NASA holds out hope that the Opportunity rover will phone home

It's make or break time for the longest-living rover on Mars. 
NASA's Opportunity rover has survived 15 years exploring the red planet thanks to solar power, but due to an extreme, planet-enveloping dust storm, the space agency hasn't been able to communicate with it since June 10. 
Now, however, the dust is clearing, and NASA is listening for the little rover to phone home once it powers up.
SEE ALSO: The Opportunity rover is caught in a huge dust storm on Mars, but NASA remains hopef