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Article #141Re: nasa-celebrates-successful-mars-landing
From: Adrian Jansen
Date: Tue, 07 Aug 2012 23:42
Date: Tue, 07 Aug 2012 23:42
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2874 bytes
On 8/8/2012 7:04 AM, Jon Kirwan wrote: >>> >>> Which reminds me of another thing. How do they convect the >>> internally generated heat away. I recall hearing about >>> multiple power systems, operating around 32V at near 2A. More >>> than one. This power must be convected/conducted away -- no >>> way they want to radiate it. I wonder if they push it >>> (costing more heat) towards a vane or arm and drag it around >>> on the surface to get rid of it? >> >> The atmosphere won't help much. >> >> Why not? Thermal conductivity of air is pretty much constant till you >> get below 1 Torr or so. Wiki says the mean pressure on mars is about >> 0.1 psi, which is ~5 torr. > > Good point. > In earth atmosphere, I understand most heat above around 300K ( 'room' temp ) is carried by radiation and convection. Conduction is a minor part. No idea what convection is like at 5 torr in a CO2 atmosphere, but I suspect its a lot lower. -- Regards, Adrian Jansen adrianjansen at internode dot on dot net Note reply address is invalid, convert address above to machine form.
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Date: Wed, 08 Aug 2012 09:42:05 +1000
From: Adrian Jansen <adrian@qq.vv.net>
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To: Jon Kirwan <jonk@infinitefactors.org>
Subject: Re: nasa-celebrates-successful-mars-landing
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