Current elsets via SatEvo WWW page

Alan Pickup (
Wed, 23 Jul 1997 19:41:45 +0100

I am pleased to announce the availability of two files of current elsets
via my WWW page at


Up-to-date orbital elements are important for accurate predictions
during the final weeks, days and hours of a satellite's life; a small
percentage change in the drag experienced by such an object can make it
run early or late by several minutes after only a few days. This can
make observations of near-decay objects all the more challenging, though
the sight of a low satellite, perhaps below 200 km in height, can be
most impressive - it may be considerably brighter because of its reduced
range, and it may be zipping along at a startling rate.

To assist observers and others who wish to "play along" with decaying
satellites, I am now publishing current elements for all the still-to-
decay objects on my SatEvo decay list in the file dklist.tle, available
via the above page. Many of these objects are small, however, and
probably too faint to be observed visually. Perhaps of more value to
observers is a second file of selected satellite elements, select.tle.
This is intended to include current elements for the brighter decaying
objects, together with elements for all recently launched or recently
catalogued objects plus a selected (some might say idiosyncratic) list
of other objects. The latter include Mir, the EORSATs (powered Cosmos
satellites which constantly adjust their orbits) and larger objects
suffering significant drag. The list is modified from time to time in
consultation with Russell Eberst (and anyone else who wishes to make

Both dklist.tle and select.tle (and their equivalent .zip files, which
are also available) are being auto-updated twice each day, at about
06.25 and 16.25 UTC, from the elements made available via the database
maintained by NASA's Orbital Information Group. I may make additional
updates at other times, for example during the final hours of a
particularly interesting object.

 Alan Pickup | COSPAR site 2707:   55d53m48.7s N   3d11m51.2s W    156m asl
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