ASUJPL Flight System

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ASU/JPL Flight System

• Group Members
• Robert Hoffman, Dusty Terrill, Adam Nikolic, Josh
  Ruggiero

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Flight System

• Sun-Synchronous Earth Orbiting Spacecraft
• Visible and Infrared Imaging of Regions of
  Interest
• Software Simulation
• Flight Dynamics
• Instrument Operations
• Command and Telemetry Processing
• Engineering Health
• Status Monitoring

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Management
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IEEE 1471-2000 System Architecture Design
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Communication

• Simulated TCP/IP Connection Between the Ground
  System and the Flight System
• Utilizing the Consultative Committee for Space
  Data Systems format for the data packets.
• CCSDS Header Format
• VersionPacket IDSecond Header
  FlagTypeSequence Flags Packet Sequence
  ControlPacket Data Length Secondary Header
• Version3 Always 000, its the first
  version Packet ID1 0 if flight is sending, 1
  if ground is sending S.H. Flag1 Always 1,
  there is always a second header Type11 Depende
  nt on our command type Sequence Flags2 00
  a continuation, 01 first segment, 10 last
  segment, 11 - un-segmented
• Packet S.C.14 Running counter for each
  command type Packet D.L.16 Number of bytes in
  the array 1 Sec Header32 Contains the
  timestamp
• The header will therefore always contain 80 bits
  worth of data and the following bits will be the
  data that needs to be sent.

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Prototype Class Diagram
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Subsystems

• Power
• Command and Data Handling
• Telecommunication
• Mechanical
• Thermal
• Propulsion
• Guidance Navigation and Control
• Payload

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Power Subsystem Peripherals

• Solar Array
• Battery
• Power Control
• Power Switching
• Power Conversion
• Cabling

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Command and Data Handling Subsystem Peripherals

• Memory
• Command

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Telecommunication Subsystem Peripherals

• Directional Antenna
• Wide Beam Antenna
• Transmitter
• Receiver

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Thermal Subsystem Peripherals

• Thermal Sensors

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Propulsion Subsystem Peripherals

• Thrusters
• Reaction Wheels
• Fuel Tank

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Guidance Navigation and Control Subsystem
Peripherals

• Star Tracker
• Sun Sensor
• Propulsion Control Subsystem
• Actuator Control

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Payload Subsystem Peripherals

• Camera

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Commanding Information

• CCSDS Timestamp Included
• Use to sort commands by time
• Use to acknowledge command received / executed
• Every command flight receives must be
  acknowledged
• Sequence of commands to run
• Must know the sequence
• Must be able to save sequence to run at a later
  time
• Format of Commands

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Command Formatting

• Commands received by flight
• 7 bit command 64 bit start time extra
  command data
• Commands sent by flight
• 7 bit command 32 bit received time extra
  command data
• Ensures compatibility among all commands
• Each commands part of subgroup
• Easy to manage commands by type
• Easy to add commands later if needed

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Flight Received Commands

• Propulsion
• 0) Fuel Tank Command Start Time(ms) 0
  0- send fuel remaining 0000000 64 bit long
  0 Fuel Tank Command Start Time(ms) 1 -
  1- stir tank 0000000 64 bit long 1
• 1) Fire Thruster CommandStart
  Time(ms)Thruster Runtime(ms) 0000001
  64bit long XXXX 32bit int
• Camera
• 10) Camera Command Start Time(ms) Sub
  Command DATA
• Sub Commands Power 00 Calibrate 01
• Picture 10
• Camera Command Start Time(ms) Power Command
  On/Off/Rst
• 000101064 bit long00XX 00 Turn Off 01
  Turn On 10 Reset
• Camera Command Start Time(ms) Calibrate
  command
• 000101064 bit long01 - Calibrate
• Camera Command Start Time(ms) Picture
  Command IR/Reg Filter aperature shutter
  speed
• 000101064 bit long10XXXX32 bit
  float32 bit int - Take Picture

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Flight Sent Commands

• Propulsion
• 00) Tank Sensor CommandTime(sec)0Fuel
  Left
• 000000032 bit int032bit Float
  Tank Sensor CommandTime(sec)1 ACK Stir
  Tanks 000000032 bit int1
•  
• 01) Thruster CommandTime(sec)Thruster 0
  Command Received 000000132 bit
  intXXXX0
• Thruster CommandStart
  Time(sec)Thruster 1 Command Executed
• 000000132 bit intXXXX1
• Camera
• 10) Camera CommandTime(sec)Power
  CommandOn/Off/Rst Power Ack
• 000101032 bit int00XX 00 Turn Off 01
  Turn On 10 Reset
• 000101032 bit int01 Calibrate Ack
• Camera CommandTime(sec)Picture
  CommandPicture Size(bits)Picture
• 000101032 bit int1032 bit
  intPicture Data (.jpg)

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Internal Commands

• Sample flow chart
• Must simulate all aspects of internal
  communication
• Each command is internally represented and
  handled specifically
• All internal communications must go across the
  system bus

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Internal Command Examples

• Fuel Tank0 Send Fuel Remaining
• Internal command 1
• System bus events Propulsion.getFuel()
• Create new packet (Fuel)
• Telecom.send(packet)
• Fuel Tank1 Stir Fuel Tank
• Internal command 2
• System bus events Propulsion.sitrTank()
• Create new packet()
• Telecom.send(packet)

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Command Run-Through Example

• Flight receives command from ground
• 0) Fuel Tank Command Start Time(ms) 0
  0-send fuel remaining 0000000 64 bit long
  0
• Command parse / execute
• Send information to system bus
• Fuel Tank0 Send Fuel Remaining
• Internal command 1
• System bus events Propulsion.getFuel()
• Create new packet (Fuel)
• Telecom.send(packet)

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Command Run-Through Example Cont

• Packet created stores all information
• Tank Sensor Command Time(sec) 0
  Fuel Left
• 000000032 bit int 0 32bit Float

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What Worked

• Plenty of Brainstorming
• Working with two groups had more ideas
• First semester is all planning phase
• Regular Meetings
• Proper collaboration with Ground Team
• Working with JPL Advisor
• Good direction
• Good plan of action and organization

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What Didnt Work

• Schedule Slippage towards beginning
• Abundant amount of proper research
• Redoing reports and paperwork
• Originally, not enough information
• Losing UML class diagrams
• Very difficult command creation
• Original set not to standards
• Complete Architecture Reorganization

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Schedule
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• Questions?