Re: Possibly reentry sighting

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 19 Mar 1998 22:00:11 +0000

In message <n1321814337.74613@cpqm.saic.com>, ROB MATSON <ROBERT.D.MATSO
N@cpmx.saic.com> writes
>Leo Wikholm asked about a possible reentry observation from western
>Finland on 18 Feb 1998 17:00 UTC.  Alan probably has a more complete
>list of decays, but I show two on that date.  One was Mir Deb MF
>(#25036), though this is not a candidate since its inclination was too
>low.  The other is STEP 2 Pegasus Deb DN (#24065).  Its inclination
>was certainly high enough -- if anyone has TLEs for this object close
>to the date of its demise, I can check it.  --Rob

The final four elsets for the Mir Deb MF have epochs later than February
18 17:00 UTC. My evolution implied re-entry between 23:00 and 00:00
(rounded to February 19.0 in my SatEvo decay list #48). But as Rob
points out, the low inclination is enough to rule it out of contention
for a decay over/near Finland.

The final elset for the Pegasus debris object was:
Pegasus deb DN                                   361 x 312 km
1 24065U 94029DN  98048.80959377  .34395161  00000-0  14420+0 0  5952
2 24065  82.0844 345.7996 0035911 157.5071 211.1681 15.77883917 87677
which SatEvo decays at February 18.03 (~00:40 UTC). In fact, a fit
though earlier elsets suggests that the above elset overestimates the
drag and a more realistic one for this epoch is
Pegasus deb DN                                   364 x 327 km
1 24065U 94029DN  98048.80809338  .16288915  10526+0  10918+0 0 95940
2 24065  82.1054 345.8301 0027492 140.6910 219.5088 15.74654949 87673
leading to decay at February 18.28 (~06:40 UTC). It is very hard to keep
it aloft until 17:00 UTC, but if were decaying northbound at 17:00 I
think its orbital plane would have taken it over Greenland, too far to
the west of Finland.

I know of no other decay candidates for this event.

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