[X] My Assistant

[sranderson]

Spaceweather (www.spaceweather.com) is reporting a dust storm on Mars visible in amateur telescopes. Hope we don't get too much dust-fall on the solar panels....

[Bill Harris]

Could the dust storm be a serious matter for our intrepid explorer? I am assuming that if the dust storm does hit and decrease the solar panel output to below the minimum, Oppy can go into a deep sleep mode and wait the storm out, waking up once the storm clears. And if the solar panels get dusted over, we'll wait for a cleaning event. Or am I too accustomed to Oppy being The Energizer Mars Rover?

--Bill

[Bob Shaw]

Could the dust storm be a serious matter for our intrepid explorer?  I am assuming that if the dust storm does hit and decrease the solar panel output to below the minimum, Oppy can go into a deep sleep mode and wait the storm out, waking up once the storm clears.  And if the solar panels get dusted over, we'll wait for a cleaning event.  Or am I too accustomed to Oppy being The Energizer Mars Rover?

--Bill

Bill:

We're talking End Of Mission!

Bob Shaw

[helvick]

Bill:

We're talking End Of Mission!

Bob Shaw

We're only talking end of mission if things get really bad and stay that way. Oppy's been generating somewhere in the 600Watt/hours per day range lately. An extended period where Tau is around 2 would reduce that by 20-30% which would make things more difficult but wouldn't kill her. A really major event (Tau~ 5) would bring that down to around 240 Watt/hours which is below the level that I think she needs to survive for an extended period. Even at that level though I think there would be enough juice to wake up and blip out a "Hello I'm still more or less alive" direct to earth message.

To give you an idea what a major planetwide storm would do - the second 1997 storm had Tau > 4 for approximately 36 Sols (based on a model from Viking data) and Tau >2 for about 80 sols. It's important to remember that the general consensus is that we're too late in the season for a storm like that.

The

[Nirgal]

We're only talking end of mission if things get really bad and stay that way. Oppy's been generating somewhere in the 600Watt/hours per day range lately. An extended period where Tau is around 2 would reduce that by 20-30% which would make things more difficult but wouldn't kill her. A really major event (Tau~ 5) would bring that down to around 240 Watt/hours which is below the level that I think she needs to survive for an extended period. Even at that level though I think there would be enough juice to wake up and blip out a "Hello I'm still more or less alive" direct to earth message.

To give you an idea what a major planetwide storm would do - the second 1997 storm had Tau > 4 for approximately 36 Sols (based on a model from Viking data) and Tau >2 for about 80 sols. It's important to remember that the general consensus is that we're too late in the season for a storm like that.

The

ok, I'm confident that the Rover could survive during the duration of most dust storms but the question is: how does the storm affect the accumulation on the solar panels *after* the storm ?

I'm afraid that the wind itself ceases long before the majority of the dust (very light particles !) eventually falls out of the atmosphere:

this could be bad because all the dust that had been kicked high up into the atmosphere would now slowly trickle out of the air like snow-flakes on a windless winter day, accumulating on the solar panels without the wind necessary to blow it away ...

Question for the experts (hevlick ?): how did the dust accumulation develop after past dust storms that Oppy observed ?

on the other hand if some of the increased wind activity associated with the dust storm continues shortly after much of the dust has fallen back to the ground, then
it could even improve the solar panel situation by "wind cleaning events"

[jamescanvin]

ok, I'm confident that the Rover could survive during the duration of most dust storms but the  question is: how does the storm affect the accumulation on the solar panels *after* the storm ?

I'm afraid that the wind itself ceases long before the majority of  the dust (very light particles !) eventually falls out of the atmosphere:

this could be bad because all the dust  that had been kicked high up into the atmosphere would now slowly trickle out of the air like snow-flakes on a windless winter day, accumulating on the solar panels without the wind necessary to blow it away ...
...

When I talked to Steve Squyres a few months back he said that dust accumulation on the panels after a storm was not a consern. Lets worry about the storm itself for now.

James