Space Cowboys
Progress Design Review
Overview
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Mission Overview
Subsystem Requirements
Special Requirements
Block Diagrams
Schematics
Activity Diagram
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Parts List
Test Plans
Canister Guidance
Canister Shared Logistics Plan
Management
Issues and Concerns
Mission Overview
• Objective
– Accurately measure flight parameters including
ambient and skin temperatures, pressure,
acceleration, spin rate, and magnetic field.
– Gain basic understanding of design requirements
and associated hurdles for designing in real-world
space applications.
Mission Overview
• Goal
– Provide an accurate base of flight parameters to
model rocket flight conditions and patterns for
assessment of associated affects on other systems.
– Attain real-world design experience.
Mission Overview
• Underlying Science/Theory
– Recognition of magnetic field changes associated
with altitude
– Quantification of varying flight parameters
– Attempt to determine rocket orientation using
post-flight accelerometer data
Mission Overview
• Previous Related Experimentation
– Previous flights have included multi-sensor
packages
– Results provide a basis for improvement on future
data collection
Mission Overview
• Mission Requirements
– Multipoint Temperature Monitoring
– Pressure Monitoring
– 3-Axis Accelerometer Monitoring
– Humidity Monitoring
– 3-Axis Gauss Meter
Mission Overview
• Success Criteria
– No mechanical failure of structure
– No electrical failures in system
– Clear and accurate data stored
• Allows for analysis
• Easily organized and identifiable
Mission Overview
• Benefits
– Other experiments on the rocket
• Accurate flight data
– Future rocket flights and teams
• Accurate flight data
• Clear identification of extreme parameters for more
efficient design
• Multi-sensor platform that allows for expansion to add
future sensors and experiments as desired
Subsystem Requirements
• Subsystems
– Power
– Sensors
– Command & Data Handling
– PCB
– Support Structure
Subsystem Requirements
• Power
– Payload will consume 1.2 amps under peak conditions
• See next slide for peak power usage breakdown
– Batteries will provide peak current for 1.5 hours
– Two 3.6V Batteries will operate in series to provide 7.2V
– Voltage regulation will be performed on the main board
and will negate effects of temperature and voltage
variations of the batteries during discharge
Subsystem Requirements
• Peak Power Usage Breakdown
Part
Power Usage
Main Processor
~200mA @ 2.5V and ~300mA @ 5.0v
Sub Processor
~170mA (x2) @ 5.0v
Accelerometer
~0.12mA (x2) @ 3.3v
Temp & Humidity Sensor
~1mA (x2) @ 3.3v
Pressure Sensor
~0.5mA @ 3.3v
Pressure Sensor Oscillator
~220mA
Magnetic Sensor
~0.5mA @ 3.3v
Data Storage Memory
~100mA
Totals:
~1.2 amps
Subsystem Requirements
• Sensors
– Main board accelerometer will be located on the center
axis of payload canister
– Each sensor requires specific sampling intervals and
returns specific sample sizes
• Command & Data Handling
– Code must be extremely robust with excellent error
handling capabilities
Subsystem Requirements
• PCB
– Multilayer construction focusing on noise mitigation and
ease of future expansion
• Support Structure
– Maximize strength, minimize mass
Special Requirements
Support Columns
University of Minnesota may only be willing to allow Option 1
Block Diagrams
Main Sensor Board
Main Sensor Board
Mechanical G-Switch
& Latch Circuit
Power Source
(Li Ion Batteries)
RBF Pin
Color Key
Data
µSD Data Storage
Memory Card
I2C
Pressure Sensor
(Hope RF: HP03)
I2C
Humidity and Temp
Sensor
(Sensirion: SHT15)
SPI
3-Axis Accelerometer
(VTI: SCA3000-E05)
5.0 v and 3.3 v
Voltage Regulators
Main Microprocessor
(FreeScale:
MC9S12XDP512MAL)
CAN Data and Power Supply
Interface to Peripheral Boards
Unused I/O for Future
Development
Power
Data +
Power
Block Diagrams
Peripheral Board #1:
Skin Temperature and Off-Axis Acceleration Measurement
Peripheral Board #1
I2C
Sub Microprocessor
(Microchip Technology:
DSPIC30F401230ISO)
Color Key
SPI
Data
Power
Humidity and Temp
Sensor (for Side of Can)
(Sensirion: SHT15)
3-Axis Accelerometer
(VTI: SCA3000-E05)
CAN Data and Power Supply
Interface to Main Board
Data +
Power
Block Diagrams
Peripheral Board #2:
Magnetic Field Measurement
Peripheral Board #2
Sub Microprocessor
(Microchip Technology:
DSPIC30F401230ISO)
Color Key
SPI
Data
Power
3-Axis Gauss Sensor
(PNI: MicroMag3)
CAN Data and Power Supply
Interface to Main Board
Data +
Power
Batter & Power Schematic
Main Board Schematic
Peripheral Board 1 Schematic
Peripheral Board 2 Schematic
Activity Chart
Operating System
• The Payload will operate with a Real Time
Interrupt Driven Operating System
• The Operating System will have extensive error
handling capabilities including multiple sensor
failures
• The Operating System will be constructed to
allow easy modification and expansion as
required by future missions
CAN bus interface
• The Main Board will communicate with all
satellite boards via a CAN bus Interface
• CAN has the ability to address over 110
devices
• CAN provides 1MB/s throughput
• CAN is commonly available and very
inexpensive
Satellite Boards Bandwidth
Sensor
Sample Size(bits)
Sampiling Interval(Hz)
Bandwidth(B/s)
VTI SCA3000-E05
16
200
400
SHT15 (Humidity sample)
14
0.13
0.22
SHT15(Temp sample)
12
0.20
0.3
MicroMag 3
16
2000
4000
Total Peak CAN Throughput (KB/s)
CAN Bandwidth Utilization (1MB/s peak)
4.30
0.42%
MicroSD Main Board Storage
• MicroSD will be implemented for project
storage
• MicroSD is inexpensive and is available in high
data densities on a small footprint
• MicroSD provides 3MB/s throughput
• MicroSD offers an 8-bit data path over SPI
Main Board Bandwidth
Sensor
VTI SCA3000-E05
SHT15 (Humidity sample)
SHT15(Temp sample)
MicroMag 3
HP03
Total Memory Requirement (MB)
Total Memory Bandwidth (KB/s)
Total Memory Bandwidth Utilization
(1MB/s peak)
Number of
Sensors
Sample
Size(bits)
2
2
2
1
1
16.72
4.76
0.46%
Sampiling
Total
Total Mission
Interval(Hz) Bandwidth(B/s) Memory (MB)
16
200
800
2.747
14
0.13
0.4375
0.002
12
0.20
0.6
0.002
16
2000
4000
13.733
16
35
70
0.240
Sensor Package
• Temperature
– Sensirion SHT15
– Temperature is measured on both the Main Board
and a single Satellite Board for approximating skin
temperature
– Resolution: 0.01C
– Accuracy: +/- 0.3C
– Response Time: 5s
Sensor Package
• Relative Humidity
– Sensirion SHT15
– Humidity is measured on the Main Board
– Resolution: 0.05 %RH
– Accuracy: +/- 3.0 %RH
– Response Time: 8s
Sensor Package
• Accelerometers
– VTI SCA3000-E05
– Three axis acceleration is measured along the
center axis and inner edge of payload canister
– Resolution: 0.002g
– Accuracy: +/- 2.0 %
– Response Time: 200Hz
Sensor Package
• Magnetic Sensor
– PNI MicroMag 3
– Magnetic field is measured on peripheral board #2
– Resolution: 0.015µT
– Response Time: 500µs
Sensor Package
• Pressure Sensor
– Hope RF HP03
– Pressure is measured on the Main Board
– Resolution: 0.1 hpa
– Accuracy: ± 0.5 hpa
– Response Time: 35ms
Analysis
• Structure
– Developed mathematical models
• Basis for initial design
• Reviewed by ME professor
– Research of Materials
• Extensive properties list determined
• Basic materials analysis performed
Support Column
3D Schematic Drawings
(Left) Nondeformed 3D
Mesh
(Right) Scaled
Deformation 3D
Mesh (20 G
vertical load, 10G
Lateral Load)
Testing
• Electrical
– Code verification will be completed in the
CodeWarrior Development Environment
– Hardware verification will be completed by a
series of tests TBD
• Structure
– Vibration testing will be completed at a local
businesses 2-axis vibration table
– Spin Stabilization Testing will also be conducted at
local business using a spin table
Testing
• Full Package Testing
– Environmental Testing using previous RockSat
flights data as a reference
– Possible Weather Balloon Launch. Local Civil Air
Patrol Squadron has offered to run our package as
a payload for a future weather balloon launch.
Testing
• Potential Points of Failure
– Electrical
• Contact to data storage card
• Electrical connection breakage during high Gs
• Unforeseen code interruption due to interference
– Mechanical
• Bolt thread shearing
• Vertical supports buckling
• Tray malfunction
Major Structural Components
• Makrolon (Tray Material)
– Bayer
• Properties are known (www.MatWeb.com)
• Price & Availability known
• Aluminum (Support Columns & Circuit Mounts)
– Provided by University of Wyoming Engineering
Machine Shop
• Properties known
• Prices & Availability known
Major Electrical Components
• Parts List
– See file “Parts List.docx”
• Lead Times
– 1.5 Weeks
• S+H
– $50 in addition to listed part costs
RockSat Payload Canister
User Guide Compliance
• Mass/Volume
– Estimate 3lbs
• Payload Activation
– G-switch activation
• Open circuit until g-switch activation
• Rocket Interface
– RBF/Shorting wires
Shared Can Logistics Plan
• University of Wyoming (UW) & University of
Minnesota (UMN)
• UW Missions
– Multi-sensor: Rocket flight parameter measurements
– Good Vibrations: Explore rocket flight effects on
electrical and crystal oscillators
• UMN Mission
– To characterize the flight of the rocket and attempt to
record data using techniques untested in suborbital
flight.
Shared Can Logistics Plan
• Interfacing Collaboration Plan
– E-mail and phone conferencing
– Exchange of 3D modeling suggestions
– Full assessment and agreement on location,
structure and interface
• Structural Interfacing
– Still to be determined
– Positioning has been discussed
Management
• Project Schedule
– See attachment
• Preliminary mass/monetary budgets
– Mass Budget: 3lb (Multi-Sensor)
– Budget: approx. $750
Conclusions
• Issues/Concerns
– Structural Interface with other Payloads within
Canister
– Electrical Interference from Payloads and External
Radiation