WASHINGTON – NASA is making a new and perhaps final attempt to restore contact with Mars Opportunity, which has not communicated with Earth for more than six months.
The Jet Propulsion Laboratory announced on January 25 that it was broadcasting a new set of commands to address what it acknowledged were "low-probability" events that could have prevented the probe from contacting Earth. These new efforts add to the "scan and beep" campaign of months of transmitting other commands and hearing a rover response.
The new commands address scenarios in which the rover's primary X-band radio failed or the main and backup X-band radios failed, as well as cases where the Opportunity internal clock has a shift that affects its time. The commands direct the rover to switch to the backup X-band radio or use its UHF transmitter to contact the Earth, in addition to resetting its clock.
These scenarios could explain why the rover failed to contact the Earth, but project officials acknowledge that these scenarios are unlikely. "A series of unlikely events would have to have occurred in order for any of these failures to occur," JPL noted in the statement about the new campaign.
Opportunity last contacted Earth June 10 as a massive dust storm, which eventually crossed the planet, darkened the skies above and deprived of solar energy. In late August, when the skies were finally cleared, NASA announced a 45-day campaign to try to restore contact with the rover. That plan was criticized by some, including former engineers involved with the Mars Exploration Rovers program, as being too short.
By the end of October, when the initial 45-day campaign was drawing to a close, JPL announced that it was extending the campaign until at least January. Project officials hoped that increased winds at the probe's location could remove any dust accumulated on the vehicle's panels, restoring energy.
However, the windy season is ending in that region, which is now entering the winter. This will bring less sunlight, in addition to lower temperatures, which could cause "irreparable damage" to the vehicle's electronics, JPL said.
"Although we have not heard of the rover and the likelihood that we will fall is decreasing every day, we plan to continue to seek all logical solutions that can bring us back in touch," said John Callas, project manager for Opportunity at JPL . in the declaration.
The JPL statement said the new rovers contact campaign will last "several weeks," but was no longer specific. "If Opportunity does not respond, the project team would once again consult the Mars Program Office at JPL and NASA headquarters to determine the way forward," the center said.
Efforts to re-establish contact continued during the five-week partial shutdown of the government that ended Jan. 25. With the closure now closed, some in the planetary scientific community hope that if the new effort is not immediately successful, NASA will resolve to end the effort. please contact the rover by mid-February. Nasa is currently funded only until February 15 and runs the risk of another shutdown if a budget agreement is not reached until then, which would delay a decision by NASA headquarters in the future of the vehicle.
JPL announced the new effort to contact Opportunity one day after the 15th anniversary of the rover's landing on Mars for what was originally planned to be a 90-day mission. The rover operated for more than 5,000 days before losing contact last June, traveling more than 45 kilometers across the surface.
Callas, in a separate statement about the anniversary, noted the "bittersweet" nature of the landmark, given the lack of communication with the rover. "We are doing everything in our power to communicate with Opportunity," he said, "but over time the likelihood of successful contact with the robot continues to decline."