If you've been following along with the Mars rover mission you should be aware that the length of the mission is highly dependent on the rovers' batteries. You should also know from reading the news that the batteries on the rovers are continually recharged by the solar panels on the rovers.
Mission scientists expect the solar panels on the rovers to become covered with a layer of dust that will ultimately lead to the inability to charge the rovers' batteries. If you're like me you'd ask yourself why the scientists didn't plan some sort of device do remove the dust from the panels? According to mission scientists the weight of wipers or other such device was not worth the benefit of including them. You can read more here: http://www.cnn.com/2004/TECH/space/04/08/mars.rovers/index.html.
· Since the mission was intended to last 90 days it doesn’t seem that this would be necessary.
· The rovers only have so many instruments, what good would it do to have these rovers with a life time of 5 years? Then think of the cost of all of the supporting cast on the ground (scientists, IT folk, developers, managers, etc.) … not very cost effective.
· Windshield wipers are such high tech devices to begin with, I’d hate to see what a bunch of highly funded scientists could dream up! J