X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
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>> In article <10346@nsc.nsc.com> andrew@nsc.nsc.com (andrew) writes:
>> >... The existence of a heatsink at 3 degK should be a great help for
>> >the engine design...
>>
>> Not as much as you think. Getting the heat out to that heatsink is
>> *not* a trivial problem. The shuttle uses the entire inner surface of
>> its payload-bay doors as a heat radiator.
>As I recall--and I'm sure I'll get some fairly hot replies if I'm wrong--
>that the rate of radiation of energy varies as the 4th power of the
>absolute temperature. Since the Shuttle is working a rather low temperatures,
>it's no surprise that it needs a large surface.
Remember that the shuttle bay is normally pointed at the Earth. Thus it does
not usually take advantage of the 3K heat sink available.
Also remember that concentrating the waste heat to increase the rate of
radiation requires further energy expenditure and consequent heating, which
must be taken into account.
>From the CRC handbook:
Stefan-Boltzmann law of radiation. - The energy radiated in unit time by a
black body is given by E = K * (T^4 - T0^4), where T is the absolute
temperature of the body, T0 the absolute temperature of the surroundings,
and K a constant.
John Roberts
roberts@cmr.icst.nbs.gov
------------------------------
Date: 14 Apr 89 14:22:18 GMT
From: prism!ccoprmd@gatech.edu (Matthew DeLuca)
Subject: Re: Soviet shutdown of manned space program
In article <631@ftp.COM> jbvb@ftp.COM (James Van Bokkelen) writes:
>
>They may also be re-thinking many engineering issues in light of cold fusion.
I'm not so sure of this. Considering that nobody (including the crowd here at
Georgia Tech (their neutron counter was faulty...they're rerunning the experiment)) has 100% conclusively demonstrated nuclear fusion with breakeven
potential. We still don't really have a solid theory, unless you count the
(still secret, patent pending) MIT claim. Are the Soviets going to cut back
their current program just to pursue something that *may* pan out sometime
in the next 15 to 20 years? I don't think so. If there really is an across the board cutback in the Soviet program, I still think the reason is economic.