Over the last weekend, NASA's “old” Mars rover, Spirit, missed its regular data transmission and remained silent for the next days. This prompted an immediate reaction from the agency's staff, to rescue the long-lived robot, which is now entering its sixth year of service, despite the fact that it was originally programmed only for a few months of active duty. The Jet Propulsion Laboratory (JPL), in Pasadena, California, announced that not only did the rover not send its recordings for the time frame, but it would also appear it failed to record anything altogether.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days. Our next steps will be diagnostic activities," explains Sharon Laubachm, the leader of a JPL team responsible for writing commands for Spirit and its twin Opportunity. She says that the machine was operating in the massive Gusev Crater, and, more specifically, in a portion known as Home Plate, and adds that on Sunday the rover marked its 1,800th day on Martian soil.

Also on Sunday, Spirit received its commands to move to its next designated way point but apparently failed to move at all from its previous position. This of course sparked worries at NASA, although engineers are perfectly aware of the fact that this mission should have only lasted for 90 days to begin with. On Monday, new commands asked the rover to find the Sun, which was supposed to help it determine its position on the planet, but it reported back that it was unable to find the star.

Scientists at JPL say that it's only natural for such problems to occur at this time, as both rovers suffer from old age. They survived serious computer glitches and endured five freezing Martian winters. During each of them, their batteries were nearly depleted, but were able to fully recharge again when the weather warmed. Some say that the huge amount of radiation that hits the planet is responsible for the new malfunctions. Mars is not surrounded by a protective field as strong as Earth's, which means that electronic equipment is more susceptible to damage.

"Right now, Spirit is under normal sequence control, reporting good health and responsive to commands from the ground," concludes John Callas, the chief of the rover mission at NASA.