At 18:45 2003-01-04 +0000, Phillip Clark wrote: >Regarding the SZ 4 high orbit, way back in 2000 as an exercise I ran some >software to calculate the repeating orbit patterns for SZ orbits, and for a >31 circuit repeater at 42.4 minutes the repeating orbit period is 91.212 >minutes. You must mean nodal period = 91.098 min, i.e. mean motion = 15.7871549 revs/day >Using USSPACECOM data, SZ 4 manoeuvred straight into this orbit, >and the decay rate (or lack of, compared with SZ 2 and 3) makes me wonder >whether the Chinese are using regular low thrusts to maintain altitude. >There was a manoeuvre announced for January 2nd, but the change in altitude >was only of the order of 1-2 km - not 5-10 km as seen on the earlier >flights. Yes, it sure looks that way. The three latest elsets all show increasing period (see my little SZ-4 article: http://www.svengrahn.pp.se/histind/shenzhou/sz4notes.html) Sven ----------------------------------------------------------------- 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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