Quick -- what's got six wheels, lives on Mars and has been stuck in a sand trap named Troy since May 1 of this year? If you answered, "NASA's Spirit Rover," pat yourself on the back. Spirit, along with its twin rover Opportunity, was only supposed to provide three months of Martian exploration. Incredibly, both Spirit and Opportunity are still kicking, having lasted over 20 times longer than initial NASA projections. In fact, Spirit just passed a major milestone as a result of it having landed on the Red Planet before its twin: 2,000 days on the job. Longer than that, actually, as Martian days (called "sols") take longer than our earth days. To wit, Spirit had been on Mars for 2,000 earth days a few weeks ago, but yesterday marked 2,000 sols.

Sadly, reports indicate that Spirit has been stuck in sand for the last several months. One of its wheels has died and there appears to be a rock jutting up into the robot rover's belly pan. Worse, Spirit's downhill facing wheels have spun so much that they've buried themselves in the loose sand. Luckily, Martian winds have been potent enough to blow most of the dust off Spirit's solar arrays and the robot has plenty of power.

Back here on Earth, NASA's Jet Propulsion Laboratory scientists have been working with a replica of Spirit in a sand box, trying to duplicate its sticky predicament and devise a solution. They did this four years ago when Opportunity became mired in a sand dune named Purgatory, then – as now – using techniques you might use to free your car from a snow drift. If all goes well, the scientists will be able to send freeing instructions to Spirit during the second week of September.

You can follow all of Spirits ups and downs as well as the earthbound rescue planning on NASA's cleverly named Free Spirit website.

[Source: MSNBC Cosmic Log]