So, what have you done with your life for the last three and a half years? Have you explored alien planets 125 million miles from home? Have you expanded the boundaries of science? Have you endured extreme hardship while exceeding your initial performance goals by a factor of 12?
Don't feel ashamed if the answer to any any of these questions is no. Instead, just pause for just a moment to appreciate the accomplishments of Opportunity and Spirit — Planet Earth's free-range ambassadors on the surface of Mars. Launched in 2003 and landed in 2004, the robotic rovers have been traversing Mars for three and a half years — even though they were certified to last for just 90 days.
Sure, they've taken a few knocks. Mars is a harsh place, and on top of temperatures that range from midday highs of 95 F (35 C) in spring and summer to nighttime lows of minus 166 F (110 C), the rovers have also endured alien storms and routine pounding over the Red Planet's rocky surface. Spirit's right front wheel has seized up, causing the rover to roll with a limp. Opportunity's robotic arm often goes on the fritz (especially when it gets cold) and it has a busted right front wheel steering actuator.
Spirit gazes over a Martian landscape from the top of Husband Hill in 2005.
All in all, however the rovers are doing remarkably well on their new home. It was a little touch-and-go recently, as Mars experienced a nasty dust storm in July that significantly reduced the rovers' ability to generate electricity from their solar arrays. For a while if it was even unclear if Opportunity would survive. But now the storm has cleared and both rovers are back in action. Opportunity is currently poised on the edge of Victoria Crater, a 230-foot deep hole blasted out of the Martian surface by a meteor impact long ago. In the weeks ahead, the rover will enter the crater — and it may never come out.
Opportunity's wheel tracks visible along the edge of Victoria Crater.
Photographed by NASA's Mars Reconnaissance Orbiter on June 26, 2007.
Aviation Week explains the potential rewards of the mission—and the mortal risks involved:
"Victoria is a window back into the ancient environment of Mars," says Alan Stern, NASA associate administrator for science. "Entering this crater comes with unknowns, but we are leaning forward with our risk posture."
By that he means the rover could die in Victoria, but if that happens, the science will have been worth it all. Engineers at JPL have been making extensive preparations to give the vehicle the best chance to get in and out, doing strong science in the crater.
Even if Opportunity does survive, wear-and-tear will continue to take their toll, and it will be at least three years until a replacement rover lands on Mars. The the Mars Science Laboratory, a next-generation machine powered by a nuclear-fueled generator, is slated to touch down on Mars in 2010. Until then, it's up to Spirit and Opportunity to continue going boldly where no rover has gone before.
LINKS:
Mars Exploration Rover Mission (NASA blog with updated status information about Opportunity and Spirit)
VIDEO: Surveying the Scene Above Opportunity (NASA animation showing Opportunity's position on the rim of Victoria Crater)
(Photos from NASA)
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