NASA originally expected they’d only last a few months, but the plucky Martian rovers are still crawling across the surface of Mars – more than 3 years later. So the agency has gone ahead and extended their missions… again. This is the fifth time NASA has extended their mission, keeping them operational potentially through 2009.
The twin rovers landed on the surface of Mars in January, 2004. Mission planners expected that it would only take a few months before dust coated the rovers’ solar panels so thickly that they wouldn’t be able to generate power any more. But the Martian weather had a trick; dust devils and wind gusts came by often enough to keep the solar panels relatively clear of dust. Without the loss of power looming, the rovers have been able to keep going, and going, and going.
Their accomplishments to date have been staggering. So far, Spirit has driven a total of 7.26 kilometers (4.51 miles) and has returned more than 102,000 images. Opportunity has driven 11.57 kilometers (7.19 miles) and has returned more than 94,000 images.
Opportunity turned up evidence of the planet’s watery past, when oceans affected rocks for long periods of time, and deposited layers of material. Spirit also found that water altered the mineral composition of the rocks and soil in its surroundings. The rovers have been instrumental in helping scientists understand the Martian dust devils. And both have discovered metallic meteorites sitting the surface of the Red Planet. One of these has a similar composition to the meteorite that reached Earth from Mars.
Original Source: NASA/JPL News Release