Low cost, minimal complexity and rapidly prototyped "common bus" design


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Lunar Atmosphere and Dust Environment Explorer (LADEE) is a NASA mission that will orbit the Moon and its main objective is to characterize the atmosphere and lunar dust environment.

  • Lunar Atmosphere and Dust Environment Explorer (LADEE) is a NASA mission that will orbit the Moon and its main objective is to characterize the atmosphere and lunar dust environment.

    • Low cost, minimal complexity and rapidly prototyped “common bus” design.
    • Model-Based Software Development










Phasing Loops

  • Phasing Loops

    • 3 Perigee Manuevers
    • Time, Opportunity for Adjustments
    • Similar to past missions
    • (Clemintine, Wind WMAP)
  • Lunar Orbit Insertion



3U Compact PCI – Broad Reach

  • 3U Compact PCI – Broad Reach

  • Active Memory

  • BAE Rad750 128Mb

    • Nibble Correct (64 Bit)
  • Broad Reach DMOAB SDRAM Storage

    • 1GB SECDED (32 Bit)
    • 4 FAT16 Partitions* (*Primary)
  • Other C&DH Memory

    • SRAM – Devices
    • EEPROM & Flash – Program Storage


Requirement Summary:

  • Requirement Summary:

    • Provide ability to enable/disable scrubbing
    • Provide corrected/uncorrected memory error counters and last error address
    • Enable/Disable EDAC interrupts
    • Provide corrected, uncorrected, and critical error events
    • Overwrite uncorrected memory error locations to prevent continuous reporting


Flight Software built on CFE

  • Flight Software built on CFE

    • Separate Tasks
    • Message Based
  • Memory Scrub Task

    • VxWorks Driver
      • Handles Interrupts
      • Silences Correctable and “Uncorrectable”
    • MS Task
      • Configures Drivers
      • Records and Logs Events


Orbital Position Plot

  • Orbital Position Plot



Periapsis #1 Detail

  • Periapsis #1 Detail



Periapsis #2 Detail

  • Periapsis #2 Detail



Periapsis #3 Detail

  • Periapsis #3 Detail



Normal Activity

  • Normal Activity

    • Average about 1 to 2 a Day
    • Some Groups of Events
    • Patterns or Locations
  • “Uncorrectable” Errors



Events can happen fast in Groups

  • Events can happen fast in Groups

    • (May loose events due to rapid frequency)
  • Van Allen Belt effects higher than expected

  • Events happen anywhere

  • Unusual Events



Mapping Locations by usage

  • Mapping Locations by usage

  • Improved logging of Events

  • Better ways of injecting events during testing





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