Space Cowboys

University of WyomingKyle Fox, Sean King, Erich Lichtfuss,

Jeff Parkins, Anne-Marie Suriano

Progress Design Review

Overview• Mission Overview• Subsystem Requirements• Special Requirements• Block Diagrams• Schematics• Activity Diagram• 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 UsageMain Processor ~200mA @ 2.5V and ~300mA @ 5.0vSub Processor ~170mA (x2) @ 5.0vAccelerometer ~0.12mA (x2) @ 3.3vTemp & Humidity Sensor ~1mA (x2) @ 3.3vPressure Sensor ~0.5mA @ 3.3vPressure Sensor Oscillator ~220mAMagnetic Sensor ~0.5mA @ 3.3vData Storage Memory ~100mATotals: ~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 RequirementsSupport Columns

University of Minnesota may only be willing to allow Option 1

Block DiagramsMain Sensor BoardMain Sensor Board

Power Source (Li Ion Batteries)

Main Microprocessor(FreeScale:

MC9S12XDP512MAL)

µSD Data Storage Memory Card

3-Axis Accelerometer(VTI: SCA3000-E05)

Humidity and Temp Sensor

(Sensirion: SHT15)

Pressure Sensor(Hope RF: HP03)

CAN Data and Power Supply Interface to Peripheral Boards

RBF PinMechanical G-Switch & Latch Circuit

Color KeyDataPower

Data + Power5.0 v and 3.3 v

Voltage Regulators

I2C

I2C

SPI

Unused I/O for Future Development

Block DiagramsPeripheral Board #1:

Skin Temperature and Off-Axis Acceleration Measurement

Color KeyData

Power

Data + Power

Peripheral Board #1

Sub Microprocessor(Microchip Technology: DSPIC30F401230ISO)

CAN Data and Power Supply Interface to Main Board

Humidity and Temp Sensor (for Side of Can)

(Sensirion: SHT15)

3-Axis Accelerometer(VTI: SCA3000-E05)

I2C SPI

Block DiagramsPeripheral Board #2:Magnetic Field Measurement

Color KeyData

Power

Data + Power

Peripheral Board #2

Sub Microprocessor(Microchip Technology: DSPIC30F401230ISO)

CAN Data and Power Supply Interface to Main Board

3-Axis Gauss Sensor(PNI: MicroMag3)

SPI

Batter & Power Schematic

Main Board Schematic

Peripheral Board 1 Schematic

Peripheral Board 2 Schematic

Activity Chart

• 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

Operating System

• 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

CAN bus interface

Satellite Boards BandwidthSensor 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) 4.30

CAN Bandwidth Utilization (1MB/s peak) 0.42%

• 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

MicroSD Main Board Storage

SensorNumber of Sensors

Sample Size(bits)

Sampiling Interval(Hz)

Total Bandwidth(B/s)

Total Mission Memory (MB)

VTI SCA3000-E05 2 16 200 800 2.747SHT15 (Humidity sample) 2 14 0.13 0.4375 0.002SHT15(Temp sample) 2 12 0.20 0.6 0.002MicroMag 3 1 16 2000 4000 13.733HP03 1 16 35 70 0.240Total Memory Requirement (MB) 16.72Total Memory Bandwidth (KB/s) 4.76Total Memory Bandwidth Utilization (1MB/s peak) 0.46%

Main Board Bandwidth

• 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

Sensor Package

• Structure– Developed mathematical models

• Basis for initial design• Reviewed by ME professor

– Research of Materials• Extensive properties list determined• Basic materials analysis performed

Analysis

Support Column3D Schematic Drawings

(Left) Non-deformed 3D

Mesh

(Right) Scaled Deformation 3D

Mesh (20 G vertical load, 10G

Lateral Load)

• 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

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