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EDAC Concerns for Flight Software and Hardware Design. Craig Pires LADEE C&DH Lead NASA-Ames Research Center Moffett Field, CA Craig.Pires@nasa.gov. Scott Christa Karen Gundy- Burlet Greg Limes Larry Shackelford (GSFC). Mission Overview.
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EDAC Concerns for Flight Software and Hardware Design Craig Pires LADEE C&DH Lead NASA-Ames Research Center Moffett Field, CA Craig.Pires@nasa.gov Scott Christa Karen Gundy-Burlet Greg Limes Larry Shackelford (GSFC)
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! Gene Cernan’s drawings of the lunar sunrise Clementine spacecraft image of moon dust corona
Frog Photobombed Launch! 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
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 Trajectory
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 Avionics C&DH
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 Software Requirements
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 Software Structure
Orbital Position Plot Experiences - Phasing Loops
Periapsis #1 Detail Experiences - Phasing Loops
Periapsis #2 Detail Experiences - Phasing Loops
Periapsis #3 Detail Experiences - Phasing Loops
Normal Activity Average about 1 to 2 a Day Some Groups of Events Patterns or Locations “Uncorrectable” Errors Where in Memory Sensitive Spots Lunar Orbit
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 Lessons Learned
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 Lessons Learned - Improvements