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Mars rovers hit 5-year mark

NASA / JPL-Caltech / Cornell / NMMNHS
This portion of a 360-degree mosaic known as the "Bonestell Panorama" shows
McCool Hill, named after one of the astronauts lost in the Columbia tragedy, and
some of the Spirit rover's tracks on the Martian surface.

NASA's Mars rovers were designed to last for at least 90 days on the Red Planet, and from the start, mission scientists hoped that they'd keep working well after their "warranty" expired. But few dared to predict that both Spirit and Opportunity would still be on the move five Earth years after they bounced to the surface.

To celebrate Spirit's five-year anniversary, mission managers have released a sweeping new panorama of the rover's winter refuge in Gusev Crater.

Spirit touched down, cushioned by airbags, on Jan. 3, 2004 (or Jan. 4, depending on your time zone). Since then it has traveled almost 4.7 miles (7.5 kilometers). It spent the last few months waiting out the Martian winter near an intriguing light-colored formation nicknamed Home Plate.

"This last winter was a squeaker for Spirit," John Callas, the rover mission's project manager at NASA's Jet Propulsion Laboratory, said in a news release issued Monday. "We just made it through." 

Once the weather brightens up enough to boost Spirit's solar cells, the rover will resume investigating the Home Plate area. Meanwhile, on the other side of the planet, the twin Opportunity rover is making its way to 13.7-mile-wide (22-kilometer-wide) Endeavour Crater, a feature that's bigger than anything the rover has studied to date.

NASA intends to keep the rover mission funded as long as the rovers keep working, at least until the end of this year, at a minimum cost of $20 million. Over the past five years, the rovers already have turned up scads of evidence documenting the Red Planet's warmer, wetter past.

NASA / JPL-Caltech
NASA's Opportunity rover looks back at its tracks on Oct. 22, during its trek toward
Endeavour Crater. This mosaic image was released on Dec. 29.

Ed Weiler, associate administrator for NASA's science mission directorate, said the mission (originally budgeted at $820 million) has proven to be one of the space agency's best deals ever.

"The American taxpayer was told three months for each rover was the prime mission plan," Weiler said. "The twins have worked almost 20 times that long. That's an extraordinary return of investment in these challenging budgetary times."

Even though the five-year mission has lasted longer than anyone ever expected, the rovers' marathon still has a way to go to match the record for surface operations on Mars. The Viking 1 lander sent data back from its touchdown site for more than six years. So Spirit and Opportunity - and the scientific teams behind them - still have something to shoot for.

To get the full story about the twin rovers, including a recent recap of what we know about Mars, check out our "Return to the Red Planet" section.