Decay watch: Oct 21

Alan Pickup (
Fri, 22 Oct 1999 00:05:12 +0100

There is another update to my Decay Watch page at
with updated decay predictions and predicted elsets for the four
decayers I mentioned yesterday. SpaceCom also posted a decay warning for
#25929 = 99- 54 A = Resurs F-1 M earlier today, but I am convinced that
this was an over-hasty reaction to an elset that suggested that the
perigee had been lowered and the drag greatly increased. Although this
object does manoeuvre from time to time, I do not think there was a
manoeuvre in this instance and I believe this one elset is a rogue.

Of the other decayers...

#12134 = 81-  2 B = Molniya 3-14 r2
   Decay is now predicted for Oct 23 06:00 +-10h. Apologies for omitting
my usual summary of the eclipse entry/exit circumstances for this
yesterday - I was just being lazy after a day's travelling and an
evening battling with an ISP problem. In fact, this enters eclipse near
southern apex, 62 deg S, at ~21h local time near perigee. Eclipse exit
occurs while northbound near 5 deg N at ~03:30 as it climbs towards
apogee. As the orbit contracts, the exit latitude shifts northwards.

#25500 = 98- 69 B = SAC A
   Decay prediction hardly changed at Oct 23 12:49 +-10h. This has
eclipse entry while southbound near 20 deg N latitude at ~18:30 local
time. It leaves eclipse near southern apex (47 deg S) at ~01:30 local

#25550 = 98- 69 B = SAC A
   Decay now predicted for Oct 25 05:12 +-20h

#25917 = 99- 48 E = Foton 12 debris
   Decay now predicted for Oct 22 21:41 +-6h. This puts it over the
Aleutian Is a few minutes after northern apex. The preceding northbound
equator at 21:13 UTC occurs just off E Africa and the track from this
point carries it over Afghanistan towards E Russia. The following
southbound equator crossing at 21:56 occurs over the E Pacific as it
heads towards its southern apex to the S of S America.

 Alan Pickup | COSPAR 2707:  55d53m48.7s N  3d11m51.2s W   156m asl
 Edinburgh   | Tel: +44 (0)131 477 9144     Fax: +44 (0)870 0520750
 Scotland    | SatEvo page:

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