Spalling?

More on this?
> ... one paint fleck chipping a shuttle window ..." vs. "... It broke
the window." See, http://www.wstf.nasa.gov/Hazard/Hyper/debris.htm , where
the word "pit" was used, and
http://science.ksc.nasa.gov/shuttle/missions/sts-73/news/sts-73-mcc-16.txt
where the word "ding" was used. I don't think we should panic at this
point.
I agree we "... don't know exactly. Some satellites go away and are
never heard from again...", and about "... the more things there are to
hit, and the more fragments get produced. The more fragments get produced,
the more things get hit..." I understand exponentials, they work both ways,
as in exponential growth and decay. But what about "> ... the natural
background, the meteoroids? " As an aside, this weekend is the annual
Leonid meteor shower. See
http://www.space.com/scienceastronomy/leonids_update_011115.html.
I also have not studied the math of collisions and orbits. And I agree
that an object in a Highly Eccentric Earth Orbit (HEEO) could catch an
object in a Low (and circular) Earth Orbit (LEO) from "behind" at perigee
and scatter debris forward. Pieces which go straight ahead will also end up
in less eccentric HEEO. But pieces which angle down from LEO will reenter.
Less obvious is that objects which angle up will also. To see this, extend
their trajectories back past the collision site. Those extensions which
pass into the atmosphere indicate that the associated objects will reenter
on the other side of Earth. So both types will be taken out of orbit, which
is not all of the material, I agree. The lower the orbit the higher the
percentage of material that will be lost from orbit this way. A significant
question is how the materials scatter from such collisions.
But, most collisions will be "head-on" not "rear-end", probably by a huge
margin, I would suggest by a ratio of (V1 + V2)/(V1 - V2), where these V's
are the satellite speeds. And in "front-end" collisions the debris will
share linear momentum and I believe most pieces will end up in the
atmosphere in less than a couple of hours.
This is how I respond. Sincerely, Jay Huebner