Re: Decay space debris ID over S'pore 5/20

Alan Pickup (alan@wingar.demon.co.uk)
Sun, 24 May 1998 10:10:04 +0100

Tony Beresford <starman@camtech.net.au> writes
>This was a meteor. the duration is way too short for a satellite. The direction
>of travel is also unlikely for a satellite. There is nothing in orbits
>greater than 135 degrees inclination. 

Yes, yes and no :)  Yes that it was probably a meteor. Yes that the
duration is too short for a re-entry. But the direction, from SW to S,
does *not* imply a rare retrograde orbit.

I've been unable to find a decay candidate for this. The only decayer on
that day, so far as I know, is #24633 = 94- 29 AAM (STEP-2 Pegasus deb).
The OIG has yet to list it among the recent decayers, while the current
60-day decay forecast (issued on the 21st) predicts its decay on the
21st. My SatEvo analysis suggests that it decayed at about 09:00 UTC on
the 20th, but given that the final elset was issued about 38 hours
earlier, the uncertainty is ~10 hours. In fact, the orbital plane was
well away from Singapore at the time of the report (11:34 GMT=UTC) so
this cannot have been what was seen.

For the record, the final OIG-issued elset for this was 

Pegasus deb AAM                                  429 x 346 km
1 24633U 94029AAM 98138.71574888  .05312914  00000-0  51108-1 0  5367
2 24633  81.3364 227.7027 0061332 329.2681  30.5438 15.60219406 97135

while my final SatEvo predicted elset is

Pegasus deb AAM                                  261 x 247 km
1 24633U 94029AAM 98140.30509314  .94890246  41998+1  11892+0 0 95313
2 24633  81.3245 225.7188 0010438 325.3153  34.6166 16.07492867 97387

For anyone interested, here is a sneak preview of the beginning of my 
next SatEvo decay list...

   #    Designation    Name               ----- Decay (1998) -----
                                            Predicted   Actual?

 24633   94- 29 AAM STEP-2 Pegasus deb                  May 20
 24958   97- 58 C   Sputnik-40                          May 21.50
 24899   97- 41 E   C 2345 SL12 aux mot                 May 21.61
 24419   86- 17 LV  Mir deb                             May 22.0
 24747   97- 10 D   Zeya deb                            May 22.5
 ...

Alan
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