Starship Asterisk*

Posted: **Sat Jan 25, 2014 5:24 am**

Opportunity's Decade on Mars

Explanation: On January 25 (UT) 2004, the Opportunity rover fell to Mars, making today the 10th anniversary of its landing. After more than 3,500 sols (Mars solar days) the golf cart-sized robot from Earth is still actively exploring the Red Planet, though its original mission plan was for three months. This self-portrait was made with Opportunity's panoramic camera earlier this month. The camera's supporting mast has been edited out of the image mosaic but its shadow is visible on the dusty solar panels arrayed across the rover's deck. For comparison, a similar self-portrait from late 2004 is shown in the inset. Having driven some 39 kilometers (24 miles) from its landing site, Opportunity now rests at Solander Point at the rim of Endeavour Crater.

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Posted: **Sat Jan 25, 2014 6:01 am**

I'm pretty sure that Opportunity has outlasted the Energizer Wabbit. It just keeps going and going and going and going and going and ... well, you know.

Posted: **Sat Jan 25, 2014 7:01 am**

Begs the question: how was the camera lens kept sufficiently clean for ten years to take the image?

Posted: **Sat Jan 25, 2014 7:04 am**

n.igma wrote:Begs the question: how was the camera lens kept sufficiently clean for ten years to take the image?

With..a..lens cap?

Posted: **Sat Jan 25, 2014 7:37 am**

Why didn't NASA design it dust-proof?

Posted: **Sat Jan 25, 2014 7:53 am**

Sinan İpek wrote:Why didn't NASA design it dust-proof?

For the same reason they didn't design the solar cells dust proof? Remember, its design life was only three months!

Seriously, ten years is a long time and the panoramic camera was exposed to the atmosphere a lot when you consider all the photos that were taken over the decade. Lens cap or not, its pretty remarkable.

Posted: **Sat Jan 25, 2014 9:22 am**

So much dust on the solar panels, it's amazing it works at all.

Posted: **Sat Jan 25, 2014 9:51 am**

http://asterisk.apod.com/viewtopic.php?f=8&t=32810

Posted: **Sat Jan 25, 2014 10:04 am**

Sinan İpek wrote:Why didn't NASA design it dust-proof?

I suppose it could have been built with dust brushes or similar devices, but I wasn't footing the bill. Regardless, it has way more street cred covered in dust.

Posted: **Sat Jan 25, 2014 12:21 pm**

Ahh! The little rover that could, and did!

Posted: **Sat Jan 25, 2014 1:36 pm**

Both of these smaller rovers had/are having tremendous longevities. Let’s hope Curiosity can live up to the durability legacy.

Opportunity looks however like a car that’s been parked out on Padre Island for 10 years. (Well, no, THAT salty environment is so oxidizing that only a rusty stain in the dunes might be left.)

Is all the reddening from dust, or could some of its exposed metal surfaces have actually oxidized? And if there is now no free O₂ to have caused current rusting, how did the dust on Mars get so rusty looking?

Bruce

Posted: **Sat Jan 25, 2014 1:56 pm**

Somebody needs to go up there with a Swiffer and clean off those solar panels! Here's a closeup comparison of the central area of the rover, from December 2004 and January 2014.

Rob

Posted: **Sat Jan 25, 2014 2:08 pm**

Wow Rob. Nice before and after comparison. Clearly dust is the main culprit, as many parts are non-metallic (such as the solar cells) and wouldn’t rust. I still wonder about oxidation of metal parts though.

Bruce

Posted: **Sat Jan 25, 2014 2:21 pm**

Do we have any solar panel engineers hanging out here at the Asterisk? I was wondering what percentage of the panel's full potential is lost due to this dust coverage? Obviously Opportunity is getting enough power to keep going, but I'm guessing it has to spend at least twice as much time as it did at first, to charge its batteries to do the same amount of work.

[edit] I found a 2007 paper which shows that Opportunity had not, to that date, suffered more than a 40% reduction in power generation due to dust deposition. Dust periodically gets blown off the panels at the beginnings of dust storms, then redeposited as the storm subides and dust falls back out of the atmosphere. Given the continued operation of Opportunity, I have to assume that pattern has continued since.

Rob

Posted: **Sat Jan 25, 2014 3:06 pm**

There is a cleaning service on Mars, but the Marians are rather undependable.

See the Wikipedia article (linked to here in the description under "dusty") “Cleaning Event.”

Bruce

Posted: **Sat Jan 25, 2014 3:10 pm**

BDanielMayfield wrote:Wow Rob. Nice before and after comparison. Clearly dust is the main culprit, as many parts are non-metallic (such as the solar cells) and wouldn’t rust. I still wonder about oxidation of metal parts though.

There aren't a lot of iron-based components. Aluminum, magnesium, titanium... metals like that. Not a lot of oxidation possible there (or the surfaces are pre-oxidized by anodization).

Posted: **Sat Jan 25, 2014 3:23 pm**

rstevenson wrote:
I was wondering what percentage of the panel's full potential is lost due to this dust coverage? Obviously Opportunity is getting enough power to keep going, but I'm guessing it has to spend at least twice as much time as it did at first, to charge its batteries to do the same amount of work.

[edit] I found a 2007 paper which shows that Opportunity had not, to that date, suffered more than a 40% reduction in power generation due to dust deposition. Dust periodically gets blown off the panels at the beginnings of dust storms, then redeposited as the storm subides and dust falls back out of the atmosphere. Given the continued operation of Opportunity, I have to assume that pattern has continued since.

http://nmnaturalhistory.org/rover-field-reports-from-mars.html wrote:
L. Crumpler, MER Science Team & New Mexico Museum of Natural History & Science: Status Reports for MER Opportunity Rover at Endeavour Crater, Meridiani Planum

<<A steady series of recent solar panel "cleaning events" has resulted in better power for this time of the year than seen in the previous few winters. So chances of Opportunity being "on the move" again in the not-too-distant future are good.>>

Posted: **Sat Jan 25, 2014 3:25 pm**

Chris Peterson wrote:There aren't a lot of iron-based components. Aluminum, magnesium, titanium... metals like that. Not a lot of oxidation possible there (or the surfaces are pre-oxidized by anodization).

Ah, makes sense, as those are all light-weight metals. Aluminum rusts, but forms white rust instead of red or brown. And as shown by the longevity, no steps must have been skipped in making these rovers durable.

Does the abundant reddish dust on Mars show that it once had plenty of oxygen in its atmosphere? Is this dust iron oxides?

Posted: **Sat Jan 25, 2014 3:29 pm**

Chris Peterson wrote:
BDanielMayfield wrote:
Clearly dust is the main culprit, as many parts are non-metallic (such as the solar cells) and wouldn’t rust. I still wonder about oxidation of metal parts though.
There aren't a lot of iron-based components. Aluminum, magnesium, titanium... metals like that. Not a lot of oxidation possible there (or the surfaces are pre-oxidized by anodization).

There isn't a lot of oxygen in the atmosphere either:

Code: Select all

Chemical species 	Mole fraction
-------------------------------------
Carbon dioxide 	     96.0%
Argon 	               2.1%
Nitrogen 	            1.9%
Oxygen 	              0.145%
Carbon monoxide 	     0.0557%

Posted: **Sat Jan 25, 2014 3:36 pm**

neufer wrote:There isn't a lot of oxygen in the atmosphere either...

True, but you don't need much for the sort of surface chemistry involved. Metals oxidize even in high vacuum systems, with much lower oxygen molarities than found on Mars.

Posted: **Sat Jan 25, 2014 3:43 pm**

n.igma wrote:Begs the question: how was the camera lens kept sufficiently clean for ten years to take the image?

It's not a horizontal surface (like the solar panels), so it's not a very efficient dust collector. I expect the main mechanism involves static electrical charges. But like most lens systems, you can have a lot of dust on the outer surface with only minimal impact on image quality. The dust is so far from the focus plane that all it can do is attenuate the light and produce scatter (particularly if it's directly illuminated by the Sun). While those tings do degrade the image quality somewhat, you can still collect remarkably good data. Reduced contrast is the biggest problem, and that can be substantially compensated for with simple processing.

Posted: **Sat Jan 25, 2014 4:04 pm**

Although a windshield washer system was omitted due to budget constraints, why can't the rover put each pair of panels in turn vertical, maybe even clap the tips together to shake off the dust? Seems the two roving rovers could go pull the third out of the sand trap, shake the dust off each other, then go on about their business.

Posted: **Sat Jan 25, 2014 4:10 pm**

Psnarf wrote:Although a windshield washer system was omitted due to budget constraints, why can't the rover put each pair of panels in turn vertical, maybe even clap the tips together to shake off the dust? Seems the two roving rovers could go pull the third out of the sand trap, shake the dust off each other, then go on about their business.

Well, the distance the various rovers have traveled ranges from under a kilometer to a few tens of kilometers. So traveling hundreds or thousands of kilometers for a rescue mission is going to be a challenge.

I'm not sure that the panels can be stowed again... I'd guess not. But even if that were possible, I expect the risk of a mechanical failure in doing so far outweighs the harm of a loss in efficiency from dust. Better a lower power, functional rover than a completely dead one with stuck panels.

Posted: **Sat Jan 25, 2014 4:39 pm**

Psnarf wrote:
Although a windshield washer system was omitted due to budget constraints, why can't the rover put each pair of panels in turn vertical, maybe even clap the tips together to shake off the dust? Seems the two roving rovers could go pull the third out of the sand trap, shake the dust off each other, then go on about their business.

Keep dreaming...

It's a Wonderful Life (1946)

George Bailey: I'm shakin' the dust of this crummy little town off my feet and I'm gonna see the world. Italy, Greece, the Parthenon, the Colosseum. Then, I'm comin' back here to go to college and see what they know. And then I'm gonna build things. I'm gonna build airfields, I'm gonna build skyscrapers a hundred stories high, I'm gonna build bridges a mile long...

http://astrobob.areavoices.com/?blog=78068 wrote:
[b][color=#0000FF]Researchers used the rover to find water-related minerals on the ground that had been detected from orbit. [/color][color=#FF0000]After brushing the rocks free of dust[/color][color=#0000FF], Opportunity found this dark rocky veneer (center) in the Whitewater Lake outcrop. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.[/color][/b]
Mars Opportunity Rover makes a juicy discovery
Astrobob, January 24, 2014

<<Ten years ago this evening, NASA’s Opportunity Rover parachuted to the surface of Mars and settled on the red, iron-stained soil of Meridiani Planum. That iron was likely deposited eons ago in hot springs and steaming pools of superheated water. If Yellowstone National Park comes to mind, this now-dusty, chill and wind-swept place may once have been its cousin. After traveling 24 miles spread over all those years, today Opportunity sits perched on the rim of 14-mile-wide Endeavour Crater near an area called Matijevic Hill. Beginning in 2010, the rover used its Compact Reconnaissance Imaging Spectrometer there to find brand new evidence of a ancient wet environment that was milder and older than the acidic and oxidizing conditions seen in other places examined by the rover.

Opportunity detected an iron-rich clay mineral known as smectite. Researchers believe the wet conditions that produced the smectite preceded the formation of the Endeavor Crater about 4 billion years ago. Anyone who’s gotten their foot stuck in slippery, juicy clay knows that it’s intimately associated with water. “There’s more good stuff ahead,” said Steve Squyres of Cornell University, Ithaca, N.Y., the mission’s principal investigator. “We are examining a rock right in front of the rover that is unlike anything we’ve seen before. Mars keeps surprising us, just like in the very first week of the mission.”>>

Posted: **Sat Jan 25, 2014 6:52 pm**

Seems to me that this is something that the smart people at NASA could have foreseen (they knew the planet was covered in fine reddish dust long before any of these 'explorers' landed). A little Swiffer-type mechanism with soft brush used regularly shouldn't have been that hard to make, considering the marvel of the rest of this little machine. For some reason or other, men just don't see or think about dust until it's to the point of ruining things! Poor little "Spirit" could have used the brush and still been motoring around.

Starship Asterisk*

APOD: Opportunity's Decade on Mars (2014 Jan 25)

APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)

Re: APOD: Opportunity's Decade on Mars (2014 Jan 25)