IT IS a common complaint these days: things are just not made to last any more.
But it is one gripe that does not hold water on the red planet. The warranty on NASA’s two, six-wheeled Martian rovers – Spirit and Opportunity – guaranteed their survival for only 90 days on the planet’s dusty surface, and promised that they would drive a mere 600 metres.
But this weekend Spirit celebrates its fifth birthday on Mars. Its identical twin, Opportunity, reaches the same milestone on January 24.
Since its landing Spirit has motored more than 7.5 kilometres, while Opportunity has clocked more than 13.6 kilometres. Together the rovers, which set down on opposite sides of Mars, have snapped about 250,000 pictures.
When Spirit opened its robotic eyes on January 4, 2004, after bouncing to a halt, it spotted a series of hills about one kilometre away. Engineers wondered whether the mechanical explorer, no bigger than a small ride-on mower, could be coaxed to reach them.
Spirit not only reached the hills, but climbed 110 metres to the summit of the highest peak, and then trundled down the other side.
The rovers have found Mars was awash with salty water 4 billion years ago but was drained bone dry by some environmental catastrophe. They have sent back movies of willy willies dancing across the Martian plains and pictures of eerie sunsets.
Yet it hasn’t been one long Sunday drive. Spirit spent much of last year parked on a hill, struggling to soak up enough sunshine to survive another bitterly cold six-month winter.
“This last winter was a squeaker for Spirit,” John Callas, the rover project manager, said.
Both rovers have been hampered by a build-up of red dust blanketing their solar panels. Spirit drags one wheel that failed long ago.
In June 2005 Opportunity found itself bogged for three weeks on a sand dune.
Engineers can only guess how much longer they will last. “A major rover component on either vehicle could fail at any time,” Dr Callas said. …
via World – smh.com.au.