Decay watch update: January 9
Alan Pickup (alan@wingar.demon.co.uk)
Sat, 9 Jan 1999 17:32:28 +0000
The recent SpaceCom decay notices are:
Object Notice issued Predicted decay
UTC UTC
#21148 = Lacrosse 2 r Jan 8 21:38 Jan 9 03:54 +-5h
#21148 = Lacrosse 2 r Jan 9 02:06 Jan 9 03:40 +-2h
#21148 = Lacrosse 2 r Jan 9 03:25 Jan 9 03:40 +-2h
#25533 = Sputnik 41 Jan 9 07:45 Jan 11 06:48 +-2d
-------------------------------
The final elset for #21148, the Lacrosse 2 Titan 4 rocket is:
Lacrosse 2 r 9.8 3.0 0.0 5.0 141 x 136 km
1 21148U 91017B 99009.02478336 .16987426 56974-5 19263-3 0 1089
2 21148 67.9361 279.2828 0004042 323.6149 36.4794 16.50208634 64958
This shows it running 11 seconds early on my prediction posted to SeeSat
at 01:19 UTC (and based on a fit including the preceding elset at
99008.78). The discrepancy implies that the final decay was more rapid
than I (or SpaceCom?) expected, though it is a pity that elsets were
so infrequent near the end - only two being issued during its final
twelve hours. I now place decay near the southbound equator crossing
at 02:46 UTC at longitude 51 deg W, near the mouth of the Amazon in
Brazil. My estimated uncertainty is still at least one hour.
-------------------------------
...and then there was one :)
My current prediction for Sputnik 41 is for decay on January 11
at 02:55 UTC +-8h. This object, rather small and faint, leaves eclipse
near 41 deg N at ~06h local time. It enters the earth's shadow near
20 deg S at #19h local time.
Predicted elsets:
Sputnik 41 0.2 0.0 0.0 9.5 v 206 x 200 km
1 25533U 98062C 99010.05437938 .04532823 12092-1 13705-2 0 91206
2 25533 51.6481 67.0066 0004806 17.6058 342.4108 16.26093171 9473
Sputnik 41 0.2 0.0 0.0 9.5 v 190 x 185 km
1 25533U 98062C 99010.54522342 .07640329 37514-1 13637-2 0 91208
2 25533 51.6464 64.2772 0003550 19.6405 340.3732 16.31783799 9557
Sputnik 41 0.2 0.0 0.0 9.5 v 152 x 150 km
1 25533U 98062C 99011.03353646 .32397716 86934+0 89478-3 0 91204
2 25533 51.6424 61.5288 0001472 21.6896 338.3166 16.45681227 9638
Alan
--
Alan Pickup | COSPAR 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | SatEvo page: http://www.wingar.demon.co.uk/satevo/