Will the real Shenzhou...

Alan Pickup (alan@wingar.demon.co.uk)
Mon, 22 Nov 1999 23:14:07 +0000

I believe I have finally made some sense of the various elsets issued
for the five objects from the Shenzhou launch. My surprising conclusion 
is that possibly none the elsets published under the designation #25956
= 99- 61 A is for Shenzhou itself.

The initial elsets issued for #25956 (epochs 99324.30-99324.55) relate
to the object that became #25959 = 99- 61 D. This was in an eccentric
orbit that decayed from 508x194 km to 409x181 km by the final elset at
99325.50. My calculations suggest that this should have decayed at about
13:00 UTC today, November 22.

All the elsets for #25957 = 99- 61 B, with the exceptions of its first
elset and those between epochs of 99324.60 and 99325.29, relate to the
same object which I presume to be the Long March 2F rocket. The elsets
for #25956 since epoch 99324.6, and the initial elset for #25960 (epoch
99325.16) also relate to this object. It is the object that was observed
by Ruben Velasco on Nov 21, and the first of the two objects spotted by
Jim Hale later on that day. Its orbit has contracted from 326x197 km at
99324.48 to 303x192 km by 99326.53. This should decay about November 28.

The elsets for #25957 between the epochs of 99324.60 and 99325.29 relate
to the object that became #25960 = 99- 61 E since epoch 99325.44. I
suspect that the earlier elsets for this relate to the real Shenzhou
craft and that the later ones, still being issued under #25960, relate
to the Shenzhou Orbital Module detached from Shenzhou before re-entry
(the "cabinet" in the China Daily account). This was the second of the
two objects observed by Jim Hale on the 21st. This (as Shenzhou) was in
a 332x205 km orbit when first tracked as #25957 at 99324.60 and was in a
315x201 km orbit by 99326.78. This is decaying more slowly than any of
the other Shenzhou objects and may decay about December 1.

Contrary to one of my remarks yesterday, all the elsets for #25958 = 99-
61 C relate to the one object whose orbit contracted from 450x188 km at
epoch 99324.42 to 330x155 km by 99325.49. It probably decayed at about
20h UTC on November 21.

If I am correct, only #25957, the rocket, and #25960, the Orbital
Module, remain in orbit. Here are their latest elsets...

Shenzhou CZ-2F r                                 303 x 192 km
1 25957U 99061B   99326.53391552  .01544555  84323-5  89867-3 0   171
2 25957  42.5972  10.7521 0084420 146.5954 214.0288 16.09770703   394
Shenzhou Orbital Module ?                        315 x 201 km
1 25960U 99061E   99326.78766483  .00998111  83803-5  78315-3 0    78
2 25960  42.6028   9.1935 0085338 149.9488 210.6322 16.05939401   276

Alan
-- 
 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:   http://www.wingar.demon.co.uk/satevo/

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