Spirit’s Solar Panels Stuck Towards Southern Sky

Image credit: NASA/JPL-Caltech

NASA’s Mars Exploration Rover Spirit is now parked for the winter, but at an angle that has the solar panels pointed away from the winter Sun.

The rover team had hoped to shift Spirit’s position within the sand trap so that the solar panels would be pointed northward, since during the winter the Sun remains in that part of the sky. The solar panels need to collect photons from the Sun in order to provide the rover with enough energy to sustain operations. If the rover can not get enough sunlight, it will go into hibernation mode. The risk is that hibernation could cause the rover mechanisms to become damaged by the extreme Martian cold.


On Sol 2169 (Feb. 8, 2010), the rover’s last drive before winter, the team changed the angles of the rover’s suspension system but this did not produce a hoped-for improvement to the overall tilt of the solar array. Spirit will spend the coming winter tilted 9 degrees toward the south.

Spirit’s parking positions for its previous three Martian winters tilted northward. Engineers anticipate that, due to the unfavorable tilt for this fourth winter, Spirit will be out of communication with Earth for several months. The team does not plan further motion of the wheels until spring comes to Spirit’s location beside the western edge of a low plateau called Home Plate.

Spirit’s self portrait.
Credit: NASA/JPL



Spirit is more than six years into a mission originally planned for three months on Mars. The rover has returned invaluable information about the Martian environment, both past and present. Its twin, Opportunity, is exploring an area halfway around the planet and closer to the equator. Opportunity’s equatorial position provides it with enough sunlight to continue operations during the winter.