NASA is increasing its efforts to re-establish contact with the stranded Mars rover, fearing falling levels of solar energy will soon make getting the robotic machine out of its hibernation mode increasingly difficult. The Spirit rover accidentally broke through the Martian earth surface and got two of its wheels stuck, and despite the best efforts of scientists could not extricate itself.
"The amount of solar energy available for Spirit is still increasing every day for the next few months. As long as that's the case, we will do all we can to increase the chances of hearing from the rover again" Mars Exploration Rover Project Manager John Callas
NASA's fear is that the cold Martian winter may overwhelm what little power reserves Spirit has left, permanently damaging the rover and scuppering future chances of rescuing it.