Build your own Sputnik (for £50)
Guinness - 22/10/07 at 09:03 PM
Nothing about the cost of actually getting it into space though!
http://news.bbc.co.uk/1/hi/magazine/7049002.stm
Obviously way beyond me, but no doubt some of my fellow locostbuilders would find it easy!
Mike
minitici - 23/10/07 at 07:58 AM
Slightly confused as to how a fan can cool the electronics in outer space 
JAG - 23/10/07 at 08:16 AM
You're dead right of course - no air!
Also when in outer space you don't need any cooling - it's pretty chilly and quite big up there 
A quick search provides;
quote:
If we put a thermometer in darkest space, with absolutely nothing around, it would first have to cool off. This might take a very very long time. Once
it cooled off, it would read 2.7 Kelvin. This is because of the "3 degree microwave background radiation." No matter where you go, you
cannot escape it -- it is always there.
So that's -270 Celsius'ish 
[Edited on 23/10/07 by JAG]
scoobyis2cool - 23/10/07 at 08:57 AM
The only thing I can think is that it was a sealed unit with air, or some other gas, trapped inside. Then you just continually circulate that.
Pete
wilkingj - 23/10/07 at 09:02 AM
quote:
Originally posted by JAG
You're dead right of course - no air!
Also when in outer space you don't need any cooling - it's pretty chilly and quite big up there
Thats not quite true.
The Suns radiant heat will heat up parts of the satellite. Thus you will get huge temperature swings on parts of the satellite.
I had a friend who was in control on one aspect of a satellite's temperature and its was damned involved. Yup its cold up there, but the suns
rays can heat one side of a satellite, causing thermal issues. Hence a lot of the satellite is covered in reflective foil to try to stabalise the
temperatures caused by the suns radiant heat. Plus there is internal heat from the equipment to deal with.
In 1980, the Universtity of Surrey launched a Satellite with a couple of radio beacons on it. This cost £186,000, and was designed and built at UoS. I
have visited the Labs there, and the command room for the satellite. It was ALL controlled with BBC Micro's. Talk about done on a budget. The
Satellite flew for about 10 years. The BBC's were more than adequate for control purposes.
Consider the processor in the space shuttle is about the same power.
Higher level technology is more unreliable, as the track widths inside the chips are thinner and more prone to damage by cosmic particles / rays.
A little data from www.amsat.com
UOSat-OSCAR 9 (UoSAT 1)
UOSat-OSCAR 9 was launched on 6 October, 1981 from Vandenberg, AFB aboard a Thor Delta and was inserted into a 538.00 x 541.00 Km orbit inclined 97.51
degrees.
The satellite measured 74 x 42 x 42 cm, and weighed 52.000 Kg. It was a project of University of Surrey.
The satellite re-entered the earth's atmosphere on 13 October, 1989.
At least its not a bit of space junk littering the heavens
JAG - 23/10/07 at 09:07 AM
quote:
The Suns radiant heat will heat up parts of the satellite
...of course I didn't think about that!
Bluemoon - 23/10/07 at 09:18 AM
A lot of the Russian early sats were pressurized.. It means that you can use standard electronics with less thermal issues... That's why Russian
early sat's look so 1950's sci-fi (polished spheres and alike)...
Dan
02GF74 - 23/10/07 at 09:48 AM
... and race it?
MikeR - 23/10/07 at 12:24 PM
Space shuttle uses a number of 80x88 processors - pretty decent stuff considering when it was designed. IE VERY early IBM PC processors. They had an
issue a couple of years ago cause intel no longer made them - they had to buy a batch on ebay!
(this is internet folk lore so likely to have a high degree of inaccuracy).