14 DAY TRIAL // Scientists managing the Spirit rover say that the Martian winter is closing in fast, and that considerable progress in extracting the robot from its predicament has yet to be made. It has been stuck inside a patch of loose soil called Troy since late May, 2009, and all of the tests, drive attempts and simulations conducted have thus far yielded little concrete results. With only a couple of more months to go until temperatures drop considerably, Spirit's faith looks bleak, mission managers at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, say, quoted by Space.
There aren't many options on the table for Spirit at this point, JPL experts say. They have been attempting to drive the robot carefully out of Troy for several weeks now, but they have only managed to go forward a few centimeters, and to sink some more into the sand. In addition to the loose soil that hampers all extrication attempts, the robot has also lost control over two of its wheels, both on the right side. One of them has been nonoperational since 2006, and forced the rover to drive backwards ever since. The other one has failed while inside Troy, and engineers are doubtful they can extract the explorer by using just four of its wheels on a low-adherence terrain.
Some proposed using the robotic arm on Spirit to push into the ground, in an attempt to pull at least some of the wheel out of the sand. But the arm proved to be too weak for this, so the only other option that involves extrication is to attempt to drive the machine backwards, on the exact same course it came. Still, it would involve using the arm as a shovel, clearing the sand from the path that the left front wheel is to follow. This is the only working wheel within the arm's reach, so this attempt is considered as a last, desperate one. However, the issue is that JPL mission managers need to decide what to do very quickly. They only have a few days in their window of opportunity left.
The Martian winter is approaching quickly, and, with it, reduced sol (Martian day) lengths, less solar energy, and freezing temperatures. As it got stuck in Troy, Spirit was driving towards a feature known as Home Plate, where it would have been in a good position to receive sufficient amounts of energy to survive the winter. Now, perched on a 12-degree slope, its situation is precarious at least. The amount of power in its batteries is diminishing with each passing sol. The last solution experts could think of was tilting the rover in an angle that would ensure it received the maximum amount of solar radiation available during the Martian winter.