By Matthew Patterson

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By Matthew Patterson
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LowEarthOrbitNanosatelliteIntegratedDistribut
edAlertSystem
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Why focus on Nanosats?

• The cost and time to design, develop and complete
  an entire mission for typical large satellites is
  enormous.
• Microsatellites and Nanosatellites allow quicker
  mission overturn.
• Risk for missions are reduced
• Provide a means to test new scientific
  technologies
• Because we have the ability to complete an entire
  mission from concept design to launch

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The LEONIDAS Team

• Project Director-Dr. Luke Flynn
• Principal Investigator- Lloyd French

Aukai Kent Payloads Dennis Dugay -
Communications Matt Patterson - Power Zachary
Lee-Ho - Systems Engineer
Jennie Castillo Orbits Kaipo Kent
Thermal Lynette Shiroma - Attitude Control Minh
Evans Command Data Handling Mike
Menendez - Structure and
Mechanical Devices
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What have we accomplished?

• Learned the basic concepts in mission design
  and development
• Developed a mission concept report for the
  LEONIDAS BUS
• Prepared proposal for Air Force Office of
  Scientific Research University Nanosatellite
  Competition
• Presented our mission design to Jet Propulsion
  Laboratory and Ames

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Mission Objectives

• We will send a microsatellite into a LEO,
  sun-synchronous, polar orbit
• The microsatellite will serve as a platform for
  demonstrating scientific technologies
• Data attained through the operations of the
  scientific technology payloads will be
  transmitted to the ground station
• The development, manufacturing and launching of
  the satellite will serve as an educational tool
  for aiding the development of students at the
  University of Hawaii at Manoa

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Plug and Play Bus
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Mission Requirements

• Satellite must accurately point and orient itself
  to take a picture of Hawaii
• Satellite shall be robust and reliable
• This will be accomplished through
• Minimizing the use of mechanical devices
• The use of COTS components and interfaces
• Operation of payloads or communication with
  ground station will be accomplished within the 14
  minute viewing window of each orbit.
• Cost of components must not exceed 500k
• Cost estimation does not reflect the cost for
  structure and sublimation thrusters
• All scientific demonstrations will be performed
  within the projected mission lifetime of six
  months
• The shall be sufficient amount of battery power
  to operate the satellite for a duration of 12
  hours, in the event the photovoltaics should
  fail.

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Power Regulation and Distribution
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Power Management and
Distribution

• Objective
• To provide, store, distribute, and control the
  satellites power at Beginning of Life (BOL) and
  End of Life (EOL).
• Key Requirements
• To provide a continuous source of power to loads
  and subsystems through out the mission life (6
  months 1 year).
• Support and distribute different voltages (3, 5,
  -12, 28V) to variety of loads.
• Provide enough power to support peak electrical
  load and provide enough power at total loss of
  solar cells for 12 hrs.
• Protect against failures in the System.
• Fit volume and weight budget 20x27x11cm3, 4.1
  kg

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Space
Shunts
PV
Batteries
TTC
Thermal
Sun
Earth
PV
PRU
PDU
ACS
Payloads
CDH
Batteries
PV
Shunts
Space
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PV Ultra Triple Junction Cells
GaInP/GaAs/Ge
(Gallium Indium diphosphate/Gallium
Arsenide/Germanium)

• Bare Cells
• Weight 76.608 mg
• Dimensions .5 x .22 (m)
• Thickness 0.140 mm
• Operating Temperature range (0C 75 C)
• For every degree off, degrades by .5
• UTJ (Ultra Triple Junction) Solar Cell
• BOL average efficiency 28.3
• EOL average efficiency 24.3
• Degrades .8 per year
• BOL
• Power _at_28.3x1,367 W/m2(average solar
  illumination intensity) 386.86 W/m2
• Power of Sat 386 W/m2 x .114 m2 44 W per
  panel
• Peak Power output of solar panels (ideal 3
  panels) 106.225 W
• EOL (5 year lifetime)
• Power _at_24.3 332.181 W/m2

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Rechargeable Lithium-ion
Battery

• Characteristics
• Height .065 m
• Width .060 m
• Thickness .0196 m
• Weight .153 kg
• Energy 26 Wh
• Life 500 cycles
• Charge Temp range (-20C 75 C)
• Charge rate 2 to 3 hrs _at_ 6.8 A
• of batteries ?
• In order to meet last for 12 hrs at total failure
  of Solar Cells
• of batteries needed to operate 16

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Power Regulation Unit HESC
104 High Efficiency and Smart
Charging Vehicle Power Supply

• Characteristics
• Length .09525 m
• Width .09017 m
• Height .01524 m
• Weight .186 kg
• Temp range (-40C 85 C)
• Charge Current 0 to 4 A
• Charge Voltage 9.5 to 19.5 V
• Input Voltage 6 to 40 V
• Provides for 3, 5, -12 V

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Analysis of Requirements

• Given
• WBol, avg 106.225 W
• WEol, avg 91.499 W
• Need
• Wpeak, bus 76 W x 30 99 W
• Wellipse, bus 40 W x 30 52 W
• Weight lt 4.1 kg
• .186 kg (PRU)
• 76.608 mg (Bare Cells)
• .153 kg x 10 (batteries)
• 1.716 kg
• casing for solar cells, extra batteries,
  more PRUs if needed, wires, resistors)
• lt 4.1 kg

• Volume lt 20x27x11 cm
• PRU 9.5 x 9.0 x 1.5 cm
• Battery 6.5 x 6.0 x 1.96 cm
• Plenty of room because the batteries may be in
  their own side compartment.
• Temperature, to satisfy all (0C 75 C)
• Life
• Ideally we can last for 2 yrs. If everything
  doesnt degrade faster than expected and still
  needing the same power.

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Whats left?

• Everything!!!!
• Cost
• Integrating
• My parts
• Sats parts
• Case for solar panels meeting mass budget
• Team analysis on subsystems needs
• More calculations!!!

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Gantt Chart
Team Chart
My Chart
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Thank You!!

• Till the next time!!!
• Happy Thanksgiving Everyone!!!