Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Mars (probably off Topic!)
Date: Wed, 25 Oct 2000 14:45:16 GMT

In article <39F6D565.8E6CED01@bigpond.net.au>,
David Sander  <surfren@bigpond.net.au> wrote:
>> Is there any danger of
>> dust "collecting" on habitation modules/landers/what have you?
>
>Of course - in the same way that any structure in any desert environment will
>collect dust. On Mars though, short of a sandstorm, there's little other than
>the crew tracking around the place to pick up the dust and attach it to the
>lander.

Not exactly true.  There is a little bit of suspended dust in the Martian
atmosphere all the time -- which is why it looks brown or pink rather than
blue -- and it settles out slowly, hence there is slow dust accumulation
on almost any surface.  There was an experiment on Sojourner to try to
assess the rate of dust buildup, although some unfortunate data loss
resulted in only the most approximate numbers coming out of it.

>I don't believe there'd be any serious problems with thermal transfer and
>insulation either, since the lander is also a spacefaring vehicle and already
>requires a certain amount of insulation to survive the depths of
>interplanetary space.

However, surface properties are often crucial to spacecraft temperature
control, so a change in same -- e.g., a white or aluminized surface
getting covered with dark dust -- is not to be taken lightly.  It only
takes a bit of surface crud to cause serious overheating, sometimes.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)