Re: Help needed again from meteorland

Alan Pickup (
Wed, 11 Mar 1998 20:49:03 +0000

Regarding the decay of Molniya 1-73 r2, Tony Beresford
<> writes
>Alan, wouldnt the forced decay in such a situation lead
>to an orbit at decay of appreciable eccentricity and hence
>a decay at perigee, which is deep in southern hemisphere.

Yes, Tony, decay is much more likely near perigee which is deep in the
southern hemisphere, and I said as much in a sentence I trimmed from my
earlier message :-(

In fact, I don't expect it to decay directly from a 2-4 revs/day orbit,
but rather for the drag to increase the mean motion to within the range
of 10-16 revs/day by which time the ndot2 term in the tles will be over
0.99999999. Re-entry near perigee is probable, but there is an outside
chance that it could just survive to drop anywhere along the ensuing

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