I have updated the elements using the observations made last night by Ed Light and Mat Bartley: http://satobs.org/seesat/Feb-2008/0288.html http://satobs.org/seesat/Feb-2008/0292.html I arrived at the following by using Satevo to propagate my high-drag elset of Feb 11 to the ascending node prior to Mat's observation, then performing a differential correction only on rate of decay, mean anomaly and mean motion. The result is somewhat rough, but should be more than adequate to re-acquire the object over the coming days. Predicted arrival times tonight are uncertain by at least 10 s; track errors may be considerable, perhaps one degree at high elevation above the horizon. Rate of altitude decrease has increased to about 1.4 km/d (kilometres per day). Using the updated elements and a 10.7 cm solar flux of 70, Satevo v0.51 estimates decay from orbit on 2008 March 11, seven days earlier than the estimate posted on Feb 11. The uncertainty is at least several days. USA 193 5.0 2.5 0.0 4.3 v 249 X 260 km 1 29651U 06057A 08048.09979129 .00257471 00000-0 31999-3 0 00 2 29651 58.4812 43.9247 0008448 75.1492 285.0544 16.07103915 05 Arc 2008 Feb 10.21 - 17.11, WRMS residuals = 0.7 deg Definition of 2-line elements format: http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/SSOP _Help/tle_def.html Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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