Famous 73-86 debris

Eberst (eberst@cableinet.co.uk)
Wed, 3 Dec 1997 21:33:33 GMT

Craig Cholar mentioned a number of pieces of the 1973-86 break-up, but failed
to include the most famous of all these pieces.  About 20 years ago, I spotted
a faint tumbling polar retrograde object, which I eventually identified as
73-86AW.
I noticed that its elements had a value of 13.00 for its revs/day. Since it is
in a sun-synchronous orbit, this means that it had the same track over the
Earth's surface every day after completing 13 revolutions. This made it very
sensitive to
the 13th order harmonics in the Earth's Gravitation field, or to put it another
way, it would get the same gravitational perturbation every day, which would
build up over a long period. I therefore suggested that it be added to the
priority
list, which was agreed.  However most observations on this were by the radar
network.  The Royal Aircraft Establishment's space department at Farnborough,
England used the observations to determine its orbit and the changes in the
orbit,
over several months.  A paper was published detailing the changes and how they
were used to help determine some of the finer detail in the gravity field of the
Earth.  So 73-86AW has a scientific paper entirely dedicated to it, and is
probably
the only bit of space debris that could make that claim. 
So add this to your list of observable pieces, its catalog number is 07054, and
remember that even the most inconspicuous member of the space community can
sometimes make a most valuable contribution!
 
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best wishes  Russell  Eberst  @   North: 55 degrees, 56 minutes, 55 seconds
             West:  3 degrees, 8 minutes, 18 seconds: 
             43metres (150 feet) above sea-level

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