Posted
by
michael
from the aliens-want-some-privacy dept.
GTM writes: "The surface of the Red Planet is currently hidden by the most impressive dust storm seen in decades. Mars Global Surveyor and Hubble provide us with pictures, see the press release here."
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manned exploration of mars is certainly a good long way away, but this is certainly something that needs to be kept in mind. as far as that goes, unmanned surface explorer designers would probably want to know about it too...
considering NASA/JPL has plans for inflatable rovers [nasa.gov] for surface exploration, it might be good for them to know how these craft will peform in high wind dust storms.
right now, the more immediate question is how will this affect the aerobraking [yahoo.com] performance of the Mars Odyssey [nasa.gov] spacecraft which is supposed to arrive in 11 days. Last week, there was an article/discussion [slashdot.org] on aerobraking, if you feel like browsing it at +3 and seeing if anyone had something really intelligent to say about it.
how these craft will peform in high wind dust storms.
While I agree, keep in mind that the thin atmosphere means that a gale wind on Mars has very little pressure to it. Any physics experts want to talk about the energy difference between a dust storm on Mars versus one in the Sahara? (Which has a global dust storm quite often, pushing dust over to at least Florida all the time - grant you, I'm talking area, not force there...)
Well first of all, the atmospheric pressure on Mars is a lot lower than on Earth (as i recall 5 mBar opposed to 1000 mBar) this makes the wind force much lower even for high winds. This low pressure also reduces the size of the particles that can be suspended in the Mars atmosphere and only dust can be suspended for longer periods of time. The effect of this is that wind erosion on any surface on Mars will proceed much slower than on Earth.
The aerobreaking will also not be influenced, as this takes place at the upper edge of the Mars atmosphere, where no dust particles would be. The breaking do not use a heat shield, so the effective density of the Mars atmosphere at the breaking altitude is small indeed. This is also why the breaking is scheduled to run over many orbital flybys, as a faster breaking would destroy the spacecraft.
For manned trips to Mars you would use a far lower point of entry for your breaking maneuver, so that the breaking could be achieved in a few flyby's. In that case, however, the spacecraft would have an ablative heat shield as the Apollo modules, or ceramic tiles as the Space Shuttle and even then, the breaking altitude would be far higher than the highest dust particles would reach in a storm.
i beleive (correct me if i'm wrong) that the article points out that the heating effects which induced the dust storms in the first place also caused the atmosphere of the planet to increase in volume. although there would of course be a corresponding decrease in atmospheric density, the calculations used to determine the flight characteristics of the aerobraking maneuver would be affected, i'm 99% sure.
i'm just saying, if we earthlings have called mars the god of war, it's odd that the war god is having a "perfect storm" at this particular moment in earth history.;-P
first it was either tritan uranus's moon which started exhibiting signs of a global warming and now mars with its crazy global dust storms. the atmosphere is heating up and glaciers all over are melting--- hold on wait a minute, could it be we're entering a interglacial between ice ages? Maybe we'll see water on the surface of mars yet!
A while ago/. posted a simalar story. Two months ago storm was extreamly active ans seems much quieter now.
You can always check out the current conditions by going to here [asu.edu].
In San Diego the weather never changes so this gives me something to look at.
Every one talks about the weather but no one does anything about it.
Mark Twain
God is angry! (Score:1, Funny)
Your enemies shall we smite, O Lord! Your Name shall be written upon the holy temples of their land.
Cursed be they that dare to stand against Your mighty armies!
lots of good stuff to learn (Score:4, Insightful)
considering NASA/JPL has plans for inflatable rovers [nasa.gov] for surface exploration, it might be good for them to know how these craft will peform in high wind dust storms.
right now, the more immediate question is how will this affect the aerobraking [yahoo.com] performance of the Mars Odyssey [nasa.gov] spacecraft which is supposed to arrive in 11 days. Last week, there was an article/discussion [slashdot.org] on aerobraking, if you feel like browsing it at +3 and seeing if anyone had something really intelligent to say about it.
Re:lots of good stuff to learn (Score:3, Interesting)
While I agree, keep in mind that the thin atmosphere means that a gale wind on Mars has very little pressure to it. Any physics experts want to talk about the energy difference between a dust storm on Mars versus one in the Sahara? (Which has a global dust storm quite often, pushing dust over to at least Florida all the time - grant you, I'm talking area, not force there...)
--
Evan
Re:lots of good stuff to learn (Score:3, Informative)
The aerobreaking will also not be influenced, as this takes place at the upper edge of the Mars atmosphere, where no dust particles would be. The breaking do not use a heat shield, so the effective density of the Mars atmosphere at the breaking altitude is small indeed. This is also why the breaking is scheduled to run over many orbital flybys, as a faster breaking would destroy the spacecraft.
For manned trips to Mars you would use a far lower point of entry for your breaking maneuver, so that the breaking could be achieved in a few flyby's. In that case, however, the spacecraft would have an ablative heat shield as the Apollo modules, or ceramic tiles as the Space Shuttle and even then, the breaking altitude would be far higher than the highest dust particles would reach in a storm.
Yours Yazeran
Plan: To go to Mars one day with a hammer.
Re:lots of good stuff to learn (Score:1)
Re:lots of good stuff to learn (Score:1)
isn't mars the god of war? (Score:2)
sun heating up? interglacial? (Score:1)
once again (Score:2)