Re: Mars Rover Windshield Wiper

Doctor Bombay wrote:
I may not be a highly paid robot building type of guy BUT. When they built the Mars Rovers did they not foresee dust storms? Why not put a simple brush or wiper on the solar panels to remove any accumulated particles? I know the solar panels are not square or rectangular but surely they should have made something to get rid of the dust.

DB


The real answer is to dump the solar cells and use radioisotope thermal generators (RTGs). The viking landers used them and of course all of the deep space probes (pioneer, voyager, etc) must use them due to the great distances from the sun they are required to operate at. RTGs have become politically incorrect for completely unscientific reasons. The most egregious recent example of this is the Phoenix Polar Lander whose launch is imminent. It is supposed to land at a high latitude (70 Degrees if memory serves). I believe it is pretty much guaranteed to have a short life span since the solar angle will be so low during the Martian winter that there will be insufficient power to maintain the batteries (dust or no dust) and the electronics will lose power during the night, causing the electronics box to see such low temperature that they will be damaged and cease to function. I guess you could make a case for the MER rovers using solar power since at their low latitude the occasional cooperative dust devils have been sufficient to keep the panels clean enough to run longer than anyone expected. However, if the landers were using RTGs the Martian dust storms would not be a problem and in fact you probably could conduct some interesting science during these storms since you would not have to assume a minimal power consumption mode.

For the Mars polar landers to me it is not debatable. If solar powered they are guaranteed to have a short life since the electronics *will* lose power during the Martian winter and the extreme cold *will* kill them. Maybe they can do all the science that is worth doing during the likely lifespan but you never know what you are going to find when you get there and it is not unusual to find that there are observations you want to make that you never anticipated.

When they land a polar *rover* in the future it better have an RTG since it will not be locked in one place and there will always be features out on the horizon that you will want to go look at. I'd love to see a polar rover last as long as the current MER rovers.

That said, I am very excited by the fact that we may be getting some ground images of a high latitude Mars region in the near future. So far everything we have seen on the ground on Mars looks like desert. I'm looking forward to seeing some Martian snow.

JC
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Relevant Pages

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