by Staff Writers
Pasadena CA (JPL) Dec 15, 2014
Persistent computer resets and "amnesia" events on NASA's Mars Exploration rover Opportunity that have occurred after reformatting the robot's flash memory have prompted a shift to a working mode that avoids use of the flash data-storage system.
The most recent reformatting of Opportunity's flash memory was last week. Following that, performance of the flash memory remained intermittent, and difficulty in placing data into the memory led to computer resets during the weekend.
Flash memory retains information even when power is shut off during the rover's overnight power-conserving "sleep" time. In the no-flash mode, the rover can continue normal operations of science observations and driving, though it cannot store data during the overnight sleep.
Data gathered each Martian day is stored in volatile memory, which on Opportunity is random-access memory, or RAM. That data stored in volatile memory is relayed Earthward before sleep because it is lost when power goes off.
The team is developing a set of commands to restore usability of the flash memory through an overhaul more extensive than the reformatting that has been used so far.
The incidents of Opportunity's flash memory not accepting data for storage have occurred in only one of the seven banks of flash microchip circuitry on board. The team plans to send commands for the rover to avoid that entire bank.
"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," said Mars Exploration Rover Project Manager John Callas or NASA's Jet Propulsion Laboratory, Pasadena, California.
"While we're operating Opportunity in that mode, we are also working on an approach to make the flash memory usable again. We will be sure to give this approach exhaustive reviews before implementing those changes on the rover."
Opportunity is examining outcrops on the western rim of Endeavour Crater while traversing southward toward "Marathon Valley," where clay minerals have been detected in observations by NASA's Mars Reconnaissance Orbiter.
Mars Rovers at JPL
Mars News and Information at MarsDaily.com
Lunar Dreams and more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|