It's been many long days since NASA's Mars Opportunity rover last phoned home.
The rover has been quiet since June 10, when acut off its access to solar power. The storm is subsiding and now NASA is playing a tense waiting game to see if the vehicle will come out alive and rolling.
Opportunity is nearly 15 years old and has long outlived its initial three-month mission plan while continuing to deliver science observations back to Earth.
While the extended silence is worrisome, NASA says "there's reason to be optimistic." Studies of the rover's batteries before the storm show they were in good health and likely won't suffer much degradation during its time in the dust storm shadows. The temperatures in its location also mean the rover should have stayed warm enough to make it through the stretch of darkness.
NASA is reaching out to the rover in hopes of hearing back if and when it awakens. The Opportunity team pings the machine several times each week and listens for a response. NASA is also listening for radio signals from Mars that could be coming from the rover.
NASA warns there could be a long lag between the first signs of the rover's awakening and any further signals. "It's like a patient coming out of a coma," NASA says. "It takes time to fully recover."
There's a plan of action in place should the rover get back in touch. Opportunity's team will strive to learn more about the state of the rover, its batteries, solar cells and temperature. The rover's clock may need to be reset, and mission control will ask it to image itself to look for dust contamination.
Now here's the potentially scarier part. "Even if engineers hear back from Opportunity, there's a real possibility the rover won't be the same," NASA says. The dust storm could have a negative impact on the rover's batteries, which could put a crimp in its ability to heat itself during the frigid Mars winter.
Opportunity's science team is keeping the world informed through a series of mission status updates. Here's the latest: "The science team does not expect to hear anything from Opportunity until the atmospheric opacity over the rover site clears further." And so we wait.
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