Rover Hasn't Sent Data; Scientists Investigating

After all the hoopla with the Spirit Mars rover's landing and first exploration of the red planet, recent news about some communication problems may put a damper on NASA's starry mood.

The Spirit rover has stopped transmitting data from Mars, NASA mission controllers said Thursday, but there were signs it is still operating at a basic level. Flight-team engineers for NASA's Mars Exploration Rover Mission were encouraged Thursday morning when Spirit sent a simple radio signal acknowledging that the rover had received a transmission from Earth. However, the team is still trying to diagnose the cause of earlier communications difficulties that have prevented any data being returned from Spirit since early Wednesday.

"We have a very serious situation," said Pete Theisinger of NASA's Jet Propulsion Laboratory, project manager for Spirit and its twin, Opportunity.

Spirit did send a radio signal via NASA's Mars Global Surveyor orbiter Wednesday evening, but the transmission did not carry any data. Spirit did not make radio contact with NASA's Mars Odyssey during a scheduled session two hours later or during another one Thursday morning. It also did not respond to the first two attempts Thursday to elicit an acknowledgment signal with direct communications between Earth and the rover, and it did not send a signal at a time pre-set for doing so when its computer recognizes certain communication problems.

Charles Elachi, Director of the NASA's Jet Propulsion Laboratory, said Thursday night that engineers are planning to send Spirit a series of commands very early Friday morning. Since the craft has responded to initial electronic prodding, the JPL team hopes to receive a diagnostic report from the rover, which Elachi believes may have inadvertently switched into "a safe mode".

Meanwhile, mission leaders decided to skip an optional trajectory correction maneuver today for Opportunity, the other Mars Exploration Rover. Opportunity is on course to land halfway around Mars from Spirit, in a region called Meridiani Planum, on Jan. 25.

FMI:  www.nasa.gov