Next Steps

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AA236 Thrusters
Team Members Adam Collazo, Andy Sadhwani, Bill
Storck, Cedric Bayart, Mitul
Jambusaria, Olivia Billett, Pierric Jammes
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Passive magnets

• Theoretical calculations
• Measurements (Helmholtz chamber)
• gt m 0.1L (cm) ex 0.1 Am2 gt 1cm gt 0.5g
  
• Simulations (Cubesim)
• Small mass of magnet (1-2g)
• Hysterisis rods (choose and size them well)
• Stabilization after a few orbits (no
  disturbances)
• still small oscillations (5 deg, freq)

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Passive magnets

• Theoretical calculations
• Measurements (Helmholtz chamber)
• gt m 0.1L (cm) ex 0.1 Am2 gt 1cm gt 0.5g
  
• Simulations (Cubesim)
• Small mass of magnet (1-2g)
• Hysterisis rods (choose and size them well)
• Stabilization after a few orbits (no
  disturbances)
• still small oscillations (5 deg, freq)

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Torquer Coils System Issues
Control
AD

• Need to know?, ?, ?, F, B, I
• Control logic (PD or LQR method)
• Kalman Filter

• Gyros give ?
• B gives ?,?,F
• Propagation of ?

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Attitude Determination Control

• Att. Determination
• 1) Predict future positions on orbit
• 2) Model B
• 3) Compare with Bmeasured
• gt attitude
• 4) Gyros propagate
• Att. Control
• gt 3 axis control possible, over several orbits

on the ground
solving non linear equations onboard
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Torquer coils vs. Magnets
gt What goal do we want to achieve?
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2-Thruster Design
Use centrifugal effect to separate different
phases of butane
Inlet tube
Perforated baffle plate
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New vs. Old

• Advantages
• Combined tank plenum
• Simplified control law
• Simplified sensor system
• Ability to spin up and spin down
• Disadvantages
• Initial sputter of 2-phase (low efficiency)

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Status

• Now SolidWorks modeling of system
• Next week Manufacturing of prototype
• 2 weeks Testing Characterizing

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Fuel Tank Sizing
PVnRT n (Moles) Number of grams/gram molecular
weight T(K)t (c)273
P
T
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Calculate Requirments
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Tank Sizing and Characteristics
Volume 62.7cm3 Pressure 44 psi _at_20oC
Two Phase Isobutane Storage Tank
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Tank Location in 2U Assembly
Moment of Inertia Single Axis Rotation Temperatu
re Protection
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Vacco Prototype

• Proof of Concept
• Material Selection
• Pressure Testing
• Isobutane Handling
• Characterize Design
• Motivate Interest for Next Year

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Got Thrusters?