With powered vehicles much is possible, but very little of that is happening. This is the scenario which has repeated many times: When launched to the ISS, the shuttle enters an orbit very similar to that of the ISS. But this orbit is lower and, thus, faster. So as the shuttle approaches the ISS, during overflights, the ISS will be seen to be leading the shuttle. When leaving the ISS, the shuttle often performs a fly-around in the immediate vicinity of the ISS. You would need a telescope to separate the images. Then she again enters a lower and faster orbit. So then, during overflights, the shuttle will be seen to be leading the ISS. Propagation from typical elsets, such as is obtained from Heavens-Above, does not refute this scenario. Great care is required to analyze the detailed meaning of elsets, which are somewhat deficient because they presume unpowered flight and somewhat inaccurate when applied outside a limited-duration interval of time. An elset intended for a day may be quite different than that intended for a month. Any variation from the scenario described here would be of very high interest. But it is not helpful when observers (or kibitzers) post spurious "results" of propagation based on disparate elsets. As I understand it, no actual variations were noted for STS-113. Last evening, during a 32-degree altitude pass here, the dynamic duo were, anomalously, invisible naked-eye, but very bright in binoculars. I cannot offer an explanation for this. It was very much unexpected. I recall a discussion with Jay Respler about whether EGP should be included in his list. I've never seen it naked-eye. But from seeing it in binoculars from horribly polluted sites, I am under the impression it should be easy naked-eye from a dark site. Careful observations demolish unwarranted assumptions. Cheers. Walter Nissen wnissen@tfn.net -81.8637, 41.3735, 256m elevation --- Wouldn't a conservative be _opposed_ to experimentation on his only available atmosphere? ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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