Decay watch: January 28

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 28 Jan 1999 20:53:40 +0000

The latest SpaceCom decay notices are:

Object                            Notice issued    Predicted decay
                                       UTC              UTC

#25065 = ETS-7 H2 r               Jan 27 16:52     Jan 27 18:14 +-2h
#25065 = ETS-7 H2 r               Jan 28 01:48     Jan 27 18:36 +-42m

#25617 = ROCSAT-1 Orb Adjust Mod  Jan 27 19:32     Jan 29 13:59 +-1d
#25617 = ROCSAT-1 Orb Adjust Mod  Jan 28 20:31     Jan 29 20:59 +-4h

               -------------------------------

The final published elset for the H2 rocket is:

ETS-7 H2 r      13.5  2.5  0.0  3.0 v            144 x 144 km
1 25065U 97074C   99027.70379450  .49637631  81981-6  86712-3 0  4485
2 25065  34.5154 100.0478 0000259 166.2684 194.1772 16.48137421 66304

This has it 4 seconds early against the final prediction I issued
yesterday. The decay prediction (for January 27 18:48 UTC) I made then
may have been a little too far around the orbit; SpaceCom's final decay
time (18:36 UTC) is probably closer to the mark.

               -------------------------------

The latest elset for the ROCSAT-1 Orbit Adjust Module ...

ROCSAT-1 OrbAdjMod                               429 x 125 km
1 25617U 99002B   99028.77174398  .11358894  00000-0  34823-3 0   202
2 25617  34.6675 272.6846 0228446 219.0064 139.4475 15.98972094   318

... shows it running 10 seconds late on yesterday's prediction. I now
compute decay for January 29.93 (22:13 UTC +-6h). This would place it on
a descending (ESE-bound) track near 33 deg S, 51 deg E over the SW
Indian Ocean. It overflies Johannesburg, S Africa, only five minutes
earlier at 22:08 UTC.

SatEvo-predicted elsets
ROCSAT-1 OrbAdjMod                               393 x 125 km
1 25617U 99002B   99029.02093001  .13748012  26888-1  37855-3 0 90209
2 25617  34.6662 270.9141 0202379 221.5706 136.8730 16.05629849   356
ROCSAT-1 OrbAdjMod                               353 x 124 km
1 25617U 99002B   99029.26907916  .16329595  41911-1  40684-3 0 90206
2 25617  34.6645 269.1336 0172515 224.1493 134.4606 16.13050909   397
ROCSAT-1 OrbAdjMod                               304 x 124 km
1 25617U 99002B   99029.51598945  .20655587  86667-1  44374-3 0 90207
2 25617  34.6626 267.3414 0136460 226.7451 132.1079 16.22045990   432
ROCSAT-1 OrbAdjMod                               237 x 123 km
1 25617U 99002B   99029.76133214  .32609083  20435+0  51249-3 0 90209
2 25617  34.6600 265.5339 0086906 229.3632 129.8778 16.34652950   475
ROCSAT-1 OrbAdjMod                               214 x 123 km
1 25617U 99002B   99029.82234208  .41177641  90702+0  56659-3 0 90205
2 25617  34.6589 265.0787 0069378 230.0226 129.3660 16.39014279   482
ROCSAT-1 OrbAdjMod                               181 x 122 km
1 25617U 99002B   99029.88316887  .73562024  45102+1  73864-3 0 90205
2 25617  34.6576 264.6215 0045372 230.6848 128.9119 16.45476904   492


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/