On Sat, 17 Apr 2010 23:50:45 +0000 (UTC), (Don
Poitras) wrote:

Roger wrote:
Now that we have lost LORAN and are scheduled to lose most other
ground based navigation aids, I wonder what the thoughts are now that
the unthinkable happened this past week.

Two large communications? satellites collided at very high speed
creating a debris cloud about 200 X 300 miles and spreading. This
increases the chances of other Low Earth Orbit (LEO) collisions by at
least an order of magnitude. Technically there should be two debris
clouds diverging and spreading out like a shotgun blast even if the
collision had been at a shallow angle, which it wasn't.

As one astronaut said, the greatest danger in the flight going back to
the moon or mars is getting through the cloud of junk surrounding the
earth (paraphrased).

I wonder what this has done to the risk for our GPS constellation?

Roger (K8RI)

Was it somehow kept secret? I can't find any such news report. The last
one I remember was a year ago when the russian satellite hit an Irridium (sp?).
I think that was a fairly low orbit. GPS is way up at 20,000 km.

The way it was reported it sounded like the collision had just
happened, but these are the satellites to which they referred.

At such low orbits and with solar storms increasing, (2 in the last
several weeks) it's unlikely much of the debris, or at least the
smaller pieces, will stay in orbit long. Each solar storm impact on
the atmosphere causes it to expand substantially which creates a
slight increase in drag that has a much more noticeable affect on the
less massive pieces.


Roger (K8RI)