[Server-sky] TLE access, database is small

[Keith Lofstrom]

I got access to Space Track, and downloaded the "complete" data set.
It turns out that the "70 million TLEs" is 99.9% repetitive snapshots
of the same data; there are only 13209 objects tracked.  Not much
little stuff, and it downloads very quickly.


I found this page of an article:

http://apollo.cnuce.cnr.it/rossi/publications/iau/node2.html

The author simulates the space debris from known collisions (
up to 1994).  Figures 2 and 3 are especially interesting - they
show the very small population of debris at m288 (semimajor axis
of 12789 km ) with small eccentricity and small inclination.  It
would be nice to find a newer version of that sort of article.  

The article also mentions the sizes of objects actually tracked -
10cm for LEO, 1m for GEO.  And that the smaller stuff is mostly
"shedding" from larger objects and collisions, hence the debris
will be in the region of the older tracked objects.

I will take those two figures and plot a locus of orbits that 
might even potentially interfere with m288.  Note that our 
exact "spot" with small eccentricity and inclination and 
12789 km semimajor axis is very lightly populated compared to
the rest of the graphs.  

BTW, I need to think more about Tony's "reality check".  I think
he and I though it through correctly, but I want to compare our
picture of what is happening to the NASA online java satellite
orbit app.

Keith

-- 
Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs