Sputnik Stan

[Mike Holmes]

On 30/03/2012 22:43, Jonathan Jarrett wrote:
> On Fri, 17 Feb 2012, Mike Holmes wrote:
>> Or perhaps Sputnik Heidi:
>>
>> http://www.theregister.co.uk/2012/02/16/swiss_junk_grabber_satellite/
>
> Man, so more raw materials burnt up just so as to burn up raw materials.
> Can't they get a scrap and recycling wing built onto the ISS? We'll
> probably need that metal and so forth after a while... Yours,

The problem is the deltavee cost of capturing the scrap and then 
changing its orbit to match that of the ISS. It's a non-trivial issue 
and orbital mechanics will tell you that in the age of rockets, it's teh 
deltavee costs which are mission-limiting. This is because the weight 
and volume of fuel (which supplies the deltavee) is compounded by the 
magic of second order differential equations when you have to lift all 
the fuel out of a gravity well, using yet more fuel.

There's also no way to process the materials at the ISS since there's no 
real manufacturing requirement there.

All that could change in the future of course. Maybe we'll ultimately 
get away from rockets and into nuclear-electric drives which won't be so 
deltavee-limited (pace the ion drive probe moving around the asteroid 
belt now). It could be a while before anyone is doing manufacturing up 
there which would require raw materials. So for now, the best thing to 
do with all the junk is burn it up to get it out of the way.

FoFP

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