1 EDAC Concerns for Flight Software and Hardware Design Craig Pires LADEE C&DH Lead NASA-Ames...
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1 EDAC Concerns for Flight Software and Hardware Design Craig Pires LADEE C&DH Lead NASA-Ames Research Center Moffett Field, CA [email protected]
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Transcript of 1 EDAC Concerns for Flight Software and Hardware Design Craig Pires LADEE C&DH Lead NASA-Ames...
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EDAC Concerns for Flight Software and Hardware Design
Craig PiresLADEE C&DH Lead
NASA-Ames Research Center
Moffett Field, CA
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Mission Overview• 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
• Specific objectives are:– Determine the global density,
composition, and time variability of the lunar atmosphere;
– Confirm the Apollo astronaut sightings of dust jumps and diffuse emission
– Laser Communications Demonstration: 622 Mbs Record download rate from the Moon! Clementine
spacecraft image of moon dust corona
Gene Cernan’s drawings of the lunar sunrise
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Photo: Buddy Secor
4Photo: Bill Anderson
5Photo: Ben Cooper
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This photo was taken by a still camera which was on a sound trigger at Pad 0B at WFF. The photographer is Chris Perry of the WFF Optical Systems Group.
Photo went viral as soon as released. Examples of coverage:
http://www.cnn.com/2013/09/12/tech/innovation/frog-and-rocket/index.html?hpt=hp_c4
“Meet the Press”, on September 15, 2013
Frog Photobombed Launch!
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Trajectory
• Phasing Loops– 3 Perigee Manuevers– Time, Opportunity for Adjustments– Similar to past missions – (Clemintine, Wind WMAP)
• Lunar Orbit Insertion– First LOI for Capture– 2 additional LOI lowering orbit
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Avionics C&DH
• 3U Compact PCI – Broad ReachActive 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
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Software Requirements
• 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
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Software Structure
• 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
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Experiences - Phasing Loops
• Orbital Position Plot
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Experiences - Phasing Loops
• Periapsis #1 Detail
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Experiences - Phasing Loops
• Periapsis #2 Detail
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Experiences - Phasing Loops
• Periapsis #3 Detail
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Lunar Orbit
• Normal Activity– Average about 1 to 2 a Day– Some Groups of Events– Patterns or Locations
• “Uncorrectable” Errors– Where in Memory– Sensitive Spots
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Lessons Learned
• Events can happen fast in Groups(May loose events due to rapid frequency)
• Van Allen Belt effects higher than expected
• Events happen anywhere – Groups of events at random times– Multi-bit errors occurred far from Earth
• Unusual Events
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Lessons Learned - Improvements
• Mapping Locations by usage– FAT Tables mapped out– Reverse mapping on Addresses– Exact location of data files (LLCD has helped)
• Improved logging of Events
• Better ways of injecting events during testing
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