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…

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…

Both rovers have been hampered by a build-up of red dust blanketing their solar panels. Spirit drags one wheel that failed long ago.

Engineers can only guess how much longer they will last.

I have the same problem.

Still, the spirit of exploration that characterizes the best of our species creates a bond between humans and machines – properly founded in science and forethought – that serve us for generations to come. Or so I hope.