Greg Roberts' observations of 2006 Jan 15 UTC detected a recent small orbit-raising manoeuvre by Lacrosse 2 (91017A / 21147, confirmed by his observations of Jan 18 UTC. The new orbit is: Lacrosse 2 18.0 4.5 0.0 3.6 v 1 21147U 91017A 06018.84762828 .00000100 00000-0 14696-4 0 07 2 21147 67.9981 106.1788 0005273 288.0338 72.0219 14.75361066 07 Arc 2006 Jan 15.85 - 18.91, WRMS residuals = 0.018 deg The increase in altitude was about 50 m. Possible explanations for the manoeuvre: momentum wheel unloading, maintain the frozen orbit within specifications or collision avoidance. This manoeuvre confirms that Lacrosse 2 remains alive, less than two months short of its 15th anniversary in orbit. It is by far, the longest-surviving LEO imaging reconnaissance satellite ever launched (unless the stealthy Misty 1 (90019B / 20516) remains in orbit). Prior to the launch of Lacrosse 1 (88106B / 19671), Aviation Week and Space Technology reported in its issue of 1988 Nov 07, pg. 25, that "the technology involved is highly advanced, involving a multitude of sensors designed for an especially long life." Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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