NASA’s rover Spirit has been on Mars for 6 years, since January 2004. It’s traveled just under 5 miles and has sent back many, many images of the surface of Mars. The original mission was only 3 months long, but Spirit has outlasted that by far.

Ten months ago, Spirit was traveling south beside the western edge of a low plateau called Home Plate, in an area designated as Troy. Some of its wheels broke through a crusty surface and landed in the soft sand below. Only 4 of the 6 wheels of Spirit are working, and they’ve been churning and churning to get free from the sand. Spirit hasn’t been able to free itself. Scientists are trying to reposition Spirit a little bit so the solar panels will be better aimed at the sun as the winter season on Mars approaches.

If Spirit remains immobile, it will be used as a stationary science platform. The continuing mission can only be done by a stationary vehicle. Spirit has already begun one of those missions. It’s studying the tiny wobbles in the rotation of Mars to learn more about the planet’s core. It will take months of radio-tracking to calculate long-term motion. Scientists want to know if the core of Mars is liquid or solid. Spirit will use its robotic arm to study any variations in the soil that has been affected by water. Spirit will watch how the wind moves soil particles and monitor the Martian atmosphere.