Kevin got a reply back from MCC saying they don't release TLEs for Soyuz (though OIG may). Assuming OIG doesn't- at least not in a timely manner- this seems like an opportunity for the SeeSat folks. Since changing a plane of orbit is expensive (except for the "free" precession of orbital plane provided by the earth's equatorial bulge), it would seem that Soyuz must launch into approximately the same orbital plane as the ISS... at the time of rendezvous, the orbital planes must coincide (if Soyuz is initially in an elliptical orbit, with a shorter orbital period than the ISS, then its orbital plane should precess a bit faster than that of the ISS). It seems to me that initially you'd want to go into an elliptical orbit, having an apogee about the same as the ISS. The orbital period would be such that, between launch & rendezvous, Soyuz would catch up with the ISS- obviously, some substantial rocket firing must be necessary to get Soyuz into the same orbit as the ISS, not long before rendezvous (i.e., basically circularizing its orbit). The MCC has released TLEs for shuttle flights to the ISS, which should shed some light on how rendezvous is accomplished- one would think that Soyuz & the shuttles would do it basically in the same way. Does anybody have the TLE ephemeris for a past shuttle to ISS mission? ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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