AA236 Thrusters Update

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

• Team Mission Statement
• Thruster Technologies
• Thruster Dynamics
• Nozzles Exhaust Residue
• Power System
• ADC Control Logic
• Next Steps

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Mission Statement

• We will develop and demonstrate thruster
  capability for CubeSats

• Purpose Statement
• Attitude Determination Control
• 3 Axis Control
• Reliability
• Proof of Concept
• Test Manuevers
• 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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Requirements
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Schedule
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Previous Missions

• 1 CubeSat (expected launch 2006) UIUC ION
• Multiple nanosats (UW, MTU, U Toronto, etc)

UK-DMC Micro-Resistojet, 2003
MTU HuskySat micro-Vacuum Arc Thruster
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Thruster Requirements
1 kg, 10x10x10 cm
Minimum slew rate low impulse bit
and of course.
Is it flight ready? Can we afford it?
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Thruster Options
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Thruster Locations on CubeSat
Deorbit
KatySat
Thruster cluster
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
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Thruster Locations on CubeSat
Alternate solution with 6 thrusters
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Attitude Control Rotation
Mass of propellant to be burned (mg)
Length of each burn (s)
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AC Rotation
BUT Discontinuous thrust Ex Micro-PPT

• T 40.10-6N
• Pulses of 0.05 sec,
• every 0.5 sec!

gt 20 min for a half turn
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AC Translational motion?
?V 5 mm/s
?Vltlt Mean velocity 7500 m/s !
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Deorbit / Orbit Changes
Deorbit
KatySat
Thruster cluster
Need good ADC!
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Deorbit Orbit Changes
Mass of propellant needed to deorbit (g)
Mass of propellant needed to change orbit (g)
Spiral transfer gt more!
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Exhaust Issues!!!

• Factors of Contamination
• whats the RESIDUE? (Xe, Cs)
• how FAST? For how LONG?
• how HOT?

TASC Cells composed of Gallium Arsenide covered
by Protective Glass
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and in no case was substantial backflow
contamination found. -PPT studies
POSSIBLE SOLUTIONS
Deployable Thruster Cluster
Deployable Solar Arrays
Fuel Selection
Thruster orientation
Surface Treatment
Protective covers
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Electrical Power System

• Power Source?
• Energy Storage?
• Power Distribution?
• Power Regulation Control
• Power Source
• Solar Panels Si, GaAs, InP
• Deployable Solar Arrays / Solar Sheets

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Electrical Power System

• Energy Storage
• Batteries NiCd, NiH, Li-Ion, NaS
• Power Distribution
• Keep power loss and mass to a minimum
• Centralized vs. Decentralized
• Power Regulation and Control
• Prevents battery overcharging and excess heat
• Main Power Control Techniques
• Peak-Power Tracker
• Direct-Energy-Transfer

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ADC Thruster Control

• - KatySat (3 Axis Control)

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S
Crosstudio for MSP430
We plan to integrate our code into the CDH
system code aboard KatySat.
A slow maximum rotation rate will allow us to
control the On/Off command logic.

• The thruster logic will be overridden by the ADC
  logic to a default of Off if any major problems
  occur.

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Winter Quarter Schedule
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Next Steps
Possibility of Waterjet
Gather Pulsed Plasma Thruster Specs
Determine Power Requirements
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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.sstl.co.uk/index.php?loc27id733
• http//www.me.mtu.edu/researchAreas/isp/AIAA20Spa
  ce20200420Paper.pdf
• http//www.grc.nasa.gov/WWW/RT1999/5000/5480degroh
  2.html
• http//www.gps.caltech.edu/genesis/Thrusters.html
• http//www.stormingmedia.us/61/6118/A611804.html
• http//www.stanleysupplyservices.com/images/p/cecb
  40.GL.jpg
• http//www.tsgc.utexas.edu/archive/design/foci/mpd
  .jpg
• http//www.tripandtrek.com/webboard4/photo/2005031
  819080236103610.jpg
• http//grin.hq.nasa.gov/IMAGES/SMALL/GPN-2002-0001
  32.jpg