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Huge Martian Dust Storm Threatens Rovers
Riding with Robots writes "NASA reports that a severe ongoing dust storm on the Red Planet has blocked 99 percent of the direct sunlight that powers the Opportunity rover. If these conditions persist for too long, it could finally bring an end to the marathon mission of this robot geologist, and perhaps of its partner Spirit as well. 'Before the dust storms began blocking sunlight last month, Opportunity's solar panels had been producing about 700 watt hours of electricity per day, enough to light a 100-watt bulb for seven hours. When dust in the air reduced the panels' daily output to less than 400 watt hours, the rover team suspended driving and most observations, including use of the robotic arm, cameras and spectrometers to study the site where Opportunity is located ... A possible outcome of this storm is that one or both rovers could be damaged permanently or even disabled. Engineers will assess the capability of each rover after the storm clears.'"
The problem is that without power the heaters don't run, without heaters the components get too cold and stop working permanently..
They opted to not install panel wipers because of the added mechanical complexity, weight, possible damage in transport to mars, and that they didn't know how Martian dust would behave to the wipers.
Grump
Is it true that more people vote for the winner of American Idol, than vote for the president? -Ali G.
Go into Firehose, find the article (it'll be a dark green bar), click on "-", then click on "dupe".
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
If I knew the wedgies I gave you back in 6th grade would have resulted in this . . . I might have taken a moments pause.
A) The dust is charged (static electricity). Brushing would just shove it around and scratch the solar panels. So some other means of cleaning them would be required, e.g. charging the solar panels so it repels the charged dust?
B) What good are clean solar panels when the sky is opaque with dust? Needs more nuclear power, which is what the upcoming rover will have.
while true; do eject; eject -t; done
You're confusing the possibility that a dust storm can lift enough dust into the atmosphere to block sunlight with the possibility that the wind intensity is sufficiently high to drive a wind turbine. Mars has a very thin atmosphere, and this wind isn't nearly enough to drive a turbine that would produce enough power for the rovers. Lifting dust is a lot easier than pushing the blades of a fan.
w ith-generato.html
m l
... even at peak windspeed it's going to be hard to generate enough power with turbines that the rover could reasonably carry, and that would all be deadweight for the solar panels during non wind times.
Also, whatever turbine you added would go into the weight of the rover, which then affects the parachute/airbag requirements for landing, and during drive around time you're carrying that extra weight uselessly most of the time.
This setup:
http://store.motorwavegroup.com/8-micro-turbines-
generates about twice as much power as the article suggests is needed, on earth (presumably 1atm pressure) at 10m/s wind speed.
http://www.nap.edu/openbook/0309084261/html/22.ht
claims that martian windspeeds peak at 50m/s, but that the dynamic pressure is only 1/9th of that due to the lower atmospheric pressure.
That gives you an equivalent of only 6m/s equivalent speed (at peak intensity!).
So
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
As I understand it, they were pretty sure they could add useful panel wipers -- not perfect, but useful. Or maybe peel-away disposable covers. Or any of several options. The eventual decision was that there were several viable methods, and they all would take the place of about 1 instrument. And the researchers decided they'd rather have another instrument, even if it meant shorter life. As it turns out, they got very lucky and mostly don't need the wipers.
Really, it's not fair to blame mediocre writers for writing badly. Ideally, it is the job of the editor to keep crap off the front page. Of course, the quality of the editors/janitors at slashdot needs no more elaboration...
If a job's not worth doing, it's not worth doing right.
The problem is that the dust storms are blocking the light before it hits the panels, not just covering the panels with dust. I doubt they'll know how much dust has accumulated on the panels as a result of this storm till it's over.
Chernobyl 'not a wildlife haven' - BBC News
You really think you know better than hundreds of the top scientists and engineers in America who have spent their entire lives working in the space industry?
Wow. Okay.
To help you gain a little perspective I'll give you one word to consider: tradeoff.
Here are two more: design parameters.
Now be a good boy and google about the Mars rovers and someone will explain why they built them the way they did, in language you should understand.
"The worst-case scenario is that enough dust in the sky decreases solar energy to the point that we have to shut down too many things to save power," Lemmon said. "The rovers keep their battery alive by keeping their electronics alive."
l
http://www.space.com/news/070705_dusty_rovers.htm
However, the article also mentions the cold breaking solder joints:
John Callas, project manager for the Mars Exploration Rover (MER) mission at NASA's Jet Propulsion Laboratory in Pasadena, Calif., explained that a dead rover battery could allow cold temperature to maim Opportunity's electronics.
"It's like leaving your laptop out in an Antarctic winter," Callas said. "Soldered joints in the electronics can contract due to thermal contraction. If a rover gets too cold, something essential will fail." Callas explained the situation is unprecedented, so the team isn't certain how much more light-blocking dust the rovers-especially Opportunity-can take.