NASA gets 20-minute signal from Mars rover
PASADENA, California (CNN) --After two days having trouble sending transmissions, the Mars rover Spirit sent data Friday morning to its NASA flight team in a communications session lasting 20 minutes, said the agency's Jet Propulsion Laboratory.
"The spacecraft sent limited data in a proper response to a ground command, and we're planning for commanding further communication sessions later today," said Mars Exploration Rover Project Manager Pete Theisinger.
The transmissions were detected at a NASA antenna complex near Madrid, Spain, NASA said.
The Spirit rover stopped transmitting data from Mars on Wednesday, but mission controllers remained hopeful, saying there were signs of it operating at a basic level.
Their efforts at restoring communications with Spirit come at a time when they are also focusing on a safe landing for the rover's twin, the Opportunity, set to descend Saturday on the other side of red planet.
Since Wednesday, NASA scientists had received a basic communication tone from the rover indicating it was alive, but the solid flows of data that marked its first 18 days on Mars stopped, said deputy project manager Richard Cook.
The tone is programmed into the spacecraft, to be emitted when there is a serious problem onboard.
"We know that we have had a very serious anomaly on the vehicle," said Pete Theisinger, manager of the $400 million Spirit mission, told reporters Thursday.
"Our ability to determine exactly what has happened has been limited by our inability to receive telemetry from the vehicle."
To find out what went wrong, scientists need additional data.
The team was pursuing several scenarios, such as a possible software crash or a problem with the solar power supply, sources said.
The problem initially was blamed on rain in Canberra, Australia, where NASA operates a major radio dish that receives radio messages from space.
But several opportunities to communicate with Spirit since then came and went with the space agency receiving no solid data, said Cook, who managed the ill-fated Mars Polar Lander, which presumably crashed into Mars in 1999.
Mars project engineers sent a query to the rover Wednesday afternoon, and it did respond. But the craft was silent when the Mars Odyssey, a satellite in Mars orbit, passed over the six-wheeled robot, Cook said.
Later, when another red planet satellite, the Mars Global Surveyor, passed over the rover, NASA received radio communication but no data. Several opportunities came and went Thursday with no communication. But later the basic communication tone was received.
Previously, the rover's performance had been virtually flawless. Scientists were reviewing the early data to see if they might have missed some predictor of trouble.
CNN's Jeordan Legon, Miles O'Brien, and David Santucci contributed to this report.
