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sailhog 02-13-2009 09:27 AM

GPS and space debris...
 
Wondering if we may want to dust off our sextants in the coming months and years. A derelict Russian satellite and a functioning American satellite collided a few days ago, creating a debris field 500 miles above the earth. Apparently this is a popular orbit for the satellites that give sailors, airmen and drivers coordinates for our navigational devices. Once you have a collision like this, it's like a chain reaction, causing more collisions and more debris, so on and so forth. And it apparently takes a little time for gravity to clean up the mess (10,000 years, according to some sources). I'm wondering when space is going to be all but inaccessible to us...

Read it and weep:

Space crash debris to orbit Earth for 10,000 years - Yahoo! News

Valiente 02-13-2009 09:52 AM

Well, this is why I keep up my CN, not because I'm a Luddite, but because I understand physics and probability.

Kessler Syndrome - Wikipedia, the free encyclopedia

From a launch perspective, a thin, wildly dispersed field of coin-sized spalls is much worse than chunks of dead satellites here and there. It's like dioxin: a barrel of the stuff in one place is bad enough, but a few micrograms in everybody is deadly.

sailhog 02-13-2009 10:19 AM

I didn't realize there was a name for the phenomenon. Looks like we'll be kissing the blessing of satellite technology goodbye in the near future. Goodbye Captain Garmin, hello Captain Cook! Seems inevitable at this point.

Valiente 02-13-2009 07:46 PM

Maybe not, but the phrases "clear and present danger" and "law of unintended consequences" come to mind.

Space is very, very big, but time is very, very long. See "what was that container doing there?" for the yachting equivalent.

Anyone who's evolved on a planet like this one that's had two and possibly more major extinction events due to fairly modest space rocks slamming into us with gigatons of TNT equivalent explosive power has no right to be smug about the rapidly moving crap they've left in a can't decay fast enough orbit.

bubb2 02-13-2009 08:02 PM

How do we hide this thread from Cam! He will Panic!!!!!!!!

Valiente 02-13-2009 08:16 PM

Well, he's been a little on edge lately as it is...

My wife starts her celestial navigation course on the 17th. This is purely coincidental. I took mine four years ago.

Can't hurt, might help, certainly improves the navigation, and a sextant is a precision instrument. A man can't have too many of those.

Boasun 02-13-2009 09:34 PM

You have to remember that the GPS Satellites are 11000 miles above the earth. The debris field should not be of any worry. Unless that debris is flung outwards toward the GPS orbits. Then you can worry abit about it.

JiffyLube 02-13-2009 11:38 PM

Quote:

Originally Posted by Boasun (Post 447965)
You have to remember that the GPS Satellites are 11000 miles above the earth. The debris field should not be of any worry. Unless that debris is flung outwards toward the GPS orbits. Then you can worry abit about it.

and the US and Russian communications satellites that collided were about 500 miles above Earth.

Valiente 02-14-2009 12:09 PM

True, but the intervening space between LEO and HEO can be covered by flying debris in under an hour...heh heh.

Seriously, it's not the satellites in HEO I worry about, but the fact that they eventually fail or otherwise go out of service. If a thin layer of debris exists between the surface of the Earth and that altitude, for lack of a better term, and the debris is randomly moving at 10X bullet speed, the problem becomes "how do you fly a great big rocket full of rocket fuel through that to reach high orbit?"

The situation is analogous to motoring through the Great Pacific Gyre without trapping a plastic bag against your raw water intake. The ocean is very big, but the plastic bits and pieces in the water column are numerous and randomizes once inside the gyre.

sailhog 02-14-2009 12:12 PM

Quote:

Originally Posted by JiffyLube (Post 448000)
and the US and Russian communications satellites that collided were about 500 miles above Earth.

The problem as I understand it is that high earth orbit will eventually become inaccessible due to the space debris in low earth orbit. Once these global positioning satellites come to the end of their working lives, we won't be able to get one through the gauntlet.


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