NASA has spent several months trying to free the Mars Exploration Rover Spirit from a sand trap. Now, engineers are calling it quits. After six years of exploration, and significant scientific discoveries, the rover will remain a stationary science platform.

“Spirit is not dead; it has just entered another phase of its long life,” said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington, D.C., in a press release.

Assuming it survives the upcoming Martian winter, the rover will continue its scientific endeavors for several months to years. The NASA press release continues:.

One stationary experiment Spirit has begun [is studying] tiny wobbles in the rotation of Mars to gain insight about the planet’s core. This requires months of radio-tracking the motion of a point on the surface of Mars to calculate long-term motion with an accuracy of a few inches.

“If the final scientific feather in Spirit’s cap is determining whether the core of Mars is liquid or solid, that would be wonderful–it’s so different from the other knowledge we’ve gained from Spirit,” said [Steve] Squyres, [a researcher at Cornell University and principal investigator for Spirit and Opportunity.]

Tools on Spirit’s robotic arm can study variations in the composition of nearby soil, which has been affected by water. Stationary science also includes watching how wind moves soil particles and monitoring the Martian atmosphere.

The Mars rovers, Spirit and Opportunity, landed on Mars in January 2004 for what was supposed to be a six-month visit. Since then, these plucky explorers have revealed new and exciting features of the red planet. Spirit discovered deposits of salts and minerals such as sulfur and silica that only form in the presence of water. This happened when it inadvertently dug a trench behind itself while dragging a broken right front wheel. Opportunity, which is currently driving toward a large crater called Endeavor, has crossed approximately 19 kilometers and returned more than 133,000 images.

“There’s a class of science we can do only with a stationary vehicle that we had put off during the years of driving,” according to Squyres. “Degraded mobility does not mean the mission ends abruptly.”