14 DAY TRIAL // After almost six months of being stuck in a patch of loose soil on the surface of the Red Planet, the rover Spirit has begun experiencing a new bout of amnesia, its controllers at the NASA Jet Propulsion Laboratory (JPL) say. This behavior was recorded in four different instances this year, and so experts have been thrilled that, ever since it got jammed in Troy, the Martian robot has been able to keep its “head straight.” But their joy did not last long. Between October 24 and October 27, the rover sent back telemetry indicating that its flash memory was again out of commission.
The part of Spirit that seems to be malfunctioning is the non-volatile “flash” memory, which is in charge of storing data and information the rover collects during the day over the period of time in which the robot is powered down. Spirit goes to “sleep” every sol (Martian day), in order to preserve battery power. Even if gusts of wind have recently cleared its solar panels of large amounts of dust, mission controllers still don't have large amounts of electricity at their disposal. If the flash memory fails, then all data that have not been saved on other memories as well is lost.
“We still don't have information about what causes these amnesia events. If they are intermittent and infrequent, they are a nuisance that would set us back a day or two when they occur. If the condition becomes persistent or frequent, we will need to go to an alternate strategy that avoids depending on flash memory. We would only get data collected the same day and any unsent data from an earlier day would be lost. The total volume of data returned by the rover is expected to be about the same,” Mars Exploration Rover project manager John Callas says of the options his team has available right now.
There is also another downside to the fact that Spirit's bouts of amnesia have returned now. JPL experts are currently getting ready to perform a number of maneuvers, aimed at removing the stuck rover from the loose soil it’s been trapped in since October 6. In order for them to have the least chance of being successful, they need to be unhindered by the fact that the rover “forgets” what it's doing from one day to the next. It took many months of testing in JPL sandbox for the engineers to come up with a set of guide lines that could see the exploration robot set free.
Spirit's predicament is made even more serious by several other factors too. For starters, the robot has been driving backwards for the better part of the last three years. Secondly, its front-left wheel was damaged a long time ago, and has since been lifted off the ground. Additionally, limited power levels and the machine’s venerable age of five years make it less “agile” than it was in its youth. But its main problem is a large rock that lies just beneath it. The formation does not yet touch Spirit's underbelly, and, if it does, JPL experts believe that the event would mean the end of the road for the rover.
Spirit has been roaming the surface of Mars for more than 69 months, while its original mission was scheduled for three. With its twin, Opportunity, the rover has offered its mission controllers the chance to learn a great deal about Mars, and about handling damaged robots during space exploration.