AA236 Thrusters Update

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AA236 Thrusters Update
Team Members Adam Collazo, Andy Sadhwani, Bill
Storck, Mitul Jambusaria, Olivia
Billett, Pierric Jammes
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Presentation Outline

• Team Mission Statement
• Address Concerns
• Thruster Technologies
• Torquer Coil Study
• Torquer Coil Dynamics
• Power System
• Next Steps

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Mission Statement

• We will develop and demonstrate 3-axis attitude
  control for CubeSats

• Purpose Statement
• Attitude Determination Control
• 3 Axis Control
• Reliability
• Proof of Concept
• Test Maneuvers
• Orbit Changes and De-Orbit Capability

• Main Requirements
• Low Power
• Minimum Rotation Rate
• Minimum and Maximum Thruster Requirements
• Integration with KatySat
• Power System
• Control Systems
• Thruster Operating Temperature Ranges

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Schedule
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Momentum Wheels

• Issues
• Physical size and mass
• Power Requirements
• Case Study
• Aalborg University (Denmark)
• Structures issues
• Weight issues

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Surrey Water Micro-Resistojet

• Flown on UK-DMC in 2004
• Initial system developed in less than 8 months
• mNs of thrust
• Green propellant
• Low power
• High propellant mass
• Low Isp
• Failure during test

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Alameda MVAT

• Local NorCal company
• High Isp 2000
• mNs of thrust
• Previous flight experience
• No limit on propellant
• 1 kg total mass
• High power

Photo courtesy of Alameda Applied Sciences
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Vacco MiPS

• Low mass, very small!
• Designed for CubeSat
• 35 mNs of thrust
• Extendable tank
• Low power average
• Needs work student?
• High peak power
• 2 axis control?

Photo courtesy of Vacco Systems
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Cold Gas Thruster
(Marrotta)
Model SV14 Operating Gas N2, Xe Size
1.6x1.6x5cm Input lt3.5W Mass lt75g Thrust
10mN Cycles 2,000,000
Model CGMT-000-9 Operating Gas N2, He Size
1.6x1.6x6.6cm Input lt1 W Mass lt70g Thrust
10mN Cycles 6,000
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Pulsed Plasma Thruster
(John Elliss Model)
Components DC2DC Converter, 0.1uF Capacitor,
Coax Teflon Barrel Input 6 Volts at 30
milli-Amps (average) Output 1400 Volts at 200
Amps for 10 nanoseconds Pulse Rate 6
pulses/second Thrust 6 micro-Newtons Lifetime ?
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Torquer Coils How They Work
The Earth is a Dipole
Parameters Number of Turns Cross Sectional
Area Direction of Current Magnitude of Current
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Why? Why Not?
The Wheel, its been done
Three Axis Control!!!!
EMI/Magnetometer
KISS
Computational Power and Control Logic
Reliability
Precession
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Torquer Coil Requirements
Compiled from research of seven universities
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And I care because 

• ADCS
• Magnetometer and EMI
• International Geomagnetic Reference Field Model
  (UToronto-CanX)
• -operation time 2/3 of total attitude code
  execution
• -directional information for torquers

• Power
• Low power requirements
• We may have our own power source

• Spacecraft Bus
• EMI
• Coil Placement
• Mass

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Torquer coils
Bearth

• T M x Bearth
• with M nt.I.S

90 in 120 seconds T 3 uN.m M 0.1
A.m2 gt 300 turns 0.1 A or 100 turns 0.3 A
M
Torque
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Torquer coils
Bearth

• T M x Bearth
• with M nt.I.S

90 in 120 seconds T 3 uN.m M 0.1
A.m2 gt 300 turns 0.1 A or 100 turns 0.3 A
M
Torque
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Possible Layouts
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Possible Layouts
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Possible Layouts
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Possible Layouts
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Thruster Module Interface
Telemetry
Sensors
KatySat CPU
Thruster 1
High level commands (modes, maneuvers)
Thruster 1
Thruster 1
Firing command
Control Logic CPU
Thruster 1
Thruster 1
Firing Module/ Actuator
Thruster 1
Thruster 1
Thruster 8
Batteries
?
KatySat Power System
Tq. Coil 1
Tq. Coil 1
Tq. Coil 3
Thruster Module Solar Cells
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Winter Quarter Schedule
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Next Steps
Finalize Thruster Selection (2wks)
Lab Work PPT and Torquer Coil Development
Determine Power Source
Control Logic Development Integration With KatySat
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Got Thrusters?
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Sources Cited

• Data from Micropropulsion Options for the
  TechSat21 Space-Based Radar Flight, J.H.
  Schilling et al, Air Force Research Laboratory.
  Published in Micropropulsion for Small
  Spacecraft, eds. Micci Ketsdever
• Pictures from
• http//www.scs.carleton.ca/barbeau/Picosat/CanX_P
  aper.pdf
• http//www.utias-sfl.net/nanosatellites/CanX1/CanX
  1System.html
• http//www.ndt-ed.org/EducationResources/Community
  College/MagParticle/Physics/CoilField.htm
• http//courses.ece.uiuc.edu/cubesat/Files/ACS_Brya
  n_Gregory_Thesis.pdf
• http//www.ncube.no/project_documents/masterthesis
  /svartveit03.pdf
• http//cubesat.calpoly.edu/_new/workshop/CalPoly20
  04/second/kansas.ppt585,15,Pathfinder Overview
• http//www.conformity.com/0205iz.pdf
• http//news.thomasnet.com/fullstory/9727/3284