Slight Hiccup For Opportunity Before Getting To 'Erebus Crater'
Pasadena CA (SPX) Oct 05, 2005 Opportunity suffered a warm reboot last week. After the flight computer rebooted, the spacecraft went into "safe mode." This error caused the team to miss two Odyssey passes. The evening pass was missed because the reboot occurred during the Odyssey pass. The morning pass was missed because safe mode enforces the deep sleep behavior. Real-time commands were sent on sol 597 in order to access the state of the vehicle. Opportunity was healthy and the team regained control of the vehicle. A "lite" master sequence was loaded and sol 597 became a stand down day. On sol 598, the initial system recovery steps were taken and subsystems were tested. All subsystems look good. This is the first time this fault has been seen on Opportunity. It was seen twice before on Spirit, in May and August of 2004. The decision at that time was to not fix the software bug that causes this problem, and accept the rare interruptions in operations. The bug is a window of vulnerability in the process of lifting memory write protects and replacing them. The bug allows a 51 microsecond window where another write request can interrupt the first request. When the writes collide, the software protects itself and the vehicle by terminating activities. This week Opportunity will continue with nominal operations. The rover will continue to move west around Erebus Crater.
Sol-by-sol summaries Sol 592: Drove 1.75 meter (69 inches) and approached target "Deception" on the feature "South Shetland." Sol 593: Unstowed the robotic arm, used rock abrasion tool brush, took a stereo microscopic image and then placed the alpha particle X-ray spectrometer. Sol 594: Continued the robotic arm campaign. Placed the alpha particle X-ray spectrometer, then changed tool to the Moessbauer spectrometer. Sol 595: Continued the robotic arm campaign. Placed alpha particle X-ray spectrometer on new target then change tool to the Moessbauer spectrometer on the next sol. Sol 596: Anomaly - warm reboot day. Sol 597: Stand-down day. Sol 598: Recovery day, subsystem testing. Community Email This Article Comment On This Article Related Links Mars Rovers at JPL Mars Rovers at Cornell SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Mars News and Information at MarsDaily.com Lunar Dreams and more
Spirit Heading To 'Home Plate' Pasadena CA (JPL) Jan 09, 2006 Last week Spirit completed robotic-arm work on "El Dorado." The rover used all three of its spectrometers plus the microscopic imager for readings over the New Year's weekend. |
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