The Storm, Dust storm of 2007 |
The Storm, Dust storm of 2007 |
Jul 5 2007, 05:57 PM
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#1
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Member Group: Members Posts: 710 Joined: 28-September 04 Member No.: 99 |
Oh no...This is getting bad:
The new and potentially bleak outlook is a stark shift from the prognosis earlier this week. The dusty squall has reduced direct sunlight to Mars' surface by nearly 99 percent, an unprecedented threat for the solar-powered robotic explorers. If the storm keeps up and thickens with even more dust, officials fear the rovers' batteries may empty and silence the robotic explorers forever. Opportunity's energy-gathering ability has been slashed to a dangerous 280 watt-hours-enough power to light only three 90-watt light bulbs. "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." "The reality of the situation is that we're limited as to what we can do from the ground by cutting power use," Callas said. "If it continues to worsen and stay that way, it's a survivability issue for Opportunity. If Mars wants to kill the rovers, it can." http://www.space.com/news/070705_dusty_rovers.html |
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Jul 20 2007, 09:03 AM
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#2
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
Gusev remained at Tau = 4.0 for 1259, for those few not watching Mark's page closely.
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Jul 20 2007, 09:49 AM
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#3
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
Pre-storm, I was wondering whether the decision to go with a nuclear-powered MSL was wise in the light of the MER's solar-electric longevity.
I have no doubts now. Andy |
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Jul 20 2007, 01:25 PM
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#4
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
Pre-storm, I was wondering whether the decision to go with a nuclear-powered MSL was wise in the light of the MER's solar-electric longevity. I have no doubts now. Andy The reason that dust storms are so deadly at high tau is because critical parts of the rover get too cold, right? The lack of power is not a problem in itself, as the rover can hibernate. So why not go with solar-electric power, plus insulation and a small radioisotope heat generator to keep the main body warm? Things like arms, that are not warmed by the heat generator but still need to be kept warm, would have the same system of heaters that the MERs do -- the difference being that those heaters would be the only electrical load during hibernation. I believe that even the worst dust storms should allow enough energy to keep those heaters going -- especially given the lower-atmosphere heating observed during dust storms. The advantages of such a system would be lower total power-system mass (I think), lower development costs, and possibly a longer lifetime (going by the MER experiences) if, as I seem to recall, the reactor only has a several years lifetime. Bill |
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Jul 20 2007, 01:27 PM
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#5
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
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Jul 20 2007, 08:22 PM
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#6
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
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