Email, phone, road-trips to Greeley and Boulder
o
Communication with UNC on a weekly basis.
o
Grant UNC access to the AstroX private website.
Presenter: Tal Wammen
16
Subsystem Overview
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Subsystem: Magnet source
o 100 seconds of activation
o Must Sit for 5 Days
o Must be reliable and safe.
o Must perform well.
Score Performance
Weighting factor
Commercial electromagnet
Rare earth magnet
Custom designed electromagnet
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250
290
260
Safety
10
2
10
10
Reliabiltiy
10
8
5
8
Weight
10
10
10
5
5
10
8
6
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Subsystem: Wireless
o Must transmit data after reentry.
o Critical to success.
o Must be able to operate legally.
Weighting factor
Pair of 900 Mhz Xbee
STX2 transmitter
Digi M10
Spot communicator
APPRS Packet radio
10/27/2011
Score Communication Range Reliablility Logistical ease Access
10
10
5
5
205
3
10
5
10
215
10
7
7
2
255
10
7
7
10
220
10
7
5
5
175
5
8
5
4
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Subsystem: Power Supply
o 3 Minutes of Power
o Must Sit for 5 Days
o Large, Quick Draw Needed
Score Cost
Weighting factor
Super capacitor
Batteries
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295
218
Safety
5
8
3
Draw rate
10
8
6
Weight
8
1
5
Feasabiltiy Complexity
5
10
7
7
9
6
5
5
4
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Subsystem: Heat Shielding
o
Silicone
o
Inexpensive
o
Reliable
o
Durable
Score Safety
Weighting Factor
Thermal Soak
Ablative
Silicone
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176
217
311
Cost
3
9
8
6
Durability
8
1
2
7
9
4
8
6
Reliability Feasibility Complexity
9
9
8
8
1
3
7
2
3
6
9
6
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Subsystem: Ejection System
o Spring w/Ribbon
o
Safe
o
Effective
o
Simple
o
Reliable
Score Safety
Weighting Factor
Scissor Lift
Linear Actuator
Spring w/ Ribbon
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377
317
385
Cost
3
7
8
9
Strength
8
8
3
6
9
5
7
7
Reliability Weight
9
7
8
8
8
7
6
8
Feasibility Complexity
9
8
8
7
6
4
7
6
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Subsystem: Nose Geometry
o Nose Assembly
o Stable
o Create Drag To Reduce Plasma Buildup
Score Cost
Weighting Factor
Flat
Conical
Rounded
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196
207
163
2
3
5
5
Stabilization Drag
10
9
2
4
Weight
10
1
8
4
5
2
5
5
Feasibility Complexity
8
8
9
1
4
5
3
3
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Subsystem: Fin Attachment
o Strong
o Must survive Reentry
o Create Drag to Stabilize Craft
o Must Be Inexpensive
Score Cost
Weighting Factor
Fin Can
Mounted
Machined
Drag Tail
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202
240
204
267
2
5
3
9
7
Stabilization Strength
10
5
5
5
3
Weight
10
3
8
1
6
5
8.00
8.00
6
7
Feasibility Complexity
8
8
4
5
6
2
9
3
7
9
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Subsystem: Temperature sensor
Thermocouple
Integrated Chip
Pros
• High temperature range
Cons
• Additional hardware needed to
interface with controller
Pros
•
Cheap
•
Easily interfaces with controller
Cons
•
Poor temperature range
Score Range
Weighting factor
Thermocouple
Semiconductor
213
209
Precision
10
10
5
Feasability
8
6
8
Cost
5
10
10
5
3
9
25
Conceptual Model
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11/1/2010
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Electromagnet Modeling
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Electromagnetic Equations
o Ampere’s Law:
Simplified to:
Where B is the magnetic flux vector.
N is the number of turns.
L is the length, and I is the current.
μ is μo * μr, where μo is the permeability of free space (4πE-7 H/m), and
μr is the permeability of soft iron (200).
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Electromagnet Matlab Code
o Equations implemented in matlab.
o Takes variety of parameters including: diameter, length,
wire gauge and internal battery resistance.
o Another script loops through available parameters
building potential electro magnets.
11/1/2010
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1
11
21
31
41
51
61
71
81
91
101
111
121
131
141
151
161
171
181
191
201
211
221
231
241
251
261
271
281
291
301
311
321
331
341
351
361
371
381
391
401
411
421
431
441
451
461
471
Preliminary Matlab results
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25
20
15
weight
tesla
coilcurrent
10
5
0
11/1/2010
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Prototyping Design
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Subsystem: Risk Matrix/Mitigation
o RSK1: Probe fails to be
released.
o RSK3: Probe fails during
reentry.
o RSK4: Fins shear during
reentry.
Consequence
o RSK2: Radio signal not
acquired before splash
down.
RSK1
RSK3
RSK2
RSK5
RSK4
Possibility
o RSK5: Recovery system
fails.
11/1/2010
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Prototyping Plan
o Electromagnet
o
Fabricate and Test
o Ejection System
o
Fabricate and Test
Prototyping will begin
later this month and
carry into next semester
o Parachute System
o
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Fabricate and Test
Presenter: Tal Wammen
34
Project Management Plan
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Organizational Chart
Project Manager
Shawn Carroll
Engineering Faculty Advisor
Physics Faculty Advisor
Dr. Rob Erikson
Dr. Paul Johnson
Team Leader
Tal Wammen
Payload Ejection System
Michael Stephens
Marshall Moore
Bryan Overcast
Alex Antonacci
10/27/2011
Advanced Heat Shield System
Michael Stephens
Jonathan Melton
Colin Lucas
Jeffrey Watters
Eric Robinson
Aeroframe/Probe Housing
Electrical Power System
Jonathan Melton
Jeffrey Watters
Joe Backstrom
Andrew Hellquist
Eric Robinson
Michael Stephens
Marshall Moore
Matthew Lehmitz
Colin Lucas
Joe Backstrom
Andrew Hellquist
Alex Antonacci
Matthew Lehmitz
Bryan Overcast
Presenter: Tal Wammen
36
Mechanical Schedule
o Major Mechanical Milestones:
o
Design Freeze at CDR (11/29/2011)
o
Blueprints submitted for manufacturing by CDR
o
Mechanical prototype constructed mid-January, 2012
o
Mechanical prototype fully tested by end of January, 2012
o Impact and submersion testing
o Electromagnet Testing
o
Plasma Testing
o Structural Testing
o Drop Testing
10/27/2011
Presenter: Tal Wammen
37
Electrical Schedule
o Major Electrical Milestones:
o
Electrical Schematics completed by CDR (11/29/2011)
o
Components ordered by end of November
o
Electrical assembly and testing starting this month
o Control function test
o Telemetry and SD card output test
o
10/27/2011
Fully functioning payload by early next semester
Presenter: Tal Wammen
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Budget
o Mass Budget (14 lbs)
o
Structure (4lb)
o Probe Housing (1lb)
o NASA Structure (3lb)
o
Probe (6.5lb)
o Electromagnet (5lb)
o Aeroshell(1lb)
o Parachute(0.5lb)
10/27/2011
o
Ejection System (0.5lb)
o
Electrical System (2lb)
o
Battery(1lb)
Presenter: Tal Wammen
39
AHHS
Payload
Budget
10/27/2011
Device
Price
Qty
Xbee
54.95
Antenna
9.95
7.2 V NiMH Battery
19.99
Thermocouple
10
Amplifier
10
SD card holder
2
Power mosfets
4
Arduino Mega
Nichrome wire
17.32
PC boards
33
Xbee
Antenna
7.2 V NiMH Battery
Thermo couple
Amplifier
9V
Iron core
Copper wire
PC boards
Rare earth magnet
54.95
9.95
19.99
10
10
2
15
138
33
417
Total
1 54.95 http://www.sparkfun.com/products/9099
1
9.95 http://www.sparkfun.com/products/558
1 19.99 http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXXUP0&P=8
2
20 http://www.adafruit.com/products/270
2
20 http://www.sparkfun.com/products/307
1
2
1
4
1
1
17.32 http://www.amazon.com/Nickel-Chromium-0-0320-Diameter-Length/dp/B000
33
1 54.95 http://www.sparkfun.com/products/9099
1
9.95 http://www.sparkfun.com/products/558
2 39.98 http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXXUP0&P=8
2
20 http://www.adafruit.com/products/270
2
20 http://www.sparkfun.com/products/307
2
4 Walmart
1
15
1
138
1
33
1
417
Total 933.09
Presenter: Tal Wammen
40
Work Breakdown Structure
Aeroframe/Probe Housing
•
•
•
•
Payload Ejection System (PES)
•
•
•
•
•
Finalize Design
Design Freeze at CDR
Submit Work Request
Test Prototype
Finalize Schematics
Design Freeze at CDR
Order Parts by End of Fall Semester
Build Circuits
Test Systems
Advanced Heat Shield System
•
•
•
•
•
10/27/2011
Finalize Design
Design Freeze at CDR
Order Parts by End of Fall Semester
Build Prototype
Test prototype
Presenter: Tal Wammen
41
Conclusions
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10/27/2011
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Questions?