wintering Spirit

The Mars Exploration Rover Spirit, roving the surface of Mars for two and a half years, has recently begun an 8 month "wintering" over. Further from the sun than Earth, Mars takes about two terrestrial years to complete a revolution around the sun. As a result, seasons on Mars last about twice as long as on Earth. The Spirit rover, located in the Martian southern hemisphere, finds itself in a tough spot during the Martian winter. As the sun drops lower and lower in the sky, it becomes harder and harder for the solar panels on the rover to produce enough electricity for lengthy operations. At the height of the Martian winter, Spirit is able to perform science operations for about 1 hour each day. In preparation for the Martian winter, the MER team attempts to position Spirit on a north facing slope to maximize the amount of sunlight striking the solar panels. This time around that task proved difficult for a number of reasons. The most significant is that one of Spirit's 6 wheels has stopped functioning. Dragging a dead wheel and low on power, the rover then encountered soft terrain that proved impassable. The original wintering location had to be scrapped in favor of a spot that was easier to reach. Thankfully, Spirit made it to the new location and is parked there now. Spirit will remain in this location for the next 7 months until the sun climbs high enough in the sky to fully power the rover again. Seven months is a long time to sit in one place, but the long hiatus will provide an excellent opportunity to perform long duration studies of the Martian atmosphere and climate at Spirit's location. Already at 8 times it's expected lifetime on the Martian surface, Spirit continues to function despite inevitable deterioration. Here's hoping it survives the long, cold winter.