'Something' Cleaning Mars Rover

bluenirve writes "'Something' has been cleaning the solar panels of the Mars rover Opportunity. "NASA's Mars rover Opportunity seems to have stumbled into something akin to a carwash that has left its solar panels much cleaner than those of its twin rover, Spirit. A Martian carwash would account for a series of unexpected boosts in the electrical power produced by Opportunity's solar panels.""

Re:NASA Planning?

[Moridineas]

Blind luck had no part in it. If you would have actually bothered to learn anything about the Rover project before back seat quarterbacking you would have quickly realized why they didn't build in wipers or some other mechanism.

However, since you didn't, I'll summarize in brief:

wipers--would increase weight and electrical requirements of the rovers, thereby decreasing lifespan. Also, the wipers themselves would most likely end up scratching the solar panels or embedding detritus into them, thus decreasing efficiency.

liquid--compressed air--soemthing else: weight, and dubious effectiveness. Would quickly run out anyway.

Re:hmmm...

[cmowire]

No, it's more the case that the cost, primarily in weight, of adding the required fan, wiper, or other cleaning system outweighs the value added with more scientific instruments. And given that the panels are relatively fragile (remember, every gram of mass has a dollar amount attatched to it) you'd need to be awfully careful -- wipers are out.

Also, it's something else that can fail. Sure, it sounds like a good idea, but if you ruin the solar panels halfway into the base mission because it doesn't work, people start looking really dumb. Or if the shape of grains of martian soil is not quite the same as earth soil and it ends up not working. Or there's something else that might fail, you leave a backup for it out, and then look really stupid when that part fails and you've still got plenty of solar energy.

The biggest problem, of course, is that the designers of the probe are hamstrung by rather unreasonable launch costs that are showing little signs of getting better and are prevented by vast armies of rather stupid anti-nuclear-power whackos from using a 5 year power source. Oh yeah, and most of the NASA budget is reserved for a space shuttle that is far too expensive and has not been able to be retired and replaced due to a variety of issues.

But, in general, it's much better to get a different assortment of tools on a different probe in a completely different location every 2 years, with a chance to have design improvements, instead of having two massive probes that last for 5 years and can only be launched every 10 years.

Re:Nitrogen

[prisoner-of-enigma]

Perhaps it's because an exploding bottle of nitrogen would probably total the probe. Always consider what failure of the doo-dad would do to the overall mission before including the doo-dad. Dirty solar panels are one thing, shredded panels is another.

Re:Design

[Tablizer]

NASA engineers decided not to put wipers on the solar panels, because it would have been too much trouble / added too much weight. I guess they're pretty happy with their decision now, with the 'unexpected' cleaning events...

But the cleaning is limited to one rover and perhaps not permanent. Some speculate it might be due to Opportunity's tilt while in the crater. Now that it is out of the crater, the washing may end.

Nor do they know the impact of wipers on Mars dust. It may make the problem worse for all we know. Certain kinds of dust made a bigger mess on my car winshield until several passes of both the wipers and water. That much water and power would not likely be practical on a rover.

Anyone considered this...

[jbwolfe]

Static charge?

That contradicts why it got dusty in the 1st place

[cheekyboy]

Dude, if the air pressure is TOO LOW to blow the dust around, then how DID THE DAMN DUST get ONTO THE panels in the first PLACE!?!?!?!

You cant say fact A)
"The wind is not enough to blow the dust off the panels"

and yet say B)
"The panels got dusty because of wind blow dust around the planet"

So which is it?

But we do know mars gets dusty as wild storms do happen, but we havent seen that in any camera footage this year.

Re:Wind maybe?

[i41Overlord]

They set up the chamber at Martian atmospheric pressure, then cranked up a fan to blow some insanely high wind speed. The fine dust on the floor didn't even budge; there just wasn't enough air to make anything happen.

Did they decrease the gravity also? Of course not. That's a huge factor right there. We have more than double the gravity of Mars.

Re:Nitrogen

[NanoGator]

"Or maybe $5 windshield wipers would do?"

What amazes me about this suggestion (which has been posted ad nauseum) is the assumption that NASA engineers didn't consider this.

Re:watt-hours per day

[Sinner]

They expressed their figures in Watt-hours/day because that's how it makes the most sense for the topic at-hand.

Um... kilojoules anyone? What is it with you Americans and your bizarro units of measure, anyway?

Re:That contradicts why it got dusty in the 1st pl

[Kiryat Malachi]

It's actually possible (for A and B to both be true) if the coefficient of static friction is lower for dust-dust contact than it is for dust-panel contact. In this case, the force required to break dust-dust stiction could be lower than wind forces, allowing the wind to kick the dust into the air, while the wind force could in turn be lower than dust-panel stiction, preventing the wind from clearing the panel.

I have no idea if that's how it is, I just like saying stiction.