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

• Updates on actuators
• PPTs
• Torquer coils
• The complete ACsystem
• Global schematics.
• Control logic
• Power subsystem
• Structural Layout
• Future directions. 1U vs 2 U.
• Next Steps

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Pulsed Plasma Thruster
Vacuum Chamber Test (1E-5 Torr)
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PPT / Torquer Coil
Hovercraft Test on Air Table
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PPT Status

• Much development and optimization to do
• Most likely will not be ready for KatySat
• Next Steps
• Test Vacuum Breakdown Voltage as a function of
  Coax Diameter
• Create Power Supply for Air Force Coax
• Measure PPT Thrust

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Torquer coils

• 3 optimization constraints
• max magnetic moment m a (V S)
• min power P a (V2 S) / n
• min size Size a (nS)
• New torquer coil
• OK with 3 constraints
• see rotation
• Testing in Helmholtz chamber

- V voltage - S section of wire - n number turns
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Thruster5
Thruster 1
Thruster 3
TLM Sensors
Thruster 3
Mux
Thruster 2
Thruster Module Solar Cells
Mux
Thruster 1
KatySat CPU
Digital outputs
Analog inputs
TLM
CPU
EPS board
Power input
I2C
ground

• Orientation, rotation rate
• Pointing command
• High level command (off)

I2C
DAC
Analog
Tq. Coil 1
Batteries
KatySat Power System
Tq. Coil 2
Tq. Coil 3
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Control logic

• Digital control (MSP430)
• Thrusters
• Torquer coils

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Thruster Power Supply

• 7.2V 600mAh  Li-Ion battery  module is made of 2
  pcs high quality cylindrical 14430 rechargeable
  cells with PCB and poly-switch for full
  protection 
• Capacity  600mah
• Voltage  7.2V (Peak at 8.4V)
• Dimension  1.7" L x 1.1" W x 0.55" H.    ( size
  is same as  2x 4/5 AA NiMH pack )
• Weight 1.3 oz
• Max. charge current  1C (600 mA)
• Max. discharge current  2.5C (1.5 A)

• Internal smart charger module designed for all
  types of 7.2V (2 cells)  Li-Ion Battery packs
• Worldwide input AC power from 90V - 260V. Mod for
  DC 9V
• 1000 mA constant charging current for faster
  charging.
• Charging time for 2000mAh battery pack is about 4
  hr.  For 1000mAh charging time is 2.5Hrs
• Built in IC to cut off fully charge
• Dimension  .7" L x 1.5" W x 1" H

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Status Report
Only the VACCO MiPS can be ready in time.

• Currently under consideration at VACCO.
• If accepted, MiPS will be flight-ready in
  September

• Other projects continue to be pursued as part of
  the new

STunkWorks
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However
Torquer coils CAN and WILL be ready. Why use
them?

• Can provide a standard, easy-to-implement active
  3-axis control for future SSDL CubeSats
• Despite several attempts, only one successful
  CubeSat launch of coils to date, and no feedback.

Cute 1.7 Torquer coils
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2U or not 2U

• Increased power generation
• Increased volume for KatySat
• No launch date

• Strong interest in nanosatellite propulsion
  already exists
• AFRL ANGELS program
• Next stage in CubeSat missions require 3-axis
  control formation flying, deorbit, rendezvous,
  etc.
• Keep SSDL in the news

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Got Thrusters?