A further search of Jonathan McDowell's indispensable Satellite Catalog yields evidence that convinces me that the elliptical orbit debris from the Shenzhou 1 and 5 launches are separation motor covers. http://www.planet4589.org/space/logs/satcat.txt Consider this excerpt from the Satellite Catalog for an Iridium launch by China: Perigee Apogee Inc S025779 1999-032C CZ-2C Stage 2 174 610 86.3 S025781 1999-032E CZ-2C Stage 2 motor cover 174 742 86.0 S025782 1999-032F CZ-2C Stage 2 motor cover 175 737 86.6 S025783 1999-032G CZ-2C Stage 2 motor cover 173 777 86.6 S025784 1999-032H CZ-2C Stage 2 motor cover 174 758 86.1 Just as with the Shenzhou 1 and 5 launches, the covers were ejected at first perigee (i.e. orbital insertion) from the 2nd stage, with sufficient velocity to raise their apogee by 120 - 170 km relative that of the stage, including an out of plane velocity component sufficient to alter their inclination by 0.3 deg, relative the stage. I believe I can explain the out-of-plane velocity component. The separation motors fire shortly after the spacecraft separates from the 2nd stage. The in-plane component decreases the apogee of the 2nd stage, achieving the desired separation. To avoid the motor exhaust hitting the spacecraft, the motors are aimed somewhat away from the velocity vector, resulting in the out-of-plane velocity component of the ejected motor covers. The plane of the 2nd stage is not affected, because the motors are spaced symmetrically. Why 2 covers on Shenzhou 1, none on missions 2 through 4, and four on mission 5? I suspect four were ejected on each launch, but not always detected by USSTRATCOM. The objects are small and decay rapidly, so it is not difficult to imagine their going unnoticed. I believe that understanding the origin of the debris provides evidence helpful in deciding which piece catalogued from Shenzhou 1 was the 2nd stage rocket, and which one was the spacecraft. There was so much cross-tagging among pieces, that it took quite an effort to group all of the elsets by object. On that first mission, the Shenzhou did not circularize its orbit, so it remained in an orbit similar to that of the 2nd stage rocket; however, the rocket stage should have been in a lower orbit as a result of the firing of its separation motors, and also because of its greater ballistic coefficient. I found only one elset that could be of the intact spacecraft: 214 X 341 1 25956U 99061A 99324.60834382 .00606827 83585-5 56001-3 0 60 2 25956 42.5956 23.0886 0095292 134.3737 226.4995 16.02245812 77 The epoch of this elset was for the ascending node of 14:36 UTC, which was more than 2 hours before retro-fire. If it can be safely assumed that the OM would not yet have been jettisoned, than this certainly was the main spacecraft's orbit. Here is the earliest one of the rocket: 206 X 335 1 25957U 99061B 99324.48312468 .01120080 83940-5 83715-3 0 29 2 25957 42.5973 23.8808 0096522 132.0774 228.8342 16.04716322 53 Amazingly, given the rampant cross-tagging, these two elsets have the correct identifiers. Also, I see evidence in the spacecraft's elements of one or more small manoeuvres, which would make sense as part of the checkout of the new spacecraft. Finally, here are the first two elsets of the orbital module, cross-tagged as the rocket! 214 X 339 1 25957U 99061B 99324.79532490 .01480763 83373-5 13432-2 0 72 2 25957 42.5919 21.9072 0094151 132.0005 228.7773 16.02625447 106 215 X 339 1 25957U 99061B 99324.91998841 .00111823 83739-5 10691-3 0 81 2 25957 42.5967 21.1065 0092983 136.7229 224.1627 16.02406107 123 Note that the epoch of the first of the OM elsets was for the ascending node at 19:05 UTC, just minutes after retro-fire. Depending on when the USSTRATCOM observations were made, I suppose this could still have been the main spacecraft. If their practice is to use as epoch the first ascending node before the latest observation, then this would be the OM; if they use the nearest ascending node, then this could be the main spacecraft. On Shenzhou 2, for the first time the spacecraft circularised its orbit, but USSTRATCOM managed to issue at least two elsets of its insertion orbit: 206 X 345 1 26664U 01001A 01009.88060300 -.00002661 84174-5 -20482-5 0 12 2 26664 42.6086 354.6303 0104726 129.6363 231.3322 16.02871692 37 206 X 342 1 26664U 01001A 01010.40241568 .00488707 83774-5 37833-3 0 62 2 26664 42.5771 351.2888 0102358 134.0200 2.1938 16.03316553 114 Here is the rocket, in its lower orbit, similar to that of Shenzhou 1's rocket: 206 X 337 1 26665U 01001B 01010.37860834 .00854908 83828-5 63599-3 0 59 2 26665 42.5762 351.4325 0098279 133.6717 227.2330 16.04483912 107 On Shenzhou 3, USSTRATCOM did not issue any elsets of the spacecraft in its insertion orbit. Here is the first stage of the rocket: 207 X 335 1 27398U 02014B 02085.07727699 -.00002621 82924-5 -19736-5 0 16 2 27398 42.3957 25.7386 0096714 132.3633 228.5476 16.04519287 85 On Shenzhou 4, USSTRATCOM managed to issue at least one elsets of the spacecraft's insertion orbit: 207 X 341 1 27630U 02061A 02363.99130504 -.00002620 82868-5 -20368-5 0 19 2 27630 42.4085 338.1747 0100490 131.4080 229.5479 16.03477566 55 This was the first accurate elset of the rocket, though cross-tagged as the spacecraft: 206 X 338 1 27630U 02061A 02364.32865137 .00788058 82648-5 58603-3 0 37 2 27630 42.4069 336.0138 0099929 134.5463 16.8336 16.04205144 108 On Shenzhou 5, USSTRATCOM did not issue any elsets of the spacecraft in its insertion orbit. Here is the first stage of the rocket: 206 X 338 1 28044U 03045B 03288.46291200 .00131960 82982-5 10000-3 0 17 2 28044 42.4135 27.5435 0099075 132.5549 228.3729 16.04321165 62 There may be evidence of the spacecraft's slightly higher initial orbit, in the form of an observation from New Zealand, just 10 minutes prior to the spacecraft's circularization burn. The observer was puzzled as to the identity of a fainter object trailing behind what he beloved to have been the spacecraft. I am attempting to contact the observer to obtain further details, but I strongly suspect that the brighter leading object was the rocket, and the fainter one was the spacecraft. A number of people mistook the tumbling rocket for the spacecraft, unaware that the spacecraft was not far behind. I will post a follow-up if I receive any further information from New Zealand. Ted Molczan ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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