NASA has abandoned efforts to pull Spirit, one of the two Mars rovers, out of a sand trap where it's been stuck since last April, according to the New Scientist.
Spirit landed on the red planet in January 2004. Opportunity, the second rover, followed about three weeks later. Both rovers were originally designed to complete missions a little over 90 Martian days (92.5 Earth days) in length, but they've managed to stay mobile considerably longer than expected. Opportunity is still moving around. Spirit's roving days are now over, though.
That said, Spirit may yet be able to add a few more lines to its extensive resume, as New Scientist explains:
NASA has designated Spirit a 'stationary research platform', and if it survives the six-month winter, which will peak in May, its first priority will be to transmit radio signals that can be used to pinpoint its location in space.
Over time, these signals could help researchers discern subtle wobbles in Mars's rotation, which could help reveal whether the planet has a solid or liquid core.
The rover could also track how Martian winds transport dust across the planet and could perform more detailed measurements of its sand trap, which may once have been part of a hot, watery landscape filled with steam vents.
Surviving the winter isn't a given, though. The rover survived past winters by driving onto slopes aimed toward the Sun, so its solar panels could capture as much energy as possible, but it's now stuck pointing in the opposite direction. To make matters worse, after withstanding "grueling temperature cycles" for six years, Spirit may not be able to handle the cold from another winter. New Scientist says NASA might have to wait until "August or September" to know if Spirit has made it.
You can view a gallery of images from both Spirit and Opportunity on NASA's Jet Propulsion Laboratory website.