TWO SATELLITES COLLIDE IN ORBIT

Accuracy.
Predicting a risk of collision is possible,
predicting if it will actually happen is not,

Jan

On Fri, 13 Feb 2009 13:36:38 +0100, nospam@de-ster.demon.nl (J. J.
Lodder) wrote (with clarity & insight):


It's amazing that an idea so plainly obvious can be so absurd at the
same time.

We track "more than 17,000 bits of debris larger than 10 centimeters"
and can't predict with decent probability when two *whole satellites*
will hit each other?

Or we can and just don't bother?

wrote:


I think the case is that we track those 17,000 items and compare their
orbits to a few "key" satellites, like the space station and perhaps a
few others. That probably chews up quite a bit of some processor. It's
a totally different problem to check all those 17,000 against each
other. Or the other reason: "it was cut from this year's budget".

--
Charlie Hoffpauir
http://freepages.genealogy.rootsweb.com/~charlieh/

If you can predict you don't need probability.


If you think that real time tracking to about one meter
and a fraction of a millisecond is possible
you should tell others howto,

Jan

+ nospam@de-ster.demon.nl (J. J. Lodder):


That was exactly my thought on the subject too. But then I wondered:
Aren't the GPS satellites tracked to the meter or less? Don't they have
to be, for GPS to work? On the other hand, they are much farther out,
and so move a lot more slowly, and they are of course equipped with all
sorts of stuff (radios, super accurat clocks and computers) that should
let them help with their own tracking. Pinpointing a defunct satellite
zipping along in low earth orbit by radar is probably quite a bit
harder. But now I am only guessing. Someone will surely tell me if I am
way off the mark here.

--
- It is undesirable to believe a proposition
when there is no ground whatsoever for supposing it is true.
-- Bertrand Russell